Chrysler 8.25 Yoke Installation--Using old Yoke

Ok I have done some searching and research. I have found some very good leads, but nothing sounds close to what I am looking for/at. When I bought my latest Cherokee Sport, the PO had claimed that the pinion nut had come off. I got with the XJ, the rear driveshaft and axle yoke. I also got the bolts and straps to retain the U-joint, which I won't be using. My problem is that I have the old pinion yoke and have to clean it up some, as the PO let it get some rust on the seal area. I am cleaning the surface as good as I can, so that I don't have an issue with the seal leaking. Problem is I have a new pinion nut, and straps for the Ujoints(had to find another driveshaft as the original one had the ears on both the slip yoke and shaft that were all beat up, and I probably wouldn't be able to get the joint out. How should I go about reinstalling, and here is something else. Currently its in 4wd to hold it, as well as the parking brake. Can the yoke be just placed on any which way, since it wasn't marked prior to its deinstallation?? If so, when I tighten down the nut, do I just crank it down as tight as I can with my socket and that's it?? I have a click type torque wrench that is pretty darn accurate, and I wanted to make sure I am not overtightening it or not tightening it enough that it comes loose again. Any thoughts or help here would be awesome. I have several of the other threads I have read up so I have some reference as to what I have found.

Jeff

Pinion yoke is not keyed, or timed. It's relationship to the rest of the driveshaft is fixed by the yoke on the driveshaft it's self.

You clan cleanup the machined seal surface with some 600grit sandpaper and oil just as you would a journal.

The 8.25 has a crush slieve to set preload, so be sensitive about torque.
If you are like most folks though you will not be able to hold the yoke by hand and exert enough torque with the wrench to affect preload.

Stated torque spec is 150 IIRC, and preload with used bearings is 10-20 inch lbs .
New bearing preloads is around 30 inch lbs.. That is the force it takes to turn just the pinion, not the whole axle or diff.
Use some tread lock. Also, there should be a washer between the yoke and nut.

I'm kinda worried about the gears. Inspect them well. Also the pinion bearings. Pinion nuts don't just fall off

-Ron

Good 1/2" impact gun should do the trick. Even Jeep technicians do it. Ask Bryan C.

I have an electric impact gun, can use if I need to. I have to obtain the diff seal first, since I don't want to do it again. I will drain the diff and verify the condition of things. Not sure what else to do. I keep hearing two different numbers here and I am not quite sure whats going on here. Im being told that preload is in in/lbs, yet seeing a number 150 which is telling me ft/lbs. How is it preloaded at in/lbs, then torqued to ft/lbs?? Im not all that on the up and up with differentials, so the explanation is going to help me out here. Once I see it in terms I can digest, I should be good to go. Thanks for the help so far.

Jeff

Torque and preload measurement are 2 separate figures.
Preload measures how much drag there is on the assembly in inch/lbs.
The torque spec for the nut just says how tight to make the nut in ft/lbs.

With a new sleeve, you tight the nut until you achive the appropriate preload.
With a use sleeve and bearings, you gradually adjust to spec while checking preload. When the nut is tight and you have not exceeded preload, it's good.

Many folks just hit it with an impact, then check preload.

-Ron

You can't get a pinion preload reading with the carrier and axles in place.
Preload is set during gear set up with the carrier preload out of the equation ie. pinion by itself after determining correct pinion depth.
So unless you're replacing an existing yoke that you could measure total rotational preload before removal from and duplicate upon reassembly, it's gonna require some additional work.
Hans

in an attempt to clarify things further:

Preload is the force required to turn the yoke/pinion gear assembly on its bearings in the case.

Pinion nut torque is the force required to turn the attachment nut itself on the pinion gear during assembly

Ok so here is my next question. If I am to replace this unit, with the original yoke, and a new pinion nut, do I hold it with slip joint pliers, then torque it to a value?? Or do I torque it to a value to start, then a second?? I am getting ready to clean the splines on both the pinion and the tcase outputs, since the PO hadn't had a driveshaft in it for some time and the rust monster has started to come out to play. I'll check back when I get that done. Thanks again for the help to this point, cause I am definitely learning some things

Jeff

ihscoutlover said:

Ok so here is my next question. If I am to replace this unit, with the original yoke, and a new pinion nut, do I hold it with slip joint pliers, then torque it to a value??

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The truth is you can't properly set the pinion pre-load to Factory specs with the axle shafts in place. The crush ring has already been crushed and the pinion nut was missing. Someone has been messing with the axle and it may already be damaged. Pinion nuts don't fall off
There is no way to hold the yoke tight enough with pliers. Using a yoke holder, along with a 6' cheater, is hard enough.

I would just take the advice of others and hammer it on with an impact wrench and hope for the best.

I am going to add here that I was told by the PO that he lost the nut. Whether that was lost while driving, or lost as it was being taken apart. I am going to preload it to 20 inch lbs, then torque the nut to 150 ft/lbs. This should get me to where I need to be. I have consulted several persons here locally and they agree that the values here should work. I don't believe the vehicle was driven during any of this, so this information might clear up some issues. I will post up what I get as I get there. Thanks for the help guys and gals.

Jeff

ihscoutlover said:

I am going to add here that I was told by the PO that he lost the nut. Whether that was lost while driving, or lost as it was being taken apart. I am going to preload it to 20 inch lbs, then torque the nut to 150 ft/lbs. This should get me to where I need to be. I have consulted several persons here locally and they agree that the values here should work. I don't believe the vehicle was driven during any of this, so this information might clear up some issues. I will post up what I get as I get there. Thanks for the help guys and gals.

Jeff

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He was messing with it and lost it, or someone went up to the Jeep in a parking lot and took it.

They are not easy to come off. I had to use a 36'' pipe on the end of a breaker bar to remove one from the junkyard. They don't come off on their own.

ihscoutlover said:

I am going to add here that I was told by the PO that he lost the nut. Whether that was lost while driving, or lost as it was being taken apart. I am going to preload it to 20 inch lbs, then torque the nut to 150 ft/lbs. This should get me to where I need to be. I have consulted several persons here locally and they agree that the values here should work. I don't believe the vehicle was driven during any of this, so this information might clear up some issues. I will post up what I get as I get there. Thanks for the help guys and gals.

Jeff

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the 8.25 pinion nut doesnt have a torque value. It uses a crush sleeve so once you crush the sleeve its all down to the preload to get your setup right. Preload for used bearings is 6-8 in lbs, I dont know how whoever you talked to figured it but apparently they are figuring 12-14 in lbs of load coming from the carrier and gears still being in the diff? More information on how you plan to do this would help, such as axles still in or not? Carrier still in or not? Do you have enough time or the tools to actually do it right instead of rolling the dice like you are now?

Johnnie Walker said:

Good 1/2" impact gun should do the trick. Even Jeep technicians do it. Ask Bryan C.

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Why do you have to drag me into this? :anon: :laugh:


As mentioned here, there is no present nut torque. The pinion bearing preload is set with the carrier and axles removed.

Personally, I use an impact gun and stop hitting the trigger when the gun starts to really hammer the nut down. Another idea is to constantly measure the turning torque using a dial or beam style inch pound torque wrench. Tighten the nut using a long ratchet until there is a few inch pound increase in turning torque. You can hold the yoke with a large pipe wrench if you don't have/can't make a yoke holder.

The crush sleeve takes quite a bit of force to crush it, so as long as you don't go crazy with the torque it will work just fine.

In the "shade tree" mechanics' department, I've had pretty good luck reusing a used yoke, and re-torquing in place. On an old differential, there's a fair amount of free play in the pinion, enough so that you can wiggle it and determine if it's getting tight. I held the yoke with an enormous pipe wrench, and tightened the nut with a big socket wrench. As the correct torque was reached, I checked for drag.

The way I figure it is that if the thing has a zillion miles on it, the preload has decreased anyway, so if you reinstall the yoke, and then tighten it enough to crush the sleeve just a tiny bit more, then you're probably better off than you were before. If it's just the same, you're no worse.

I'm guessing that the previous owner here was replacing, or about to replace, the seal, and lost the nut. If you don't know whether the seal is new, I'd replace that now. An old seal on an already worn surface is asking for trouble.

I would caution also that before replacing the yoke at all, you check it very very carefully to make sure that the surface against which the universal joint mounts is not worn. I have had a couple of old Jeeps (and this is why I've replaced one of the yokes) on which there was a tiny amount of end play allowed, and this ate universal joints up. If a new joint does not fit very snugly into the pinion, no amount of strap tightening will prevent it from premature wear. The tiniest bit of end play will hammer the joint loose in a few thousand miles.

Here is what's been done and the next course of action. First the carrier and axles are still in it and it's on jackstands. I went to do a "preload" on the bearings tonight after replacing the pinion seal which by the way mad me feel much better about how I was going about removing it. The way I was instructed was to tighten down the pinion nut till the pinion had no play/slop in it. By the time that was done I was actually well over the value of 20 in/lbs. I enlisted the help of a buddy, after making a run to the parts store for the needed 33mm socket. We turned the nut again and again and never hit the 150 ft/lbs to tighten down the nut the rest of the way. I am thinking the pinion bearings are shot for a couple of reasons. 1. No gear oil came out when I pulled the pinion seal out. The cage around the outer pinion bearing was messed up some on two opposite sides. I haven't pulled the cover yet as I am needing to get a lubelocker seal. I'm guessing that there is some kind of either damage, or issue with this rear axle. I'm gonna curb any further work on it till I pull the cover for further inspection. I'm probably gonna find another rear axle, and swap it in, as long as I can be assured that this one can still be salvaged somehow. Now I might have to look for that hard-to-find rear Dana 44. Thoughts here??

Jeff

there is no 150ft.lbs torque value. By torquing it down that far what you likely do is way overload the bearings. You need to ignore torque values completely when reusing a crush washer aside from maybe if you notice that the preload is good but the nut isnt even tight on the yoke yet. When you get the new axle, take no advice from whoever told you to tighten to 20 in.lbs and then torque to 150ft.lbs, if they tell you to get a McChicken you should get a quarter pounder. You obviously have all or most of the tools to actually do the job correctly, so why are you half assing it? Going to take you a lot more than the couple extra hours to do it right when you have to fix it after it inevitably blows up

ihscoutlover said:

Here is what's been done and the next course of action. First the carrier and axles are still in it and it's on jackstands. I went to do a "preload" on the bearings tonight after replacing the pinion seal which by the way mad me feel much better about how I was going about removing it. The way I was instructed was to tighten down the pinion nut till the pinion had no play/slop in it. By the time that was done I was actually well over the value of 20 in/lbs. I enlisted the help of a buddy, after making a run to the parts store for the needed 33mm socket. We turned the nut again and again and never hit the 150 ft/lbs to tighten down the nut the rest of the way. I am thinking the pinion bearings are shot for a couple of reasons. 1. No gear oil came out when I pulled the pinion seal out. The cage around the outer pinion bearing was messed up some on two opposite sides. I haven't pulled the cover yet as I am needing to get a lubelocker seal. I'm guessing that there is some kind of either damage, or issue with this rear axle. I'm gonna curb any further work on it till I pull the cover for further inspection. I'm probably gonna find another rear axle, and swap it in, as long as I can be assured that this one can still be salvaged somehow. Now I might have to look for that hard-to-find rear Dana 44. Thoughts here??

Jeff

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You guys are absolutely clueless about what you're doing!
Read through this thread: http://www.jeepforum.com/forum/f11/chrysler-8-25-rebuild-writeup-933741/ before you attempt anymore repairs.....maybe you'll understand what we've been trying to tell you.....there are no torque values on a crush sleeve set up.
Your pinion bearings are probably dust now.
Hans

Well, that's some fine thing.

Jeff, I'm sorry for confusing you with the 2 values. Given that you are working with a used sleeve, I should not have mentioned the nut torque. :anon:

As someone mentioned before, that sleeve was likely crushed too far already. My guess is that someone backed the nut off to get the preload right after over tightening it, but didn't realize that you can't do that.

I measure the preload by "feel" with the axles and carrier in, but there is such a small distance to do it in that if you have never done it before you'll want to yank the carrier and do it the "Right Way".

Unfortunately, that means resetting the carrier preload, but it can't be helped. Careful dissasembly and counting the number of threads on the adjuster goes a long way to putting it back in OK. There are a few install manuals on lockers on-line, you could reference those.

I've had some luck straightening sleeves, but for the cost of one, just get a new one and start over.

The FSM covers adjustment of a new sleeve, but I'll post it here.

1) Tighten nut to 200ftlbs
2) Measure Preload torque. (Since we don't know what the old value was, look for 20inlbs. with used bearings)
3) If the preload is less an spec, increase nut torque by 5 ftlbs and remeasure.

For a used sleeve, I delete step one and get out the impact. Chances are the bearings are "loose" and I can get the appropriate preload and still have a good 100-150lbs on the nut. If I over tighten it, then I remove the sleeve, bang it straight and try again.

They need to make a "Crush Sleeve Eliminator Kit"

-Ron