TH400 question.

[82355]

My 1989 V1500 Suburban has a previous owner installed TH400/NP241 in place of the factory TH700R4/NP241. When you shift it into manual 1st, it drags. Feels like the brakes are locked up, you can power through it, but it fells funny. Is it that normalish?

I could have bought another 1989 Suburban with a blown engine for $700 with a fresh TH700R4. I kind of regret not doing it and getting rid of this stupid TH400.

Martin

 

[COCHEV]

That doesn't sound normal to me. Th400s do have a much taller 1st than the 700,but I think you have something else going on...

And th400 aren't so bad, man. In fact they can take a ton of abuse. At least that's been my experience.

 

[TheBeast_88K5]

Some Things that make TH400's drive like a rock, in Low gear are:

- band applying at incorrect time.
- band off-centered.
- reaction carrier failure. (Off center, drags the shaft).
- improper fluid application to Forward clutch pack. (Burn, baby, burn!!!)

I'd say #1 is pull the dipstick, and wipe the trans fluid on a clean paper towel.
If its burnt smelling (you'll know), AND a semi-opaque reddish color, Its the lack of fluid to the clutches.

 

[diesel4me]

It does it only in manual low?...sounds like it could be a valve body problem,maybe a pressure leak from the manual low circuit to another gear like reverse or other forward gear makes it try engauging both at once or something..I'm no expert on automatic trannys by any means though..just a guess..

 

[dyeager535]

Can any of that be caused by the selector lever being "between" gears?

Since this was a 700 truck, if the column wasn't replaced, that is likely, no?

 

[82355]

Can any of that be caused by the selector lever being "between" gears?

Since this was a 700 truck, if the column wasn't replaced, that is likely, no?

The selector is in the transmission.

Martin