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I have the stock rear end in my '55 F100 and yesterday it started leaking. I took it to my local Transmission shop and they wouldn't replace the pinion seal because they said it was too complicated. Is it really that hard to do? Does it require special tools? I'd do it myself but now I'm nervous based on their response. I'm a pretty good DIY guy and will do it if I can get some coaching. Thank you!
The issue is that there is a "one-time use" crush sleeve between the bearings on the pinion. It "should" be replaced when the yoke is removed for seal replacement. In real life, lots of people simply leave the old one in, and re-torque, with (usually) no harm. You'd know pretty much right away if you did that whether it was unsuccessful. (noise from rear end) I've re-used them with no problem. YMMV...
Ross's advice is absolutely correct for axles that have a crush sleeve on the pinion to set pinion bearing preload. The original axle in your '55 F100 should be a Dana 44, however, and that model did not use a crush sleeve in the years our trucks were built. They used a solid spacer and shims. That's a good thing for you as that makes a seal change a very straightforward proposition.
Start by removing the rear cover to drain the oil and disconnecting the driveshaft. Remove the nut and washer, pull the yoke, and remove the old seal being very careful not to nick, scratch or damage the seal bore. Leave the bearings and slingers in place on the pinion. No need to remove them and risk getting something out of order. Inspect the yoke's seal journal for pitting or a deep groove. If it looks ok, wrap the journal with a piece of red scotchbrite soaked with WD-40 and spin the yoke in it in the direction of normal forward rotation to polish the journal. Clean the bore up a bit and then install the new seal making sure to grease or oil the seal lip. Follow that by installing the yoke, washer, and a NEW pinion nut. Use a little red Loctite on the nut and torque to 160 ft./lbs. Put the cover back on, refill with fresh 80W/90 gear oil, and reattach the driveshaft. Easy peasy!
You should be able to pick up a cover gasket, pinion seal, and a pinion nut for a Dana 44 at your local parts store. It's a common axle and those parts were the same for decades.
Sorry, I didn't realize that. I guess that explains why my seal changeout went well!
No worries - it's always better to ere on the side of caution. Some of the later 44's did in fact have a crush sleeve. We got the good stuff on the early ones though!
Crush sleeves are great when you're building thousands of axles and need to be able to set the preload quickly. They're a real nuisance down the road when the time comes for repairs, though.
I don't know why you would need to pull the diff cover. Start with dropping the driveshaft and go from there. When done re-fill diff and call it good. I have done it this way for years with never an issue.
Ross's advice is absolutely correct for axles that have a crush sleeve on the pinion to set pinion bearing preload. The original axle in your '55 F100 should be a Dana 44, however, and that model did not use a crush sleeve in the years our trucks were built. They used a solid spacer and shims. That's a good thing for you as that makes a seal change a very straightforward proposition.
Start by removing the rear cover to drain the oil and disconnecting the driveshaft. Remove the nut and washer, pull the yoke, and remove the old seal being very careful not to nick, scratch or damage the seal bore. Leave the bearings and slingers in place on the pinion. No need to remove them and risk getting something out of order. Inspect the yoke's seal journal for pitting or a deep groove. If it looks ok, wrap the journal with a piece of red scotchbrite soaked with WD-40 and spin the yoke in it in the direction of normal forward rotation to polish the journal. Clean the bore up a bit and then install the new seal making sure to grease or oil the seal lip. Follow that by installing the yoke, washer, and a NEW pinion nut. Use a little red Loctite on the nut and torque to 160 ft./lbs. Put the cover back on, refill with fresh 80W/90 gear oil, and reattach the driveshaft. Easy peasy!
You should be able to pick up a cover gasket, pinion seal, and a pinion nut for a Dana 44 at your local parts store. It's a common axle and those parts were the same for decades.
Can I use the same proceedure to replace a leaking pinion seal on a Dana 60?
Absolutely. The 60 is just a larger version of the 44. Construction is nearly identical otherwise. The only exception to using the above procedure is that the torque spec for the pinion nut will be 250 ft./lbs. Yes, it really needs to be that tight!
Absolutely. The 60 is just a larger version of the 44. Construction is nearly identical otherwise. The only exception to using the above procedure is that the torque spec for the pinion nut will be 250 ft./lbs. Yes, it really needs to be that tight!
Thanks Blue Oval! I appreciate your reply very much!
This post is very helpful. Thanks to all contributors. Closely related question....
I need to replace the pinion seal on my Dana 44 too (also in a 55 f100). When the truck was running, it would drip a little after each drive, but then the leak would stop. I had assumed that was because oil wasn't really hitting the seal much (if at all) standing still.
What I wasn't expecting is this.... couple of days ago i freed the leaf springs from the frame (getting ready to make some lowering adjustments). The diff is on jack stands and did tilt slightly forward. The next morning, I had a nice size puddle of gear oil under the pinion. So is it normal for a diff that had a slight leak during normal operation to have a dramatically worse leak, with the pinion nosed down slightly?
I'm still guessing it is just a bad seal (worse than I thought), but I am curious about it.
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