350 Turbo Rebuild Questions - The 1947 - Present Chevrolet & GMC Truck Message Board Network

BLACK AND BLUE 67-72 · 07-11-2002, 06:20 PM

How hard is it? What all should be replaced? Do I need a new Torque Convertor? What the He** is a Sprag and what does it do? Should I use heavy duty clutches? What is the difference between Heavy Duty and regular Clutches? Any bearings that Need to be replaced? How much would it cost? Any other things that I need to replace or Know about? Thanks

colohusker · 07-11-2002, 06:38 PM

I haven't rebuilt mine yet, but I read through this book and it seems to cover most questions and walks you through everything.

ISBN 0895860511
http://www.amazon.com/exec/obidos/AS...roduct-details

Scott

bouncytruck · 07-11-2002, 07:03 PM

I just finished my TH350 rebuild. The work wasn't hard (getting the transfercase back in was the hardest part) but it is very time consuming. I got a rebuild kit and it was around $125. I also had two books on rebuilding the TH350 which was nice. If I didn't understand what one book was saying, I could refer to the other. I did put in a new torque converter but only because I had a sprag explode inside the case and there were metal fragments and bearings everywhere. I also had to buy a new case, have some machine work done to it, and get several internal parts. My total cost was around $515 with the case, parts, kit, torque converter, hot tanking the case and shop work to the case. If you decide to rebuild, don't open any parts until you have disassembled the tranny and inspected all the parts and the case. If I hadn't opened the kit, I would have slapped the thing back together and used it for a core on a rebuilt. The books said I needed a special tool to compress the last set of springs (this will be obvious when you get into it) but I just made my own with a couple chunks of wood and a threaded rod.

You can see some pictures of the damaged parts I had at http://info.imageink.com/chris/tranny.htm. The part titled "front clutch" is the first sprag clutch.

It's worth a try if you have the ambition. Just read the book and inspect your parts before you open the new stuff and can't return it. The problems inside will determine if you need a new torque converter (stock ones run around $80)

Good luck.

colohusker · 07-11-2002, 07:33 PM

bouncytruck

Just curious what your tranny was doing before you rebuilt it. Whether it was just slipping, or whether you had lost any gears, or just plain wouldn't work. Mine is just slipping now, and getting worse, but I haven't lost any gears yet. Just trying to get an idea of what I might expect when I open it up.

Scott

bouncytruck · 07-11-2002, 07:56 PM

Mine made a huge noise and jerked the whole truck when it went into second one day. I limped it home (luckly I was just on the next street over) and then it made a grinding noise when I put it into park. I had to shut down the truck to stop the noise. Yours sounds like it is just worn out or over heated. If it is just worn out, you might get away with a smaller rebuild kit. Crack the pan open and see if you have a lot of metal in there. Depending on the condition of the residue in the pan, you can get an idea of what is wrong with it. The books explain this in detail, but I can't remember what the differences are. They usually have a pretty good trouble shooting section too. I did some browsing at the local Barnes & Noble book store before I bought a book. I'll see if I can remember the titles. There was also a guy on Colorado K5 that had a detailed account of his TH350 rebuild. I think his was a little more straight forward than mine. I can't remember who it was though.

colohusker · 07-11-2002, 08:03 PM

Well, according to the books I've read, mine probably just needs the soft parts, clutches etc, and I shouldn't have to replace the carriers, etc. I haven't had a chance to drop my pan yet since I tore up my ankle last month, for some reason it's hard to crawl around under a truck in a cast. I guess we'll see this fall when I get around to doing it.

I think I've seen the site regarding the detailed, pretty straightforward rebuild.

Thanks for the info!

Scott

68 with 350 TPI · 07-11-2002, 08:46 PM

Rebuilding the th350 is pretty easy but as said it does take some time.

I would get a new torque converter just to be safe.... If you cant afford a new (TC) find someone that can flush out the old one.

BTW make sure you blow out the cooler lines with compressed air to get the junk out of the radiator or you will be back where you started.

Sinister · 07-11-2002, 10:27 PM

hey bouncytruck, i thought that was the rebuild from hell...

mines starting to slip

getting ready to rebuild or replace...

just got haynes tech book for gm auto trannies...

total tear down/rebuilds of 200-r4,turbo 350, turbo 400, and the 700-r4...:p
tci sells a rebuild kit with heavy duty clutches
fo about 2 bills, which is the way i'm probaly gonna go if i decide to do this myself...

but i'm getting lazy in my old age...
i reckon if the tranny your trying to rebuild ain't to f#cked up, it should make for a smoother rebuild...
.

BLACK AND BLUE 67-72 · 07-11-2002, 11:06 PM

Thanks Guy's. I guess I'll try to get a couple of manuals on rebuilding transmissions!!

Sinister · 07-13-2002, 10:03 PM

hey, 68 with 350 TPI or bouncytruck,
what bushings come with the rebuild kit?
and where did you get your bushing drivers?

68 with 350 TPI · 07-14-2002, 02:48 PM

The bushings depend on the kit you get.But you can get some trans tools from snap-on or ati transmissions.

bouncytruck · 07-15-2002, 01:17 PM

The only reason mine was the "rebuild from hell" was because it cost almost as much as a rebuilt tranny! Had I known it was going to cost so much, I would have just got the rebuilt tranny and had it back in the truck in a weekend. Instead, it took well over a month. Locating the busted internal parts and a good "K" case was a real hassel too. The tranny shop wanted $450 for a "K" case. I was able to purchase a core for $125.

I still have alot of the internal parts from the core if anyone needs them. Some of the parts have heat discoloration and probably aren't usable.

Sinister · 07-15-2002, 10:07 PM

but now you know how to rebuild an auto tranny...

where did you get your bushing drivers, or did you use sockets?

bouncytruck · 07-16-2002, 12:03 PM

I used sockets, etc. I was attempting to make it a budget rebuild so I avoided buying any tools that weren't 100% necessary.

Sinister · 07-16-2002, 10:44 PM

righteous...

been looking all over for them...
the GM one's that the dealerships use are supposed to be available to the public, but i haven't had any luck finding a set so far...

07-11-2002, 06:20 PM	#1
BLACK AND BLUE 67-72 Firefighter Join Date: Feb 2001 Location: Yellville, Ar, USA Posts: 1,943	350 Turbo Rebuild Questions How hard is it? What all should be replaced? Do I need a new Torque Convertor? What the He** is a Sprag and what does it do? Should I use heavy duty clutches? What is the difference between Heavy Duty and regular Clutches? Any bearings that Need to be replaced? How much would it cost? Any other things that I need to replace or Know about? Thanks __________________ '72 Chevy SWB 350 Auto '67 GMC LWB 350 4 speed '70 Chevy 4x4 Stepside 350 Auto Yellville, Ar. USA

07-11-2002, 06:38 PM	#2
colohusker Registered User Join Date: Apr 2002 Location: Longmont, CO Posts: 436	I haven't rebuilt mine yet, but I read through this book and it seems to cover most questions and walks you through everything. ISBN 0895860511 http://www.amazon.com/exec/obidos/AS...roduct-details Scott __________________ ------------------------------------------------ I say it's only money, my wife says it's only a truck.... '71 C10 Deluxe, factory ac, ps, pb, should be done by 2102 Longmont, CO husker95@hotmail.com

07-11-2002, 07:03 PM	#3
bouncytruck SKINNY TIRES RULE! Join Date: Sep 2001 Location: Bothell, WA Posts: 11,049	I just finished my TH350 rebuild. The work wasn't hard (getting the transfercase back in was the hardest part) but it is very time consuming. I got a rebuild kit and it was around $125. I also had two books on rebuilding the TH350 which was nice. If I didn't understand what one book was saying, I could refer to the other. I did put in a new torque converter but only because I had a sprag explode inside the case and there were metal fragments and bearings everywhere. I also had to buy a new case, have some machine work done to it, and get several internal parts. My total cost was around $515 with the case, parts, kit, torque converter, hot tanking the case and shop work to the case. If you decide to rebuild, don't open any parts until you have disassembled the tranny and inspected all the parts and the case. If I hadn't opened the kit, I would have slapped the thing back together and used it for a core on a rebuilt. The books said I needed a special tool to compress the last set of springs (this will be obvious when you get into it) but I just made my own with a couple chunks of wood and a threaded rod. You can see some pictures of the damaged parts I had at http://info.imageink.com/chris/tranny.htm. The part titled "front clutch" is the first sprag clutch. It's worth a try if you have the ambition. Just read the book and inspect your parts before you open the new stuff and can't return it. The problems inside will determine if you need a new torque converter (stock ones run around $80) Good luck. __________________ bouncytruck 1972 K5 The Hauler 1994 K1500 Suburban The Daily2010 Kia Soul Wife's Ride2014 Fiat 500L

07-11-2002, 07:33 PM	#4
colohusker Registered User Join Date: Apr 2002 Location: Longmont, CO Posts: 436	bouncytruck Just curious what your tranny was doing before you rebuilt it. Whether it was just slipping, or whether you had lost any gears, or just plain wouldn't work. Mine is just slipping now, and getting worse, but I haven't lost any gears yet. Just trying to get an idea of what I might expect when I open it up. Scott __________________ ------------------------------------------------ I say it's only money, my wife says it's only a truck.... '71 C10 Deluxe, factory ac, ps, pb, should be done by 2102 Longmont, CO husker95@hotmail.com

07-11-2002, 07:56 PM	#5
bouncytruck SKINNY TIRES RULE! Join Date: Sep 2001 Location: Bothell, WA Posts: 11,049	Mine made a huge noise and jerked the whole truck when it went into second one day. I limped it home (luckly I was just on the next street over) and then it made a grinding noise when I put it into park. I had to shut down the truck to stop the noise. Yours sounds like it is just worn out or over heated. If it is just worn out, you might get away with a smaller rebuild kit. Crack the pan open and see if you have a lot of metal in there. Depending on the condition of the residue in the pan, you can get an idea of what is wrong with it. The books explain this in detail, but I can't remember what the differences are. They usually have a pretty good trouble shooting section too. I did some browsing at the local Barnes & Noble book store before I bought a book. I'll see if I can remember the titles. There was also a guy on Colorado K5 that had a detailed account of his TH350 rebuild. I think his was a little more straight forward than mine. I can't remember who it was though. __________________ bouncytruck 1972 K5 The Hauler 1994 K1500 Suburban The Daily2010 Kia Soul Wife's Ride2014 Fiat 500L

07-11-2002, 08:03 PM	#6
colohusker Registered User Join Date: Apr 2002 Location: Longmont, CO Posts: 436	Well, according to the books I've read, mine probably just needs the soft parts, clutches etc, and I shouldn't have to replace the carriers, etc. I haven't had a chance to drop my pan yet since I tore up my ankle last month, for some reason it's hard to crawl around under a truck in a cast. I guess we'll see this fall when I get around to doing it. I think I've seen the site regarding the detailed, pretty straightforward rebuild. Thanks for the info! Scott __________________ ------------------------------------------------ I say it's only money, my wife says it's only a truck.... '71 C10 Deluxe, factory ac, ps, pb, should be done by 2102 Longmont, CO husker95@hotmail.com

07-11-2002, 08:46 PM	#7
68 with 350 TPI Registered User Join Date: May 2002 Location: Wingate NC Posts: 456	Rebuilding the th350 is pretty easy but as said it does take some time. I would get a new torque converter just to be safe.... If you cant afford a new (TC) find someone that can flush out the old one. BTW make sure you blow out the cooler lines with compressed air to get the junk out of the radiator or you will be back where you started. __________________ Life is good with a 6-71 supercharged 355 in a 72 camaro

07-11-2002, 10:27 PM	#8
Sinister Between Trucks... Join Date: Mar 2002 Location: Los Angeles, CA. Posts: 3,830	hey bouncytruck, i thought that was the rebuild from hell... mines starting to slip getting ready to rebuild or replace... just got haynes tech book for gm auto trannies... total tear down/rebuilds of 200-r4,turbo 350, turbo 400, and the 700-r4...:p tci sells a rebuild kit with heavy duty clutches fo about 2 bills, which is the way i'm probaly gonna go if i decide to do this myself... but i'm getting lazy in my old age... i reckon if the tranny your trying to rebuild ain't to f#cked up, it should make for a smoother rebuild... . __________________ Beat it to fit, Paint it to match...

07-11-2002, 11:06 PM	#9
BLACK AND BLUE 67-72 Firefighter Join Date: Feb 2001 Location: Yellville, Ar, USA Posts: 1,943	Thanks Guy's. I guess I'll try to get a couple of manuals on rebuilding transmissions!! __________________ '72 Chevy SWB 350 Auto '67 GMC LWB 350 4 speed '70 Chevy 4x4 Stepside 350 Auto Yellville, Ar. USA

07-13-2002, 10:03 PM	#10
Sinister Between Trucks... Join Date: Mar 2002 Location: Los Angeles, CA. Posts: 3,830	hey, 68 with 350 TPI or bouncytruck, what bushings come with the rebuild kit? and where did you get your bushing drivers? __________________ Beat it to fit, Paint it to match...

07-14-2002, 02:48 PM	#11
68 with 350 TPI Registered User Join Date: May 2002 Location: Wingate NC Posts: 456	The bushings depend on the kit you get.But you can get some trans tools from snap-on or ati transmissions. __________________ Life is good with a 6-71 supercharged 355 in a 72 camaro

07-15-2002, 01:17 PM	#12
bouncytruck SKINNY TIRES RULE! Join Date: Sep 2001 Location: Bothell, WA Posts: 11,049	The only reason mine was the "rebuild from hell" was because it cost almost as much as a rebuilt tranny! Had I known it was going to cost so much, I would have just got the rebuilt tranny and had it back in the truck in a weekend. Instead, it took well over a month. Locating the busted internal parts and a good "K" case was a real hassel too. The tranny shop wanted $450 for a "K" case. I was able to purchase a core for $125. I still have alot of the internal parts from the core if anyone needs them. Some of the parts have heat discoloration and probably aren't usable. __________________ bouncytruck 1972 K5 The Hauler 1994 K1500 Suburban The Daily2010 Kia Soul Wife's Ride2014 Fiat 500L

07-15-2002, 10:07 PM	#13
Sinister Between Trucks... Join Date: Mar 2002 Location: Los Angeles, CA. Posts: 3,830	but now you know how to rebuild an auto tranny... where did you get your bushing drivers, or did you use sockets? __________________ Beat it to fit, Paint it to match...

07-16-2002, 12:03 PM	#14
bouncytruck SKINNY TIRES RULE! Join Date: Sep 2001 Location: Bothell, WA Posts: 11,049	I used sockets, etc. I was attempting to make it a budget rebuild so I avoided buying any tools that weren't 100% necessary. __________________ bouncytruck 1972 K5 The Hauler 1994 K1500 Suburban The Daily2010 Kia Soul Wife's Ride2014 Fiat 500L

07-16-2002, 10:44 PM	#15
Sinister Between Trucks... Join Date: Mar 2002 Location: Los Angeles, CA. Posts: 3,830	righteous... been looking all over for them... the GM one's that the dealerships use are supposed to be available to the public, but i haven't had any luck finding a set so far... __________________ Beat it to fit, Paint it to match...



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