Muncie 4 Bearing replacement (Page 1/3)
BadNewsBrendan DEC 05, 11:47 AM
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.

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

Tetanus
1984 3800 II SC Build

pmbrunelle DEC 05, 01:20 PM
http://www.realfierotech.co...topic.php?f=3&t=3770

http://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).]

Gall757 DEC 05, 10:30 PM
What a post! More information there than you can read in days..... + for you!
BadNewsBrendan DEC 07, 11:20 AM
Exactly what I needed. Thanks for the help as always!

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

Tetanus
1984 3800 II SC Build

BadNewsBrendan MAY 01, 04:56 PM
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.
pmbrunelle MAY 02, 01:25 AM
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?
BadNewsBrendan MAY 02, 09:12 AM
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.
pmbrunelle MAY 02, 11:53 AM
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).]

BadNewsBrendan MAY 02, 12:37 PM
Wow I don't know how I made it this far without knowing about that p-book but glad I have it now. Thanks!!!!
BadNewsBrendan MAY 02, 01:23 PM
Heat made the shield brittle and I broke it trying to scrape the mud off it. Also saw the PN of the shield I melted is the other shield listed in the P-book which I haven't been able to find for sale anywhere yet.

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