Automatic Transmission 2-Speed thru 10-Speed GM Autos | Converters | Shift Kits
Sponsored by:
Sponsored by:

th350 / th400

Old Apr 28, 2019 | 06:53 AM
  #1  
freeky's Avatar
Thread Starter
TECH Apprentice
5 Year Member
Liked
Loved
Community Favorite
 
Joined: Jul 2017
Posts: 312
Likes: 14
From: Stephens city VA
Default th350 / th400

whats everybody using for kickdown linkage ? ive got a lm7 5.3 truck manifold cable im gonna use either a th350 or th400 .
Reply
Old Apr 28, 2019 | 12:09 PM
  #2  
vorteciroc's Avatar
TECH Junkie
15 Year Member
Shutterbug
Loved
Community Favorite
 
Joined: Jun 2008
Posts: 3,194
Likes: 1,377
From: Nitro Alley
Default

Just in case you did not know; the THM400 transmissions do not use any linkage or cable for high-speed down-shifts.

A vehicle originally equipped with the THM400 transmission will have an electric switch on the accelerator pedal to close a circuit going into the transmission and operate a down-shift solenoid on the valve-body.

When swapping the THM400 into a vehicle; a micro-switch on the throttle-body or carburetor throttle-plate will serve the same purpose, instead of an electrical switch on the accelerator pedal. You can use the micro-switch that is commonly sold for nitrous-oxide use.

Now for the THM350, make sure to purchase a down-shift/ kick-down cable.

You do NOT have to purchase a throttle-valve cable, as for the THM700-R4/ THM200-4R transmissions.
Reply
Old Apr 28, 2019 | 05:20 PM
  #3  
freeky's Avatar
Thread Starter
TECH Apprentice
5 Year Member
Liked
Loved
Community Favorite
 
Joined: Jul 2017
Posts: 312
Likes: 14
From: Stephens city VA
Default

Originally Posted by vorteciroc
just in case you did not know; the thm400 transmissions do not use any linkage or cable for high-speed down-shifts.

A vehicle originally equipped with the thm400 transmission will have an electric switch on the accelerator pedal to close a circuit going into the transmission and operate a down-shift solenoid on the valve-body.

When swapping the thm400 into a vehicle; a micro-switch on the throttle-body or carburetor throttle-plate will serve the same purpose, instead of an electrical switch on the accelerator pedal. You can use the micro-switch that is commonly sold for nitrous-oxide use.

Now for the thm350, make sure to purchase a down-shift/ kick-down cable.

You do not have to purchase a throttle-valve cable, as for the thm700-r4/ thm200-4r transmissions.
thanks i didnt know that about the th400 . Im prolly going with the th350 to start with because i can get one cheap . Is there a bracket for the lm7 throttle body ? If so do you have a link ?
Reply
Old Apr 29, 2019 | 06:59 AM
  #4  
MaroonMonsterLS1's Avatar
TECH Junkie
10 Year Member
Liked
Loved
Community Favorite
 
Joined: Dec 2012
Posts: 3,605
Likes: 1,316
From: Iowa
Default

Just block the low-control valve inboard on the th350 and then you can manually downshift any time you want/need

The kickdown cable in a th350 is not needed (unlike the 700r4 where it's a necessity)
Reply
Old Apr 29, 2019 | 08:41 AM
  #5  
64post's Avatar
TECH Fanatic
Photogenic
Liked
Loved
Community Favorite
iTrader: (5)
 
Joined: Nov 2011
Posts: 1,710
Likes: 228
From: Sonoma Co. Ca.
Default

This^^^^^ Don’t forget to remove the kick down rod/pin and plug the hole. ICT Billet makes a real nice o-ringed plug for that hole. You can pull the pin up and cut it off with with good wire cutters vs removing the pan.
Reply


Thread Tools
Search this Thread

All times are GMT -5. The time now is 11:59 AM.