leaking differential fluid from my rear axel.the rear end on my '53 is'nt original and has no markings. I've been told it looks like something seventy-ish( the differential). well come to find out , the leak is coming from the seal behind the u-joint on the front"face" of the diff'housing. Could this be replaced by me provided I find a pinion seal or does this require some expert knowledge?Who sales pinion seals??? NAPA does'nt!

 

Don't know about the "70-ish" rear end you may have but I replaced the pinion seal on my 1956 F-250 with the original Dana (Spicer) 60 rear end. The only part that took planning was putting together some fixtures to get a grip on the yoke without trashing it and getting enough torque on the nut to remove it. There's a photo on my web site (http://www.clubfte.com/users/earl/index.html) showing the setup I used. Course, mine was out of the truck but you probably can use something similar even working under the truck.

BTW, once I had the old seal out I took it to my local NAPA store and the fellow, who I know fairly well, looked up a new seal using the dimensions of the old one. JobLot Automotive (www.joblotauto.com) has seals listed by original model and type.

George

 

The pinion seal is easily replaced but you have to be careful when replacing the pinion nut. Don't over tighten it, only snug it down. The point is not to further crush the 'crush' spacer in the pinion shaft. The spacer affects how the gears mate up in the differential, if crushed further you may have too much slop in the gears causing excess noise.

 

Thanks guys! I'm pretty handy with tools though I'm no "mechanic",maybe I should leave this to the shop as I can't vision any aspect of whats mentioned above. How many hours of labor(shop) should I expect?

 

Replacing the seal is a very simple operation and should take less than an hour.

The drive shaft would have to taken loose at the rear unniversal joint and dropped down. Tape the end caps on the unniversal joint to keep from loosing the roller bearings inside. The shaft should not be removed from the transmission.

Next, mark a line on the side of the pinion shaft and onto the differential housing. This is only for reference so that it can be positioned correctly when reinstalling. Loosen the large nut in the pinion shaft and pull out the shaft from the housing. You may loose a little oil but that should be expected.

Pry out the old seal, position and tap in the new seal and reassemble. Slide the pinion shaft back into the differential (aligning the marks you made earlier). Snug up the large pinion nut but be careful not to further crush the internal crush washer. Re-bolt the drive shaft and your done.

 

[updated:LAST EDITED ON 22-Aug-02 AT 07:20 PM (EST)]The nut on mine is tough to get off. If I get after it with a real long cheater will it damage the gears? If I hammer on a ratchet will that cause damage? It is a right hand thread?

 

On my 1956 F-250 with a Dana 60, the drive pinion nut is a 7/8-14 and the shop manual recommends tightening to 200-220 ft-lbs. I don't know the rear axle model on a 1956 F-100 (Dana 44???), but the shop manual says the drive pinion nut is a 3/4-16 and recommends it be tightened to the same torque, 200-220 ft-lbs. Hmmm, that's just a little odd that they give the same torque spec for two different size threads.

Here's what I used on my 1956 to put the yoke back on. I used the same setup to take it off (with the pipe wrench and ratchet reversed, of course). I don't know if other years are the same but my drive pinion nut was down inside the yoke. The method in the photo avoids putting any strain on the gears. I'm not sure about the crush washer referred to in earlier posts, I didn't see any reference to it for my particular axle. Did I miss something?

http://www.clubfte.com/users/earl/20000325TighteningtheRearAxlePinionGearYokeNut.jpg

Obviously, your axle might be different from mine but I hope this helps a little.

George

By the way, that's a Craftsman 1/2" drive ratchet with a BIG cheater bar on it. Won't claim Sears has the best quality tools but that one still works! ;-)

 

The pinion shaft on the rear has two tapered roller bearings on each end. These are set-up and look sort-of like the front wheel bearings. Just like the front wheel bearings, the tension needs to be set between these two bearings. On a front wheel bearing you set it by feel and then lock the nut with the cotter pin. In the rear-end, there is a thin spacer(like a piece of exhaust pipe) or "crush sleeve" separating the two tapered bearings. The factory torques the nut to a specified setting that actually crushes the thin sleeve. They have it figured out that when the sleeve collapses, the bearing tension is then correct.

Theoretically, when you disturb the set-up, you are supposed to replace the sleeve and then re-torque to the factory setting. But a common way to do it that seems the least risky is to put a mark on the nut, and a corresponding mark on the shaft. Then when it's re-installed, instead of torquing the nut, you just put it back in the same position it was originally in.

 

once I get the seal it self out is it plastic or rubber and could I take it to some pinion "dealer" and eye-match it to the correct replacement?

 

Franklin and Huntsman,

I just re-read the whole section on changing the drive pinion for the 1956 model year in my shop manual. There is a long and detailed discussion about making sure you have the correct total thickness of shims both aft and foreward of the two bearings. These shims allow adjustment so the pinion sits at the correct, factory set location with respect to the ring gear and they also set the bearing preload. The shop manual indicates that as long as you get the correct total thickness of shims in both locations you are fine. The very last paragraph in the whole section on the drive pinion replacement reads "Install the universal joint flange, washer, and nut. Tighten the nut to 200-220 foot-points torque (F-100) and to 200 to 250 (F-250 and P-350)". I followed these instructions to the letter. I didn't remove or disturb any of the drive pinion shim packs or bearings except to flush them out with kerosene. The shims on the drive pinion in my axle seemed pretty substantial - like washers. I don't think I could crush them by tightening the nut but I could be wrong if they are made out of some soft metal. I did't find any reference in the shop manual to crush washers and/or tubes for the F-100 or F-250 rear axles. All the checks for end-play, etc. listed in the manual came out right on the money when I was done.

Are the crush washers/tube used only on earlier (or later) rear axles? I'm pretty certain I have a Dana (Spicer) 60 in my F-250 and I'm also pretty certain it's the original axle but it's certainly possible that it's not.

Your experience and comments are most welcome and appreciated. I'd like to find out which rear ends need the extra care with the crush components and which don't. Bet some other folks would too. :-)

George

 

If you have sets of shims in two different locations on the shaft, then they must be setting the preload with one of the sets. The later model rears have only one set of shims to set the gear mesh with the ring gear. I haven't a clue as to what applications/years had the crush sleeves, and which ones did not.