Transfer Case Noise

[MountaineerGreen]

Well, I’ve spent all morning poking around under the front end.

I bought a new u joint for the other end. (this one has a grease fitting) Got that installed and put the d shaft back in. Test drive revealed the same noise.

Jacked it up, put on four jack stands, two under the rear axle tube to have weight on the suspension, two on the front jacking horns on the lower A arms. Started it, put in 4hi and gave it some gas. There is definitely some noise there, but the A arms are not fully loaded and drooping down making the CV angle pretty steep, so the noise could be those, it seemed like it was coming from the front diff. There isn’t anyone to help me to allow me to check things out while its moving. Cruise doesn’t work with no load either.

Loosened the bolts that hang the diff and the bracket on the rear of the diff that bolts to the frame. The bracket bushings are just about shot, this could be transmitting the noise through the frame, but I would think It would do so with no DS since the front diff spins anyway.

Tightened everything back up, checked to see if the diff was touching any frame or other brackets, saw nothing.

One more road test, same noise as before, but at about 35, put into 4 hi. The noise stopped as soon as the case engaged. Kick it out of 4hi and the noise comes back but louder. If I pull over and stop, then start again, the noise is there but not as loud.

After all of this, I suspect that maybe the front diff gear set is worn in on the acceleration side of the gears, not as much on the coast side. With the driveshaft installed, the rotating mass puts a load on the gears in the opposite way than they are used to since the AWD was always pulling, now the tires are pushing. Maybe when I cleaned the diff, it made this worse?

Secondly, maybe the worn out busing on the bracket that bolts right to the diff is transmitting the noise from the differential to the frame and then to the cab. I can definitely feel a vibration on the floorboard. But the question is how does this go away when in 4 hi?

My last guess is that the driveshaft needs to be a double cardian. But if the sound goes away when in 4hi, then that couldn't be it right?
Front diff joint

From passenger side looking out- rear joint

From drivers side looking in- rear joint

 

['97 V8]

That looks like a pretty step angle for the u-joint. Looking at the pictures, it looked like the u-joint was making contact with the ears. A double carden type shaft will eliminate the vibratiion you are getting according to V8Boatbuilders post.

 

[MountaineerGreen]

[QUOTE='97 V8]That looks like a pretty step angle for the u-joint. Looking at the pictures, it looked like the u-joint was making contact with the ears. A double carden type shaft will eliminate the vibratiion you are getting according to V8Boatbuilders post.[/QUOTE]

The picture I posted last night must have been from the machine shop handling it, when I rotated it by hand, there was no contact between the yoke and flange.

The angle is steep, but why would the noise only be present in 2wd? Seems to me that it would continue just the same in 4wd?

 

[IZwack]

That angle is nowhere near the limits of the 1310 U-joint.

But having said that, I assumed that your front drveishaft was a double-cardan or CV type. But now I see its a single.

Looking at the three pictures and comparing the angles, it really seems like the front diff is not at the right angle. Because you have a single cardan, the front differential should be parallel with the transfer case - the reverse of what I said previously because I assumed you had a double-cardan or CV type. But obvsiouly you dont, so instead of having the front diff point at the transfer case, it instead needs to be parallel with the transfer case.

The image below illustrates the proper angle for a single cardan driveshaft (ignore the leaf spring):

So if the problem is indeed the angle, then you have two options:

1) since it already seems like the differntial is pointing at the transfer case, then you can swap over to a double cardan or CV type.

2) change the angle and keep the single cardan.


For comparison, here is what a double cardan or CV type should look like:

 

[410Fortune]

so teh superlift drop brackets dont adjust the angle of the differential housing/pinion, or they do?
I would think the kit needs to have some correction built in?

I dont think cruise will work under 45 mph, and 45 mph with nobody in the truck is a BAD idea. I cant believe you tried that!!
You need to have somebody behind the wheel with all 4 in the air, going REALLY SLOW and then find your noise.
Your driveshaft and U joints look good to me.
A double cardigan can't hurt, but if you think the noise is coming from the front diff I would first confirm this is true.

 

[MountaineerGreen]

Nice drawing-

The transfer case angle is way different than the diff- The TC leans toward the back kind of like this but not as steep / the front diff is nearly flat. However, I dont really have any way to change that angle. It hangs from drop brackets which dont allow for much tweaking. There is also the bracket that bolts right to the pumpkin that bolts to the frame. To change/modify those would be exceedingly difficult.

Your diagram and reasoning make sense to me, but help me understand why the noise/vibration goes away when in 4wd?? I dont want to drop more money in a double cardian if that wont solve my problem.

 

[MountaineerGreen]

so teh superlift drop brackets dont adjust the angle of the differential housing/pinion, or they do?
I would think the kit needs to have some correction built in?

I dont think cruise will work under 45 mph, and 45 mph with nobody in the truck is a BAD idea. I cant believe you tried that!!
You need to have somebody behind the wheel with all 4 in the air, going REALLY SLOW and then find your noise.
Your driveshaft and U joints look good to me.
A double cardigan can't hurt, but if you think the noise is coming from the front diff I would first confirm this is true.

The kit has some correction built in, not much but some. It is intended for use with their double cardian d shaft though.

My cruise works at 30. I didnt get out with the cruise set, I tested the waters first.

The noise isnt really evident until about 30, so I dont know??

I cant get it in the air without the CV angle being way off, so how to I check everything out in motion? Dyno? ha ha ha

 

[IZwack]

Nice drawing-

Those arent my diagrams, they are from this JeepWire.com article: http://www.4x4wire.com/tech/pinionangle

...help me understand why the noise/vibration goes away when in 4wd?? I dont want to drop more money in a double cardian if that wont solve my problem.

I can not be 100% sure it is the angle of the front differential. But, since the sound goes away when the front driveshaft is removed, that leads me to believe that the front driveshaft is not at the proper angle - causing vibrations.

I wish there was an easy way to determine whether or not it is the pinion angle, but from the looks of things, your pinion anlge is definitely not proper so either way, I would take care of that - by either getting a CV/double cardan driveshaft, or changing the pinion angle.

 

[410Fortune]

What does your transmission mount look like? I plan to ditch my stock piece for a urethane mount when I put in this t case, since its about twice the size of the AWD case it cant hurt.
New engine mounts would also be a great idea.
Fabbing some sort of T case mount might also be something to look at.
From the angle you describe it sounds like that sucker is hanging down!

Shim your transmission mount and see if it helps?
What does your rear pinion angle look like currently?

I am thinking a first gen Explorer front D shaft might be a good unit to take to the driveline shop and have built to fit our gen II's for these converisons??

 

[MountaineerGreen]

Thats going to suck if I need a doulbe cardian, I just paid $50 to have my driveshaft shortened. I assume I can cut some more off my driveshaft and add the double cardian? The wife is not going to be happy with this.

I was able to look under the truck with the driveshaft in motion, although it was slowly, I couldnt see any vibrations or anything. But I guess they would be so fine I couldn't see them unless I was at higher speeds.

 

[MountaineerGreen]

What does your transmission mount look like? I plan to ditch my stock piece for a urethane mount when I put in this t case, since its about twice the size of the AWD case it cant hurt.
New engine mounts would also be a great idea.
Fabbing some sort of T case mount might also be something to look at.
From the angle you describe it sounds like that sucker is hanging down!

Shim your transmission mount and see if it helps?
What does your rear pinion angle look like currently?

I am thinking a first gen Explorer front D shaft might be a good unit to take to the driveline shop and have built to fit our gen II's for these converisons??

I was laying under there looking at the transfer case today thinking, man this thing needs a brace or bracket, something. But, the F150's run em just like that, and I havent seen any broken tailhousings.

I hadnt thought of shimming the mount, Ill go have a look at that ASAP. Probably take some pictures while Im at it

A first gen may be the key, then you wouldnt need the conversion u joint, and they should be near the right length, you would just have to get a flange for the u joint. V8 boat bulider didn't have any problems with his driveshaft, I may have gotten one that was just a touch longer than specs?

 

['97 V8]

You couldnt ask if the shop could let you use a d-carden, just to be sure its the problem.

 

[410Fortune]

I bet the F-150 trans mount and engine mounts are beefier??? Or maybe the tail of the auto trans is shorter? Not sure....

Thats a huge TC to leave hangin! espec on worn out stock mounts

 

[MountaineerGreen]

PICTURES

Front Pinion

T case Flange angle

Trans Mount

Tailshaft Angle

Rear Pinion

 

['97 V8]

Your t-case seems like its sagging down, tailshaft pointing down and the front flange pointing up. On mine, dont have that much sag. Im guessing that it must be the angle of the case that is making the noise. Maybe putting power down in 4wd it corrects the angle of the case.

 

['97 V8]

As for the rear pinion angle on the axle mine is more at an angle and i only have a shackle lift and add aleaf.

 

[MountaineerGreen]

So new trans mount??

 

[MountaineerGreen]

Since I dont have BL room above the case is already tight, I dont know how I am going to lift that thing up any............

 

[Turdle]

can you get a pic of your trans mount, so I can compare with one I have laying here?

 

[MountaineerGreen]

This is the best picture I can get with it in the truck:

It has two studs that go down through the crossmember-