Rear End Question

[Gray035]

So my pinion seal has been leaking for some time and I went to change it this morning. When i separated the drive shaft from the yoke I wiggled the yoke to check the bearing and noticed that the nut securing the yoke into the rear end is loose enough to allow the yoke to wiggle behind the nut (otherwise it seems to be tight, which makes me think the bearing is okay?). What does this mean? Did the PO change out the seal and fail to tighten the bolt to spec? what do I need to do to fix it? Do I need to put a new crush sleeve in there? If yes, how do I know how tight to tighten the bolt once the new sleeve and seal are installed?

On a related note, there had always been a fair amount of vibration when I got the truck above 55 or so, and I thought it was just some play in the driveshaft and U-joints. I changed out the U-joints a couple months ago and now the one I just disconnected from the yoke has a bunch of broken and missing needle bearings (it should last longer than a couple months I think). Is it possible this was all caused by the mis-torqued yoke (If in fact that is what happened. Do crush sleeves ever just go bad and need replacing?) Any help would be great!! I'd like to fix the problem, but it would be helpful to know the cause so I can pre-empt it breaking again.

 

[Timmy390]

You have several things going on at once so lets sort through them.

First, tell us about your rig, how much lift? what gears? tire size? How long have you has the rig etc.

For starters, if the pinion nut is loose, you got issue with bearing preload and more than likely the bearings are shot. If it's been that way for long or for lots of miles, you coudl have otehr damage inside the 3rd member. More than likely the vibration is the result of the pinon bearings having no preload.

The U-joint failure could due to the vibration as well or could be bad pinion angle if you a lift.

Based off what you've stated thus far, you may be in a pickle. At a minimum, I would pull the pinion, replace the bearings and races, new crush sleeve/solid spacer (I would go solid spacer if it were me) new seal and speedy sleeve on the yoke if it's groved.

Tim

 

[rwill]

thight'n the nut to specs on the rear end. Time to replace u joint again, Just snug the u bolts down(using a short wrench, less torque) I learned this th$$$$ way.

 

[broncnaz]

X2 on the possible bad pinion bearings I'd pull them and check them. Also install a new crush sleeve(I like solid spacers better but you probably wont find one locally)
As for the ujoint as was said more info is kinda needed. but if you have a lift and pinion angle is bad ujoint life is reduced. wobbley pinion yoke can do it so can over tightend ubolts or maybe you just got some cheapy ujoints. Or it could just be a combonation of everything.

 

[Gray035]

I removed the yoke and seal and can see the bearing behind it. How much movement in the bearing is okay? Also, where is the crush sleeve supposed to go? behind the bearing? or in front between the bearing and the yoke? There wasn't anything in between the yoke and the bearing except for a thin washer when I removed it.

If I need to remove the bearing, how do I do it? Do I have to remove the third member? Ugh...what I thought would be a simple seal change has turned into so much more...typical.

 

[Timmy390]

Ugh...what I thought would be a simple seal change has turned into so much more...typical.

I feel your pain.....I put up with a leaky seal for years because once you go down the rabbit hole things get complicated.

To inspect the bearing, you need to pull the pinion out. This can be done by removing the 5 or is it 6 bolts that hold the pinion support in the pumpkin. Be ready for some fluid to come out when you pull the support. The support will come out with the pinion, inner bearing, race, crush sleeve, outer bearing and race washer pinion nut and yoke. Note, there will also be a spacer/shim between the pumpkin housing and the pinion support. Also there is a O ring seal in a grove in the pinion support. Make sure not to damage that or it will leak when reassenbled.

Once out, you'll need to tap the pinion out of the support. I always put the pinion nut on several turns and use a rubber hammer to tap it out. That will release the pinion out of the support exposing the races. The crush sleeve is the thing in the middle of the pinion between the two bearings. To get the outer bearing out, will will need to remove the seal from the pinion support.

You will need to reassemble the pinion and bearings in the pinion support and set the preload using a vise to hold thngs then install it into the pumpkin.

Getting the initial "crush" on the sleeve is the hard part. It takes lots of force to get it started but once it starts, it will go easy. Be careful not to over crush as there is no going back. You have to get a new crush sleeve and start over.

I used a solid spacer (it takes the place of the crush sleeve) on mine becasue once you set the preload it's set so you can change seals in the future without tking things apart. As stated, finding one local will be hard. I ordered mine off ebay for $28

Tim

 

[Gray035]

Alright so I took the pinion out to look at the bearings and they look fine to me, but not having looked at this stuff before I can't be sure. Can anyone tell me if the race looks okay? And if there is anything else I should inspect? The bearings themselves don't look damaged.

On a separate note, I went to Napa and picked up a crush sleeve, but I didn't notice until I got home that the package says that it's for an 8.8" pinion. Here is a picture. Do I need to go change it out for a different one? The part number is 735-4269. If I do need to get a different one does anyone know the part number? Thank you guys for the help!!!

 

[Gray035]

BTW The original crush sleeve is on the left in the above pic

 

[broncnaz]

Hard to say if it will work on not it looks like it will. I would double check at the parts store.
your race kinda looks like it has pitting. If it does then its toast and so are the bearings.

 

[Timmy390]

As far as I know, all Ford axles, 7.5" 8.8" 9" 10.25", share the same crush sleeve so it will work just fine. That said X2 on the double check with NAPA.

That race looks a little used to me. If it were me, I would repalce both races and bearings. It's money well spent and will eliminate the bearings being part of the vibration issue. That's easy for me to say as I have all the tools in my shop to remove the old and press on the new inner bearing. A shop will charge you $30-$60 bucks for that here local. My 20 ton HF press paid for it's self whe I rebuild my 9 and D44 this summer.

The races can be driven out with a brass punch or a seal/race driver. I bought a seal/race driver at HF this summer to help with my D44 rebuild and I'm kicking myseld for not getting one years ago. Makes removing and installing races SO much easier.

Tim

 

[TAC71]

The crush sleeves are the same. Replace the bearings since your there. This happened to me also it comes from years of use on/off the throttle. Crush sleeves are absolute CRAP . Throw that away and get a shim kit for the pinion bearings. Check the fit of the splines of the yoke on the pinion gear splines, chances are they are now loose from working back and forth and if you use a crush sleeve again it will for sure come back eventually. The splines on the yoke are softer and will wear first. If this has been banging around for some time check the casting around the pinion roller bearing support in the main case, chances are good , especially if its been ground for gear clearance, thats its cracked also.

Do it right , do it once....because it sucks when it does this on a trail.

 

[OldBlue77]

X2 on what Tac71 said about the pinion support on the 3rd member. I know it is a pain but I would go ahead and pull it and check. Your description of the problem sounds like it may be broken but it's hard to say, better to find it now than to have to take it back apart.