leaky rear pinion seal...Questions

[Motorhead]

My neighbors '92 4x4 5spd needs a rear pinion seal. I have manuals for my '01. 5. Is his dif a Dana 70? Can anyone tell me the torque on the pinion nut or do you guys just use an impact wrench? Thanks... Chris

 

[bgilbert]

Yep D70, IIRC torque on pinion nut is 250-275ftlb, don't quote me, haven't done this before, just going on memory of reading.

 

[Philip]

My 93 manual says min torque is 210 ft. lbs. It does not list a max torque.



Before you take it apart. See if there is any play in the pinion bearings before you take it apart. If there is you will need to find/fix that problem also or it will just eat the new seal up.



Also have a speedy sleve when you take it apart. Most likely the yoke has a groove in it.

 

[1stgen4evr]

Depending on mileage, you may have other problems as well. The pinion can sometimes start to leak from weeds, etc having wraped on the yoke. If your pinion brgs have gotten loose from wear and miles, you almost certainly have similar wear on the carrier bearings, especially on the ring gear side. With the cover off and before removing the carrier (which will be required if you do anything to the pinion bearings) test for side play on the carrier bearings. There should be NONE. You will need to addres that as well.



The preload on the pinion shaft bearings is set with shims. You may or may not be able to use the original set for correct preload. Some pinion bearings are set as to preload by a 'crush' sleeve and the torque on the pinion nut. In those cases, the torque value is far more critical than those with shims. The Dana 60s that I have serviced had the crush sleeve. Also a Dana 70s from a Chevy application. I don't think you will encounter those. The Dodge Dana 70s that I have serviced DID NOT.



After I have the preload set to my satisfaction, I then tighten and use medium Locktite.



As Philip states 210 ft lbs and I second the speedy sleeve. A leaking seal will have almost always attracted grit resulting in some wear on the yoke seal surface.



There is a sticky on the Dana 70.



James



edit: typo

 

[ARhine]

Just got mine back together. Got a new yoke and seal from quad4x4. Ended up needing all new brearings and a new carrier.



My axle is a non-crush sleeve type. FSM stated 275-300 ft-lbs. Put some loctite on it before reassembly.

 

[1stgen4evr]

Ended up needing all new brearings and a new carrier.



ARhine, could you expand on that. I am trying to learn a bit more of why/when the 70 starts to deteriorate for a 'head em off at the pass' preventive maintainence statment. Of course I realize that how the truck is used will be significant as to any repair but I let my high miles 93 go too far (happened at about 500k) and had a near catastrophic failure of the carrier bearings which eroded the bearing stub on the ring gear side. I had some spare parts and the repair was not too terribly expensive. There are plenty of sources of parts and this would not be the end of one's truck nowdays but it can be heavy on the wallet.



Thanks for any insight you might add to the forum.



James

 

[Scot]

Before you tear it all down, check the diff vent hole and tube to make sure it is open. Take it out and blow through it. I have seen more leaky pinions caused by that than actual seal failure.