My 04 has a leaking rear pinion seal.. 70k just ticked over, and well,, It seems a bit early to be needing it but surely does. I replaced the seal on our 83(f350) after having a shop loosen the yoke for me but I think that was because I didn't have an impact at the time.
The research I did at that time showed the pinion as a shimmed unit, and all I remember doing was removing the yoke nut & yoke, replacing the seal, and torquing it back up. Are the newer Dana's similar or should a shop do it? If I remember right, the nut is real hard to get off? Should a long extension be used instead of an impact wrench. I haven't looked up the specs yet. Also; I've been told by techs on other occasions that a leaking axle seal, is most commonly caused by a bad bearing. Is this leaking pinion the precursor to a pinion bearing failure. What do you all think?

 

It depends on what axle you have I did mine I have the 10.25" and I did it with a 1/2" drive rachet no problems,no leaking ,no troubles,easy fix.

 

I haven't studied the sterling axles, but there is some type of crush collar/bushing some pinions (I think the 9" pinion is pressed on to a shimmable carrier plate). Once it's set you don't want to crush it further. The idea I've read about doing a crush collar pinion seal is to record the torque to remove the nut and put it back on the pinion at the same work unit (say if it took 70ft/lbs to get it off, you need to apply 70 ft/lbs when you put it on.

If the pinion is pressed on to a carrier plate, than unbolting the yoke shouldn't change the pinion's relationship to the ring gear making the swap nice and easy. It still would be a good idea to replace it at the same torque it took to remove it.

 

ReAX is correct about recording, and then re-setting the correct pre-load adjustment on the pinion bearing with the torque wrench (Ford axle).

If you mess up, you have to start over with another new nut and crush washer (or whatever that thing is called).

I had to replace my seal at about 80K ..... very minor leak. 2002 F250. I could not detect any bearing problem.

Good luck.

 

I count the threads and replace it back were I found it without any problems but recording the tourqe sounds better

 

Check the axle breather first - if it's clogged, when the unit heats up it'll push oil out the weakest seal. Usually the pinion seal

 

Per Fords instructions the nut requires 470 lb-ft of torque. Have fun holding the flange if you dont have the tool to do so.

 

Just did mine today 2005 F250. I removed the bolts holding the drive shaft flange on..pushed the drive shaft out of the way...then removed the pinion nut. Let me tell you..I"ve removed pinion nuts before and had to grunt, groan and use a few choice words to get them off. Well this one i put the big wrench on it and touched it with my hand and it it came loose. Which now makes me wonder..it being that loose allowed for play which probably caused vibration issues i was having. Well anyway..after removing the nut i used hammer and tapped on the pinion flange to get it off. Popped out the old pinion seal..cleaned thing up and put a new one in and put things back together. Thing are MUCH better now!! You can do the job without jacking the truck up..just lay under there. Just remember to refill the rear. ..and yes i checked the pinion bearing and it was good.

oh yeah..the flange wont turn with the emergency brake on and the tires on the ground.

 

I've been through this before with others on here, but not replacing the crush collar and resetting the pinion preload the "right" way is a recipe for disaster.

A Dana 80 (DRW) can be done without removing the pinion, it uses shims to set pinion preload - but a Sterling (and the 8.8") that use crush collars need to be re-setup the right way.

If you happen to have perfect bearings, and only the seal is leaking, you CAN re-torque the nut back to where it was (mark it before removal) and it should be OK. Operative word is "should".

Personally, I've setup many gears, and I wouldn't do it that way, but that's just me

 

Agreed. However, Im used to doing warranty work and they wont pay for a entire set-up Wham bam thank you mam.

 

Another reassuring insight from the warranty world!

However, I believe that the inch pound torque wrench is the key to getting it as close as possible without having to find something to crush a new collar. The critical component here is the preload on the pinion bearings. It doesn't affect the pinion to ring gear relationship at all. That is set by the shims under the pinion head bearing.

For years I changed seals and reset them by hand, either marking the nut or by feel. I became more scientific by measuring and recording the pre-seal change pinion rotational torque drag with an inch pound wrench. When re-assembling, I slowly come up to the point again and measure to make sure I get back to where I started. Theoretically if you get right to the same point with the crush collar, and don't crush it any further you are find. The risk of crushing it further is slim, but at the point of preload it doesn't take much crush to send the preload sky high, which can lead to bearing failure over time.

 

Theoretically...

I used to work on Triumph Tr7's a lot back in the day... The little 4-speed rear ends used a crush collar, and the crush collar would fail over time, increasing the pinion bearing preload. The crush collar itself would look strange, in terms of striations in it. The pinion bearings would go bad pretty quick after that. Whenever I worked on one for someone, I'd check the pinion preload and it'd be WAY high...

Anyway, that crush collar does a lot of things, and if you crush it, back off, and then crush it again, it doesn't keep pushing back as much over time and the pinion preload goes up, ruining the bearings.

I hate crush collars. I really really do ...

 

So they aren't one time use? I always thought once you compressed it, it was done and if you over tighten it, you had to replace the crush collar.

 

The one time use of a crush collar was my understanding as well. But as many have said in this thread, and other past threads, I read after my initial post, that setting up a pinion yoke after seal replacement can be done with some good results. I apologize for not doing the research as to what differential is under the rig. I'll slip under today.
I was hopping it was similar to the 83 with a shimmed pinion setup. At that, the process seems straight forward and I would approach the task although not sure I have a wrench that goes to 475lbs (Dana 80)$. I guess being a 1ton crew doesn't mean any particular diff. would be under there.
I took a look at the tags the other day, and most of the digits didn't ring any bells at the time, although alittle research on the 4.35 mentioned on one tag hasn't meshed with what I've found as available gearing yet? Anyone know what code I should look for on the tags? I have seen the super duty spec sheet section, I'll go there as well as check service manual. Thanks to all that chimed in, I'm sure it seems repetitive for those who've been involved before , But Your help and guidance is VERY appreciated.

 

I've always done them the way aldridgec suggests. I do pull the axleshafts out before I take the inch/pound reading on the pinion nut.