T-Case Noise (1 Viewer)

[enox]

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.

 

[White Sheep]

I dont know what the issue is, but I will be listening,

 

[inkpot]

Have you checked out your rear driveshaft, especially the ujoint next to the transfer case and the slip joint ??

 

[enox]

Heres some sound, this was taken out of the passenger window pointed down.

 

[enox]

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]

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]

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]

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.

 

[White Sheep]

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.

 

[LandLocked93]

Hmmm, my t-case is looser than grandma on bingo night. But at least she's quiet. lol
Curious what it is.

 

[White Sheep]

The t-case is on the back burner for a min. Last week my engine crapped out on me.

 

[enox]

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

 

[White Sheep]

@enox I think the part number is 90521-84002 or 90521-84003.

 

[enox]

@enox I think the part number is 90521-84002 or 90521-84003.

Yeah for that snap ring but I have to replace that case, since it sheared off right where that snap ring sits.

 

[White Sheep]

Yeah for that snap ring but I have to replace that case, since it sheared off right where that snap ring sits.

Oohh. . Now I see

 

[enox]

For reference:
Broken - Left photo
Proper - Right photo

 

[LandLocked93]

Wow. Good deal on the case. It appears to have cracks anyway?

 

[enox]

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]

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]

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.