Transmission downshift problem and thump

[Juice3]

My holden vx series 2 has an intermittent problem with downshifting sometimes when I speed off from a stop it speeds up gradually like its starting off in 3rd gear other times it speeds off like a rocket same thing when going up hills. A new thing it did today when I tried to speed off from a stop is that it didnt speed off at all i went to speed through the roundabout and got two harsh thumps. This transmission has been serviced regularly and recently replaced tps sensor,shift solenoids but didn't make any difference.

 

[ant797]

might have something to do with torque clutch lock up solenoid

 

[Immortality]

Maybe the trans is just worn out?

Been a lot of new but faulty tps problems of late too.

 

[ant797]

Maybe the trans is just worn out?

Been a lot of new but faulty tps problems of late too.

im replacing my new tps see if it solves my prob i got it for 17 bucks a year ago for another vy i got when the online auto stores wee selling cheap ebay stuff they are selling name brands now

 

[Trevor loves holden.]

Might be the valve body, you can get a upgrade kit with a better spring, best to have a transmission place have a look.

 

[Utel67]

Sounds like a electrical problem, check wiring harness to transmission or faulty PCM.

 

[BlackVXGTS]

Has the check engine light come on at all? Have you displayed your error codes? Sounds like you trans might be going into "limp home mode".

 

[Juice3]

Has the check engine light come on at all? Have you displayed your error codes? Sounds like you trans might be going into "limp home mode".

Check engine light not on and checked for codes with tunerpro and got none the only faults I got is quad drive 1 and 2 but this is normal from what i've read.

 

[Juice3]

Maybe the trans is just worn out?

Been a lot of new but faulty tps problems of late too.

I replaced the tps twice this time it's got a delphi sensor other one I bought from supercheap online. If trans was worn out tho why would it shift beautifully one day and then the next day not downshift when its supposed to? also this trans has only 200,000km on it and I have serviced it regularly since I got the car when it had only 47,000km on it and dont abuse it either.

 

[Immortality]

This is a question I've pondered often. I'm suspecting it could be a seal issue as there are a number of rubber seals in the various parts and seals go hard with age and effected by heat which might effect how the transmission performs day to day.