mark kibort

How difficult is it to rebuild a transmission. I have no idea how the first bolt comes apart, other than doing some miraculous adjustments to the shift forks after studying that mechanism for many months and taking a plunge to adjust one that worked.

do you need presses and special tools, or does the transmission just fall apart in your lap with a few ring clips removed.

it kills me to see that holbert 5 speed transmission in my backyard shed with only one thing wrong with it.......... the 5th gear set stripped out, so I had no drive in any gear but 5th.

if I was to find a used 5th gear set, how hard would it be to replace just that one gear ? (and maybe if I got bold, replace the 2-3rd gear synchro too)

otherwise, the transmission just sitting around... rare, partially broken, but too valuable to just toss out or forget!

Rob Edwards

What transmission model is it? The Holbert car was originally a very early (like, the 2nd one off the line) '86 automatic, so clearly it's not original to the chassis. So what's the stamping on the underside rear rib of the diff housing?

According to the link below, it should have a 2.54 rear end in it, though originally it had a 2.64 rear end which likely makes it a G28.12 (?)

http://perfexmfg.com/holbert_history.php

Reason I ask is that the box defines which input shaft bearing you're going to need along with that new 5th gear. Which at least for a G28.12 (928.302.905.32) is NLA.

I guess the other question is why isn't that transmission with the rest of the Holbert car in Connecticut?

Mark Anderson

You still have your met wrench set and a cresent wrench right?
no problem

FBIII

I really don't think teething on a 928 transmission is a wise place to start. Parts are becoming to rare and costly. Should something be assembled incorrectly resulting in a larger failure your going to be SOL.

mark kibort

good point. I guess, im getting a little cocky, having fixed a major problem with a shift fork adjustment through the top of the transmission cover. I was thinking there might be an easy way to get all the gears out, drop out 5th and replace it with a new one , if only a ring clip or two had to be removed.

yes, and they have rebuilt many 928 928 engines to date, just wonder if they are up to the task of fixing a transmission.

[QUOTE=Rob Edwards;11738034]What transmission model is it? The Holbert car was originally a very early (like, the 2nd one off the line) '86 automatic, so clearly it's not original to the chassis. So what's the stamping on the underside rear rib of the diff housing?

According to the link below, it should have a 2.54 rear end in it, though originally it had a 2.64 rear end which likely makes it a G28.12 (?)

QUOTE]

Its the 928S4 standard US 2.2 manual transmission. I can go look. it also had the open diff when I got it, and added the LSD.
yes, the holbert chassis was a automatic to stick conversion.

im wondering what kind of a job is it to replace the 5th gear, if all else in the transmission is in decent shape. I know 5th gears are like unicorns now, but eventually a used one might show up.... heck, even if I have to buy a new 5th gear for $1500, it might be worth it to rebuild..... no real urgency to rebuild, but wanted to know the options.

mark kibort

Is there a picture thread of a 928 transmission rebuild?

Rob Edwards

This is probably the most detailed thread on the topic but not quite Dwaynesque.

https://rennlist.com/forums/928-foru...ocal-shop.html

mark kibort

no way...... I think ill leave this one to the pros. probably have to find a 5th gear and send this thing to GB.