Scarring on transmission input shaft housing (Page 1/2)
Indy-453 JAN 25, 12:10 AM
Hello,

Looking for advice on my Muncie M19 from my 84 Indy. The housing for the input shaft that the clutch release bearing rides upon has some nasty scarring on it. The scar is somewhere between 1/32 and 1/16 of an inch deep, and it is over 90 degrees of the circumference of the shaft. The bearing doesn't seem to have any issues passing over it when I move it by hand. I have never driven the car, when I bought it the license plate had expired in 1997, so I have no idea how well it works when the clutch is pressed (or the overall condition of the transmission either!)



So Im looking for some advice on this one. Should I pretend the problem doesn't exist, or should I be looking at repair sleeves, or possibly sourcing a replacement input shaft housing / new transmission?

Thank you
Dennis LaGrua JAN 25, 09:42 AM
That's a weird problem. Looks like the inner race of the throwout bearing was rattling or spinning. I would not reuse that input shaft housing or bearing assembly with those cuts in it. It would also check the transmission input shaft bearing for excessive wear.

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" THE BLACK PARALYZER" -87GT 3800SC Series III engine, custom ZZP /Frozen Boost Intercooler setup, 3.4" Pulley, Northstar TB, LS1 MAF, 3" Spintech/Hedman Exhaust, P-log Manifold, Autolite 104's, MSD wires, Custom CAI, 4T65eHD w. custom axles, Champion Radiator, S10 Brake Booster, HP Tuners VCM Suite.
"THE COLUSSUS"
87GT - ALL OUT 3.4L Turbocharged engine, Garrett Hybrid Turbo, MSD ign., modified TH125H
" ON THE LOOSE WITHOUT THE JUICE "

Gall757 JAN 25, 12:00 PM
I am thinking that yellow fuzz is from the clutch pads. Seems like a lot to me and perhaps abrasive......maybe it's not a stock clutch or improper throughout bearing.
pmbrunelle JAN 25, 12:17 PM
If the housing isn't bent, it looks like the kind of part that could be built back up (weld for steel, or braze for cast), and then turned smooth on a lathe by a decent repair/machining shop.
Indy-453 JAN 26, 01:47 AM
So I went and played with the bearing, definitely garbage. There's a lot of play and you can move the inner race while holding the outer. I can see how the inner race could get misaligned vs the outer and dig into the shaft.

The "fuzz" is sawdust from the transmission being left on the garage floor for a year. There's paper towel stuffed into the holes for the axle shafts. Its super "clean" and "hi tech".

I like the idea of welding up and turning down on a lathe. Aside from taking apart the transmission. I have extended family that owns a machine shop, so that's definitely a route worth exploring.

However first I am going to send some pictures to the local transmission shop, see what they have to say about it.

I'm just glad that this is a problem and I'm not worried about nothing.
Dennis LaGrua JAN 26, 08:44 AM

quote
Originally posted by Indy-453:

I like the idea of welding up and turning down on a lathe. Aside from taking apart the transmission. I have extended family that owns a machine shop, so that's definitely a route worth exploring.
However first I am going to send some pictures to the local transmission shop, see what they have to say about it.
I'm just glad that this is a problem and I'm not worried about nothing.



Filling those cuts with welds and machining down the input shaft housing should work well but I would also check the input shaft bearing for excessive. Sounds like you are on it.

------------------
" THE BLACK PARALYZER" -87GT 3800SC Series III engine, custom ZZP /Frozen Boost Intercooler setup, 3.4" Pulley, Northstar TB, LS1 MAF, 3" Spintech/Hedman Exhaust, P-log Manifold, Autolite 104's, MSD wires, Custom CAI, 4T65eHD w. custom axles, Champion Radiator, S10 Brake Booster, HP Tuners VCM Suite.
"THE COLUSSUS"
87GT - ALL OUT 3.4L Turbocharged engine, Garrett Hybrid Turbo, MSD ign., modified TH125H
" ON THE LOOSE WITHOUT THE JUICE "

Oregon88 JAN 27, 12:52 PM
Oh the lengths we go to restore our beauties!

Good luck bud!
Will JAN 27, 01:39 PM
For that, brazing--rather than welding--should work fine and has a lot lower probability of warping the part.

Any new clutch kit you buy will have a new throw out bearing in it.

Check the throw out fingers for wear where they touch the bearing... if the bearing inner race was rotating against the TOB guide to make those grooves, then the throw out fingers should show a lot of wear as well.
Indy-453 FEB 10, 11:13 AM
Update: took the transmission in to the local transmission specialists. Their first suggestion was a repair sleeve, but they couldn’t find one any more. So I gave them the go ahead to open it up to press out the shaft and braise it (since it’s cast iron).

However, the bearings are rough, one has worn through the hardened surface on the race and it’s now heavily pitted.

The only parts kit that they can find is bearings only, and would be $600 including shipping to Canada. The stuff like synchros are worn but still functioning, but replacements cannot be found through the shop’s usual parts channels.

Aside for opening the giant can of worms that would be swapping in a Cobalt F23 transmission, does anyone know of a supplier for a rebuild kit? Or do kits like this exist any more?
pmbrunelle FEB 10, 12:20 PM
The "rebuild kit" vendors don't actually do much, they just take readily available off-the-shelf bearings and seals, put them in a box for the Muncie 4-speed, and then gouge you on the price.

Instead, you buy the readily available bearings and seals piece-by-piece.
Look here for a parts list:
http://www.realfierotech.co...topic.php?f=3&t=3770

The bearings and seals can be had easily from Rockauto, or wherever else...

As for the blocking rings, that's kind of a more tricky topic... could just try to stretch the ones you have, or else get another Muncie to scavenge its parts.