Th350
Thread Starter
7th Gear
Joined: Jun 2009
Posts: 7
Likes: 0
From: Älmhult
Th350
HI
I have tried to Rebild my TH350 but must have done something wrong.
I bough the book from ATSG GM THM 350C
I have used a rebuld kit TCI-328800 into a TH350 from -76.
I thought everything went ok and managed to replace all clutches, bands seals and so on.
But when I now done a test run the 1st gear doesnt work. When I put the shifter in nr 1 gear , nothing happends, it as neutral. When I put it in Drive it starts on the second gear and smoothly up to third gear and the reverse is also working ok.
There is no noise that should not be there.
One strange thing. I got 1pcs clutch drive plate (faced) and 1 pcs Clutch drive plate (steel) left over. I counted the qty of the old and put in the same nrs and then this was left over, is that correct ?
Hope someone could help with an idea and maybe mounted the same kit as me.
BR
Kenneth Lindkvist
I have tried to Rebild my TH350 but must have done something wrong.
I bough the book from ATSG GM THM 350C
I have used a rebuld kit TCI-328800 into a TH350 from -76.
I thought everything went ok and managed to replace all clutches, bands seals and so on.
But when I now done a test run the 1st gear doesnt work. When I put the shifter in nr 1 gear , nothing happends, it as neutral. When I put it in Drive it starts on the second gear and smoothly up to third gear and the reverse is also working ok.
There is no noise that should not be there.
One strange thing. I got 1pcs clutch drive plate (faced) and 1 pcs Clutch drive plate (steel) left over. I counted the qty of the old and put in the same nrs and then this was left over, is that correct ?
Hope someone could help with an idea and maybe mounted the same kit as me.
BR
Kenneth Lindkvist
Burning Brakes
Joined: May 2009
Posts: 1,232
Likes: 6
From: Tucson AZ
St. Jude Donor '12
I'm not tranny guy, but based on what you've said, I'd check first that the shifter linkage isn't binding and is properly adjusted.
Good onya for building your own tranny though!
Good onya for building your own tranny though!
Burning Brakes
Joined: Jul 2008
Posts: 876
Likes: 0
From: Canastota Ny
it realy sounds like the detent cable is off from the indicator. so when its in drive its second and so on.
good job building your own trans! big props for trying that! on overhaulin there was a kid who built transmissions blindfolded!!!
good job building your own trans! big props for trying that! on overhaulin there was a kid who built transmissions blindfolded!!!
Thread Starter
7th Gear
Joined: Jun 2009
Posts: 7
Likes: 0
From: Älmhult
I could have found the problem now. It seems like the vacum modulator valve is stuck in the bottom. The problem is that I dont know what I need to dismount to release this. I took away the Itermediate clutch but that was not the way to reach it as I could see. Will I reach it if I take away the body valve ?
Pro
Joined: Aug 2005
Posts: 613
Likes: 2
From: West Central Florida
I could have found the problem now. It seems like the vacum modulator valve is stuck in the bottom. The problem is that I dont know what I need to dismount to release this. I took away the Itermediate clutch but that was not the way to reach it as I could see. Will I reach it if I take away the body valve ?
Thread Starter
7th Gear
Joined: Jun 2009
Posts: 7
Likes: 0
From: Älmhult
It was the vacum modulator in the tranny that I thought was stuck but it was rather easy to take it out with a plier. But should it be a spring there ?? On mine it wasnt, and I cant find that it shows any in the book either. My guess is that this piston is regulated by oilpressure and not by a spring. I dont know what to do now if I should put it together and hope that is was some small trash at the piston that I couldnt see and make a new test run. Maybe it isnt enough oil pressure at this piston?
There is three different location to check oil pressure and one of them is where the vacum modulator valve in the tranny is fitted. How high should the oil pressure be there ?? Is it 62 psi at Idle speed ?
There is three different location to check oil pressure and one of them is where the vacum modulator valve in the tranny is fitted. How high should the oil pressure be there ?? Is it 62 psi at Idle speed ?
Last edited by Red Corvette -76; Jun 14, 2009 at 05:05 AM.
Melting Slicks
Joined: Jan 2003
Posts: 2,877
Likes: 13
From: Doha
St. Jude Donor '08
Did you make sure of the final clearance between the last plate and the cover plate?
Corvette Stories
The Best of Corvette for Corvette Enthusiasts
8 Coolest Corvette Pace Cars (and Replicas) of All Time
Verdad Gallardo
Top 10 Corvette Engines RANKED by Peak Torque (70+ Years of Muscle!)
Joe Kucinski
Corvette ZR1X Will Be Pacing the Indy 500, And Could Probably Race, Too!
Verdad Gallardo
Top 10 Corvettes Coming to Mecum Indy 2026!
Brett Foote
Top 10 C9 Corvette MUST-HAVES to Fix These C8 Generation Flaws!
Michael S. Palmer
10 Revolutionary 'Corvette Firsts' Most People Don't Know
Joe Kucinski
5 Reasons to Upgrade to an LS6-Powered Corvette; 5 Reasons to Stay LT2
Michael S. Palmer
2027 Corvette vs The World: Every C8 vs Its Closest Competitor
Joe Kucinski
10 Most Common Corvette Problems of the Last 20 Years!
Joe Kucinski
Pro
Joined: Aug 2005
Posts: 613
Likes: 2
From: West Central Florida
It was the vacum modulator in the tranny that I thought was stuck but it was rather easy to take it out with a plier. But should it be a spring there ?? On mine it wasnt, and I cant find that it shows any in the book either. My guess is that this piston is regulated by oilpressure and not by a spring. I dont know what to do now if I should put it together and hope that is was some small trash at the piston that I couldnt see and make a new test run. Maybe it isnt enough oil pressure at this piston?
There is three different location to check oil pressure and one of them is where the vacum modulator valve in the tranny is fitted. How high should the oil pressure be there ?? Is it 62 psi at Idle speed ?
There is three different location to check oil pressure and one of them is where the vacum modulator valve in the tranny is fitted. How high should the oil pressure be there ?? Is it 62 psi at Idle speed ?
Last edited by VETTEVIC; Jun 14, 2009 at 11:39 AM.
Thread Starter
7th Gear
Joined: Jun 2009
Posts: 7
Likes: 0
From: Älmhult
VETTEVIC, I found one gold spring that I didnt know where it should fit , its .43 " diam and .55" long , could it be it ?
Please feel free to send TCI insruktion, the one I got with the kit was not good at all. Only showed some of the rebuilding.
Mail: lindqvist.kenneth@telia.com
Please feel free to send TCI insruktion, the one I got with the kit was not good at all. Only showed some of the rebuilding.
Mail: lindqvist.kenneth@telia.com
Thread Starter
7th Gear
Joined: Jun 2009
Posts: 7
Likes: 0
From: Älmhult
I just want to say that the problem seems to be solved. It was a golden spring at the vacuum modulator piston inside the tranny that was missing. I didn’t have any spring there as original and ref TCI manual was this golden only if you wanted to have earlier shifting points.
But VETTEVIC suggested me to put this in anyway, I did so and then the thirst gear worked !! I have still some small adjustments to do because the kick down function is slow, I need to have the pedal in the floor longer than I want before it kick down. Also it seems to not kick down by the vacuum when I not full throttle but that could be that I have low vacuum since the cam is for rather high rpm. I must empty some oil also because it was little to high when it was hot , then can it be foam in oil and that’s not good. Thanks VETTEVIC and everybody else who have come up with ideas.
But VETTEVIC suggested me to put this in anyway, I did so and then the thirst gear worked !! I have still some small adjustments to do because the kick down function is slow, I need to have the pedal in the floor longer than I want before it kick down. Also it seems to not kick down by the vacuum when I not full throttle but that could be that I have low vacuum since the cam is for rather high rpm. I must empty some oil also because it was little to high when it was hot , then can it be foam in oil and that’s not good. Thanks VETTEVIC and everybody else who have come up with ideas.
