Th400 kickdown switch

Disclaimer: Links on this page pointing to Amazon, eBay and other sites may include affiliate code. If you click them and make a purchase, we may earn a small commission.

Hamgrease

Hamgrease

Junior Member
Joined
Jan 17, 2020
Posts
22
Reaction score
44
Location
Tennessee
First Name
Jonathan
Truck Year
87,85
Truck Model
C10
Engine Size
350,454
Hey everyone, I have a 85 C10 that was originally a 6.2 diesel/700r4 truck. It now has a 454/400. I’ve installed the kickdown switch solenoid on the petal bracket and made my own harness, it works I’ve tested it. My question is are the accelerator petals different for the TH400 from other transmissions ? My petal doesn’t reach far enough to engage the switch. I’m considering fabricating and welding an adapter rod to it for engagement of the switch.
 
Rickf

Rickf

Full Access Member
Joined
Jul 29, 2017
Posts
574
Reaction score
717
Location
Grafton NH
First Name
Rick
Truck Year
1974, 1954 & a 1937
Truck Model
K20
Engine Size
350
Flower power.
 
DoubleDingo

DoubleDingo

Full Access Member
Joined
Jul 3, 2012
Posts
11,325
Reaction score
17,372
Location
Right where I am
First Name
Bagoomba
Truck Year
1981
Truck Model
81-C20 Silverado Camper Special-TH400-4.10s
Engine Size
Carb'ed Vortec 350
So what you're saying, the switch works fine, just that pedal, when mashed down to the floor, doesn't trigger the switch? Those are designed to kick down at full throttle and under 55. Well, mine won't kick down over 55.
 
slammed84

slammed84

Member
Joined
Oct 16, 2024
Posts
30
Reaction score
65
Location
Oklahoma
First Name
Nick
Truck Year
1984
Truck Model
C10
Engine Size
350
Hamgrease said:
Hey everyone, I have a 85 C10 that was originally a 6.2 diesel/700r4 truck. It now has a 454/400. I’ve installed the kickdown switch solenoid on the petal bracket and made my own harness, it works I’ve tested it. My question is are the accelerator petals different for the TH400 from other transmissions ? My petal doesn’t reach far enough to engage the switch. I’m considering fabricating and welding an adapter rod to it for engagement of the switch.
Click to expand...
I believe that factory TH400 cars and trucks did have an specific bracket that had provisions for the kickdown switch. I've looked into this because I also need to install the switch, but it's been awhile since I Googled it. You could try to research it, I'm fairly sure this was the case.

But I'm with you, I would just fab up a bracket that mounts it in the correct position you need, would probably be easier and cheaper than finding the correct pedal/bracket and whatever it takes to mount it correctly in a squarebody.
 
Hamgrease

Hamgrease

Junior Member
Joined
Jan 17, 2020
Posts
22
Reaction score
44
Location
Tennessee
First Name
Jonathan
Truck Year
87,85
Truck Model
C10
Engine Size
350,454
Hamgrease

Hamgrease

Junior Member
Joined
Jan 17, 2020
Posts
22
Reaction score
44
Location
Tennessee
First Name
Jonathan
Truck Year
87,85
Truck Model
C10
Engine Size
350,454
It’s way off
 
Hamgrease

Hamgrease

Junior Member
Joined
Jan 17, 2020
Posts
22
Reaction score
44
Location
Tennessee
First Name
Jonathan
Truck Year
87,85
Truck Model
C10
Engine Size
350,454

Attachments

  • IMG_4969.jpeg
    IMG_4969.jpeg
    98.4 KB · Views: 21
Hamgrease

Hamgrease

Junior Member
Joined
Jan 17, 2020
Posts
22
Reaction score
44
Location
Tennessee
First Name
Jonathan
Truck Year
87,85
Truck Model
C10
Engine Size
350,454
Picture was before I reattached the throttle cable
 
Hamgrease

Hamgrease

Junior Member
Joined
Jan 17, 2020
Posts
22
Reaction score
44
Location
Tennessee
First Name
Jonathan
Truck Year
87,85
Truck Model
C10
Engine Size
350,454
slammed84 said:
I believe that factory TH400 cars and trucks did have an specific bracket that had provisions for the kickdown switch. I've looked into this because I also need to install the switch, but it's been awhile since I Googled it. You could try to research it, I'm fairly sure this was the case.

But I'm with you, I would just fab up a bracket that mounts it in the correct position you need, would probably be easier and cheaper than finding the correct pedal/bracket and whatever it takes to mount it correctly in a squarebody.
Click to expand...
The bracket for the switch was actually already on the truck I just had to find a bolt to install it I had one
 
DoubleDingo

DoubleDingo

Full Access Member
Joined
Jul 3, 2012
Posts
11,325
Reaction score
17,372
Location
Right where I am
First Name
Bagoomba
Truck Year
1981
Truck Model
81-C20 Silverado Camper Special-TH400-4.10s
Engine Size
Carb'ed Vortec 350
Hamgrease said:
I fixed it today it works perfectly
Click to expand...
Glad you got it fixed and working properly. Having that kickdown with the secondaries roaring sure does get the ticker to tick faster...lol...
 
You must log in or register to reply here.

Similar threads

NickTransmissions
  • Sticky
TH400 Information Thread
5 6 7
Replies
94
Views
13K
NickTransmissions
NickTransmissions
R
Looking for 1960s/70s TH400 Rear slip Flange, used with those old CV double cardan ujoint drive shafts.
Replies
0
Views
241
racprops
R
GoingCustom
Hello from NM
Replies
10
Views
511
Long Rider
Long Rider
M
Th350 or th400? Help please
Replies
4
Views
697
nvrenuf
nvrenuf
Truck82
New to forum
Replies
8
Views
319
legopnuematic
legopnuematic

Latest posts

Forum statistics

Threads
44,420
Posts
957,290
Members
36,766
Latest member
briochey
Top