Archived How do I reassemble front diff yoke?

[LarryWaddell]

After 2 trips to a "reputable" driveline shop my front diff was still leaking so I decided to replace the seal myself with a NAPA part (a tip from member Got HO?). Please read this thread to understand what I am doing: https://www.turbodieselregister.com...n-of-my-front-diff-seal-replacement-with-pics

After much difficultly, I managed to get the nut off the yoke (with a torch) and found that they had used RTV silicone as a spline sealant, completely "glueing" the nut and washer to the yoke.
Now, here is the question: since the silicone would have created an additional barrier between the nut/washer and the yoke, there is no way they could have retightened the nut to the original (correct) position. I have removed the silicon and will use a normal thread sealant on the splines, install the washer and nut but now I have no way to make sure it gets tightened back to the correct position since the silicone is no longer behind the nut/washer. How do I Proceed?

Also, the seal on the Yoke looks bad but I can't find any info regarding replacing it, only the seal on the differential itself. Is it replaceable or do I need a new yoke or is the seal on the yoke a non factor?

Silicone on the washer:

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How much silicone I removed from the yoke:

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Condition of the yoke seal: any good?

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[Joseph Donnelly]

What a mess! I hope you didn't heat the parts enough to ruin their heat treating. If in doubt, replace at least the nut and washer. Discard the burnt seal. I would assume Mopar has the part number for it. Since you don't know where preload begins, you will have a problem tightening the nut just the correct amount. Too much and you will have too much preload, by over-crushing the crush sleeve. If it were mine, I would remove the carrier with ring gear so I could turn the pinion and verify pinion bearing preload. You will have to back off the adjusters, or better, just the one on the ring gear side, a certain number of notches so you can get it back where it was. You really should make a long bar out of something like 2x2x.25" steel with bolt holes to attach it to the flange with grade 12.9 (iirc they are metric, but check) allen bolts so you can tighten the nut. If not metric, get the highest grade bolts you can get, like grade 9 (Bowmalloy, Supertanium, etc.).

 

[LarryWaddell]

I used a propane bottle torch, not real hot so I don't think that will be a problem. The seal did not get burnt at all, that was just wear on the yoke seal. The local O'Reilly auto store does not even have a part # for the yoke seal so I may be looking at replacing the yoke?

I understand the problem of over/under tightening the nut, I did mark the nut/spline shaft with a center punch so I have the old reference point. Everything else you mentioned after that is over my pay grade. I don't have any experience with diffs, gears, or verifying pinion bearing preload... I was hoping it wasn't going to be this serious. Since the truck is sitting in my garage, should I tow (flatbed) to a driveline shop (not the same one, there is another good shop 10 miles away) or just remove the front drive shaft and drive it over in the morning?
My other option is to install a new washer/nut and hope for the best...

 

[Joseph Donnelly]

It appears you have an American Axle so is a 2003-up Ram. They don't have axle disconnect so the front pinion will turn even in 2WD. You don't know if the shop tightened the nut correctly, so you don't know what the preload was after they were done. You also don't tell us where you are, in case a member is close and can help.

 

[bigblock_doc]

Also the silicone on the splines is to prevent fluid from leaking threw it. Making it look like a seal problem.
Use a new nut and washer as I didn't and the nut backed off at a real bad time going through a toll
booth in NY. Locking up the front diff. Pull the front shaft, put the yolk in and tighten until no up and
down play is felt and then tighten a little more. That is by hand, not air gun. Then take to a good
shop to have it done correctly. That will save you a tow.

 

[LarryWaddell]

Sorry I did not include the truck info in the original post, 2006 2500 mega cab 4x4.
Update:
My wife's cousin stopped by and helped me out. He had the same truck I have and is a good mechanic. The use of black silicon is more common than I thought. We both agreed that the shop I had do the work used way too much than needed, maybe because this was the second time I brought the truck in for the same problem. They did the work on their dime the second time. It looked like the wet silicone had squeezed out of the surface areas between the washer/nut and base of the yoke when they tightened up the nut so I felt pretty confident I could use my markings and tighten the nut 1/4 turn past the original spot and call it good. I know some of you will be appalled at my guesswork but I'm going to go with it. The job is finished and I will take her for a run tomorrow, check for leaks and any strange noises from that front diff. If there is any doubt it will go to a qualified shop for repair.
Thanks for the help guys!

 

[Joseph Donnelly]

1/4 turn beyond factory is way too much bearing preload. You may have over-crushed the crush sleeve and need to get a new one, remove the carrier, pinion, install new sleeve, tighten nut to crush the new sleeve just enough for propber bearing preload (about 12 inch pounds used bearings, 24 inch pounds for new bearings).

 

[Joseph Donnelly]

Actually, tightening the nut another 1/4 turn would take a lot of torque, so it is also possible you are still 3/4 turn shy of the factory setting, almost one thread loose. Check it out, and refer to TDR Issue 67, p. 80.

 

[LarryWaddell]

I don't have issue 67, and I can't find that article in the forum archives. Am I missing something? Is there another way to look that up on the TDR website?

 

[Joseph Donnelly]

Go to the TDR home page, at left click on digital magazines, click on Issue 67. That page is part of my "column" Have Ram Will Travel.