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How much play is too much? T-case and rear diff…

Cruisertrash

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I’ve been hearing a sound from the rear end of my 60 for the past few weeks, so I dropped the driveshaft today. Between the rear pinion flange and the transfer case output flange, it’s exactly what I’m hearing. The sound is mostly going into first gear and on slow speed turns. It sounds crunchy. Wondering if it’s time for a new rear diff, a transfer case (and transmission while I’m at it) rebuild, or if I should just run it.

-Rear pinion has rotational play, but not lateral play. Pinion nut was found loose last summer. Took it to Western Driveline in Aurora and they said diff looked great. They set preload, tightened the pinion nut back up, and sent me on my way. It’s still tight and staked.
-Transfer case flange has rotational play and a slight amount of lateral play. Nut is tight, but it looks like it’s moved because the staking appears to have shredded itself.
-I know the seal in the split case leaks because t-case fluid migrates to the transmission. It’s a small amount, and the t-case is pretty close to full (3/8” below fill hole).
-Rear diff fluid is full. Both rear diff and t-case fluid were changed in March.
 

Rzeppa

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Rear pinion looks normal from the video. Rotational play in the t-case output is normal, lateral play is not. I have that in my 60, and what I need to do is bite the bullet and set aside the time to pull the companion flange, speedo cover and reshim the output bearing preload under the race. On mine, I was hoping it was a u-joint, but no it's the output bearing on the t-case. I've been living with it for a couple years now but I know what the fix is, just getting around to it is the thing.
 

rover67

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Boulder, Co
Diff seems ok to me. I might avoid taking apart the t case completely. You could do like jeff says and take apart the output section and inspect and resign to tighten it up.
 

Cruisertrash

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@Rzeppa ”A couple years” is heartening, haha. I have enough other immediate work I need to do on this damn thing! At some point I’ll need a clutch and to replace the leaky rear main seal … might be the time to fix the split case seal and all the other things I can while it’s pulled down. Fixing or replacing the speedo cable would be nice too, the shaky speedo needle drives me crazy.

FYI the lateral play at the t-case flange is about 1mm. Like I said it’s so small I can’t even get a video of it. As always I appreciate your wealth of knowledge on the old ones.
 

jps8460

Cruise Moab Committee
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Just like in the diff, “lateral” play means 0 preload and the bearing/race is being shock loaded constantly. If not taken care of, eventually the fragments get circulated and start wiping out other much more expensive stuff.

One thing to examine is that the rear driveshaft extends and collapses properly.

I’ve seen them over greased, splines twisted, and rust seized. These conditions tend to grenade the outer pinion bearing first, then take out the tcase bearing.
 

powderpig

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Aug 25, 2005
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The clicking sound and the fact you have to use a good bit of force to turn the diff seems a bit concerning to me. I find there are two
movements I want to feel, the first is back lash, this is usually done with very little force, to feel the slack between the ring and pinion.
the second is when the spiders back lash is felt.
With you video, I see you push thru back lash into the spiders rather harshly, and then there is the click/clunk sound. To me, there is something
up, but it may just be the video.
As others have stated, (I did not see a video of the t-case) You could get away with just doing the output re-shim the t-case is a temp fix.
How much metal and what type are on the t-case drain Magnet? if only fines, great, but if you find flakes and bigger bits, you may want to
buy all the parts for the clutch /remain work along with the t-case rebuild kit, spend a weekend getting it all done.
May also want to check the drain magnet on rear diff for type of metal, as well as the fluid.
As for the drive shaft. One usually has to collapse the drive to get it out. So extend the drive shaft in the running position, and see how much play
is in the drive shaft it self. You may have a bunch that can then give some of the symptoms of the clunk you are talking about.
 

Cruisertrash

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@powderpig Really great info - thanks! I was probably being forceful with the rear diff flange; laying on my back, holding my head up, holding the camera in one hand, contorting to get my other hand to the flange. Rear driveshaft got a clean bill of health from Bill’s driveshaft last summer when they rebuilt my front, but things can change of course. To me it still feels fine - no play in the splines and the joints feel good.

The rear diff fluid has always drained clean with almost nothing on the plug magnet. After a year the fluid drains honey-colored and nearly as clear as the day I filled it. The T-case fluid comes out darker, and with a little more on the drain plug, but still just fines - no flakes or bigger pieces.

I have a spare transmission and t-case in a parts truck that I can rebuild (in Ohio - different story for a different time). I just don’t know row much time I’ve got.
 

On the RX

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If you ever need those spares in Ohio brought out, I may be able to facilitate the transportation from a friend or family member that would come out here from Wayne Co.
 

Cruisertrash

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If you ever need those spares in Ohio brought out, I may be able to facilitate the transportation from a friend or family member that would come out here from Wayne Co.
I’m 100% into this. The quotes I’ve gotten so far are high and I’ve been waiting for a chance to hop a plane and go back to disassemble the thing and start sending parts to folks in need - and back to my house.

The truck is in Toledo (junction of I-25 and I-80), so pretty convenient for a Wayne Co. -> Denver trip. Let’s talk more.
 
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