Any Autobox Specialist In The House?

[KevShek]

Ive a problem with a Toyota autobox whereby its changing up thru the gear too soon. The only way i can explain it is that its shifting up at around 4.5K rpm instead of revving upto 6K rpm at WOT. Also, it wont kick down from 4th to 3rd gear if i plant my foot down. This basically make the car slower during acceleration as it doesnt stay in gear long enough to benifit from higher rpm or the VVTi for that matter!

Ive check the fluids, will be changing it soon cos ive simply run out of ideas. Ive been told to change the MAF as the shift points can be load related, still no good. Ive checked the TPS, its within tolerances. What else can cause the shift points to change?

[norkep]

Not a G/B expert by no means but by past experiences , have found some gear change errors to be down to a solinod inside the G/B, upon having having mine rebuild a few times, the wiring inside has caused a shortage giving irratic gear change.

With mine, during change from First to Second, there was a second of no power and then changed, also kick down was irratic, would not always change down and when did, was unexpected as not always during a heavy flooring of the acc. pedal, sometimes lite acc.

Also had the friction pads in the G/B changed as this can also cause problems during modded motors when heavy acc and kick down.

Maybe not be a cause, but gives you another possible cause.

[KevShek]

Thanks mate, will look into those options.