Pinion seal replacement

[JLibert]

has anybody changed the seal on the front diff? Mine just started leaking at 101K, just out of warranty so it looks like I'll be doing it myself. I have the cheapo haynes manual. Any pointers?

 

[DPKetchum]

A couple friends of mine got theirs done for less then $90. 00 bucks which tells me its not hard. Bet they mark the threads and re install pinion nut back to same spot. They both WAITED on theirs to be repaired. One had a front go the other truck a rear.

 

[Thump]

I haven't looked at the front axle of these trucks, so I'm not sure if you can replace it without removing the pinion.
I also am not aware if these axles use a cruch sleeve or torque to preload the pinion.
Most times, without the use of a crush sleeve, you remove the pinion nut and knock off the yoke (locks on after a while).
Then remove the seal (tearing it to shreds normally).
Then tap the new seal into place using a brass drift or plastic hammer, if you don't have a properly-sized seal tool.
Replace the yoke
Torque the nut to proper specs
After driving in 4wd for a few miles (10 or so at around 20mph, to get some heat in the diff and you stated it is a front diff), you remove the front driveshaft and re-tighten the pinion nut.

That last step is often overlooked and left off without harm, but is the best practice.
You can also use some blue threadlocker if you plan on skipping the re-check.

If it's a crush sleeve, you're looking at more of a process to get it to the right preload.
There was a thread recently discussing improper torquing of a pinion nut and the subsequent and quick failure in that area, so you don't want to just hammer it down with a big air impact gun.

 

[DPKetchum]

A experienced tech can and often does even the crush sleeve method without resetting preload. In fact I bet most do.

 

[CBradford]

My pinion seal went out just before i crossed my extended warranty coverage @ 75k miles... ... i was going to have them fix under warranty but it wouldn't have mattered parts and labor was only quoted out at just over $50 (same as deductible)..... well worth having someone else do it... ... . and i set up rear ends in my off time..... but couldn't beat the price... ... normally when a pinion seal goes the replacement doesn't last long b/c the seals normally initially fail due to improper pinion bearing pre load or bad bearings..... but i've put about 10k on mine with no further leaks.....

 

[rbattelle]

The service manual says (paraphrasing):



1. Remove hub/bearing assemblies and both axle shafts.



2. Measure the rotating torque on the pinion using an in*lb torque wrench. You'll need the dial type, obviously. Write down that value.



3. Remove the pinion nut, washer, and flange.



4. Remove seal.



5. Install new seal.



6. Install new pinion nut. (It doesn't want you to reuse the old one).



7. Tighten the pinion nut until the pinion end play is taken up. (Not exactly sure what they mean by that, but I assume when you're actually doing the work it'll be obvious).



8. Rotate the pinion several times and measure the rotating torque again just like in step 2.



9. Very slowly and gradually tighten the pinion nut until the torque setting equals the value from step 1 plus 3-5 in-lb.



10. Put it all back together.



They want the axle shafts removed so the torque reading is more accurate. If you want a copy of the service manual pages, PM me.



Ryan

 

[DPKetchum]

One shop I worked at 14 years we gave the customer the option of both ways. By the book and by putting pinion nut back to same thread/feel etc. One with no warranty. They always opted for the cheap way and we never had a return/recheck. Depends on the tech and his experience.

 

[JLibert]

thanks for all the help. Getting it done at the dealership for about $95. They didn't offer two methods for doing the job. They are only charging 1 hour labor, so I'm not even sure if they will be removing the wheels/tires.

 

[RBell]

For anyone who doesn't have the nice factory manual, here is the link to a free download... http://www.hemitruckclub.com/04manual



It has the diesel info as well as the gas engines. ROB

 

[DPKetchum]

The reason "I" always offered the correct way and the "cheaper way" ($95. 00) was in case of a issue(it HOWLS NOW! OPPS) that the owner was informed. (cover thy butt)The $95 way is marking or counting the threads and reinstalling the pinion nut to same threads. No need to remove wheels. Hour labor,seal and top off fliud.

 

[JLibert]

thanks RBELL, you just saved me some $

 

[Tomeygun]

thanks RBELL, you just saved me some $

Ditto that! My cable modem's smoking right now with that 88mb file

 

[betterthanstock]

For DIY, the easiest is to mark with a paint spot the axle, the flange and the nut.

Count the exact number of turns and write it down.

Use fine emery cloth to clean up flange where seal spins, then compressed air or water to wash all abrasive and put grease where the seal makes contact, otherwise you will wear out new seal very fast.

Use blue loctite and put it back to the same number of turns and have all 3 marks line up when finished. Otherwise you will not have the correct preload on bearings, and will damage bearings and gears. (unless you remove the shafts and the carrier, and then you have to use the "old bearing" (lower torque) preload to put everything back like new. If it's not noisy, don't do it)

 

[GDouglas]

Remove the driveshaft and clean the area around the pinion nut. Take a center punch and mark one corner of the pinion nut. Then make a punch mark on the face of the pinion shaft close to its edge inline with the punch mark you just made on the pinion nut. Then make a 3rd punch mark on the yoke inline with the 2 previous marks. You now have a matchmarked reference to be able to put the pinion nut and yoke back on exactly as they were with the same exact bearing preload as before disassembly to replace your pinion seal. You can count turns of the nut if you wish, but I ususally don't bother. If your marks are lined up, but you still have slop in the pionion bearings, it is time to go around for another turn to line the marks up agiain. You will be on the right revoulution of the nut when the bearing slop disappears. Use blue loctite on the nut threads.