Rear End Whine

[imp]

Last question (or concern) before I start.

The housing shows some wear in the area that accepts the carrier race. I am pretty sure that the race spun at some point. By this, you mean the outer race of the brg. which supports the ring gear carrier? If you have access to measuring instruments, measure the diam. of the case bore with cap installed and bolts snugged, then diam. of a brg. outer race. If a BIG amount of clearance is evident, the assembly will "wiggle around" by that amount in use, allowing that amount of gear misalignment to occur as they are working. This will produce noise. ANY factor allowing the tooth contact pattern to deviate from acceptable will produce noise. Weird as this will sound, you can "save" a worn housing brg. bore by using plain aluminum foil, cut to width of brg. race, carefully wrapped around the brg. outer race before placing it in the bore. The adjustment nut will prevent foil from moving outward and being lost in the soup. If you found, say, the "spun" race had ate out 0.005" of case material, one wrap of 0.002" foil will almost get you line-to-line. A little bit of "crush" will hurt nothing, either, maybe up to 0.002" more foil than clearance; aluminum is soft, but more will distort brg. to out-of-round condition. Believe it or not, I have used this scheme many times with engine rod & main brngs., a "fix" denounced in every publication. Must not cover oil passage holes, tho!

Forgot yesterday: Get hold of a book or other source on axle gear set-up, the Ford Shop Manuals are best, IMO, if you are not familiar with tooth contact patterns. Not wanting to bore you with all this writing, but with used gears, often the ideal pattern centered on the "drive" side of the ring gear tooth, will produce more hum or objectionable noise than a slight offset outward, usually, toward the outside of the tooth. After determining that the pinion bearings rotate smoothly by hand with carrier removed, and you already have set-up and located the ring gear for good contact pattern and backlash, support the center section assembly (the case) firmly by some means (I use a big vise) with ring gear teeth facing upward, if possible, rotate the gear assembly by grasping the ring gear in both directions, with no lubrication on the teeth. This process loads the gears a bit, since the pinion is hard to turn compared to the ring gear, and "feel" for harshness, or a scraping feeling as you go back and forth. If there is quite a noticeable noisiness, you may want to: first, move adjusting nut to allow ring gear to move away from pinion by one or two adjusting holes, then tighten the other side to restore preload; this will increase backlash a bit, and USUALLY will produce quieter tooth contact. Don't be afraid of lash on the "high-side"; I've run them as high as 0.025" without any feel of it during operation.
Thanks again for the "excellent" reply. You are most welcome!!

Here's a bit of the theory on these gears. Being "hypoid bevel gears", they are: 1. Very strong. 2. inherently quiet. 3. very susceptible to loss of rigidness of set-up.

Note on ring gear, one side of a tooth's face is perpendicular to the gear face, or in-line, let's say, with the direction of the axles. This is the drive side; the other side lies at an angle, maybe as much as 45` to perpendicular. That is the "coast" side. The drive side transmits the big burden torque of moving the vehicle forward, while the coast side merely transmits torque back to rotate drive-line parts while decelerating or going downhill. So, IN GENERAL, the closer the contact pattern is to CENTER on the DRIVE SIDE, the better, commensurate with quiet operation. Picture that as the force is applied to the drive side face of the tooth, ALL of the force is used to turn the gear. As force is applied to the angled coast side face, some of the force is used to effectively attempt to "spread" the gear teeth apart. No problem, since "coast" produces low-torque levels.

Food for thought: Take the center section, turn it around 180`, and mount it in the FRONT of the vehicle to drive front wheels, and the COAST SIDE becomes the DRIVE SIDE, not a really good thing at all! If you are perceptive, you will have noticed that some 4X4s have their front differential mounted UPSIDE DOWN, to get back the proper tooth-torque apply orientation! Am I getting too deep?

The other thing to be mentioned is that these teeth do not "rub" over one-another during operation, but actually present a "rolling" action like a roller bearing; this drastically reduces friction and heat generation, 2 things which "eat" gears. Hope I have helped some.....imp

 

[rydrew55]

Ready for assembly

Thamks IMP,
Really cool idead about the foil.But let's see how things measure up first.

The rest of your instructions are clear enough along with the hours of research I did on line. I have some reprints from the ford manual, but just like my cadillac shop manual, they are all "use this tool" and "use that tool". Who has this stuff unless you are a dealer. Just like in Pirates of the Carribean, "It's more of a guideline than an actual rule". I try to sort through all the info and piece together what works for me.

I knocked the inner and outer races tonight with a 9" soft steel punch and am ready to start the setup this weekend. Wow, these were tight too. Would have been easy on a stand, but swinging a 5 lb hammer on your back between the drive shaft, leaf springs, gas tank and mufflers......tons o' fun.

I have my inch lb torque wrench coming tomorrow $60 used on ebay. Got my dial indicator, bearings, shims, paint, crush sleeve, nut, breaker bar with pipe extension, gear oil and RTV ready to go.

I just have one comment about your suggestion in the last post. You say to focus on the drive side pattern, but I have read in a few places (one being the Yukon install guide) that the focus should be the coast side when using old gears. They suggest that if the coast side is good, don't worry if the drive side is not where it belongs. I really don't know the answer, but thought you would like to consider an alternate point of view. Anyway, I'll see what my pattern looks like and go from there.

BTW, anyone interested in how I came to this, you can see my thread in stock 95-2001 explorers titled "engine swap 98 sohc" The Mustang motor I threw in runs excellent. I wasn't expecting the truck to have a bad rear and transfer case (also replaced) along with the busted crankshaft. Oh well, what can you expect when you buy a project truck, not running, for $650. The tires are good (LOL). Oh yeah, the parking brakes were toast and so was the cable. Cable is in, brakes torn down and ready to install once the axle is done. I also put some wheel bearings in this week, but there was a little play in the passenger side. Probably was stressed by the loose carrier (or visa versa) Still contemplating a new axle shaft, but it's not that bad.

Sounds worse than it is. Everything is done except the rear and I'm still under $2,000 for a real nice truck, a new 2 ton shop crane and some cool new tools.

Later......

 

[rydrew55]

Shim Driver

Couldn't find a shim driver anywhere except on line. Too late now. One Gear shop I spoke with said they don't use them. They just pound the carrier in.

Any insight on where to hit it? Sequence? Keeping everything square while forcing it in? How to keep the shims centered?

Thanks

 

[rydrew55]

Dry Fit looks good

Torque wrench came today at work. I worked on it for about 2 hours tonight.

I drove in the new races, assembled the pinion without the crush sleeve, and loose fit the carrier with just the original shims which were ground flat, about 10 thou less than original (they were scored as noted before).

Some "very" early observations.

- Pinion pre-load of 20 in/lbs is way tighter than I expected. I had not done this before and I was suprised. The original preload must have been well below 5 now that I have a better refernce point with the torque wrench. It spins nice and smooth and much less sound than the original. Feels like a proper bearing now.

- Backlash is 12-15 depending on which way I push the carrier. Preload is too loose at this first shot. It's late so I will wait till morning to get some more shims in there and check it right.

-I will paint the ring gear for a pattern once I get the carrier right.

All in all I am really excited that things looked this good after a dry run. I hope things look better in the morning when I start the setup.

Still could use some advice and suggestions about how to get the shims in when I do the final assembly (last step). For now I'll just get it firm in order to make my measurements and patterns.

More updates tomorrow.

Thanks

 

[rydrew55]

Setup done-Not sure about some stuff

Good news is the setup is done.
Bad news is I barely touched the brake line and it started leaking.
I will need to get to that next. I hope there are not any more rusted lines up in the frame. They look a bi%@* to get to.

Final numbers:
Backlash .009
Pinion preload 28 inch lbs. The final jump was very quick as everyone said, but it is definitely in spec.
Pattern I am not that sure. My experience is limitted, but from what I could tell, there was a wear pattern between the face and flank. I think it's OK.

My question is about the preload. The carrier seems pretty hard to turn. Not what I suspected. And the pinion had a lot more resistance than I thought it would have too.

The pinion could be moved by gripping it between index finger and thumb, but I had to give it some effort.

The carrier turns if I grip it firmly and rotate.

I measured the pinion at it was OK. For the carrier, It went in without too much trouble.


Is this just my inexperience, or does this sound right?
Please let me know what you think. I would like to feel better about this before I put the cover on.

Thanks

 

[rydrew55]

Preload reading after carrier installed

Let me be more specific about my last post.
The pinion torque went up 9 lbs. to 38 after the carrier was preloaded.
Is this OK?

 

[imp]

Thamks IMP,
Really cool idead about the foil. Please bear in mind, that this is "not kosher" practice according to most "experts". But I HAVE used the idea to save replacing expensive parts, but use caution, anyhow. If the brng. pocket is badly eggshaped, say out-of-round more than .002" to .004", the foil idea may prove a "fail" idea.

I knocked the inner and outer races tonight with a 9" soft steel punch and am ready to start the setup this weekend. Wow, these were tight too. This says the center section (carrier) is not removed from the car, right?

have my inch lb torque wrench coming tomorrow $60 used on ebay. Got my dial indicator, bearings, shims, paint, crush sleeve, nut, breaker bar with pipe extension, gear oil and RTV ready to go. Got the right stuff to check contact pattern?

I just have one comment about your suggestion in the last post. You say to focus on the drive side pattern, but I have read in a few places (one being the Yukon install guide) that the focus should be the coast side when using old gears. They suggest that if the coast side is good, don't worry if the drive side is not where it belongs. I really don't know the answer, but thought you would like to consider an alternate point of view. Anyway, I'll see what my pattern looks like and go from there. It IS possible to get away with iffy thinking, sure. Sometimes, they "luck out" I rarely do, so try to be as exacting as I can. This means, since almost INVARIABLY, noise originating from gear teeth when transmitting POWER (drive side) goes away, or is much reduced upon coasting, that drive pattern trumps coast. I have found after setting up MANY Ford 9" diffs, that getting the gears to feel smooth & quiet when rotating the ring gear assembly, as I described, always got me best results when installed and running. You pretty much can't get quiet feeling gears with a piss-poor contact pattern, but I HAVE felt noise with optimum contact pattern, and got noise when installed if I did not get those damn things to turn smooth..........

 

[imp]

Couldn't find a shim driver anywhere except on line. Too late now. One Gear shop I spoke with said they don't use them. They just pound the carrier in.

Any insight on where to hit it? Sequence? Keeping everything square while forcing it in? How to keep the shims centered?

Thanks

Do you mean a tool to drive brng, outer races into place? I know of no "shim driving" process.....imp

EDIT: DO NOT DRIVE RACES IN USING THE BEARING ITSELF, EVEN AN OLD ONE! High unit loading can "brinnell" rollers into new raceway ground surface, even invisibally, and cause noise & premature failure.

 

[imp]

Torque wrench came today at work. I worked on it for about 2 hours tonight.

I drove in the new races, assembled the pinionWITHOUT THE CRUSH SLEEVE...., and loose fit the carrier with just the original shims which were ground flat, about 10 thou less than original (they were scored as noted before).

- Pinion pre-load of 20 in/lbs is way tighter than I expected. I had not done this before and I was suprised. The original preload must have been well below 5 now that I have a better refernce point with the torque wrench. It spins nice and smooth and much less sound than the original. Feels like a proper bearing now.
- Backlash is 12-15 depending on which way I push the carrier. Preload is too loose at this first shot. It's late so I will wait till morning to get some more shims in there and check it right.
-I will paint the ring gear for a pattern once I get the carrier right.
All in all I am really excited that things looked this good after a dry run. I hope things look better in the morning when I start the setup.
Still could use some advice and suggestions about how to get the shims in when I do the final assembly (last step). For now I'll just get it firm in order to make my measurements and patterns.

More updates tomorrow.....Thanks

YOU CANNOT ESTABLISH PINION BRNG. PRELOAD WITH THE CRUSH SLEEVE LEFT OUT! That lets you tighten the nut until the brngs. are way overloaded, and the nut is still basically LOOSE. It's OK to do this just to check for smoothness of rotation, if you do not overtighten...maybe that is what you meant, and I misunderstood?

 

[imp]

Good news is the setup is done.
Bad news is I barely touched the brake line and it started leaking.
I will need to get to that next. I hope there are not any more rusted lines up in the frame. They look a bi%@* to get to.

Final numbers:
Backlash .009
Pinion preload 28 inch lbs. The final jump was very quick as everyone said, but it is definitely in spec.
Pattern I am not that sure. My experience is limitted, but from what I could tell, there was a wear pattern between the face and flank. I think it's OK.

My question is about the preload. The carrier seems pretty hard to turn. Not what I suspected. And the pinion had a lot more resistance than I thought it would have too.

The pinion could be moved by gripping it between index finger and thumb, but I had to give it some effort.

The carrier turns if I grip it firmly and rotate.

I measured the pinion at it was OK. For the carrier, It went in without too much trouble.


Is this just my inexperience, or does this sound right?
Please let me know what you think. I would like to feel better about this before I put the cover on.

Thanks

If I understand you correctly, you measured the torque required to TURN the pinion, along with the installed ring gear carrier? Of course, the pinion brng. preload ADDS to the torque needed to rotate the diff carrier. Ford Spec. Pinion Bearing Preload, New Bearings (CARRIER REMOVED) is 16-29 lb-in. Backlash between Ring Gear & Pinion Teeth- 0.008"-0.012".

I must now apologize, and shall take title of Resident A.H., since I completely forgot this type center section is of the "integral" design, in which PRELOAD of ring gear carrier brngs. is accomplished by SHIMS, not adjusting nuts, as I suggested earlier, and the casting itself provides the "squeeze" to preload the carrier brngs. A "spreader" is recommended to open up the gap to allow insertion/removal of the carrier assembly. It can be done by prying out with a crowbar, and installing by carefully hitting side to side with soft hammer; the brute force "no special tool" available method.

The diff. brng. preload is set by shims on either side, between the brng. outer race and the case. A "special tool" is used to determine actual preload, which results from the case "squeezing" the bearings (through the shims). Your "seat of the pants" method would best be done by accurately measuring the DISTANCE existing in the case between it's shoulders, UNSPREAD, just hanging there. Then measure distance over the brngs. and outer races installed on the carrier-- This will total LESS than the opening in the case. The 2 shims must total enough to preload the bearings by at least 0.010". At the same time, the shims must LOCATE the ring gear such that correct backlash exists. This means the shims will most likely NOT be of identical thickness on both sides. The 0.010" preload amount is not so great as to prevent the assembly from being carefully driven into the case, side to side force applied, possibly using a heavy rubber hammer. If binding occurs (gears will not turn, shims must appropriately be changed to move ring gear away from pinion, TOTAL shim remaining same to establish 0.010" case spread (or preload).

 

[imp]

Let me be more specific about my last post.
The pinion torque went up 9 lbs. to 38 after the carrier was preloaded.
Is this OK?

Again, if I understand right, you measured torque needed to turn the pinion AND the diff. carrier, all as an assembly? 38 lb. in. total seems a bit high; do you have reasonable backlash present? How hard is it to turn the ring gear back and forth through the backlash "clicks". It should feel a bit snug, but not tight. It might be worth the time and effort to remove the ring gear carrier from the case, having established that your backlash and contact patterns are OK, and if turning the whole works by rotating the pinion produces no harsh feeling of scraping, dragging, or noise, then take the ring gear itself OFF of the carrier, replace carrier without the ring gear on it. This will allow you to rotate it free of the pinion, without removing the pinion (a ***** to do again). The carrier should spin nice and free, with some drag feelable, NO PLAY DISCERNIBLE of course, figure it should take a bit less torque to turn it than the pinion, maybe 5 to 10 lb/ inch.

If this proves out good, replace ring gear, insert it attached to the carrier, tighten brng. caps, turn the whole works by grasping the ring gear, as I explained earlier. Should take quite a bit of effort to turn, feel smooth, and if it "passes", put the cover on.

Again, I apologize for some of my thinking here being misleading; the basics do still apply, just a little different means to the "end". imp

 

[rydrew55]

Clarify

EDIT- We must have been writing at the same time. I see you adressed these questions.
Every thing is quiet and smooth. No noise. Just tighter than I expected. My first one.


Hi imp, thanks but I might not have explained myself properly and didn't follow some of yor comments. Let me try to clarify my situation again.

1. The "final" pinion bearing torque "before" carrier install was 28 inch lbs. Yes this was "with" the crush sleeve. I only did a dry run without the crush sleeve before hand to see where everything was. This was suggested in every write up I saw.

2. Carrier load is normally achieved by adding .006 shim to each side "after" a snug fit is established in the dry run. My install kit did not have .006 shims so I went for a slightly looser fit using the original solid shims which were ground down .011 from the original thickness and then added .012 to each side. This established a good preload and was very close to the original shim dimmensions which were .010 different from left to right. Backlash is good at .009 inches.

3. With the carrier in and fully preloaded, the pinion torque is now 9 inch lbs. higher or 37.

4. Gear mesh pattern I think was OK, but to be honest, I did have trouble reading it. It certainly does not come out so clear like in the black and white pictures. I could see evidence of mesh between the face and flank. I could also see somewhat of an oval shape near the foot on the coast side. So I think it's good.

My only questions are "how tight should this feel" and "is it OK that pinion torque went up to 37 inch lbs. after the carrier was installed and preloaded"? It just seems tighter and harder to turn than I expected. The old pinion bearing would actually spin some.

Thanks

 

[imp]

EDIT- We must have been writing at the same time. I see you adressed these questions.
Every thing is quiet and smooth. No noise. Just tighter than I expected. My first one.
Hi imp, thanks but I might not have explained myself properly and didn't follow some of yor comments. Let me try to clarify my situation again.
1. The "final" pinion bearing torque "before" carrier install was 28 inch lbs. Yes this was "with" the crush sleeve. Sounds good. To get that preload, you should have had to tighten the nut pretty tight, to "crush" the sleeve. I only did a dry run without the crush sleeve before hand to see where everything was. This was suggested in every write up I saw. A good idea, so long as nut is not tightened real tight, as brngs. could be damaged.

2. Carrier load is normally achieved by adding .006 shim to each side "after" a snug fit is established in the dry run. My install kit did not have .006 shims so I went for a slightly looser fit using the original solid shims which were ground down .011 from the original thickness and then added .012 to each side. This established a good preload and was very close to the original shim dimmensions which were .010 different from left to right. Backlash is good at .009 inches.

3. With the carrier in and fully preloaded, the pinion torque is now 9 inch lbs. higher or 37. This is now the torque needed to rotate the whole works, by turning the pinion, right? If yes, the "added" 9 inch-lbs. applied to the pinion reflects the effort needed to rotate the ring gear. Torque on ring gear brngs. is multiplied by the gear ratio, something like 3.5?, so it is requiring 3.5 times 9 or about 30 inch-lbs. to rotate the ring gear carrier. I'm gonna say that's too much.

If it were my install, my opinion only, understand, I really would yank the ring gear and carrier out, remove the gear off the carrier, and put it back in place with brng. caps snug, and check turning effort. If you do it, the carrier should spin a bit if you give it a good twist with your hand. I'm thinking you have a bit too much preload there, but if it turns smoothly, the only harm it will cause probably is increased heating and maybe somewhat shorter brng. life. Still, gears need good rigidness, so better a bit too much preload than not enough. Your call whether you want to check this out....

4. Gear mesh pattern I think was OK, but to be honest, I did have trouble reading it. It certainly does not come out so clear like in the black and white pictures. I could see evidence of mesh between the face and flank. I could also see somewhat of an oval shape near the foot on the coast side. So I think it's good. Most important thing is whether the gears feel nice and smooth when you turn them, no "scraping" sound.


My only questions are "how tight should this feel" and "is it OK that pinion torque went up to 37 inch lbs. after the carrier was installed and preloaded"? It just seems tighter and harder to turn than I expected. The old pinion bearing would actually spin some. Well, "how tight" or "how hard to turn" are qualitative, difficult to accurately describe. Grasp the ring gear with your fingers, and make it turn, either direction. It will with good gear set-up take a surprisingly large amount of "oomph" to rotate those gears thusly, especially if nothing inside has been lubricated yet. Main thing: smooth feel during rotation. imp

Thanks

 

[rydrew55]

seal leaks

Everything is buttoned up, but I have 2 more things to do.

That stupid brake line. I brought it to NAPA, and he threaded it into a metric nut and said that's what I need. So I bent it nice and went to install it, it will not thread into the junction. I don't know if I am madder at the parts guy or myself for not double checking him. An American 3/8 fitting (24 tpi I think) will easily go into a metric just looser, but not the other way around. Shame on me for trusting that guy. Need to go get another line and bend it again.

Can anyone confirm my suspicion? Is this a std american SAE thread?

The other problem is the pinion seal leaks a little. I must have ****ed it going in or knicked it.

I am an optimist, so I figure this is a good thing. I can now replace the crush sleeve and nut, and reset the pinion preload. I will target about 6 inch/lbs less than current which was 28 without the carrier, and 35 with the carrier (it got a little better once the bearings set a bit). I'll measure again before taking off the flange to be sure.

That gives me a target of 29 (with the carrier) which should equate to approx 22 without. That gets me back towards the middle.

This should be a safe number as I was at the highest possible end of the spec before the carrier went in.

Is this sound?

 

[rydrew55]

Done

It's done.
Quiet as a church mouse.
No more whine or vibration on coast or drive.
It was warm to the touch after a run on the freeway. Hope that's normal.

REVISED- It's actually fairly hot after a 35 mile trip. I could hold my hand on it for 2 seconds then had to remove it. I'm guessing 150F or so.
As a related side note, When I put on the new crush sleeve, I was targeting 29 in/lbs with carrier (down 7 from my previous attempt). But when I got to 25, and turned another 1/12th turn, it jumped back up to 35 again. In both tries, it did exactly the same thing. I am hoping it's not too tight, but I have to wonder why, and also about the heat. It is super quiet and smooth though.

I'll open it up in 500 miles or so to look around and change the gear oil.
Thanks,

 

[imp]

An American 3/8 fitting (24 tpi I think) will easily go into a metric just looser, but not the other way around. Shame on me for trusting that guy. Need to go get another line and bend it again.
Can anyone confirm my suspicion? Is this a std american SAE thread? 3/8-24 sounds pretty normal, to me, just from memory of last brake line work. This would be a "reverse flare" type fitting, where the threaded part which squeezes the flared end of the tube is actually a male part which enters the junction, which is female, and contains the mating flare within it?

Why not try a good 3/8-24 bolt for fit in the junction, see if it screws in without interference, and does not "wiggle around". A "true" 10mm outside diameter screw thread would "mike" 0.394"; the actual part is always ABOUT 0.005" smaller than the nominal, in either SAE or metric, so, the metric fitting would measure maybe 0.389" or so, WAY TOO BIG to thread into a 3/8" (0.375" nominal) threaded hole. Then there's the pitch discrepancy.....

The other problem is the pinion seal leaks a little. I must have ****ed it going in or knicked it. What did the ground surface on the U-Joint companion flange look like? Where build-up of crud happens to coincide with location of the new seal lip, leakage can occur; or scoring or wear can cause it, also. Being a "pick", I always seek 100% sealing, but forgive you if you do not, after this ordeal!

I am an optimist, so I figure this is a good thing. I can now replace the crush sleeve and nut, and reset the pinion preload. I will target about 6 inch/lbs less than current which was 28 without the carrier, and 35 with the carrier (it got a little better once the bearings set a bit). I'll measure again before taking off the flange to be sure.

That gives me a target of 29 (with the carrier) which should equate to approx 22 without. That gets me back towards the middle.

This should be a safe number as I was at the highest possible end of the spec before the carrier went in.

Is this sound?Sound as a "GO"! Sorry I got to this post late.....imp

 

[imp]

It's done.
Quiet as a church mouse.
No more whine or vibration on coast or drive.
It was warm to the touch after a run on the freeway. Hope that's normal.

REVISED- It's actually fairly hot after a 35 mile trip. I could hold my hand on it for 2 seconds then had to remove it. I'm guessing 150F or so.
As a related side note, When I put on the new crush sleeve, I was targeting 29 in/lbs with carrier (down 7 from my previous attempt). But when I got to 25, and turned another 1/12th turn, it jumped back up to 35 again. In both tries, it did exactly the same thing. I am hoping it's not too tight, but I have to wonder why, and also about the heat. It is super quiet and smooth though. At this point, I say DRIVE IT, my guess is after a few weeks your concern will go away, as I believe the thing is "ready to go".

I'll open it up in 500 miles or so to look around and change the gear oil.
Thanks,

I may be more relieved than you are! Really hate it when help I try to give comes back to bite me on the a$$! The experience you gained doing this job is worth far more in $$ than having some shlock do the work for you. I am happy if you are! BTW, most authorities say the average person cannot withstand 140` sustained on their palm; 150` might be a good guess on your part. These gear sets most often run hotter than 150; I have seen as high as 220 on test stands (too high for your vehicle!).

What shall we tear into next?? imp

 

[rydrew55]

Next....go Exploring

Thanks IMP,
I have driven it about 100 miles and still quiet. I'll give it 500 miles and open it up to change the oil and check on those carrier bearings.
I hope "not" to be tearing anything apart for a while.
On a side note, the Mustang motor is doing fine as are the e-brakes, cable and brake line. I think the project was pretty successful. I have a nice truck for less than 2,000 bucks.
Thanks again for hangin in there with me.

 

[imp]

....Thanks again for hangin in there with me.

You're most welcome! My time belongs to no one but me....I'm retired!!!

 

[Kevin Barry]

My apologies if this question(s) in the wrong forum, but you all seem rather knowledgable about the X's rear end and I am thankful for the wealth of information on this site. I have a 97 Mounty AWD with the LS rear end. Under load/on acceleration from 32 MPH to about 48 MPH I am getting a sound more of a "woop woop woop woop" that seems to diminish but not completely go away after 48MPH. If I let off the gas, no sound. I was convinced it was the wheel bearings so I changed those out yesterday with new seals and also replaced a toast parking brake. Filled the diff back up with fresh synthetic and friction modifier took her down the road and the noise is still there.

I read on a few posts that the front driveshaft/carrier can cause some noises that travel underneath. So today, I removed that. The wooping is almost a bit louder with the shaft out although it did solve a slight whining noise I have been hearing which must be the front diff. :-(.

Anyhow, the rear end isn't so much whining under load but wooping. I'm at a loss. Everything inside the diff looked OK, nothing seemed loose and only a little bit of fine metal flake on the magnetic fill plug. No chunks of anything or gold flakes in the bottom. Oil wasn't too dirty either.

Thanks in advance.