2nd Gen Non-Engine/Transmission Pinion seal replacement.

[Bartman#1]

Hello everyone,



Can someone give a quick rundown on how to change out my rear pinion seal?



I have the dana 70, I just don't want to skrew up my backlash.



it's leaking bad... it's -15, i want to do it quick and right.



Thank you all!!!

 

[bmoeller]

I don't have my book handy, but it is a pretty simple job to do. Won't change the backlash changing the seal. The shim stack on the other side is what is used to change the pinion depth.



Will want to use an impact wrench to get the nut loose, and may need a puller to get the yoke off of the shaft.



If the nut has the nylon insert, I suggest replacing it, or having one handy, just in case. They don't always do their job once taken off.

 

[EGILLILAND]

Was about to ask my own questions about this subject but noticed Bartman has already a good line of questions... .



One more for the task of pinion seal replacement... . the nut on the pinion yoke. Will a standard 1/2 or 3/4 inch drive 6pt socket fit in the yoke and reach the nut? I noticed in on another forum (ferd trucks) guys were needing to turn down a socket in a lathe to make it fit.



For all the pinion seal replacement experts out there..... Do we need a special custom socket to reach the pinion nut?

Additionally, can someone confirm the size of the nut? I think it's 1 7/8 but not sure.



Thanks in advance!



Eric

 

[Curious Dave]

I saw my pinion seal was leaking... Found out my axle seals were leaking too. One seal I could understand. . But all 3? I checked the vent line and the hose was clear - But the actual tube was plugged with dust/dirt/oil. Cleaned it out with various cleaners and a screwdriver after removing it from the axle. We'll see if this helps. You guys might want to check yours.

 

[Flinty]

These are the tools that I used for my Dana 80:



The top is of course the socket I had to have turned down to fit into the yoke. If I had to do it again I would use an impact socket because they come in a six-point configuration. This leaves more meat at the corners of the nut after machineing. The size is 1 7/8"



The lower picture is the press I built to get the yoke back on. In past instances with other vehicles I was able to force the yoke back on with the nut. However, with my Dana 80 if I tried to hold the yoke so it wouldn't spin while forcing it back on the pinion shaft with the nut it wouldn't work. The combined twisting and pushing action would bind the yoke on the shaft. To get it to work I had to press the yoke up against the bearing then hold the yoke and torque the nut to 450 ft/lbs. I can't say if the 70 and 80 are the same. Maybe someone else knows.

 

[EGILLILAND]

Thanks JMarinaccio.....



Looks like my Dana 70 nut is either a 1 1/4 or 1 5/16. I bought both today will post the results hopefully tomorrow.

 

[EGILLILAND]

Lessons learned so far.

The nut on my Dana 70 was a 1 5/16, No turning required in this case. Sorry 1 ton guys.

I used a small propane torch and carefully heated the nut for about 2-3 minutes. Then hit the hole thing with WD40 (yoke/nut etc. ). READER CAUTION... WD40 plus heat could make FIRE... ... ONLY USE A LITTLE HEAT!

I was able to break the nut w/o an impact wrench (breaker bar and 2' cheater pipe). The yoke also pulled off nicely w/a good two jaw puller.



And then I tried to remove the seal... WONT COME OUT. Bent my cheapie seal puller and mangled the inside of the old seal. It looks like the old seal is rusted in pretty good.



QUESTION: Any good techniques out there for removed a rusted-in seal without boogering up the flange?



Thanks in advance again...



Eric

 

[EGILLILAND]

Seal is out w/some very carefull use of the corner of a small chisel.



Everything has gone back together nicely.

Used a piece of PVC, a coupling 3 3/8" OD to gently seat the new seal.

Used some black RTV on the outer lip of seal that mates with the diff case to make sure no oil gets out that way.

Installed a new yoke (kit from Quad4x4). Greased the splines then torqued (plus one good grunt) the nut... THEN, removed the pinion nut. Pulled out my favorite torch, gently heated the yoke again. Again carefull not to overheat any one spot on the yoke, just wanted to swell it slightly. Once it was hot to the touch... . added blue locktite to the pinion threads, then quickly reseated the nut and torqued to spec. Got another half turn of the pinion nut w/the heating drill.



Adding oil and going for the test drive now. Wish me luck.

 

[EGILLILAND]

Last post... hopefully Bartman's original question/post is covered now.

Test drive complete, no leaks... . woohoo!

Items of note... . I didn't just buy a new seal. I went with a Yoke kit from Quad4x4. It cost a little over $100 but was well worth it. I was able to use the new parts to help me prep the repair, make sure I had the right tools etc. Additionally, it seamed like a lot of guys that keep using the same yoke after 100K mi seem to be chasing a lot of leaks, using sleaves etc. I can't do that... . only had one weekend to do this and I get paranoid when I don't have my truck around.

I was able to use a basic breaker bar, plus 2ft cheater to do all the work. Having the little propane torch around was nice too. I know a lot of aircraft mechanics use a combined heating/cooling method to fit tight parts like this so the procedure seemed to make sense. It also kept me from banging away on my differential w/an air hammer w/o any good feel for torque.

Thats it... fix is done... off to more issues next time. Good luck to anyone who is reading this... hope things work out for you as well.

 

[Flinty]

Those kits from Quad are great, aren't they?!

 

[Excessive Force]

These are the tools that I used for my Dana 80:



The top is of course the socket I had to have turned down to fit into the yoke. If I had to do it again I would use an impact socket because they come in a six-point configuration. This leaves more meat at the corners of the nut after machineing. The size is 1 7/8"



The lower picture is the press I built to get the yoke back on. In past instances with other vehicles I was able to force the yoke back on with the nut. However, with my Dana 80 if I tried to hold the yoke so it wouldn't spin while forcing it back on the pinion shaft with the nut it wouldn't work. The combined twisting and pushing action would bind the yoke on the shaft. To get it to work I had to press the yoke up against the bearing then hold the yoke and torque the nut to 450 ft/lbs. I can't say if the 70 and 80 are the same. Maybe someone else knows.

Great info here... . With the dimentions you gave i was able to buy the correct size socket,and machine it down to the correct size to fit the yoke. Man i can't believe how hard the yoke came off ( had to use a puller),but it tapped back on ok. If anyone's interested the Mopar part number for the seal on a Dana 80 is : 1-05073944AA. TDR comes through AGAIN !