My TH350 Rebuild

[adaml23]

Well I'm at a crossroad where I have to decide on whether to replace my tranny or have it rebuilt. I've been reading up on it a lot and I'm leaning toward the rebuilt option. Actually, I'm thinking about doing it myself over the winter. The reasoning (in my own head) for attempting it by myself is multi-layered. First, I’m cheap. Second, I like learning new things and, although intimidating, I’ve always wanted to know how a tranny worked (or at least see the ridiculous amount of parts it has). Third, I’ve acuatlly got two spare (although shorter car tailshafts) bad 350 trannys laying over at my parents house that I can take apart as references. And lastly, because I have a buddy whose Dad rebuilds trannys on the side. He said if I can’t get it back together, he’d rebuild it (for some $$ obviously) from a basketcase so I can always just give in and let him do it . It’ll probably be a long process as my wife is due soon with our 3rd kid so my free time is VERY sparse. But I’m pretty patient and this will keep me busy(er) inside during the coming up winter months.

What I’m wanting to do with this thread is ask a few questions before I start and I’m sure there’ll be more as I’m rebuilding.

So, to start off, I’ll let you know my plan and ask some Q’s and hopefully get some feedback and answers.

My plan is to remove the old tranny, disassemble it (taking pictures along the way) and get it all washed in a hot tank. While it’s getting washed, I’m gonna take apart one of the other trannys and set all its parts out in order of removal. This way, when the other tranny comes back clean and I go to re-install, I can just use the 2nd tranny parts as a reference and install them in reverse order. Then (if I get this far without screwing anything up) I can reinstall the truck’s tranny back in and see if it’l. work correctly. If it does, my plan is to rebuild the other tranny the same way and, hopefully by this point, remember how to assemble the last one without a physical reference and go by memory and HotrodPC’s stickies on T350 rebuilds. I bought some transjel also ordered the Ron Sessions’ Handbook just for fun. I'm going to talk to my buddy's Dad and see if I can just borrow his piston compression tool.

What do you guys think?

My questions before I start are:

• All 3 trannys should hypothetically have the same internals (if stock) other than the longer/shorter tailshafts, correct?
• When I disassemble it, do I have all the internal parts (that will be reused) hot tanked as well or just the housing?
• Do I have to take apart the planetary gears and drum assembly to get them cleaned or just leave them together?
• Other than a rebuild kit, I've read that a bushings kit and thrust washer kit should be bought. Should I order these kits and/or anything else.
• How long approximately should reassembly take for someone who’s never rebuilt one (although fairly mechanically inclined…)?

I hope none of these questions are too dumb since I haven't disassembled a tranny yet. I'm sure there's more questions to come...

 

[87scotty]

I will be following this post take lots of pictures!!

 

[adaml23]

I plan on it... I'm even getting a little space down in the basement cleaned/set up to work on them. Still rearranging but here's what it started out as...

 

[TIC]

i just finished a th350 rebuild. my 2nd tranny build. my 1st was a 700r about 6 yrs ago. this time i put the manuel aside and followed hotrod build in this section. piece of cake. but good luck trying to get anyone to give you timely advice.

 

[HotRodPC]

No need to pull a trans apart just to have a guide how to put one back together. Take the pictures as you said, and there are plenty of exploited view diagram photos I can and have provided in a few threads.

To answer the questions,
#1, All of the internals if all are Th350 will be similar. There could be some differences in year model changes and updates.

#2 I don't hot hank the internals, of course I probably would if I had a hot tank for my use. I just clean them with 100% mineral spirits solvent.

#3 You do not take the planetaries apart at all. The drum assemblies, yes you do that's where the clutch piston and drum seals are at.

#4 You can probably get by with common bushings kit. Replace them all if you wish. Don't forget a new filter. The dacron type are good and some builders say they're the best, but the screen filters work good too.

#5 How long? As long as it takes to do it right. Don't be in a hurry and don't let time be a factor, that's when you'll fugg something up. Normally I spend more time cleaning the parts than anything. I might take you half a day, but it could even end up being the whole day and into the evening and so what if it does.

 

[adaml23]

i just finished a th350 rebuild. my 2nd tranny build. my 1st was a 700r about 6 yrs ago. this time i put the manuel aside and followed hotrod build in this section. piece of cake. but good luck trying to get anyone to give you timely advice.

TIC - How long did it take you to rebuild it? And if you can remember, how long did it take you to rebuild the 700R?

 

[Irishman999]

First thing you should do is find a barnes and nobles book store and find Cliff Ruggles book on rebuilding turbo 350's. You should be replacing all the bushings, I use a small ball peen hammer with a modified punch to get them out. Getting them in is tricky since you need bushing drivers for any bushing below flush.

You can probably re use all the bushings with good results anyways. Your going to need a spring compressor, I got one for about 150 bucks on ebay. There is several different versions, the one I got has been able to remove everything I have encountered so far. The book I told you about shows how to make your own tool for the lower piston in the case though.

You can do it.

 

[crazy4offroad]

I rebuilt the one in the big truck, it was a real pain in the ass for me mainly because it was my first, and I didn't have all the correct tools. I fabricated a couple tools but there's no replacement for having the right stuff. Also when you get around to cleaning out the valve body be sure you get everything back in there like it came out. One spring has a small and big end, and I put it in backwards and paid a big price. Toasted a clutch pack and had to take the trans out of the truck and tear it all back down all over again, hard lesson to learn. Just take your time and there's plenty of people here who can help.

 

[TIC]

this is my 2nd attempt to reply to your question, i gave a long instuction on how to fabricate a simple spring depreser and other tips. but when i hit post reply it said i wasn't logged in , when i was. so then i logged in again, and it lost the whole thing. so to answer your question, one day to disdassemble and two days to assemble. i had a socket that fit every bushing and seal. made my own spring depresser out of some scap wood and a couple clamps. sorry for this condenced vertion but im not gonna type that whole thing again just to loose it.

 

[Irishman999]

this is my 2nd attempt to reply to your question, i gave a long instuction on how to fabricate a simple spring depreser and other tips. but when i hit post reply it said i wasn't logged in , when i was. so then i logged in again, and it lost the whole thing. so to answer your question, one day to disdassemble and two days to assemble. i had a socket that fit every bushing and seal. made my own spring depresser out of some scap wood and a couple clamps. sorry for this condenced vertion but im not gonna type that whole thing again just to loose it.

We should make a thread of nothing but home made tools and just compare notes on everything. I think some of the stuff people create works better than the stuff you buy. Perfect example is my blue point apply piston installers for a turbo 400, they work awesome but I saw a video of a guy building a 4l60 who had a home made tool that worked better. It was just a feeler gauge with a handle, that simple. I used a feeler gauge to install a piston last week and it was perfect! So now im working on cutting up a 1/4 driver I dont use anymore and screwing a feeler gauge to it so I can speed up my next rebuild.

I also got a big ass C-clamp from Ace hardware im going to weld some sockets to for taking the servo piston assembly apart on the overdrive automatics.

So far the most creative thing I have done is drill a hole in my work bench for shafts to go through!

 

[adaml23]

We should make a thread of nothing but home made tools and just compare notes on everything. I think some of the stuff people create works better than the stuff you buy....
So far the most creative thing I have done is drill a hole in my work bench for shafts to go through!

I would love to see that thread. And the hole in the table is gonna be my first "tool" for this job. Talked to my buddy's Dad last night. He said I can borrow his homemade compressor tool and if I get stuck he can come over and help reassemble.

t...made my own spring depresser out of some scap wood and a couple clamps. sorry for this condenced vertion but im not gonna type that whole thing again just to loose it.

TIC - do you have a picture of your homemade spring depressor?

...Also when you get around to cleaning out the valve body be sure you get everything back in there like it came out. One spring has a small and big end, and I put it in backwards and paid a big price. Toasted a clutch pack and had to take the trans out of the truck and tear it all back down all over again, hard lesson to learn.

That sucks. And is also my biggest fear; that I'll get it all put back together and it won't work. So yea, I'll be taking my time.



Got most of the stuff in the way removed last night (driveshafts, linkage, cab shifter boot/plate, ect). But I had trouble getting the tranny lines unthreaded. Any tips on removing those without ruining them or should I just say screw it and cut the lines? Pretty sure they're the originals. Before I quit last night, I doused them good with PB Blaster. Gonna hopefully get the tranny and tcase out tomorrow night.

 

[adaml23]

Finished cleaning my new winter work space. And yes that is the beer fridge peeking out on the left... Ordered some LED light strips to put up for more light. Should be here next week. Will be attempting to remove the tranny from the truck tonight as long as the wife doesn't go into labor...

Also, I'm gonna drill a hole in the table somewhere to hold the shaft. What size drill or holesaw did you guys use?

 

[TIC]

You must be registered for see images

You must be registered for see images

You must be registered for see images

You must be registered for see images

You must be registered for see images

[/IMG]

You must be registered for see images

You must be registered for see images

heres some pictures of spring depresser. i wouln't call them tools, just a means toward an end. when i was done i through the wood back in the scrap pile.

You must be registered for see images

 

[Irishman999]

Finished cleaning my new winter work space. And yes that is the beer fridge peeking out on the left... Ordered some LED light strips to put up for more light. Should be here next week. Will be attempting to remove the tranny from the truck tonight as long as the wife doesn't go into labor...

Also, I'm gonna drill a hole in the table somewhere to hold the shaft. What size drill or holesaw did you guys use?

I would cover that whole bench in pig mat, its going to get messy. I like pig mat because it absorbs the horrible mess from a tear down and you can just roll all the **** up and throw it away. Then I lay down a new layer of pig mat because I know I have a dirt free work surface.

The hole in the bench only needs to be about an inch and a half. Beer cooler is an awesome addition to the transmission rebuild area.

 

[adaml23]

Beer cooler is an awesome addition to the transmission rebuild area.

Actually the transmission rebuild stuff is in addition to the beer fridge area...