Rear End Whine | Ford Explorer Forums - Serious Explorations

  • Register Today It's free!

Rear End Whine

rydrew55

Well-Known Member
Joined
July 13, 2010
Messages
161
Reaction score
0
City, State
Connecticut
Year, Model & Trim Level
98 XLT
Replaced transfer case and the coasting rumble is gone, but the rear end is still whining mostly on light acceleration at speed. Need some help.

--------------------------------------------------------------------------------

OK, I found the problem I think (or at least part of it). Here is how I got there.

First, I noticed that the drivers emrgency brake seemed frozen and the passenger side cable was not attached to the lever. Loosened the adjuster and it spun free. Took off the rotor and everything looked OK. Went to the passenger side, took off the rotor, shoe was shot. Pieces loose and friction material mostly gone. OK, so I need shoes and some hardware.

Then I noticed the passenger side axle shaft had a lot of play, drivers side did not. OK, need wheel bearings.

Better to remove the axle for emergency brake repair, so I removed the differential cover to do that.

Carrier bearings are real loose and wobly. You can move the carrier in/out/up/down and I can also see the bearing all loose and sloppy. Has to be at least part of rear end whine which is what started all this mess in the first place.

I was more expecting that it was the pinion bearing, and it still may be, but now I know for sure that the carrier bearings are toast. The pinion shaft actually feels pretty tight, but I can't for sure know it is OK.

I have never done any work on a rear end so I am more than scared to set the pinion load. The carrier bearings "seem" a little less scary. So I am thinking, maybe, pull the axles and the carrier. Take them to the machine shop and have them press on some bearings and seals. Leave the pinion gear alone and say a prayer. If the whine goes away, I'm out $100 or so for the parts and labor. If the whine is still there, take it to a rear end shop for the pinion.

Finally, my question.

Am I just dreaming? Is this a good plan or a waste of time?
Is there any way to know if the pinion bearing/gear is OK?

Or should I bite the bullet, take the truck to a shop and pay the piper now?

Thanks for any advice or help to remove the carrier bearings and re-install.
 



Join the Elite Explorers for $20 each year.
Elite Explorer members see no advertisements, no banner ads, no double underlined links,.
Add an avatar, upload photo attachments, and more!
.





Or should I bite the bullet, take the truck to a shop and pay the piper now?
:thumbsup:
 






Just replace the diff on your own. It'll be cheaper than going to the shop. I move quite a few on here..the thread is in my signature below. Good luck!
 






Setting up a rear end isn't that hard. If you change the carrier bearings with new ones, and then don't do a proper set-up, you risk wrecking your diff.

Either do enough reading online to learn to do it yourself (thats what I did) or pay up now and get it done right. If you don't, you'll regret it in the end.
 






differential bearings

Thanks guys.
The gears look OK. The pinion does not seem to have any bearing play and is firmly seated. The only thing in the bottom of the case was some goldish dust in the oil and a few small sheet metal pieces. Most likely both from the carrier bearings. The carrier has play left / right up / down due to the loose carrier bearings so Backlash "is" affected when the carrier shifts back and forth. When I push it to the right (compressing the side with the real loose bearing) backlash is minimal. When I push it left, allowing the loose bearing to unseat, baklash is more. This is what I would expect.

I really think that it will be within limits once the new carrier bearings are in place.

The machine shop guy who can press the bearings on for me suggested that if I am not changing gears, and I use the factory shims, it should result in proper pinion depth and carrier bearing pre-load. I can always add some from the rebuild kit if needed.

I am "fairly" competent (which means incompetent some of the time) and have read about 100 threads here and around. Also done a lot of different work on my cars. I have experience in the factory using dial indicators etc. So I am pretty comfortable with the tasks described.

My biggest fear is applying the 200+ lbs of torque on the pinion nut and doing the measurements from under the truck. I'm afraid I won't be able to hold the pinion flange and get enough turn on the breaker bar. That's why I am thinking...If the pinion bearings don't exhibit any noticable play, leave it be and just replace the carrier and axle bearings (which are also shot). If the thing still whines or vibrates, I can always take it apart and do the pinion or just take it to the shop.

Replacing the whole differential is not an option I would go. Too expensive and I really don't want to fight with all the rusted bolts and brackets. Just did the engine swap (05 Mustang motor into this 98 explorer and replaced the transfer case) so I have about had it with Ford Truck rust. Plenty of gear shops around that could check it and rebuild only what is needed.

Anyway, thanks for listening and any insight into spinning that pinion bolt from under the truck would be appreciated. Also any criticism on my plan is welcome, I have thick skin and will consider all options.
 






If you're confideent you're not gonna wreck the gears by not doing a proper set-up, I say go for it. It's not that hard to crush the sleeve. I built a tool from half an old driveshaft flange and some square tube. Held it tight while I leaned into it.
If you've got it that far apart, might as well fix it right. There was a great how to on a mustang forum for setting up the 8.8 while under the car. I'll post it if I find it.. I figure its easier to just pull the rear axle and do iit on the bench.
 






Proper rear end set up

Thanks KPsqured.
I agree wholeheartedly that I should not do this if I am not prepared to do it right. But are you saying that the pinion bearings "must" be replaced even if there is no sign of a problem?

I know the carrier bearings and axle bearings need to be replaced. If I get it back together and pinion depth looks good, carrier preload is done, backlash looks good, and mesh pattern looks good, then it is improper to leave the pinion bearings alone?

Appreciate the comments....
 






I guess I'm not saying that it "has" to be replaced, but if you have the whole thing apart, then why not.

If your carrier bearings are shot, then there has probably been quite a bit of fine grit pass through the pinion bearing as well. For the little bit of effort that it is, why not do it, rather than have it grenade on you in a year or two? It may not happen, but who knows.

Like I said, if you can be OK with the fact that it might not work without a proper set up, then giv'er and see what happens. I just can't make myself get that far into a project and not fix everything that could have a problem...

When I had my axle out, I did everything, brakes, bearings, seals, and I even painted it for good measure.

Like I said, throw it back together and see how it sounds, if you end up having to adjust the pinion after, then I guess you should do the bearing, but maybe you will get away with it.

The trouble is, your pattern and backlash are all affected by pinon depth, so if the bearings aren't exactly the same as what was there, and you have to account for any wear on the pinion. You may get away with just throwing it back in and adjusting the shims on the carrier but you still may end up with a cooked pinion after a while.
 






Quick way out, FWIW! You CAN replace differential side bearings yourself, adjust them to get an appropriate amount of preload on the bearings, while being certain the absolute LOCATION of the ring gear is such that correct BACKLASH is present. At that point, check tooth contact pattern using some Prussian Blue.

Above assumes pinion gear & bearings were OK. While the ring gear is OUT of the case, pinion teeth should be wiped clean, examined for signs of scoring, chipping, pitting; if they LOOK OK, turn pinion by hand, rotation should be SMOOTH, no rough spots, and TRY to "feel" the torque needed to turn it, better yet, measure it. Used pinion bearings should still require perhaps 10 inch-pounds or so of rotational torque preload; that's about 1 LB. applied at the end of a 12-inch wrench when turning the pinion. Replacing the pinion bearings, if needed, represents a whole NEW dish of worms, which you are undoubtedly NOT PREPARED to consider. Main reason is, new bearings cause slightly DIFFERENT location of pinion gear, and shims needed to locate it correctly are not easily added or removed. Guesswork there WON'T CUT IT. imp
 






Carrier out

Carrier Pulled out with no preload, it was actually very loose. Factory Shims were scored and can not be reused. I will need to use new shims I guess, close to original split left/right and add from there equally until snug. Check backlash, adjust accordingly and add a little more to each side to get the preload.

Pinion rotates very smooth and sturdy. Preload is 5 in/lbs. There is a "light" steady sound but could lust be normal from preload. Is that normal? Or should it be very quiet?

I am still undecided on replacing the pinion bearings. I have read a ton and the steps are doable with my abilities. I just lack "feel" as in my question above.

Any opinion based on what I mentioned?
Thanks
 






From my experience a whine that comes on accel and goes away on decel is usually ring and pinion. Pinion bearings usually make a constant noise.
 






Makes sense

That's logical. My carrier was so loose from the bad bearings that the backlash would vary by a good 25 thousanths. It might explain that the whir would come on light acceleration, not coast.
Gears show no sign of wear or damage.
Are you suggesting leaving the pinion alone?
 






I decided

I thought about all the options, and decided to do what I always do...replace the pinion bearings while I'm in there. Stuborn I guess, but it has served me well for all these years.

I got the pinion nut and flange off. I put some m12 1.75 machine bolts in 2 of the alternate threaded holes (there are 4 for the u joint and 4 extra). Chased the rusty threads first. Then a crow bar to hold it against the floor. Worked nice and I hope to use the same method to tighten.

Used a gear puller to pull the flange off the pinion spline, it was really tight.

Now what? The pinion will not push out. Am I forgetting something? Should I just put the old nut back on and whack it with a sledge? I don't want to do that unless I know it's the right thing to do.

UPDATE
Thought about it and rulled out hitting the nut. Don't want to ruin the threads in the pinion shaft.
Hit it repeatedly with a rubber mallet and again with a drift and a sledge. Hit it pretty hard and wont budge.
Am I trying to unseat the bearing race? Is that what is frozen to the case?
HELP !!!!

Thanks
 






I thought about all the options, and decided to do what I always do...replace the pinion bearings while I'm in there. Stuborn I guess, but it has served me well for all these years.

I got the pinion nut and flange off. I put some m12 1.75 machine bolts in 2 of the alternate threaded holes (there are 4 for the u joint and 4 extra). Chased the rusty threads first. Then a crow bar to hold it against the floor. Worked nice and I hope to use the same method to tighten.

Used a gear puller to pull the flange off the pinion spline, it was really tight.

Now what? The pinion will not push out. Am I forgetting something? Should I just put the old nut back on and whack it with a sledge? I don't want to do that unless I know it's the right thing to do.

UPDATE
Thought about it and rulled out hitting the nut. Don't want to ruin the threads in the pinion shaft.
Hit it repeatedly with a rubber mallet and again with a drift and a sledge. Hit it pretty hard and wont budge.
Am I trying to unseat the bearing race? No. The outer races are pressed into recesses in the case, their openings facing away from each other, separated by a web of case material having their "seats" machined into it. Is that what is frozen to the case? Probably, what is "frozen", may not be frozen at all; the front pinion bearing is USUALLY a non-press fit (perhaps 0.002" loose) on the pinion shaft, whereas the rear (closest to the gear teeth) bearing is a decidedly tight press fit on the shaft (perhaps 0.001-0.002"). However, it is the front bearing which is preventing the pinion from sliding back and out of the case. This leads me to suspect the bearing may be seized on the shaft, or is simply too tight a press-fit for you to comfortably drive out the pinion using hammer blows; you DEFINITELY do not want to ruin those threads!

Options: Contrive to make a "pusher" or "puller" using a screw which could either push the pinion out by applying force from the front, or if space permits for jaws to grab pinion behind it's teeth from within the case, to PULL it out. If case is out of vehicle, a hydraulic press would be useful, with care to support the case properly to prevent cracking it.

IMO, if you DID feel any coarsness, or roughness when hand-turning the pinion shaft, your decision to replace it's bearings was a sound one. Pinions should feel almost absolutely smooth when turned by hand by themselves. Now, to get it out of there.........imp

HELP !!!!

Thanks
 






Got it

Ahhhh!!!! Got it. So the pinion shaft slides through the outer bearing (front one). The inner (rear) stays on the shaft and comes out throgh the back.

Thanks, now I know exactly what I'm dealing with.

So only the inner needs to be pressed on for installation?
Or should I just have him do both?
 






Pinion gear is finally out

Wow, that was something. Alternated between a 4x4 with a BFH and a punch. It was very slow, took 45 minutes, but I got it. There is like a varnish film on the shaft and inside the bearing. It was definitely on tight. Cleaned it all up, ready for install.

I had the carrier bearings pressed on today, and I'll drop off the pinion in the morning.

Couple questions.

1. The spacer is still on the pinion. The machine shop needs to install it before pressing the new bearing. Is that right?

2. Just press the inner, correct?
The pinion shaft should just slide through the outer when I install it if I understand correctly?

3. The official ford write up says not to replace the races unless they are damaged. Does that sound right? Best way to remove with a brass drift?

4. RTV or gasket. I have both. How thick of a bead?

5. Lok-tite carrier bearing cap bolts? Drive shaft bolts? The new diff shaft bolt and pinion nut came with lok-tite on them.

Well thanks. Wish me luck.
 






Wow, that was something. Alternated between a 4x4 with a BFH and a punch. It was very slow, took 45 minutes, but I got it. There is like a varnish film on the shaft and inside the bearing. It was definitely on tight. Cleaned it all up, ready for install. After cleaning the shaft surface where front brg. fits on, the new bearing should not be a tight fit. The glop you describe on there evidently is what was preventing easy removal.

I had the carrier bearings pressed on today, and I'll drop off the pinion in the morning. Any of these brgs. may be driven on using hammer force, as long as a tool contacting the bearing race only between the roller cage and ID lip, (i.e., a short section of pipe having reasonably thick wall) is used to drive the brg.

One big problem on pinion: Generally, a pinion depth locating shim is positioned behind the rear brg., that's the tight drive-fit one. Without a pinion-depth gauge tool, using the OLD shim (same shim thickness, that is), will likely NOT result in correct pinion location with respect to ring gear. The reason is that manufacturing tolerances on roller bearings are such that no two will stack up to exactly the same height when installed. The pinion should have a number etched on it's face, like +5, or +2, whatever; this number is used to tell the installer HOW MUCH that pinion deviates from the STANDARD dimension for installation purposes. In other words, the starting shim thickness would be 0.005" (for +5) MORE than the standard indicated shim thickness, whatever that may be. The standard is called out in the Ford Shop Manual. I am currently working from public access away from home, and have no info. available except "off the top of my head", sorry!

After the shim & rear brg. is pressed home completely on pinion, a NEW crush-washer is slid on. At this point, you CANNOT install the front brg; the pinion must be inserted into the diff. case, and the FRONT brg. slid on through the front opening in the diff. case. I believe this design uses no other pinion shims, however, some do, to secure rock-solid bearing preload. Such design is more difficult to set up, and more commonly is found in high-performance/racing applications, as an improvement over the crush washer concept.

The crush washer gets "squeezed" between the 2 bearings. It "yields", or squishes out at it's center when a fairly high clamping force is placed on it by tightening the front nut. It is important to tighten (that is, continue crushing the washer) ONLY until proper turning preload is reached. DO NOT loosen the nut once this occurs! If OVER-TIGHTENED, backing off nut to reach acceptable preload MAY leave room for clearance between washer and bearings, with result that preload may be lost during operation, and the set-up can FAIL.

Oh, yeah, before you begin with the nut, BE SURE that oil-slinger and/or thick washer often used beneath nut, AND OIL SEAL are in place; tighten that nut only ONCE! NOTES: New crush washer always needed, as they do NOT return to original thickness once removed. A used one MIGHT or might not, start out thick enough to secure proper brg. preload. Oil seal ADDS turning resistance of a couple inch-pounds, at least, to bearing preload, keep that in mind. Doing this set-up of pinion without recourse to depth measuring tool is iffy, to say the least. I do it by leaving out the oil seal, tightening up properly, checking tooth-contact pattern with Prussian Blue", then making changes as needed to get 1) proper contact pattern, and 2) proper ring-gear preload AND backlash (clearance) between gears. I MIGHT have to remove the rear pinion brg., and change shim thickness, then put back together, and check again, installing oil seal (using new crush washer) as last operation.




Couple questions.

1. The spacer is still on the pinion. The machine shop needs to install it before pressing the new bearing. Is that right? NO! Need corrrect terminology here! SHIM is installed beneath rear brg. SPACER is the crush washer (or solid spacer, if used) between the 2 pinion brgs.

2. Just press the inner, correct?
The pinion shaft should just slide through the outer when I install it if I understand correctly? You got it!

3. The official ford write up says not to replace the races unless they are damaged. Does that sound right? Best way to remove with a brass drift? Yes to both. I would replace them as a matter of course having gone in this far.

4. RTV or gasket. I have both. How thick of a bead? Cover plate? 1/8" bead continuous, be sure cover surface FLAT, clean all oil and debris off gasket surfaces, of course!

5. Lok-tite carrier bearing cap bolts? Drive shaft bolts? It can't hurt. Have never seen diff. brg. cap bolts loosen, however. The new diff shaft bolt and pinion nut came with lok-tite on them.

Well thanks. Wish me luck. Luck MIGHT help, but your skill and proper attention to detail is most important. Hope this all works out well for you. Remember, the first one is always difficult; the following ones are easy! imp
 






Thanks

Thanks.

New outer bearing slides on with little or no force.
The rest of the instructions are great.

I will check the old and new inner bearing for any +/- markings. If they are different, I will pull and re-press adding or subtracting the proper adjustment. The original had .026 shim.

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. No way to know if it spun because of improper load or the other way around, the spinning chewed up the shim which caused it to unload. It was not my truck and I do not know the history.

Either way, I think I will just continue. If it goes bad again, then I know the housing is bad and need a new one anyway. At least I didn't spend $700 for someone to replace the bearings only to have it fail again. My investment so far is minimal.

Thanks again for the "excellent" reply.
 






Pinion nut

Check pinion rotational torque with carrier installed? Or without?
 



Join the Elite Explorers for $20 each year.
Elite Explorer members see no advertisements, no banner ads, no double underlined links,.
Add an avatar, upload photo attachments, and more!
.





Pinion nut

Check pinion rotational torque with carrier installed? Or without?

Never mind. Found it. Check without carrier installed.
 






Back
Top