tko 500 5 spd wont downshift ??
Thread Starter
Instructor
Joined: Jun 2016
Posts: 169
Likes: 39
From: Savannagh, Ga
tko 500 5 spd wont downshift ??
I have a new tko 500 5 spd in my 71 vette. and it will not down shift from 4th to 3rd. it will upshift in all gears fine and downshift in all gears except from 4th to 3rd and no grinding at all. the shifter just stops at 3rd like its locked out. if I go out of 4th and bump 2nd gear lightly it will go right in 3rd gear. I sent trans back to American power train where I bought it and the say nothing wrong with it. but it wont work right. I can drive car fine but I need this fixed I have a lot of money in this trans. tia
Burning Brakes
Joined: Sep 2017
Posts: 1,219
Likes: 365
From: Tolland CT
Everything that I have heard says that American Powertrain is a solid company that knows whats what. Assuming that they are correct and that nothing is wrong with the trans, you should be looking at your shifter. Are you using a complete kit from them or did you fabricate something?
Thread Starter
Instructor
Joined: Jun 2016
Posts: 169
Likes: 39
From: Savannagh, Ga
Everything that I have heard says that American Powertrain is a solid company that knows whats what. Assuming that they are correct and that nothing is wrong with the trans, you should be looking at your shifter. Are you using a complete kit from them or did you fabricate something?
Burning Brakes
Joined: Sep 2017
Posts: 1,219
Likes: 365
From: Tolland CT
Then you have no choice to go back to AP. If you purchased an entire kit from them, there is no reason why it should not downshift.
Best bet is to just hammer them until they replace/repair it.
Best bet is to just hammer them until they replace/repair it.
Melting Slicks
Joined: Jun 2011
Posts: 3,116
Likes: 598
I have a new tko 500 5 spd in my 71 vette. and it will not down shift from 4th to 3rd. it will upshift in all gears fine and downshift in all gears except from 4th to 3rd and no grinding at all. the shifter just stops at 3rd like its locked out. if I go out of 4th and bump 2nd gear lightly it will go right in 3rd gear. I sent trans back to American power train where I bought it and the say nothing wrong with it. but it wont work right. I can drive car fine but I need this fixed I have a lot of money in this trans. tia
Now you may what to check the transmission indexing to the bell housing and check the TOB Release clearance to make sure it can shift as smooth as possible. When they test the transmission at there shop I would guess its without a clutch and bell house / flywheel attached.
It is possible if the indexing to the bell housing is off enough it may add a load to the main input shaft causing a binding somewhere that happens to show up during 4-3 down shift.
Thread Starter
Instructor
Joined: Jun 2016
Posts: 169
Likes: 39
From: Savannagh, Ga
I know how you feel. I purchased a white lightning shifter from them for my T56 magnum that never stopped leaking. They sent me 3 boot shifters seals so I could experiment on how to fix the poor design of the shifter. (that was my choice) I live in Canada and after 1 shifter replacement I was not going back to AP.
Now you may what to check the transmission indexing to the bell housing and check the TOB Release clearance to make sure it can shift as smooth as possible. When they test the transmission at there shop I would guess its without a clutch and bell house / flywheel attached.
It is possible if the indexing to the bell housing is off enough it may add a load to the main input shaft causing a binding somewhere that happens to show up during 4-3 down shift.
Now you may what to check the transmission indexing to the bell housing and check the TOB Release clearance to make sure it can shift as smooth as possible. When they test the transmission at there shop I would guess its without a clutch and bell house / flywheel attached.
It is possible if the indexing to the bell housing is off enough it may add a load to the main input shaft causing a binding somewhere that happens to show up during 4-3 down shift.
Corvette Stories
The Best of Corvette for Corvette Enthusiasts
Top 10 Most Expensive Corvettes Ever Sold on Bring A Trailer
Brett Foote
10 Things Every Corvette Owner Needs (2026 Edition)
Michael S. Palmer
8 Most "Only Corvette Owners Understand" Quirks and Problems
Pouria Savadkouei
10 Reasons the C6 Z06 is Still A Performance Benchmark After 20 Years
Joe Kucinski
How Much Horsepower Every Corvette Engine "LOST" in 1972
Joe Kucinski
Top 10 DOs and DON'Ts for Protecting Your Convertible Top!
Michael S. Palmer
Top 10 Most Explosive Corvettes Ever Made: Power-to-Weight Ratio Ranked!
Joe Kucinski
150 hp to 1,250 hp: Every Corvette Generation Compared by the Specs That Matter
Joe Kucinski
8 Coolest Corvette Pace Cars (and Replicas) of All Time
Verdad Gallardo
Supporting Vendor
Joined: Apr 2014
Posts: 254
Likes: 23
From: Maryville TN
TREMEC customer service:
Customer Service (Open from 8:00 a.m. to 5:00 p.m. Eastern Time)
Toll Free: 1-800-401.9866
Email: customer.service@tremec.com
Jamison's is an installer for us as well so I would not expect there to be any issues regarding the bellhousing runout or other aspects of the installation. If bellhousing runout or clutch disengagement were out of spec, I would expect there to be issues with other gear positions as well. Difficulty getting into first gear from a stop is a good indicator of incomplete clutch disengagement.
Jeff
__________________
Jeff Kauffman
VP Sales and Marketing
Silver Sport Transmissions
2250 Stock Creek Blvd.
Rockford TN 37853
jeff.kauffman@shiftsst.com
Authorized TREMEC Elite Distributor
Jeff Kauffman
VP Sales and Marketing
Silver Sport Transmissions
2250 Stock Creek Blvd.
Rockford TN 37853
jeff.kauffman@shiftsst.com
Authorized TREMEC Elite Distributor
Thread Starter
Instructor
Joined: Jun 2016
Posts: 169
Likes: 39
From: Savannagh, Ga
^ This is about your only option. It wouldn't hurt to call TREMEC and talk to them to see if they can offer any insight regarding the shifting issue. They will not warranty anything since the trans has been modified; repair/replacement will be up to the selling dealer.
TREMEC customer service:
Customer Service (Open from 8:00 a.m. to 5:00 p.m. Eastern Time)
Toll Free: 1-800-401.9866
Email: customer.service@tremec.com
Jamison's is an installer for us as well so I would not expect there to be any issues regarding the bellhousing runout or other aspects of the installation. If bellhousing runout or clutch disengagement were out of spec, I would expect there to be issues with other gear positions as well. Difficulty getting into first gear from a stop is a good indicator of incomplete clutch disengagement.
Jeff
TREMEC customer service:
Customer Service (Open from 8:00 a.m. to 5:00 p.m. Eastern Time)
Toll Free: 1-800-401.9866
Email: customer.service@tremec.com
Jamison's is an installer for us as well so I would not expect there to be any issues regarding the bellhousing runout or other aspects of the installation. If bellhousing runout or clutch disengagement were out of spec, I would expect there to be issues with other gear positions as well. Difficulty getting into first gear from a stop is a good indicator of incomplete clutch disengagement.
Jeff
Supporting Vendor
Joined: Apr 2014
Posts: 254
Likes: 23
From: Maryville TN
yes I spoke with Darren at tremec yesterday.he has no idea whats up with this tranny. my friend says the 3rd gear synchro is sticking when I come out of 4th and unsticking when I go to 2nd and then back to 3rd ?? American power train has been no help with this situation at all. they should man up and give me another trans. when I first got this trans they shipped it with a hole milled in the tailshaft case gear oil coming out as fast as Jamison could pour it out. and they wont refund me any of the extra labor to pull it back out. and its there fault they sent it to me that way. if I cannot get this resolved I am gonna buy a trans from SST. don't no what else to do. I have almost 7000 dollars in this trans kit and all the extra labor involved. thanks jesse Patterson
Jeff Kauffman
Melting Slicks
Joined: Mar 2006
Posts: 3,456
Likes: 102
From: Piedmont Va
St. Jude Donor '11-'12-'13,'19-'20
I would Google for their GM and find his email addy. Send him an email and express your extremem displeasure, and give them 48-72hrs to either agree to replace the trans or take it back and issue a full refund. Failure to do so will result in legal action starting with a dipsute with the CC and ultimately legal/small claims pursuit of all out of pocket funds! Not to mention that you will post in detail your experiences with his company. If they refuse or ignore you, lawyer up! 
At some point they will cave! Good luck! 
At some point they will cave! Good luck!
Melting Slicks
Joined: Mar 2006
Posts: 3,456
Likes: 102
From: Piedmont Va
St. Jude Donor '11-'12-'13,'19-'20
FWIW I purchased my TKO kit from Hurst Drivelines and got outstanding CS and tech support from them. The first trans was shipped via ConWay who managed to smash the pallet, break the shipping bands and lose the boxes with the extra parts. The trans looked intact, but rather than risk anything Hurst shipped a complete new kit immediately via special handling on a different carrier, while Conway took their dear sweet time processing the claim. The tech support during the install was also outstanding. So if you get this resolved and still want a TKO, you might give them a try! Good luck with this mess! Vendors can really suck sometimes. 
Thread Starter
Instructor
Joined: Jun 2016
Posts: 169
Likes: 39
From: Savannagh, Ga
FWIW I purchased my TKO kit from Hurst Drivelines and got outstanding CS and tech support from them. The first trans was shipped via ConWay who managed to smash the pallet, break the shipping bands and lose the boxes with the extra parts. The trans looked intact, but rather than risk anything Hurst shipped a complete new kit immediately via special handling on a different carrier, while Conway took their dear sweet time processing the claim. The tech support during the install was also outstanding. So if you get this resolved and still want a TKO, you might give them a try! Good luck with this mess! Vendors can really suck sometimes.
Thread Starter
Instructor
Joined: Jun 2016
Posts: 169
Likes: 39
From: Savannagh, Ga
I ordered a new transmission from SST and my installer has received it. I will take the car over to them this Monday for them to install the trans. I will follow up on how it goes.
Burning Brakes
Joined: Sep 2017
Posts: 1,219
Likes: 365
From: Tolland CT
