Pinion Diff/TC help

[keytothestone]

Took my van into the mechanic when I noticed a pinion seal leak in the rear. Had that fixed plus transfer case output seal and a sleeve put on the yoke. P/U 8/17 drove to Southern CA. from Co. As soon as we hit CA. traffic noticed a loud strange sound when ever I de-accelerated. Drove it back to Co. still doing it and dropped it off at mechanic today. After talking to a friend and lots of googling and finding a great YouTube video. I believe the pinion bearing preload was set wrong. So wondering if that is the case do I have to worry about any further damage because of driving the van like that for 2k miles. It wasn't making any of that sound prior to them dropping the driveshaft and replacing the seals. Or could it possibly be something else?The video below pretty much is what my van sounds like and what believe the issue is. Thanks!

https://youtu.be/CvmZ1xNTzAE

[JWA]

Whoa----that's NOT an encouraging sound my friend.

Not sure how they replaced the pinion seal without affecting the R&P pre-load but I'd get that checked out ASAP.

FWIW I have an uninstalled FF rear axle that if it moves to being installed I'll have the pinion seal changed just because its a good idea. Luckily I have quite a few mechanics I'd trust to do this, already talked to them about their process so feel confident they'd do this successfully. So long story short trusting who can or will do this sort of task is paramount, if it needs further work down the road they'd already be aware of the situation.

Hope this isn't anything too serious or costly to rectify.

[Chinook]

Did they put in a new crush sleeve or did they just replace the seal and then slam the yoke back on with an impact gun?

[keytothestone]

Originally Posted by Chinook

Did they put in a new crush sleeve or did they just replace the seal and then slam the yoke back on with an impact gun?

I'm not really sure? My receipt when I p/u the van on 8/17..." upon removal of rear diff pinion seal found that pinion yoke has a groove formed in it, install a sleeve on pinion yoke then replaced the rear pinion diff pinion seal." So sounds like they put on a new sleeve. I did ask when I grudgingly dropped it off yesterday if they inspected the pinion bearings when they replaced the seal in Aug. I was surprised they said they wouldn't of unless they heard or saw something. Looks pretty easy to do so when replacing a seal? So why not? When they replaced the front axle housing last summer they reused the ring and pinion from the UJ stage 2 axle that was originally installed on the conversion in '17

[keytothestone]

Mechanic called they think it's the pinion bearing making the noise. Still don't understand why not check the bearing when replacing the seal and replacing the sleeve. Two different vids I've watched on a Dana 60 seem to make it look rather simple to pop the bearing out and take a peak. Or isn't it? I mean you got the driveshaft off the seal and the sleeve off.

[MadScience]

I would certainly pop the cover. That could be the bearing, but it could also be more substantial damage. More substantial damage sounds like metal pieces in a very heavy duty blender. Which sounds a bit like your video. I've destroyed a diff and is sounded very similar with finger sized gear chunks flying around.

I'm about to embark on a pinion seal replacement as a DIY.

You can theoretically replace the seal without changing the pre-load by counting threads and marking and measuring where the nut is and putting it back _exactly_ where it was. The idea is not to install a new crush sleeve, and to never turn the nut any tighter than it was. Yes, it's kind of a hack, but it may work.

None of the shops around me are willing to do this due to the risk of damaging the diff. I'm willing to DIY it since I'm on the fence about re-gearing anyway.

[keytothestone]

Originally Posted by MadScience

I would certainly pop the cover. That could be the bearing, but it could also be more substantial damage. More substantial damage sounds like metal pieces in a very heavy duty blender. Which sounds a bit like your video. I've destroyed a diff and is sounded very similar with finger sized gear chunks flying around.

I'm about to embark on a pinion seal replacement as a DIY.

You can theoretically replace the seal without changing the pre-load by counting threads and marking and measuring where the nut is and putting it back _exactly_ where it was. The idea is not to install a new crush sleeve, and to never turn the nut any tighter than it was. Yes, it's kind of a hack, but it may work.

None of the shops around me are willing to do this due to the risk of damaging the diff. I'm willing to DIY it since I'm on the fence about re-gearing anyway.

Ya really hope it's just the bearing. If it's something more substantial in the diff I'll have to say good bye to my beloved van once I get it fixed. After going through the last 3 1/2yrs of receipts yesterday it would just be insanity to keep it.

[arctictraveller]

Originally Posted by keytothestone

I'm not really sure? My receipt when I p/u the van on 8/17..." upon removal of rear diff pinion seal found that pinion yoke has a groove formed in it, install a sleeve on pinion yoke then replaced the rear pinion diff pinion seal." So sounds like they put on a new sleeve.

That probably does not refer to a new crush sleeve, most likely, they were referring to a "speedy sleeve" When the pinion yoke has a groove in it due to wear from the seal, you can either replace the whole thing, or install a Speedy Sleeve which is a very thin stainless steel sleeve that is placed over the damaged portion of the shaft, giving the seal a new, smooth surface to ride on, they are far less expensive than a new yoke. Based on that description, I'd guess they didn't install a new crush sleeve. When removing the yoke to replace the seal, a complete tear down is recommended because if trying to reuse the crush sleeve there is a danger of applying too much preload to the bearings. Used bearings also require less preload.

[keytothestone]

Diff rebuild. Should have it back next week. FS ad coming soon.