Builds The Clustertruck Rides Again - Refurbishing a 1975 Chevota (1 Viewer)

[RWBeringer4x4]

Since I'm now engineless for the time being, I decided to press on and inspect the transmission and transfercase. They didn't leak too badly when pulled, and aside from being a little whiny at higher RPM, functioned fine, but this seemed like the perfect opportunity to clean them up, and check out the output shaft on the transmission.

I started at the speedo housing. I have some drilling to do... When I pulled the parking brake, I was already at 3 bolts - guess I figured out what happened to the 4th one...

I'll need to decide if I want to do the "Mudrak" double speedo seal mode while this is out. I didn't have a problem with it leaking prior - but it seems like relatively cheap insurance, and looks like something you can do with a 1/4in reamer in a drill press.

Speedo gear is still intact. Good news!

This case was re-sealed and installed by a local shop back before I had the shop or the knowledge to fool around with such things. The truck came with a grenaded transfercase, this one was the replacement. The shop had a lot of trouble getting it to seal, and finally did away with the paper gaskets for permatex. He clearly didn't scrimp, and even so, I still had a very slow leak from somewhere. Now have a big, rubbery mess to clean up. It's even on the bearing face...

Next I popped the side cover to get at the bolts holding the trans and transfer case together:

Then the outer bolts - the one pictured was already scarily loose:

One thing I did notice was that even with the transmission in neutral, the transfercase would still spin slightly when I moved the transmission input shaft. I imagine with no load, there may just be enough drag on the idler shaft to cause them to move slowly. If I grab on of the transfercase shafts and hold it still, the transmission spins freely and the transfercase stays in place.

 

[RWBeringer4x4]

Next - I put my home-built puller to work:

This worked great, but further "customization" was required as the long bolts I started with became too short as the output shaft retreated. The joy of junkyard remedies!

The end result - separated transfer case. I REALLY hope that bearing was supposed to fall out - it seemed like barely even a press fit...

This gave me a good look at the transmission output shaft. After all the setbacks, I was happy to find that, aside from a bit of discoloration on the metal where the input gear rides, there is virtually ZERO wear on the output shaft. I've seen several folks have trannies die this way on the forums, but it doesn't look like this will be one of them. I can't even catch a fingernail on the wear point yet.

Lastly, I pulled the other transfercase saver off the nose cone (for repaint) and to allow for better access to the rest of the case for cleaning. Found another "woops" from either the shop who did the install, or a previous owner. It looks like the original hole at the bottom was stripped, and re-tapped with an SAE stud. This got me thinking, however, that perhaps I should go with ALL studs around the nose cone... Might help things seal, and prevent further stripped aluminum threads.

That's about as far as I got. Unfortunately I only have a couple more afternoons to keep pushing before I end up traveling again - but it feels good to be plugging away...

 

[thebigredrocker]

Awesome! Do you have a picture of just the puller?

 

[RWBeringer4x4]

Awesome! Do you have a picture of just the puller?

Sure - it's just a piece of bar stock that I measured and drilled for 3 bolts. The outer bolt holes are for long bolts that you can screw into the back of the transfercase, where the rear "cone" cover normally bolts. I think they were fine-thread M12. The center lines up the with the output shaft. I just used a large-diameter bolt, but and washers I had laying around.

To use, you back the center bolt all the way out, and install the M12 bolts into the holes on the transfercase. Then, holding the nut on the center bolt still with a wrench and crank the bolt through it with a socket until it contacts the output shaft. From here the M12 bolts will hold the bar stock in place and turn the center bolt into a forcing screw, which will push the output shaft out of the transfercase.

What I ran into is that the side-bolts I had were either too short when I started to install the forcing screw (silver ones) or too long to allow the forcing screw to finish the job (black ones) so I wound up having to start with the black bolts, disassemble, reassemble with the silver ones, and finally disassemble a third time to stack the washers you see and "shorten" the side bolts further. The result is that it took 10min instead of 3

 

[RWBeringer4x4]

I did come across one issue between the transmission and transfercase, confirmed on a separate thread:

The short spacer that rides on the rear main bearing inside the transmission, between the trans and transfercase, was severely worn on both sides:

It's "stepped" on the transmission side and "grooved" on the t-case side where the input gear was slowly grinding it's way through. It seems like the most likely failure mode was the fact that the staked nut on this shaft was never staked. I also have no idea if the shop that installed this case a few years ago torqued it to spec. This might also be the cause of the "clunk" I had in the driveline - unsecured gears moving back and forth in the case.

Looks like I'll need to find on of these spacers. It looks like no serious damage was done to the input gear or bearing, but I'll definitely be checking tolerances on reassembly to make sure this doesn't move.

 

[velillen]

I believe I have that spacer at home (new OEM) if you haven't ordered one yet. If its the one I am thinking of I freaked out thinking I didn't have it when I reassembled my H42 to T-Case Ill try to look tonight and send you a PM with the part number for the one I have.

 

[RWBeringer4x4]

I believe I have that spacer at home (new OEM) if you haven't ordered one yet. If its the one I am thinking of I freaked out thinking I didn't have it when I reassembled my H42 to T-Case Ill try to look tonight and send you a PM with the part number for the one I have.

Thanks @velillen - I haven't bought anything yet. It's the shortest of the 3 spacers that basically rides against the transmission rear main bearing. I'm out of town until this evening but send me a measurement of the length along with the part number and that should narrow it down.

 

[bikersmurf]

Next - I put my home-built puller to work:

View attachment 1518642
This worked great, but further "customization" was required as the long bolts I started with became too short as the output shaft retreated. The joy of junkyard remedies!

View attachment 1518643
The end result - separated transfer case. I REALLY hope that bearing was supposed to fall out - it seemed like barely even a press fit...

View attachment 1518644
This gave me a good look at the transmission output shaft. After all the setbacks, I was happy to find that, aside from a bit of discoloration on the metal where the input gear rides, there is virtually ZERO wear on the output shaft. I've seen several folks have trannies die this way on the forums, but it doesn't look like this will be one of them. I can't even catch a fingernail on the wear point yet.

View attachment 1518646

Lastly, I pulled the other transfercase saver off the nose cone (for repaint) and to allow for better access to the rest of the case for cleaning. Found another "woops" from either the shop who did the install, or a previous owner. It looks like the original hole at the bottom was stripped, and re-tapped with an SAE stud. This got me thinking, however, that perhaps I should go with ALL studs around the nose cone... Might help things seal, and prevent further stripped aluminum threads.

View attachment 1518647
That's about as far as I got. Unfortunately I only have a couple more afternoons to keep pushing before I end up traveling again - but it feels good to be plugging away...

Good news on the output shaft... mine had mild wear when the shop rebuilt it and the Trans shop had no concerns about it.

I wouldn't worry about converting the other 3 bolts to studs. If there was a significant benefit to doing so, it'd be a standard modification.

 

[velillen]

Thanks @velillen - I haven't bought anything yet. It's the shortest of the 3 spacers that basically rides against the transmission rear main bearing. I'm out of town until this evening but send me a measurement of the length along with the part number and that should narrow it down.

This is thread where I thought I was missing mine. And also the part highlighted on a diagram. If that's the part you do need then im 90% sure its at home in the spare parts bin.

Transfer Case / Transmission Spacer - Dimensions Please!

Ill still try to take a measurement of it and the part number this evening though. Hopefully its the right part

 

[RWBeringer4x4]

This is thread where I thought I was missing mine. And also the part highlighted on a diagram. If that's the part you do need then im 90% sure its at home in the spare parts bin.

Transfer Case / Transmission Spacer - Dimensions Please!

Ill still try to take a measurement of it and the part number this evening though. Hopefully its the right part

Yep - that looks like the part in question!

I'm hoping this was just an issue with the staked nut that caused the grinding on mine and not a more sinister issue in the case or trans.

 

[RWBeringer4x4]

Extracted the bolt from the speedo housing. Unfortunately this took a ton of effort. I managed the snap an easy-out in the bolt when a clamp broke loose. Naturally, these are too hard to drill. As a result, I had to break out the dremel and chainsaw sharpening bits and bore out the easy out.

Then, it was a matter of drilling out the old bolt a re-tapping. I'm not 100% thrilled with the results (threads look a little weak) but it was running with 3 bolts holding the parking break on for as long as I've owned it so this is still a step in the right direction.

Then I flat-sanded the step out of my long spacer. Georg @ Valley Hybrids provided a replacement for the more heavily damaged short spacer.

I'm hoping that the slight reduction in length will be a non issue and everything still torques to spec. Only time will tell...

I also polished this turd:

After an hour or so of scrubbing and degreasing, I gave it a fresh coat of paint:

Up next - cleaning the transfercase (what a nightmare of nooks and crannies that thing is)... And figuring out how to cut/remove the radiator mounts from the frame. I'd like to cut the rivets and keep the mounts intact for posterity but they're going to be tough to get to.

Air hammer with a rivet chisel perhaps?

 

[gator25]

Think I would check the idler bearings just to be on the safe side, if it was whining man.
You could melt the head off that rivet with a torch or cut it off with a cut off wheel and then a grinder to get the rest off.

 

[RWBeringer4x4]

Think I would check the idler bearings just to be on the safe side, if it was whining man.
You could melt the head off that rivet with a torch or cut it off with a cut off wheel and then a grinder to get the rest off.

Idler bearings in the transmission? I've looked at the bearings in the transmission pretty closely, particularly since I had clutch/pilot bearing issues. Aside from some surface rust on the rear output shaft bearing on a non-critical surface nothing seems terribly amiss.

 

[gator25]

I'm sorry I was talking about the T-case.

 

[RWBeringer4x4]

I'm sorry I was talking about the T-case.

That would actually make sense. I believe back when this case was put in (by a shop about 3 years ago) the mechanic re-used the idler shaft from my old case as the used case I provided had some abnormal wear. It's very possible the mix/matched bearings and idlers are causing some whining. Haven't dug too deep in the t-case just yet.

 

[RWBeringer4x4]

Well - this new toy made short work of the radiator mounts. walked into Home Depot to buy some granite sealer for the , walked out with 6 cans of various gray spray paints and an air hammer. Forgot the granite sealer...

Cut the rivets right out - warped the rad mounts a little but they could maybe be pressed back into service someday...

Then I turned my attention to the driveshafts and started banging out the U-joints by mounting the driveshaft flange in a vice a wailing on the U-joints with a sledge and a socket.

After completely obliterating one U-joint and breaking the grease zerk off a second, I decided this was probably not the best way to go about it. Then I worked smarter, not harder:

If my vice was .01in shorter this all wouldn't have fit, but ultimately, after a few minutes of cussing and aligning everything and trying to hold it all in place while you tighten up the vice - this worked. The little socket serves to press the opposite cap into the big socket. It still took a TON of force, and penetrating oil, but it beats the heck out of a sledge.

Victory!

Sad part is this was all for paint - there was nothing wrong with the joints before I destroyed them. Luckily I have 4 brand new spares.

In short, today I turned 4 perfectly good u-joints into two trail spares in the name of paint and a hard learned lesson.

 

[RWBeringer4x4]

Digging further into the transfercase, this may likely become a full rebuild by the time I'm done. The main bearings seem ok, but inspection of the nose cone/front output shaft bearing found it feeling a bit "notchy."

Further inspection revealed what appears to be some mild brinelling on the race:

The faint "lines" barely visible in this photo on either side of the ball coincide with the "notchy" feeling felt. This bearing is typically used at pretty low speed, but it seems easy enough to change out, and I'd feel better knowing it won't be an issue when it's back under the truck.

In addition, the companion flange off the nose cone seems to have some petty significant and abormal wear at the seal surface and some pitting...and a cocoon...

The idler gear thrust washers check out visually, but I'll need to get a longer feeler gauge to confirm they are within tolerance (.016in per FSM). My current feeler is too short to reach.

That said, the truck has a significant "whine" at higher speeds when under load (whining stopped when I let off the gas). One possible cause is the idler bearings, and I remember there being some concern about the idler when this case was installed. As such, it might make sense to just replace the shaft and bearings now, since they are apparently the weak link in these cases anyway.

I've also been cleaning...and cleaning, and cleaning...

Buckets of parts cleaner, acetone, and about 10 dremel wire wheels later, I'm starting to grind through the crud:

A rebuild doesn't seem THAT involved - my major concern is that I don't have a press, and I'm not sure how I feel about hammering on bearings and gears.

I could go grab a 20 ton press from harbors freight, the real issue becomes - where do I put it? I'm quickly outgrowing my garage!

 

[TheHardWay]

I see a garage extension in your future. After all, you don't REALLY need a big back yard, do you?

 

[RWBeringer4x4]

I see a garage extension in your future. After all, you don't REALLY need a big back yard, do you?

I've already got the spot picked out now I just need a couple of tens of thousands of dollars to fall out of the sky.

 

[RWBeringer4x4]

Another setback...Tore down the transfer case completely and, at Georg's request took a look at the idler bearing races inside the bore on the idler gear set.

Found a thin line of pitting:

This is probably why:

In addition, the pressed on gears literally fell off the output shaft, which seems to imply some excess clearance. Either way, the output shaft is pretty sub-par as well with some rough spots by the clutch gear and wear patterns of all types:

In short, this transfercase is pretty shot... It sounds like most of the parts are still available in the aftermarket, but I'll need to track down a used gear set or a better used case.

At least the case is nice and clean...

Back on the hunt for parts!