Project: TH350C Rebuild

[8lugnutz]

I didn't know whether or not to keep this as part of my build thread or break it out, but I figured that somebody might be interested in this too and I didn't want them to have to wade through the banter on my build thread to get the info. So, here goes.

This thread will be a stock rebuild of my TH350C transmission using components that anyone can get from their local green, blue or orange auto supply houses. I do realize that you get one rebuilt by professional, get a lot of experience going into that "new" transmission by the skilled hands that build it, but I figure if I get it right, I will have learned something new and hopefully helped someone else with a similar problem.

I'm going to go ahead and get this out in the open. I am NOT a transmission guy. I have been in and around a garage my whole life, nearly everyone in my family is a mechanic or a machinist, but I decided on a career in IT/Information Security. I am going to make mistakes, and once these mistakes are documented I don't think I can edit them, so read the entire thread from beginning to end. I just may have an update in a later post that answers the question or corrects the mistake I made. I AM, however, a person who is not afraid to try something that I know nothing about, because I know there are vast resources on the interwebs that can help, this forum and the brilliant people who contribute to it is a great example of only one of theses resources. If you have advice for me, feel free to give it. If you want advice on how I did what I have posted, ask, and I will do my best to answer any questions, but remember, I'm NOT a transmission guy. I'm just a guy who's trying to save a buck. I'm not trying write a definitive manual on transmissions rebuilds, I'm just documenting the rebuild of mine.

A typical rebuilt kit costs ~$50-$150 depending on what you need to replace, and a rebuilt transmission is around $450. I am a guy that likes to do things myself to save money; I call it being conservative, and my wife calls that being a "cheapskate". My transmission has 1st gear completely gone. Reverse still worked, and I'm sure the higher "gears" are fine. We are about to find out.

First things first.



Now that I have music to work by, I needed to fabricate a bracket so that I could manipulate the transmission, as there is no way that I was about to try this on a table. So, using some metal I had laying around in the shop, and a welder borrowed from a friend, I welded up a bracket that I could attach to my motor stand. With the bracket made, I attached it to the tranny, drained the fluid, then mounted it on the stand. Now I can rotate the tranny however I want.





I knew I would have to fabricate some tools to compress the springs in the clutch packs, so I got some cheap tools that were similar to what I would need, and could be easily modified to suit my purpose. The muffin pans are used to collect and separate the different nuts/bolts/parts/etc.



I am using manuals (Haynes, GM Documentation, etc) and a guide from BM Racing, These are very clear and concise step by step instruction manuals so I am not going to rewrite what is already written in them.

Removed accumulator, governor, and vacuum modulator and oil pan and pan gasket. If you need a picture of the pan, please discontinue use of this site and contact an professional immediately.....



Removed filter, filter gasket, disconnected solenoid. Disconnected detent pin, mount and wire from valve. Unbolted valve body, park lock and solenoid. Removed solenoid, removed park log, removed valve body, disconnected shifter linkage.



All parts are separated in my muffin pan.