T-Case Noise (1 Viewer)

enox

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I have been chasing down a rattle that has been quite an annoyance. First thought it was the front DS, pulled that and replaced it with a new double cardan one. Well the week that the front DS was out (while waiting for the new one) I drove around and obviously had the center diff locked. Well no noise at all, I fully thought it was the front DS. Today, I installed the new DS and bam! rattle came back right away...so i started thinking the tried this..

Drive around with the center diff open - I have an audible rattle.
Lock the center diff - No rattle.

It drives fine around town unlocked. When CDL switch engaged, I can hear the tires biting on the asphalt when I turn. So these operations seem to drive normal.

Strangest thing, the center diff lock still locks and unlocks as intended, however when unlocked that rattle comes back right away.
Also changed the t-case oil recently. Its a 95'
I also dont have a VC - Thats been gone for a few years.
 
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enox

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Have you checked out your rear driveshaft, especially the ujoint next to the transfer case and the slip joint ??
Very good thought, I have not been looking at this at all, only because a few months ago I removed it, had it serviced (new u joints & balance) then slapped it back in. Haven't thought it may be the suspect.
 

enox

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Have you checked out your rear driveshaft, especially the ujoint next to the transfer case and the slip joint ??
Well...just checked and on the rear DS the U-Joint at the T-Case does have a little slop in 1 direction only.

Id guess it's like 1-2mm of movement. So would this come and go dependent on the CDL being engaged? Like from putting a load on it?
 

enox

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Okay - Just greased rear DS and checked/ tightened up the shift linkage @ the transmission.

The rattle is still present.
Seems to be audible at 10-30mph and when rolling, can't really hear it over the fan/ motor.

More prevalent when coasting.
 

enox

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update - Thanks to the help of @2KCruiser I think we've tracked down the issue. The output shaft on the front of the transfer case has in/ out play when the CDL switch is not engaged. Then engage the CDL switch and the play goes away.

I dont know for certain but I would assume that those flanges - front and rear of the t-case, should have no play at all. Gotta dig into the front of the T-Case and check it out.
 

MyWhiteSheep

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I think you were/are following my thread. I did the bearings for the rear output shaft on my transfer case. Helped with down of the noise, but not all. I'm going to rebuild the whole t-case (eventually) and see the results.
 

enox

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Update: The inside of the front case, where the snap ring is that holds the output bearing has broken off. 😐

PXL_20210616_195030243.jpg


PXL_20210616_194221102.jpg
 

enox

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Wow. Good deal on the case. It appears to have cracks anyway?
Yeah I'm not exactly sure if those are hairline stress cracks or if they're from the casting process. I know that I had those (2) side by side and the one that is in tact has similar "veins" 🤔
 

LandLocked93

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Not to noodle the sitch but what most likely caused that?
Just spitballing but wouldnt it take a severe impact to the input shaft, inward to the case?
 

enox

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Not to noodle the sitch but what most likely caused that?
Just spitballing but wouldnt it take a severe impact to the input shaft, inward to the case?
So from what I've heard so far.... It could have been from a front DS being too long and upon suspension compression it pushes the input shaft in. (Not likely the cause since I had OEM DS)
Or - It could be from an over-greased DS spline that pushed in on the T-case upon suspension compression.
Or - A severe impact to the front end pushing the driveshaft in. (not likely as i would have remembered that)
Or - Maybe a possibility with an issue with the CDL engaging/ disengaging under too much load.

....I dunno though, I cant pinpoint exactly where the fault happened.
 
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