Diff Rebuild - Solid pinion spacer or crush sleeve? (1 Viewer)

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Hi guys, I'm in the planning stages for a future rebuild of my front and rear diffs on a 1996 HZJ80, without lockers and with the factory LSD (axle code K295). No major warning signs of problems right now, but they haven't been serviced by me in the 3 years I've had it, and I doubt the previous owners ever did an oil change on them. Since I plan to keep this beast going for another 10+ years, I've been going through rebuilding and replacing things progressively, and the front and rear diffs are due for their turn soon. I'll be doing all the work myself. I'm not a qualified mechanic, just a slow and methodical amateur who likes to use the right tools and quality parts. So far I've been building my "shopping list" of parts to get, and dissecting instructions and youtube videos from people far more experienced than me. Right now I have a question, and I figured I'd ask it here to get some opinions. It's a bit of an open question, but here it is:

What do you think of using solid pinion spacers in the diffs, instead of the crush sleeves Toyota went with in the 80 series?

I've done a search on IH8MUD, and as you'd expect this topic has come up before, but none of the threads I found really gave me the answers I'm after. I'm usually someone who religiously buys genuine parts only, somewhat obsessively even, so I would normally just buy the genuine crush sleeves and be done with it, but the nature of this part bugs me. This isn't a seal or a gasket, it's actually forming an integral part of the drive train, and it's basically a collapsed piece of metal. Using a crush sleeve makes it easier to set the preload for a one-time install, but from an engineering perspective it feels like a weakness. In theory, it seems to me that over time or with heavy off road use, the crush sleeve might soften or fatigue reducing the preload resistance. A solid pinion spacer seems like a superior solution on paper, with the crush sleeve being an engineering compromise for the sake of convenience during assembly. From a serviceability point of view, I'd also like to be able to replace the pinion seal on the diff if it starts to leak without fully rebuilding the diff, and with a crush sleeve it seems that wouldn't be possible.

Maybe I've got it wrong though. Maybe there are advantages to the crush sleeve beyond ease of assembly? Maybe some of my concerns with a crush sleeve being a potential weakness are unfounded?

There's a concise and interesting youtube video about this question:

But it's also prepared by a company that manufactures and sells solid pinion spacers, so it's hardly impartial.

I've been using information from this forum for years, so I figured it was time I participated for once. If anyone has an opinion on this, please chime in and let me know what you think. If you had to rebuild your diffs, and there was no difference in price, effort or time, would you go with the crush sleeve like Toyota build these things with originally, or would you swap in an aftermarket solid pinion spacer?
 

baldilocks

Battle Ground, WA
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The crush sleeve aides in rapid assembly at the factory and is a one time use item. Use the solid spacer and enjoy the luxury of replacing the pinion seal down the road if necessary without needing to replace a crush sleeve which requires deeper disassembly.
 
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It isn’t clear why you need to reset the pinion preload. It isn’t normal preventative maintenance and the bearings typically last a long time even when the lubricant isn’t changed as often as the FSM indicates. “If it ain’t broke, don’t fix it.”. Setting the pinion depth and preload is something that people tend to screw up the first and even second times they try it. If you really want to do it, the crush sleeve is easier and more fool proof, which is why the stopped making solid spacers and shims 30 years ago. It is quite possible to replace the pinion seal with a crush sleeve.
 
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Id agree with that. I think the solid setup is great if you wheel hard and often enough that you are maybe in there all the time. The crush sleeve setup works wonders for thousands of people for millions of miles of service however.
 
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I'd prefer not to have to rebuild the diff if it's all in good working order. That said, my impression is that I can't change the pinion seal without doing that anyway if a crush sleeve was used. Am I wrong about that? If the pinion seal isn't leaking now, I doubt it'll last another decade, which is why I'm seeing a diff rebuild as inevitable and I'm trying to plan for it. A second question then would be, can I safely change the pinion seal without rebuilding the entire diff if a crush sleeve is used?
 
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Yes, you can change the seal without replacing the crush sleeve. Just reuse the old nut and tighten it just past the old stake mark so that you can re-stake it. Check the overall preload before and after to make sure it is not too tight.
 
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baldilocks

Battle Ground, WA
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I'd prefer not to have to rebuild the diff if it's all in good working order. That said, my impression is that I can't change the pinion seal without doing that anyway if a crush sleeve was used. Am I wrong about that? If the pinion seal isn't leaking now, I doubt it'll last another decade, which is why I'm seeing a diff rebuild as inevitable and I'm trying to plan for it. A second question then would be, can I safely change the pinion seal without rebuilding the entire diff if a crush sleeve is used?
I did this once on the front pinion seal of my Dodge 2500 in which the front drive shaft turns anytime the front wheels are rotating. It lasted 6 years and 70k miles before it leaked again.

I don’t understand why this is even a debate? The only thing a crush sleeve is good for is ease of pinion gear installation. I’ve never regretted using a solid spacer.
 

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