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I put gear oil in the differential, tranny, and steering box. The tranny and steering box don't leak, but it looks like I need to replace the pinion seal. How big a deal is it to replace? The seal never leaked before. (At least not the way it's leaking, now.) But, the truck hasn't been driven since about 1992 and the differential hasn't had oil in it since about 2005. Any chance that the seal will somehow "re-seal" itself after the truck's been driven for a few miles?
I put gear oil in the differential, tranny, and steering box. The tranny and steering box don't leak, but it looks like I need to replace the pinion seal. How big a deal is it to replace? The seal never leaked before. (At least not the way it's leaking, now.) But, the truck hasn't been driven since about 1992 and the differential hasn't had oil in it since about 2005.
Any chance that the seal will somehow "re-seal" itself after the truck's been driven for a few miles? Probably not, the leak may get worse.
I've skimmed through the service manual and it looks like a good part of the differential has to be taken apart to get to and replace the seal.And a lot of special tools would be required. Is there no other way to replace the seal?
Is it a Dana 44? If so, no, you only need to pull the yoke off. One of the Lisle tools for hooking seals out really helps, but a screwdriver will work too.
You may also want to make something to hold the flange of the yoke while you remove and re-torque the nut on the yoke.
I know very little about differentials. According to the service manual, I have "an Integral Housing Hypoid" axle type. I don't know if this is right, but I think I could rig something up to pull the flange. Then, using a three claw internal puller, I yank the old seal out. Then, gently tap the seal back into place. Then reinstall the flange. I think I can handle this, if that is the way to do the job. Any advice or warnings will be appreciated.I found this exploded view in the LMC catalog. It shows a piece between the flange and the seal. Any ideas what this piece is?
I think that part is on the companion flange already, I don't think you need it. Your challenge will be getting the pinion nut off. I would make a flange wrench, a 2" x 36" x 1/4 steel piece with a part circle cut out on one end for your large torque wrench. You will have to drill holes in it to bolt to the flange. That will give you the leverage to overcome the 150 lbs or so to move it. Replace your seal then use it again to torque the pinion nut.
If it were mine, I would drive it, give the seal a chance to do its job. I've seen pinion seals leak when stored for a while and then quit leaking when put to use. I've also seen them leak and keep on leaking.
My recently sold F350 was the classic "leak if not used". I would let it set for a couple weeks and it would leak. Drive it and no leaks for a couple weeks. All the reason to drive these old vehicles. BTW, it never leaked enough that I had to add lubrication.
My pinion was leaking on my F2 even though I had installed a new seal. Had to take the driveshaft off and remove the yoke to remove the recently installed leaking seal. I noted that the sealing surface that the seal rides on was worn on the pinion shaft. I bought one of those repair sleeves which are ultra thin and locked it in place. Installed a new stock size seal and my leak is gone. So, when installing a new seal, make sure to inspect the sealing surface on the pinion or you may still have leak issues after installing a new seal.
My pinion was leaking on my F2 even though I had installed a new seal. Had to take the driveshaft off and remove the yoke to remove the recently installed leaking seal. I noted that the sealing surface that the seal rides on was worn on the pinion shaft. I bought one of those repair sleeves which are ultra thin and locked it in place. Installed a new stock size seal and my leak is gone. So, when installing a new seal, make sure to inspect the sealing surface on the pinion or you may still have leak issues after installing a new seal.
Good advice, this. If driving it doesn't limber the seal and it still leaks, do inspect the seal surface on the yoke.
If driving it around a bit might take care of it, then I'll give that a shot. Almost the last thing that I want to do this weekend is spend two days on my back under the truck wrestling with a differential that hasn't been worked on since it was assembled in 1953.
Have you done the rear brakes yet? Whenever you do them, it's worth making a "rake" out of all-thread and a half-moon piece of sheet metal to scrape all the goo out of the axle tubes. I was amazed how much was in there, and it heads straight to the bearings.
The pinion nut is torqued to over 350 foot pounds. I used an impact wrench that had 750 foot pounds of torque.
It is recommended that the pinion nut should not be re-used.
The u joint companion can also be difficult to remove.
I had to start with a claw puller and finish the removal with a slide hammer.
08-21-2016, 06:06 PM
