THD 400 shift points/mph
Safety Car
Joined: Aug 2000
Posts: 3,711
Likes: 43
From: San Antonio TX
You can't find anything because there are a mountain of variables. It depends on the gear ratio in the rear for one, how heavy you are on the throttle for another. It also depends on the engine and the car it's in. If you think your 400 is shifing too high or low, it may be a leaky vacuum modulator, though that only accounts for a few mph, a non-functional kickdown, sticking governor, or maybe it's just working the way the factory designed it to.
Race Director
Joined: Apr 1999
Posts: 10,866
Likes: 717
From: Beverly Hills/Pine Ridge Florida
There are many different THM 400's, used with different engine applications.
Look at the tag riveted on the passenger's side of the trans. It'll have some numbers, but more importantly, a code like CJ, CY, etc.
Get that code. Then you can find where the trans is set "internally" to shift.
A THM 400 used with a hydraulic lifter BB has different shift points than a THM 400 used with a solid lifter BB. Same holds for SB's. Chuck
Look at the tag riveted on the passenger's side of the trans. It'll have some numbers, but more importantly, a code like CJ, CY, etc.
Get that code. Then you can find where the trans is set "internally" to shift.
A THM 400 used with a hydraulic lifter BB has different shift points than a THM 400 used with a solid lifter BB. Same holds for SB's. Chuck
