Engine/Transmission (1994 - 1998) front driveshaft seal

[MHalloran]

On another thread I titled it "driveshart" instead of "driveshaft". . this may be why no one replied so I'll try again. Front driveshaft seal into the front differential. . How easy would this be to replace cuz its leakin'. Will shaft slide right out of diff after being unbolted at transfer case or is there a retainer/clip of some type holding it indside. Special tools needed? Thanks for any input...

 

[B.G. Smith]

The front U-Joint yoke will be held in the differential by a large nut on the end of the pinion shaft, the nut also affects the pinion bearing clearance adjustment so it gerts pretty sticky. You will need a service manual for starters and an inch pound and foot pound torque wrench probably capable of about 250 ft. lbs. torque. Sorry I can't be of more help, I'm sure others will chime in when the work week gets under way. Good luck, bg

 

[MHalloran]

So BG what you're saying is that I cannot just unbolt the other end at the transfer case, drop it down some, then just slide the whole other end out of the differential in one piece? Splined shaft like? A retaining nut inside the diff holds it back? I'm in dreamland I guess & what I thought was too good to be true. Anyone else like to chime in?

 

[cerberusiam]

To do it right you would have to tear down the diff and reset the pinion nut to the correct TQ for the spin resistance.



The reality is if you can reset the nut close to what it was you will be fine.



Drop the drive shaft of the yoke, remove the nut, and pull the yoke to replace the seal. Assemble in reverse order and TQ the pinion nut. Yes, the yoke is splined to the pinion shaft and it may pull failry hard.



The pinion preload is set by a crash sleeve IIRC and as long as you don't exceed the original you won't materially change anything.

 

[MHalloran]

To do it right you would have to tear down the diff and reset the pinion nut to the correct TQ for the spin resistance.



The reality is if you can reset the nut close to what it was you will be fine.



Drop the drive shaft of the yoke, remove the nut, and pull the yoke to replace the seal. Assemble in reverse order and TQ the pinion nut. Yes, the yoke is splined to the pinion shaft and it may pull failry hard.



The pinion preload is set by a crash sleeve IIRC and as long as you don't exceed the original you won't materially change anything.

Ok... 2 questions Cerber, about what size might this pinion nut be & , what do you mean (you lost me on this one) by "pinion preload as set by a crash sleeve". Sorry brother I'm just feelin' a little dumb.....

 

[budnate]

watch this vid,



Replacing a Differential (rear end) Seal - YouTube

 

[cerberusiam]

Ok... 2 questions Cerber, about what size might this pinion nut be & , what do you mean (you lost me on this one) by "pinion preload as set by a crash sleeve". Sorry brother I'm just feelin' a little dumb.....

Not sure what the pinion nut size is, 1" or maybe 1 1/8".



Crash is supposed to be crush so that means I have fat fingers. :-laf

 

[mwilson]

Basically, you have to measure the force it takes to turn the yoke before you remove it so you can replicate the amount of drag when you put it back together. That way you don't disturb the crush sleeve and the preload remains the same.



I use a Wal-Mart 20lb portable fish scale that has hooks on each end. If it takes 8lb's of force to spin the yoke before I take it apart then that is what I shoot for after changing the seal by tightening the yoke in small steps until I again reach the 8lb's of resistance that it had before I took it apart.



It is not that bad to do. Have done it several times with good results.



Mike.

 

[B.G. Smith]

Ok... 2 questions Cerber, about what size might this pinion nut be & , what do you mean (you lost me on this one) by "pinion preload as set by a crash sleeve". Sorry brother I'm just feelin' a little dumb.....

The pinion bearings are tapered roller bearings with the smaller ends facing each other so the closer they are forced together the less clearance in the bearing. The crush sleeve is a spacer between the bearings that can be collapsed some with enough torque applied to the pinion shaft nut. By using the crush sleeve it eliminates trial and error method 0f removing/replacing shims between the bearings to get the proper clearance/preload. bg

 

[MHalloran]

Hey guys I really appreciate the returned input. It doesn't sound like a complicated job to do & I've always done my own work on this truck but I'm thinkin' maybe it may be a safer call to have it done at a shop that is more properly tooled ( a lift, etc. ) for a task of this nature. Some years back I had a ball joint replaced at a reputable truck repair shop so maybe I'll get a price from them. I know the Dodge dealer would whack me #@$%! for at least $300 to $400 to do this I'm guessing... . maybe more... They'd wanna put all new parts in, even if some could be re-used. Bite the bullet on this repair & pay someone... kinda hurts tho :{... ... ... ... . Mike

 

[MHalloran]

well i took it to the truck repair shop that had done a ball joint job for me and I had them replace the seal. $199 complete. only had it a day & a half. i feel it was worth it.....