454ss tranny problems?

[motaa]

Well im new here since I decided to join because I just purchased a 1990 454 ss two weeks ago.. but I came across a problem this morning coming back from work so I wana see if I can get some input from people here.

As i was doing 90 on the highway I felt a sudden slip on the tranny and when I tried to accelerate I felt as it was in neutral. I came to a stop and then noticed my tranny did not wana get out of first gear... It accelerated but stays in first gear.. I was wondering if any one had know of a similar problem and what will be the problem here.. i wana prepare myself as to what i will need to do...

I belive it is a TH400 tranny.

Thanks

 

[kn1ght]

Well im new here since I decided to join because I just purchased a 1990 454 ss two weeks ago.. but I came across a problem this morning coming back from work so I wana see if I can get some input from people here.

As i was doing 90 on the highway I felt a sudden slip on the tranny and when I tried to accelerate I felt as it was in neutral. I came to a stop and then noticed my tranny did not wana get out of first gear... It accelerated but stays in first gear.. I was wondering if any one had know of a similar problem and what will be the problem here.. i wana prepare myself as to what i will need to do...

I belive it is a TH400 tranny.

Thanks

Have you checked the tv cable on the driver side by the tb? Maybe that snapped for some weird reason.

Rusty Shacklefurd has spoken via tapatalk.

 

[SAATR]

No TV cable on the TH400, just a kickdown linkage and a vacuum modulator. Sounds like she's toast, to me.

 

[kn1ght]

Thanks for the learnin', Travis. In this case, I would have to say the tranny has indeed... Died.

 

[outalne94z71]

No TV cable on the TH400, just a kickdown linkage and a vacuum modulator. Sounds like she's toast, to me.

no kickdown linkage, its a electric switch on the older ones on the go petal, the 88-90 trucks have the kickdown switch as part of the throttle position sensor wiring




will the trans shift if you do it manually?

 

[SAATR]

Meh, shows you what I know! Got the 350 and the 400 backwards...

 

[motaa]

no kickdown linkage, its a electric switch on the older ones on the go petal, the 88-90 trucks have the kickdown switch as part of the throttle position sensor wiring




will the trans shift if you do it manually?

No it wont go into second even if I try to do it manually.... I check the vacuum line and i dont see a leak.. Could it just be the modulator? or is it really gone?

 

[outalne94z71]

if it wont go manually then you have something hosed, even with the modulator disconnected it would shift manually but on a good note the th400 is really cheap to rebuild

 

[WFO4X4]

but the problem is.... it's STILL a tranny...... and i personaly don't like em..... even if they are cheap....

 

[rhino]

If it won't shift, snatch the govenor out. Most likely the plastic gear has stripped. Also, you can try unpluging the wire on the side for the kickdown. It is known to go bad and the transmission thinks it's supposed to be in passing gear at all times. If still no shift, let us know. Is reverse good?