Pinion Seal Replacement D44

[ajftj]

The seal at the front end of my rear diff is leaking. I had a quick push-pull on the yoke and there does not seem to be catastrophic bearing failure, so I am going to go with an optimistic replacement of the seal only at this stage.

I trawled through a number of other forums to get a feel for the process, and watched some you tube monkeys replace it - but still confusing myself.

Looking at the workshop manual for the "REAR AXLE - 216RBI" the process is pretty straightforward, but to re-torque, it just states do it up. No mention of measuring torque to turn or collapsible spacer etc..

Am I right to assume there must be shims behind there for the D44?

I was originally planning to replace the nut and washer, but now thinking the mark-it-up and re-use with threadlock might actually be better, given the torque range is massive 217-271 Nm and if I use a new nut I don't really have any reference point to re-torque to.

(I do have another concern for the safety of my diff as I was advised my Yoke is non-standard when I was fitting a new driveshaft, so gambling that whoever replaced it did it properly)

Comments from someone who has physically done this, a few K's ago, would be great, thanks.

[Redemptioner]

Originally Posted by ajftj

The seal at the front end of my rear diff is leaking. I had a quick push-pull on the yoke and there does not seem to be catastrophic bearing failure, so I am going to go with an optimistic replacement of the seal only at this stage.

I trawled through a number of other forums to get a feel for the process, and watched some you tube monkeys replace it - but still confusing myself.

Looking at the workshop manual for the "REAR AXLE - 216RBI" the process is pretty straightforward, but to re-torque, it just states do it up. No mention of measuring torque to turn or collapsible spacer etc..

Am I right to assume there must be shims behind there for the D44?

I was originally planning to replace the nut and washer, but now thinking the mark-it-up and re-use with threadlock might actually be better, given the torque range is massive 217-271 Nm and if I use a new nut I don't really have any reference point to re-torque to.

(I do have another concern for the safety of my diff as I was advised my Yoke is non-standard when I was fitting a new driveshaft, so gambling that whoever replaced it did it properly)

Comments from someone who has physically done this, a few K's ago, would be great, thanks.

Just a suggestion, when these seals go its because of something else going and allowing movement. I suggest if you are going to the effort to reseal I would also look at replacing the pinion bearings etc or find what is causing the additional movement. Unfortunately the wear side is on the inner side of the diff, this means a full centre/diff rebuild is required to get to the inner bearing as you need to remove the carrier to access the bearing.

The pinion has an incredible amount of force on it due to being a double sided bearing setup, a small reduction in the force holding the assembly together will result in significant movement relative to the allowable tolerance.

[Classic Boy]

Originally Posted by ajftj

The seal at the front end of my rear diff is leaking. I had a quick push-pull on the yoke and there does not seem to be catastrophic bearing failure, so I am going to go with an optimistic replacement of the seal only at this stage.

Comments from someone who has physically done this, a few K's ago, would be great, thanks.

The 44A diff is pretty tuff and reliable and unless you hear some bearing whine suggesting it needs some internal attention, if not then a seal change is easy.

I have a method I have used for years successfully it involves simply marking the nut and the yoke and the pinion shaft carefully in alignment with a centre-pop mark on each part, then loosen and remove the nut, then the yoke, pop out and replace the seal put the yoke back in at the same spot and tighten the nut until your marks all line up. Never falls and I have done it this way on just about every make diff on the market over the years and it doesn't matter if it has shims or a crush sleeve, if you line up the marks you cannot over crush the sleeve.

[ajftj]

Redemptioner - you are right of course, and that's the chain of thought I'm trying not to acknowledge. My other question in the original post was going to be whether I could replace the pinion bearing at the same time as the seal, from the same end. I guess you just answered that! I'm just putting my head back in the sand for now, maybe winter 2018 as I need to do the rear axle bearings and that will put it off the road for a while.

On that I'd hope a diff rebuild kit exists from the US for my next trip.

Classic Boy - good to have your advice, have read a few of your pointers on some other issues I had and didn't need to ask as you'd answered questions for other newbies.

There is no whine as yet...
The mark it up and reuse / retorque makes sense and to be honest it's not going to make it worse and will cost me a seal. It might get me through to winter and if it fixes the leak I get lucky. Good pointer about the yoke, I'd probably not have considered marking that as it should be machined, but might as well put it back in exactly the same position.

Anyone built this diff?, Still curious if there is a collapsible spacer in there or shims.

[JaredCollins]

From what I’ve heard the Dana 44s use spacers to set the bearing preload, the Dana 30s use collapsible, just did a locker and regear on a 30 and it has the collapsible spacer, in the process of doing the 44 and it had shims under the bearings, no collapsible spacer, hope this helps


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[Tyvokka]

I just had this done yesterday but was done under warranty. Heartland motors told me it was a 2-3day job according to the service manual.

I called their bullshit and told them that it could be done in a couple of hours especially with shop tools. Magically it got completed by lunch time.

From my limited research, Classic Boy's method would be what I would do as well.

Sorry, misread the section. This was for a JK

[bonza]

the lip on an oil seal does eventually wear where it contacts the mating journal over a period of time often resulting in a corresponding groove worn into the journal causing further loss of seal lip tension. this usually happens long before play in the bearing is noticed.

for me I would just replace the seal as at 150K these sort of things start to show up