Transmission Output shaft spacer wear (1 Viewer)

[RWBeringer4x4]

Hi all,

I separated my transmission and transfercase last night, and took a look at the short spacer that rides on the output shaft of the transmission. What I found was a bit concerning...

This is the spacer in question:

When I pulled it out, there was a degree of surface rust. Is this normal? It seems like this might ride outside of the lubricated area in both the trans or transfer case so this might not be uncommon.

What is MORE of a concern is that there were metal "threads" peeling off the t-case side. It appears that there is a deep grooves worn into the face of the spacer, I assume by the input gear on the case:

On the transmission side, there seems to be a "step" worn into it.

From another angle:

I think this is supposed to be flat on both sides, and I assume this wear is abnormal. Any idea what could have caused it?

Furthermore, I assume this should probably be replaced, correct?

 

[stevebradford]

This notch on your output shaft looks abnormal to me as well I haven't seen that on any of mine. Could be wrong hopefully am...

 

[RWBeringer4x4]

I'm about 99% sure that's supposed to be there - I believe I've see it on others. The typical wear point on the output shaft seems to be just in front of that, where the t-case input gear rides. In my case there's just a bit of discoloration.

 

[stevebradford]

I had it where the nut on the end of the stack wasent tightened enough and every time I would go from gas to brake I would hear a klunk as the input gear, spacers and bearing shifted back and forth. my spacer ended up looking like that. It centers the input gear so I would replace it or risk causing wearing issues

 

[RWBeringer4x4]

I had it where the nut on the end of the stack wasent tightened enough and every time I would go from gas to brake I would hear a klunk as the input gear, spacers and bearing shifted back and forth. my spacer ended up looking like that. It centers the input gear so I would replace it or risk causing wearing issues

Interesting...I did have something of a "clunk" happening when I would let on and off the gas. I always chalked it up to bad motor mounts, or the Aussie locker in the rear. I wonder if this could have been it. I guess I'll need to source a replacement.

This transfercase was installed by a shop about 4 years ago when I didn't know what I was doing. The nut wasn't staked. I wonder if they tightened to spec, or if it backed itself off over time.

The good news is, I don't see a ton of wear on the rear transmission bearing or the collar on the input gear that ground the groove in the spacer. I'm HOPING I may have dodged a bullet on this one.

 

[stevebradford]

I broke that counter shaft once somehow...

 

[reddingcruiser]

Not normal (or as Igor to Young Frankenstein said "....Abbie, Abbie Normal). The clunk you heard was likely the t-case input gear moving back and forth as the loads and unloads. I prefer nylocks, or a properly staked OEM nut.

 

[reddingcruiser]

Not opposed to lock-tite, either.

 

[RWBeringer4x4]

So is this the only possible cause of something like this? Is there anything I should be inspecting for further damage beyond the output shaft bearing?

 

[stevebradford]

If your tcase ran fine before I would and did just replace the spacer and run it. Seems likely that was the issue.

 

[reddingcruiser]

Rick,
Just an suggestion. Get in the habit of checking things that have specific clearances (i.e. end play, gap, preload etc.) before disassembly. At least you will have some idea of the source of a problem once you get inside, or how bad things are. I would bet that if you reached up and moved the input gear and spacer (or PTO gear) around with a small bar or screwdriver you would been able to move it back and forth (in and out????) when it shouldn't have moved at all when the nut is properly torqued.

 

[RWBeringer4x4]

Rick,
Just an suggestion. Get in the habit of checking things that have specific clearances (i.e. end play, gap, preload etc.) before disassembly. At least you will have some idea of the source of a problem once you get inside, or how bad things are. I would bet that if you reached up and moved the input gear and spacer (or PTO gear) around with a small bar or screwdriver you would been able to move it back and forth (in and out????) when it shouldn't have moved at all when the nut is properly torqued.

Hey Dick,

Live and learn, I suppose. My concern is that all those metal shards clearly went somewhere. I don't feel or hear resistance from the rear bearing. The input gear doesn't look much worse for wear, but I'm concerned that a few thousands may have been ground off. On re-assembly I'll be sure to check and see if things still slide around once torqued.

Honestly, I didn't do a thorough inspection because everything worked when I pulled it, so I was operating under the assumption that this would be a simple clean-up, re-seal, and run. Really I was just planning on checking for wear on the output shaft - I wasn't aware this was a potential failure mode.

Live and learn! Now I just need to find a spacer. I bought a trans/xfer reseal kit from Georg a few years ago but looks like a lot of the gaskets got folded between moving houses twice and re-organizing the garage. Hopefully he or Mark have a few laying around in their boneyards.

My last question is the rust on that spacer - is this normal? It seems like the bearing would splash-lubricate the shaft but there's definitely some considerable surface rust on the spacer.

 

[RWBeringer4x4]

Not normal (or as Igor to Young Frankenstein said "....Abbie, Abbie Normal). The clunk you heard was likely the t-case input gear moving back and forth as the loads and unloads. I prefer nylocks, or a properly staked OEM nut.

How does one properly stake a nut? Furthermore, where does one find a metric nylock nut of that size, and how does the nylon affect the torque specs?

 

[reddingcruiser]

Metric nylock are available from larger fastener supply houses, pretty sure some 'mud vendors have them.

As far as staking nuts, I have a medium sized cold chisel with end the ground flat to about 3/32" width (just under 1\8"). Just line it up with the slot and drive the skirt into the slot.