97 AWD, Bang/Clunk under acceleration or gear shift from front end. HELP!

[phantaztix]

So, I've replaced the front CV axles because I thought that was the issue, and they were clicking anyway.

But here's what's happening:

When I apply more than grandma speed idle power from a stop, it starts bangin (like a gear slip). It also does it during the shift from 1st to 2nd. It will also do it when I apply power when already moving. Bang, bang, bang, bang.

It feels/sounds like it's coming from the front left, but that's just as I hear it. But it's loud enough to be heard 200 feet away.

I replaced the CV axles like I said, and when doing so, the only issue I encountered was the right AXLE came out of the diff with the CV axle. But I got it unclipped and it slid right back in. A little diff fluid dripped out when the axle came out, and I took that as a good sign that there is fluid.

When I took the left side out, I looked into the diff as best I could, and I should have taken a picture, but I saw the gear shaft that the CV axle goes into, and then a vertical gear looking thing. I assumed it was the ring/pinion gear I was looking at but thought it looked weird.

While the CV's were out I checked the wheel bearings and they all are perfect.

Got the new CV's installed and properly torqued and it didn't change a thing.



So... Is it the diff that is blown? And I just didn't see the damage? Or could it be a blown wheel bearing?

It drives fine if coasting or decelerating in a turn or not. No grinding or clunking.

My next step is to pull the front driveshaft and see what happens. I don't mind being 2WD for now, but I also don't want to totally destroy the front end if it's a bad diff.

Any ideas? Clues? Comments?

 

[phantaztix]

Bump

 

[shadowless127]

Pull the front DS and see if it helps.

 

[SoNic67]

Don't drive without the front driveshaft, you will damage the transfer case.
You can test it for a few yards, but i doubt it is the shaft - that would make noise always.

My suggestion: Check the differential monts - go under car and push with your hand the pumpkin "up", see if it moves (should not). One of my diff mounts is shot (top-left in picture below) and does exactly like yours - differential "moves" while is on heavy load, tries to rotate (torque).

 

[phantaztix]

I'll definitely check for play in the mounts before pulling the driveshaft. I'm under the impression with the many posts about removing the front driveshaft that it won't cause any particularly bad situation other than needing to use the parking brake.

 

[SoNic67]

Manufacturers (BorgWarner and Ford) clearly state not to run without the front shaft.
Actually they warn not to run with different sized wheels either, because of the same issue - differences in axles speeds for prolonged time will damage the Viscous Coupler inside AWD case.
See also here, last page (similar AWD form BW): www.rsgear.com/articles/1996_12.pdf

As for people that say it "works" - will they pay for your TC when you find out that putting back the front shaft leads to axles binding?

 

[RoyKelly2]

Don't drive without the front driveshaft, you will damage the transfer case.
You can test it for a few yards, but i doubt it is the shaft - that would make noise always.

My suggestion: Check the differential monts - go under car and push with your hand the pumpkin "up", see if it moves (should not). One of my diff mounts is shot (top-left in picture below) and does exactly like yours - differential "moves" while is on heavy load, tries to rotate (torque).

I am definitely going to check this out! I have replaced left and right CV axles, the front drive shaft (three times), the transmission mount, and both motor mounts over the past year. In addition to your problem I also experience this going up a hill.

 

[RoyKelly2]

So, I've replaced the front CV axles because I thought that was the issue, and they were clicking anyway.

But here's what's happening:

When I apply more than grandma speed idle power from a stop, it starts bangin (like a gear slip). It also does it during the shift from 1st to 2nd. It will also do it when I apply power when already moving. Bang, bang, bang, bang.

It feels/sounds like it's coming from the front left, but that's just as I hear it. But it's loud enough to be heard 200 feet away.

I replaced the CV axles like I said, and when doing so, the only issue I encountered was the right AXLE came out of the diff with the CV axle. But I got it unclipped and it slid right back in. A little diff fluid dripped out when the axle came out, and I took that as a good sign that there is fluid.

When I took the left side out, I looked into the diff as best I could, and I should have taken a picture, but I saw the gear shaft that the CV axle goes into, and then a vertical gear looking thing. I assumed it was the ring/pinion gear I was looking at but thought it looked weird.

While the CV's were out I checked the wheel bearings and they all are perfect.

Got the new CV's installed and properly torqued and it didn't change a thing.



So... Is it the diff that is blown? And I just didn't see the damage? Or could it be a blown wheel bearing?

It drives fine if coasting or decelerating in a turn or not. No grinding or clunking.

My next step is to pull the front driveshaft and see what happens. I don't mind being 2WD for now, but I also don't want to totally destroy the front end if it's a bad diff.

Any ideas? Clues? Comments?

You never posted if this fixed it... has bee over three years

 

[RoyKelly2]

I have checked my mounts and the bracket going back on the left side has lots of movement and the bolt does not look good. The only place I have found to get these parts new is the dealership - Bracket, bolt and nuts set me back $266. Will see if that fixes

 

[Turdle]

I have checked my mounts and the bracket going back on the left side has lots of movement and the bolt does not look good. The only place I have found to get these parts new is the dealership - Bracket, bolt and nuts set me back $266. Will see if that fixes View attachment 156745 View attachment 156746 View attachment 156747

after replacing a 4406 transfer case an a front diff, I replaced my torque bracket with a good used one. Mine moved only about 1/2" up and down at the frame ( long bolt) but still caused enough bind under load to pop the transfer case into 2wd.

I have a ( sorry for being upside down) video of the bind and movement. It's in the thread linked below. I have a feeling merging this thread with that one might be good. I have 99% confidence your issue will be solved. You might watch the video to see if this seems familiar.

BTW
The bolts holding the torque bracket to the differential will be Hercules tight. Use a good socket and air impact if you have it available. Once again, the video is upside down, the front diff will be the very bottom of screen, and only the bottom of it is visible. enough to see it popping though.

Solved - Front Differential Thumps and Jumps= Bad things happen in 4wd

 

[RoyKelly2]

after replacing a 4406 transfer case an a front diff, I replaced my torque bracket with a good used one. Mine moved only about 1/2" up and down at the frame ( long bolt) but still caused enough bind under load to pop the transfer case into 2wd.

I have a ( sorry for being upside down) video of the bind and movement. It's in the thread linked below. I have a feeling merging this thread with that one might be good. I have 99% confidence your issue will be solved. You might watch the video to see if this seems familiar.

BTW
The bolts holding the torque bracket to the differential will be Hercules tight. Use a good socket and air impact if you have it available. Once again, the video is upside down, the front diff will be the very bottom of screen, and only the bottom of it is visible. enough to see it popping though.

Solved - Front Differential Thumps and Jumps= Bad things happen in 4wd

My local junk yard had none that were better than mine. I could move them around with my hand - no prying required. I can handle tight bolts. I have a 1/2" drive impact socket set, a breaker bar that extends to 36" and a 4 foot pipe that goes over the breaker bar. If that isn't heavy enough, I will borrow my brother's 3/4" drive set and really apply some torque to it.

 

[RoyKelly2]

I am still searching for an answer. I followed Turdles thread above, new bushing and brackets all around, two different differentials with the new bracket and bushings. It did go away for a whopping two days. Hit the gas on the on ramp and BANG! BANG! BANG!! %$%#%#$%@@@#_)%!!!

I just this month replaced both upper and lower ball joints (They had movement in the upper when I jacked up the vehicle last month to work on brakes), tie rod ends, front drive shaft, and lower control arm bushings. The alignment shop said it might be the right axle as it moved in and out and seemed to be missing a keeper. Sigh, here we go again. About the only thing I have not changed is the transfer case.

 

[Turdle]

I am still searching for an answer. I followed Turdles thread above, new bushing and brackets all around, two different differentials with the new bracket and bushings. It did go away for a whopping two days. Hit the gas on the on ramp and BANG! BANG! BANG!! %$%#%#$%@@@#_)%!!!

I just this month replaced both upper and lower ball joints (They had movement in the upper when I jacked up the vehicle last month to work on brakes), tie rod ends, front drive shaft, and lower control arm bushings. The alignment shop said it might be the right axle as it moved in and out and seemed to be missing a keeper. Sigh, here we go again. About the only thing I have not changed is the transfer case.

With the front of vehicle raised, and both sides of front suspension hanging at full droop, will the front wheels rotate freely by hand?

 

[RoyKelly2]

With the front of vehicle raised, and both sides of front suspension hanging at full droop, will the front wheels rotate freely by hand?

Will have to check that. Project for this week after fixing the Wife's brakes

 

[lifted93xplorer]

Sounds like the chain in the T/C jumping teeth. The noise can sound like the front axle as it carries through the front driveshaft. At least pull the drain plug and look for metal shavings. It should be obvious if it's the T/C.

 

[RoyKelly2]

Sounds like the chain in the T/C jumping teeth. The noise can sound like the front axle as it carries through the front driveshaft. At least pull the drain plug and look for metal shavings. It should be obvious if it's the T/C.

Forgive me but I cannot think up what the T/C is. Can you expand on that?

 

[masospaghetti]

^ Transfer case

 

[RoyKelly2]

^ Transfer case

OK Will check

 

[RoyKelly2]

Update:
Turdle asked if the front wheels rotate freely with the vehicle jacked up and the front wheels at full droop. They do not rotate unless the rear is off the ground as well, and the transmission is in neutral.

lifted93xplorer suggested it may be the transfer case - I had the car up to check rotation and decided it would not hurt to change the gear oil in the transfer, no metal shavings that I could see

Yesterday late afternoon the left front CV joint went south - will change that and replace the leaking seal and see if that changes anything

 

[Turdle]

ok, this sounds like the coupler in the transfer case has locked up, along with cv joint damage. Front wheels should rotate at full droop whether or not the rears can. Try this test again after you get the new cv axle in---could be the bad one was hanging up, not rotating freely.