Need definitive answer: replacing pinion yoke on Chrysler 8.25?

So I've searched on this topic but am still unclear... I need to replace the pinion yoke on my Chrysler 8.25 axle. What is the proper way to do this so as not to disturb the pinion bearing preload? Is there even a sure way to do it without opening up the pumpkin and installing a new crush sleeve to be 100% sure?

I've heard of some people counting/marking the threads on the pinion and trying to just tighten the nut back down to the exact same place, but this seems like a really inaccurate way of gauging whether the nut is tight enough or not. I do have an inch/lb beam style torque wrench that I can measure the pinion bearing preload before and after with, I'm just concerned about potentially not getting the pinion nut tight enough, having it throw off my gear setup, and eventually ruining the gears.

If need be, I'll take it to a guy who does gears and have him install a new crush sleeve at the same time. I don't want to go to more trouble than is necessary just to replace the yoke, but don't want to ruin my gears either. Any advice?

Red91Laredo said:

I've heard of some people counting/marking the threads on the pinion and trying to just tighten the nut back down to the exact same place, but this seems like a really inaccurate way of gauging whether the nut is tight enough or not. I do have an inch/lb beam style torque wrench that I can measure the pinion bearing preload before and after with, I'm just concerned about potentially not getting the pinion nut tight enough, having it throw off my gear setup, and eventually ruining the gears.

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You have discovered the downside of crush sleeves.
The correct way is too break the axle down, install a new crush sleeve, torque it until the specified preload is reach, using an inch/lb beam or dial torque wrench, next reinstalling the carrier and ring gear and then resetting the ring gear back lash. A lot of work!
Some try to reinstall the pinion nut to the same place but it is a crap shot,
sometime it works great and other times the preload gets set too high or too low, causing a new set of expensive problems. There is no way to accurately measure the pinion preload when the carrier is left in place.
Wish there was a kit for replacing the 8.25's crush sleeve with shims, like the HP D30, allowing the yoke to be replaced without changing the preload.


Larry

So it sounds like if I want to play it safe, installing a new crush sleeve and resetting the preload from scratch is the way to go. I shouldn't really have to adjust backlash since I'm not actually changing any shims, right? (Correct me if I'm wrong, I'm not that familiar with how the 8.25's go together) Of course I'm sure it'd be smart to check it before and after to make sure it is still within spec.

I've seen people recommend using a solid spacer instead of a crush sleeve, is there not actually a source for them? I'd imagine like someone with access to a machine shop could whip one up pretty quickly if they knew the measurements...

Red91Laredo said:

So it sounds like if I want to play it safe, installing a new crush sleeve and resetting the preload from scratch is the way to go. I shouldn't really have to adjust backlash since I'm not actually changing any shims, right? (Correct me if I'm wrong, I'm not that familiar with how the 8.25's go together) Of course I'm sure it'd be smart to check it before and after to make sure it is still within spec. 8.25 uses adjustment screws to adjust backlash and preload on the side bearings. I have the special tool to do it, so I cannot offer any suggestions on how to do it without. It is essentially a long bar with a 30mm nut on the end that slides into the tube and engages the adjustment nut.

I've seen people recommend using a solid spacer instead of a crush sleeve, is there not actually a source for them? I'd imagine like someone with access to a machine shop could whip one up pretty quickly if they knew the measurements... The measurement is not static and is dependant on variances in the bearings. a non adjustable block would not fare well. IMPO

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If you measure preload before removal, and match it when you replace the yoke you should be worry free. I've done this many times without a failure. Make sure you use a new pinion nut.

Red91Laredo said:

So it sounds like if I want to play it safe, installing a new crush sleeve and resetting the preload from scratch is the way to go. I shouldn't really have to adjust backlash since I'm not actually changing any shims, right?
I've seen people recommend using a solid spacer instead of a crush sleeve, is there not actually a source for them?

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The front HP D30 uses shims to set the pinion pre-load but the 8.25 doesn't, instead having big, adjustable screws that push the carrier bearing races into the axle sousing.
The screws allow the carrier to be push to either side and is used to set the backlash. One or two long adjusting tools are used to adjust and tighten the screws to the specified torque.
Bottom line is when the carrier is removed, the backlash adjustment is lost and must be redone.
Anyone that has done one of these axles should have the tool(s).
Mine are 1/2" pipe, about 30" long, with a 34mm nut welded at one end and a female end of a 1/2" drive extention, welded at the other end, needed for using a torque wrench.
The nut is the same size as the one used to tighten the front axles.

I have looked extensively for a solid pinion shim and found none,
there may be a reason, who knows? The expense of having a machine shop make a custom spacer kit will probably be more than the cost of resetting the axle. If you go to the effort, you really should remove the carrier anyway to dial the pinion pre-load precisely. The carrier adds it's own pre-load friction, making it difficult or impossible to accurately check the pinion pre-load.

So your choices are to do the total job or give the suggested, simpler but less accurate method a shot and hope for the best.
You might want to see if member in your local Naxja chapter sets axles on the side. They usually are cheaper than a shop and it would give you a chance to meet more local XJ owners.

The 8.25" crush sleeve is a pain in the ass to crush down. I doubt you will crush it any more than it already has without some serious effort. Easiest way is to just mark the nut and pinion and count the number of threads sticking out of the nut. Remove the nut and yoke, replace the seal, reassemble. Line up the marks you made and call it done. I have done this more times than I can remember without issue and normally use an impact gun to do it. YMMV.

Bryan C. said:

The 8.25" crush sleeve is a pain in the ass to crush down. I doubt you will crush it any more than it already has without some serious effort. Easiest way is to just mark the nut and pinion and count the number of threads sticking out of the nut. Remove the nut and yoke, replace the seal, reassemble. Line up the marks you made and call it done. I have done this more times than I can remember without issue and normally use an impact gun to do it. YMMV.

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Yup, this method works well when replacing just a seal.

The OP wants to replace the yoke too, so marking the nut is not so good because no two yokes are exactly the same.

Also, a correction to my first post, the adjustment screw tool is 36mm not 30mm as I stated.

Digger87xj said:

Yup, this method works well when replacing just a seal.

The OP wants to replace the yoke too, so marking the nut is not so good because no two yokes are exactly the same.

Also, a correction to my first post, the adjustment screw tool is 36mm not 30mm as I stated.

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I guess as usual I missed a key bit of info. Even with the new yoke you can still just gun the thing down. Most. impact guns do not have enough torque to crush the sleeve.

I've done this a couple of times, once for a D35 with a bad seal, and again with an 8.25 with a worn yoke. In both cases I replaced the yokes with better looking used ones from other rear ends. Both times the vehicles had very high mileage, and my assumption was that the preload had lightened a little by then. I did a quick finger-torque test and sure enough, there wasn't a lot of preload left. So I just replaced the parts, and then put a huge pipe wrench on the pinion, and tightened the nut a little over what it had been before, restoring at least some of the preload. Never a problem with this.

They do make a solid spacer w/ shims to replace the crush sleeve on the 8.25. Put one in mine when did gears and locker, don't rememeber where I got it, but they are available.

The FSM details the proper way for doing this, which basically involves a special tool to hold the diff (of course) and an inch-pound torque wrench to measure the bearing preload. Then obviously you replace the yoke and make sure the final preload matches your initial measurement. If you're reusing the yoke then you can do the mark-the-threads trick, which is fine...

I need to replace my 8.25 yoke too, and to be honest, I'll probably let the shop do it...but that's me. I don't have a tool capable of holding the yoke still, nor do I have an inch-pound torque wrench, so paying a shop $50-$80 for the job is more than worth it.

someone needs better Google-fu
http://www.ratechmfg.com/chryslerspbs.htm

$17 problem solver

:thumbup:

Devilfrog said:

someone needs better Google-fu
http://www.ratechmfg.com/chryslerspbs.htm

$17 problem solver

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I'm running this in mine http://www.summitracing.com/parts/RAT-4114/. No more messing with that stupid crush sleeve.