My TH350 Rebuild

[87scotty]

Haha nice

 

[adaml23]

Ok got the tranny out friday night (around 4am...). I was happy to see a big "K" on the top of the housing! Got it down in the basement tonight after powerwashing it quickly to clean it off some. Now time to start tearing it down, taking pics and giving them to my brother to get hot tanked.

 

[adaml23]

Also, I took some pictures of the other trannys and crossmember for our other truck. Can someone tell me why there are different crossmembers for a 4x4 and does that affect anything as far as the other tranny for the spare truck? Do I need a different tranny for the different crossmember?

The top two pics are pics of my truck's tranny and single span crossmember and the last two are of the spare truck's tranny(s) and double span crossmember.

Any thoughts on what's going on?

 

[Irishman999]

Ok got the tranny out friday night (around 4am...). I was happy to see a big "K" on the top of the housing! Got it down in the basement tonight after powerwashing it quickly to clean it off some. Now time to start tearing it down, taking pics and giving them to my brother to get hot tanked.

It looks like your overly prepared and going to lose your organization steam before you need it, as far as the bench goes. The beer fridge is good, just remember a beer fridge that close to a transmission building area can go very wrong, very quickly.

If it was my work area I would ditch the plastic over the wood bench and just get a roll of pigmat and cover the entire surface. I would take apart the the transmission on the left side and organize the parts in order on the right with the rebuild kit being all the way to the right, for some reason that always worked for me. As of now it looks like some kind of bed for a homeless person with a transmission sitting on it.

While im on the subject you will need a parts washer for everything. Harbor freight has a cheap ass little bench top unit that works great and its dirt cheap. Go to the hardware store and fill it with a couple jugs of mineral spirits (paint thinner will melt it). That way you can properly clean all the hard parts. You also need compressed air to blow everything off, check clutch packs etc.

 

[firebane]

The bottom cross member has the skid plate for the transfer case. This was an option and not provided on all trucks. My truck surprisingly has it.

 

[adaml23]

It looks like your overly prepared and going to lose your organization steam before you need it, as far as the bench goes. The beer fridge is good, just remember a beer fridge that close to a transmission building area can go very wrong, very quickly.

If it was my work area I would ditch the plastic over the wood bench and just get a roll of pigmat and cover the entire surface. I would take apart the the transmission on the left side and organize the parts in order on the right with the rebuild kit being all the way to the right, for some reason that always worked for me. As of now it looks like some kind of bed for a homeless person with a transmission sitting on it.

While im on the subject you will need a parts washer for everything. Harbor freight has a cheap ass little bench top unit that works great and its dirt cheap. Go to the hardware store and fill it with a couple jugs of mineral spirits (paint thinner will melt it). That way you can properly clean all the hard parts. You also need compressed air to blow everything off, check clutch packs etc.

I'm not sure what you mean by that first sentence. It will all get rearranged. I just had a neighbor who happened to be available and came over to help bring the tranny downstairs into the basement so I just put it down there while I had help. Don't worry about the beer fridge; this was just the only spot I had to work on it as I'm cleaning out our (very) small garage for the winter so the wife can park in it.

I'm actually gonna put it on the right and tear it down to the left; basically the opposite of the direction you mentioned. I'm left handed and it'll work/feel better for me. I laughed at your homeless person bed comment. It looks dirty but that's a piece of cardboard I had on the benches when they were in the garage and I was painting the POR-15 on the 14 bolt rearend so it's just some dried POR-15 you're seeing on the cardboard. I'm gonna go pick up some pigmat at lunch but I also wanted something over the bench (so I could just pull it off and throw away after I take the tranny apart).

My brother (who's actually a mechanic by trade) has access to a hot tank at his work. I'm just gonna take him all the pieces after tear-down so he can wash them. Is it ok to hot tank all the internal parts? And finally, I've got a little portable air tank/compressor down there already to clean passages/test.

How's that for prepared?

My wife was due last Friday so I'm working on borrowed time right now and I'm sure it'll become a little slower build in the next couple of days when we have the next kid. fyi

And where do you guys get your rebuild kits, bushing kits and thrust washer kits from? Where's my cheapest option for quality parts?

 

[crazy4offroad]

This is who I used for rebuild parts, recommended to me by HotRodPC...
http://www.transmissionpartsusa.com/GM_Rear_Wheel_Drive_Transmission_Parts_s/238.htm
I would imagine you could hot tank any parts as long as there is no plastic involved. I wish I had that much bench space when I did mine lol

 

[adaml23]

By the way TIC - thanks for those pictures of your homemade tools. I'm pretty sure I can rig something up like those.

 

[adaml23]

This is who I used for rebuild parts, recommended to me by by HotRodPC...
http://www.transmissionpartsusa.com/GM_Rear_Wheel_Drive_Transmission_Parts_s/238.htm
I would imagine you could hot tank any parts as long as there is no plastic involved. I wish I had that much bench space when I did mine lol

Thanks!

 

[adaml23]

So I'm looking at what "extras" to do to the tranny while rebuilding. This truck will mostly just see light duty driving around but may see some heavier use as well. Maybe a little towing; maybe some plowing. It's going behind the tired, original 400 motor that may one day get rebuilt as well but not until it dies. What all do you guys suggest I beef up while in there just so I don't have to possibly redo anything in the near future if the engine gets upgraded?

So far, I'm just thinking about dual feeding it, and adding some extra bushings to the sun gear. I also, thought about removing a check ball or two but after reading thru jakeshoe's rebuild thread on nastyz28.com, I'm thinking it may not be the best idea for the possible abuse it'll put on the tcase. Here's the link http://nastyz28.com/forum/showthread.php?t=53671&page=7 . They discuss this topic on 4wds in posts #91-93. Thought about a hardened sprag race but I'd rather spend that money on a part-time kit for the 203 tcase.

Also, are these the correct extra bushings I need to get for the sun gear? http://www.transmissionpartsusa.com...aft_pilot_bushing_1969_86_p/470-000034634.htm

 

[crazy4offroad]

I used that and a couple other places for ideas. I set mine up for internal dual feed of the direct drum, doubled up the sun gear bushings (be sure to re-drill the oil holes!) and I think those are the right ones, I'll check my receipt and let you know. Also the hardened intermediate sprag race and if you got the cash the 36 element sprag and hardened input shaft. You can also drill the 2nd and 3rd gear feed holes in the separator plate to 0.125" (1/8") and increase the line pressure just enough to firm up the shifts. Dropping out the check balls makes it hit much harder, which I did but may put them back. There's also a way to have the direct drum piston machined to accept an extra clutch friction and steel but I couldn't justify the cost of machine work vs the gain. I guess the higher the horsepower the payoff might be worth it though. Also use a 0.750" direct drum bushing instead of the stock 0.500" bushing for heavier duty use. Here are the two web pages I referred to a lot, besides the info we have here...
http://www.crankshaftcoalition.com/wiki/T-350_rebuild_tech
http://www.hotrodders.com/forum/t-350-rebuild-tech-145361.html

EDIT: this is the p/n and description of the sun gear bushings...
470-000047632 47632 TH350 Transmission sun gear & rear planet bushing 1969-86.
2 $0.67 $1.34

Re-Edit: I dont see that p/n on their site anymore, might want to call them and make sure.

 

[adaml23]

New led strip lights and tranny jel showed up today! Still waiting on my pig mat and Ron sessions book to show up before tear down...

 

[Irishman999]

I'm not sure what you mean by that first sentence. It will all get rearranged. I just had a neighbor who happened to be available and came over to help bring the tranny downstairs into the basement so I just put it down there while I had help. Don't worry about the beer fridge; this was just the only spot I had to work on it as I'm cleaning out our (very) small garage for the winter so the wife can park in it.

I'm actually gonna put it on the right and tear it down to the left; basically the opposite of the direction you mentioned. I'm left handed and it'll work/feel better for me. I laughed at your homeless person bed comment. It looks dirty but that's a piece of cardboard I had on the benches when they were in the garage and I was painting the POR-15 on the 14 bolt rearend so it's just some dried POR-15 you're seeing on the cardboard. I'm gonna go pick up some pigmat at lunch but I also wanted something over the bench (so I could just pull it off and throw away after I take the tranny apart).

My brother (who's actually a mechanic by trade) has access to a hot tank at his work. I'm just gonna take him all the pieces after tear-down so he can wash them. Is it ok to hot tank all the internal parts? And finally, I've got a little portable air tank/compressor down there already to clean passages/test.

How's that for prepared?

My wife was due last Friday so I'm working on borrowed time right now and I'm sure it'll become a little slower build in the next couple of days when we have the next kid. fyi

And where do you guys get your rebuild kits, bushing kits and thrust washer kits from? Where's my cheapest option for quality parts?

I would just take him the case and oil pan, maybe even the servo cover. Internal transmission parts dont really get covered in grime but you do need to clean them. I mostly just rinse everything off with solvent in my parts washer and blow it dry.

The main problem with shipping all the parts off to get cleaned is something might get lost in the process. Anytime I tear down a transmission I just pull all the parts out, put them on my bench and send the case to the machine shop to get cleaned. From there, while im waiting for the case I can clean and rebuild the drums.

As far as rebuild kits I just order **** off ebay, I cant think of the company name right now but I have got all three kits from them for a good price, and its the premium red alto parts.

 

[adaml23]

Re-Edit: I dont see that p/n on their site anymore, might want to call them and make sure.

I called them today and they said they found one one the shelf but needed to order more. Would be a few days before they got more in. I won't get to tear into it till this weekend at the earliest and want to look over the bushings and steels and other parts before ordering anything.

 

[adaml23]

OK so I started tear down tonight and got to where the front planetary sits on the sun gear splines but couldn't get it off!? I removed the c-clip but it can't get over the splines in front of where the c-clip sits. It kind of looks like there is some wear/chips/burs on those teeth which isn't allowing me to take off the planetary gear. Also, there are some metal shavings on the edge of the sun gear bushing in the pic. Don't know what that means but it's probably not a good thing...

Any thoughts/special tricks or tools on how to remove the planetary??