Does anyone know where i can find a write up for Muncie 4 Bearing replacement? Axle shafts have a lot of play and I would like to replace the bearings myself but would feel better if I had somewhat of a guide to go off of or at least some pictures before I open it up and I can't find anything on the forum or youtube. Would appreciate any info or advice. Thanks, Brendan.

------------------
"America is all about speed, hot nasty bad-ass speed" - Eleanor Roosevelt

Tetanus
1984 3800 II SC Build

http://www.realfierotech.co...topic.php?f=3&t=3770

https://www.fiero.nl/forum/Forum9/HTML/000014.html

Some other tips:

You can weld the inside of the bearing races that are pressed into the case. With the weld shrinkage, the races can almost fall out. After burning some plastic shields, I found that packing dirt into the hole would protect the plastic shields adequately during welding.
https://www.fieromontreal.c...25.msg31819#msg31819

Also, take apart your differential spider gears and inspect. 5/6 planet gears I had were damaged in some way.
In this photo, I drew red lines to show where the teeth were cracked:
https://www.fieromontreal.c...25.msg32358#msg32358

Sometimes when the puller jaws couldn't hook underneath a bearing, I welded bolts to the bearing race and used a steering wheel puller:
https://www.fieromontreal.c...25.msg32733#msg32733

[This message has been edited by pmbrunelle (edited 12-05-2020).]

What a post! More information there than you can read in days..... + for you!

Exactly what I needed. Thanks for the help as always!

------------------
"America is all about speed, hot nasty bad-ass speed" - Eleanor Roosevelt

Tetanus
1984 3800 II SC Build

Hey Pmbrunelle, do you know what the purpose is of those plastic shields is and if they are needed or where I could find a new one? I melted one when a ball of weld spatter melted it through the dirt.

I should have added that it needs to be wet dirt, not too thin.

I am not sure what the plastic piece does, though it is pretty loose fitting IIRC, so I don't think a small hole would be too problematic.

This is the reference to the part in the P-book:


Do you have the P-book?

If you search the GM part number, you might be able to get some on ebay.

Maybe post a pic and we can see how bad your shield looks?

Sweet I found one on ebay if I need to buy one. I do not have the P-book. I think it also kind of warped from the heat but will get a picture. The dirt was somewhat wet but I had to weld a lot to get it to shrink enough so it dried out. Will make sure it's more wet for the next 2.

The P-book.

Every Fiero person should download this.
http://autoricambi-usa.com/...4-88_Euroamerica.pdf

If the race doesn't fall out on its own, you can try tapping on the outside of the case with a rubber mallet.

[This message has been edited by pmbrunelle (edited 05-02-2021).]

Wow I don't know how I made it this far without knowing about that p-book but glad I have it now. Thanks!!!!

Think I'm just gonna run it without and see what happens. Looks like the sheild is just there to keep the plastic end cap piece of the shaft on and maybe control flow of gear oil through the bearing? At this point I will be happy just to get another 25k miles on it. Hell, I've only put about 5k miles on the car since I bought it.

Isn't there a hole going down the middle of the shaft, where the oil then lubricates the speed gears? Not sure, my memory is fuzzy.

Looks like the shield may restrict flow to the first shaft, so that enough oil remains and can continue to the second shaft, but not really sure.

If you don't really know what the shield does, omitting it seems like a high degree of half-assing (and opening the door to future troubles), but that's just my opinion.

Yeah I think you're right, there's passages in the case so it looks like the shield only let's a little oil into the bearing and the rest through the shaft. Well my only other option at this point is to buy a whole used trans and completely disassemble and try and get the shield out of that one and put it in the one I'm rebuilding or just buy a used trans and put it in the car instead and wait til it also starts leaking and then take the shield out and put it in the half rebuilt one. With how much I struggled getting the races out, neither option sounds fun. Of course I had to melt the shield that you can't buy anywhere instead of the two others that are one ebay

You're sure the ebay one won't fit? Compare the photos with what you have.

I have seen two kinds of shield, black plastic and white plastic, and I think they have different part numbers, but appear to be functionally the same. I have mixed and matched the black and white ones.

You used the P-book to determine the part number you needed?

Yeah the one I melted is just a mostly flat disk, the other two have little legs on them and different hole sizes. Thought about cutting it to match and drilling the wholes out to the same size as a last resort. The part number is molded in to the part and matches the P-book. It's on the opposite side of the case as the 14008259.

Called a warehouse that sells a bunch of NOS parts and they're going to check to see if they have one on Monday. Fingers crossed.

quote Originally posted by BadNewsBrendan: Called a warehouse that sells a bunch of NOS parts and they're going to check to see if they have one on Monday. Fingers crossed.

This place I guess? (they list the 14008258)
http://www.phillipsmuscleca...-gm-part-number.html

I can look in my stash if it seems unfindable.

Thanks! Yeah thats the place I called on saturday actually and hes gonna get back to me this week. Fingers crossed!

Has anyone with a 3D printer tried to recreate these?

Got a response back and hes shipping it to me for $30. Pretty pricey for a small piece of plastic but if thats the only place i can get it oh well and can support a business with selling very uncommon NOS parts then oh well.

I thought about the 3D printing route but i don't know anyone that can do it and would need a material that can be heat cycled repeatedly. I doubt there are a lot of people willing to rebuild these trans so probably not a very common part to need replacing.

I wouldn't trust the normal ABS wire-filament type stuff, but nylon (often glass-filled) is often used for parts bathing in hot oil.

Nylon (with glass spheres even) can be printed using selective laser sintering.

SLS parts can be nice enough that I think I'd be willing to try that route.

A 3D-printing shop that does SLS could probably do this part for less than $100 or so.

The disc is a loose fit IIRC, so there are no fancy tolerances needed. It's quite flat too, so I think the part is a good fit for SLS nylon.

[This message has been edited by pmbrunelle (edited 05-10-2021).]

Part came in! Just waiting for the shim i ordered now.

Well I need the 1.8 mm shim but there isn't one listed on for the Chrysler PNs and the GM ones are discontinued it looks like. I ordered the next closest 1.58mm from a Mopar parts site and they got back to me a couple days later and said they are discontinued. Saw mitsubishi has the same part number so i ordered one from on of their site and they cancelled and said that no one has them anywhere in the US. Guess i will keep looking.

Checked www.mcmaster.com for ring shims?

If the shim you need is thinner than the one you have, you can have your existing one ground thinner.

Otherwise, buy a thicker shim and grind that, or even something like a custom laser-cut steel ring that's ground on both sides.

I think the ones I ordered on ebay should work. With feeler gauges I measured 1.9mm gap on the tool and was going to go down one size to 1.8 like the instructions said but I also have read some people set it up for 0 end play so I think 1.9mm should be ok.