TH350 rebuild/trannie hell... - The 1947 - Present Chevrolet & GMC Truck Message Board Network

Sinister · 07-07-2002, 04:02 PM

just got my new wheels and tires on...
thought i could start in on some body work...
now my trannie (th350) is starting to slip in reverse...

found a remanufactured th350 at autozone for $399...
(they also have th400's for about the same...)
seen rebuilt ones advertised for around $300...
i'd like to rebuild this one...
(i'd actually like to get a 700r4 but i'm broke)...

anybody rebuild these trannies before?
any tips?

Sinister · 07-07-2002, 04:07 PM

i almost forgot...
here's a couple cool links for the 700r4...
http://www.highperformancecars.com/crosley/700id.htm
http://purplesagetradingpost.com/sum.../techinfo.html
i'd really like to get one of these...

Sinister · 07-08-2002, 02:27 AM

ttt

68 Suburban · 07-08-2002, 03:34 AM

I got my Turbo 400 r and r for $325.

speeddemon · 07-08-2002, 08:38 AM

I have built a couple th350 trans. If you can build a engine you can build a trans. I had about $125.00 in my last rebuild with a shift kit. let me know if you need some help.

Sinister · 07-08-2002, 01:01 PM

thanks y'all...
i think i'm gonna give it a shot...
i'll wait on th700r4 til the next motor...

Sinister · 07-08-2002, 01:04 PM

hey speeddemon any tips?
tools, tricks etc.?

i'm gonna go out and get the book...

speeddemon · 07-08-2002, 02:36 PM

Becareful when istalling the lip seals on the clutch pistons. You can buy some trans grease that will help them go in alot smoother and use a feeler gauge to help guide them around. I made a tool for releasing the pressure of the clutch drums out of an old main bearing cap and some threadrod. The bigest thing is just take your time. After you are finished you will never want to look at snap rings agin. There are a lot of them lurking in there. Good Luck!

bouncytruck · 07-08-2002, 07:08 PM

I just completed a TH350 rebuild and I don’t think I’d do it again. It really wasn’t that hard but I don’t think I really save and $. Once I started into the tranny, the problem was obvious. The reverse sprag clutch exploded and sent metal fragments and bearings everywhere. The bearing chunks got wedged between the inner race and the reverse clutch support. This cracked the clutch support and marred the race. I had some problems locating replacement parts but after quite a bit of searching, I found them used for $35.After getting it all torn down, I took the case to be hot tanked. The guy at the tranny shop inspected the case and found a hairline crack. It appears that the cracked clutch support put pressure on the case, causing it to crack. Set out to find a new case and found one for $125. Had it hot tanked for $20 and it needed the hole for the governor honed and a sleeve added for $110. With all the metal fragments inside the case, I was advised to get a new torque converter, so I picked up a stock one for $80 and began the reassembly. The rebuild kit cost $125 and the shift kit was $20. It took a long time to rebuild it with several tear-down and reassembly of the clutch sets to get the tolerances right. Finally go the thing in the truck, mated up the t-case and the @#$% thing wouldn’t shift into second. On top of that, I had a bad leak between the transfer case and the adapter. I drained the tranny and, at the advice of several board members, pulled the governor and checked the vacuum. While the tranny was empty, I pulled the t-case and fixed the seal. Finally, after several months, I got it working right!

All parts totaled, the rebuild cost me about $515. I was quoted $550 for a rebuilt tranny with a one year warranty. My advice to you is, don’t open the rebuild kit until you have the transmission completely disassembled, all the parts inspected and are sure that it you can get it back together right.

Oh yeah, I made my own spring compression tool too. I used a couple of blocks of wood, a threaded rod, washers and nuts. I cut a notch in the middle of one block and drilled holes down the middle of both. I just tightened the nuts to compress the spring.

You can see some of the photos from my rebuild at http://info.imageink.com/chris/tranny.htm

Sinister · 07-08-2002, 08:25 PM

hey 68 Suburban, where did you get your 400 at?
i'm in a bit of a quandry...
i just went out and backed all the way up the hill...
swear it didn't want to do that the other morning...
maybe the fluid was to cold...
running synthetic, might be to slippery for a worn tranny...
i'd definitely rather spend this money on other things like an hei, body, paint etc..
but i don't feel like being out in bum f#ck egypt
and have the thing poop out...

so i think i'm gonna rebuild/replace it...

07-07-2002, 04:02 PM	#1
Sinister Between Trucks... Join Date: Mar 2002 Location: Los Angeles, CA. Posts: 3,830	TH350 rebuild/trannie hell... just got my new wheels and tires on... thought i could start in on some body work... now my trannie (th350) is starting to slip in reverse... found a remanufactured th350 at autozone for $399... (they also have th400's for about the same...) seen rebuilt ones advertised for around $300... i'd like to rebuild this one... (i'd actually like to get a 700r4 but i'm broke)... anybody rebuild these trannies before? any tips? __________________ Beat it to fit, Paint it to match...

07-07-2002, 04:07 PM	#2
Sinister Between Trucks... Join Date: Mar 2002 Location: Los Angeles, CA. Posts: 3,830	i almost forgot... here's a couple cool links for the 700r4... http://www.highperformancecars.com/crosley/700id.htm http://purplesagetradingpost.com/sum.../techinfo.html i'd really like to get one of these... __________________ Beat it to fit, Paint it to match...

07-08-2002, 02:27 AM	#3
Sinister Between Trucks... Join Date: Mar 2002 Location: Los Angeles, CA. Posts: 3,830	ttt __________________ Beat it to fit, Paint it to match...

07-08-2002, 03:34 AM	#4
68 Suburban Registered User Join Date: Oct 2000 Location: From Chicago, Live in Phoenix, AZ Posts: 6,802	I got my Turbo 400 r and r for $325. __________________ Just sitting here contemplating contemplation.

07-08-2002, 08:38 AM	#5
speeddemon Registered User Join Date: May 2002 Location: lexington,South Carolina Posts: 158	I have built a couple th350 trans. If you can build a engine you can build a trans. I had about $125.00 in my last rebuild with a shift kit. let me know if you need some help. __________________ 69-C10 LWB 71- fleetside shortbed It's a shame stupidity isn't painful Never play leapfrog with a unicorn

07-08-2002, 01:01 PM	#6
Sinister Between Trucks... Join Date: Mar 2002 Location: Los Angeles, CA. Posts: 3,830	thanks y'all... i think i'm gonna give it a shot... i'll wait on th700r4 til the next motor... __________________ Beat it to fit, Paint it to match...

07-08-2002, 01:04 PM	#7
Sinister Between Trucks... Join Date: Mar 2002 Location: Los Angeles, CA. Posts: 3,830	hey speeddemon any tips? tools, tricks etc.? i'm gonna go out and get the book... __________________ Beat it to fit, Paint it to match...

07-08-2002, 02:36 PM	#8
speeddemon Registered User Join Date: May 2002 Location: lexington,South Carolina Posts: 158	Becareful when istalling the lip seals on the clutch pistons. You can buy some trans grease that will help them go in alot smoother and use a feeler gauge to help guide them around. I made a tool for releasing the pressure of the clutch drums out of an old main bearing cap and some threadrod. The bigest thing is just take your time. After you are finished you will never want to look at snap rings agin. There are a lot of them lurking in there. Good Luck! __________________ 69-C10 LWB 71- fleetside shortbed It's a shame stupidity isn't painful Never play leapfrog with a unicorn

07-08-2002, 07:08 PM	#9
bouncytruck SKINNY TIRES RULE! Join Date: Sep 2001 Location: Bothell, WA Posts: 11,038	I'll second the tranny rebuild from He##! I just completed a TH350 rebuild and I don’t think I’d do it again. It really wasn’t that hard but I don’t think I really save and $. Once I started into the tranny, the problem was obvious. The reverse sprag clutch exploded and sent metal fragments and bearings everywhere. The bearing chunks got wedged between the inner race and the reverse clutch support. This cracked the clutch support and marred the race. I had some problems locating replacement parts but after quite a bit of searching, I found them used for $35.After getting it all torn down, I took the case to be hot tanked. The guy at the tranny shop inspected the case and found a hairline crack. It appears that the cracked clutch support put pressure on the case, causing it to crack. Set out to find a new case and found one for $125. Had it hot tanked for $20 and it needed the hole for the governor honed and a sleeve added for $110. With all the metal fragments inside the case, I was advised to get a new torque converter, so I picked up a stock one for $80 and began the reassembly. The rebuild kit cost $125 and the shift kit was $20. It took a long time to rebuild it with several tear-down and reassembly of the clutch sets to get the tolerances right. Finally go the thing in the truck, mated up the t-case and the @#$% thing wouldn’t shift into second. On top of that, I had a bad leak between the transfer case and the adapter. I drained the tranny and, at the advice of several board members, pulled the governor and checked the vacuum. While the tranny was empty, I pulled the t-case and fixed the seal. Finally, after several months, I got it working right! All parts totaled, the rebuild cost me about $515. I was quoted $550 for a rebuilt tranny with a one year warranty. My advice to you is, don’t open the rebuild kit until you have the transmission completely disassembled, all the parts inspected and are sure that it you can get it back together right. Oh yeah, I made my own spring compression tool too. I used a couple of blocks of wood, a threaded rod, washers and nuts. I cut a notch in the middle of one block and drilled holes down the middle of both. I just tightened the nuts to compress the spring. You can see some of the photos from my rebuild at http://info.imageink.com/chris/tranny.htm __________________ bouncytruck 1972 K5 The Hauler 1994 K1500 Suburban The Daily2010 Kia Soul Wife's Ride2014 Fiat 500L

07-08-2002, 08:25 PM	#10
Sinister Between Trucks... Join Date: Mar 2002 Location: Los Angeles, CA. Posts: 3,830	hey 68 Suburban, where did you get your 400 at? i'm in a bit of a quandry... i just went out and backed all the way up the hill... swear it didn't want to do that the other morning... maybe the fluid was to cold... running synthetic, might be to slippery for a worn tranny... i'd definitely rather spend this money on other things like an hei, body, paint etc.. but i don't feel like being out in bum f#ck egypt and have the thing poop out... so i think i'm gonna rebuild/replace it... __________________ Beat it to fit, Paint it to match...



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