Trans not staying in overdrive

[lanceb12013]

Auto trans will sometimes go into overdrive, but not for long. Goes back to third gear and revs climb, its a bit of a bugger on country trips as it chews a bit more fuel. Rather than take it to a mechanic, i'd rather have a go at it myself if it can be solved. Any ideas would be appreciated. Cheers

 

[BlackVXGTS]

The trans won't stay in overdrive if the engine is under too much load and can't maintain the car's speed, it will change back into third gear. For example, this can happen when you are going up a steep hill. If your engine is not well maintained or in bad/worn condition, the change back to third gear could happen at even lower grades of hill.

 

[dirty hands]

is it for a VT /VX or the ride VP/VR

sounds correct for the auto tranny to do that
if it was happening on flat highway then there is a problem
on flat highway speed overdrive kicks in about 80 km

 

[lanceb12013]

Its a VT, its simply not changing into overdrive when it should, ( flat ground , steady speed, over 80ks etc etc.) Not under any particular load other than normal everyday driving. Own four commodores, vp,vr,vs,vt and understand how they should drive. Vt is the only one with this problem. On flat road at steady speeds over 80 ks, it sometimes goes into overdrive then for NO apparrent reason, goes back to third gear and will NOT go back to overdrive,. Cheers

 

[st3r3otyp3]

Check Fluid level trans has to be warm on flat ground and engine running and in P, Fluid colour, pink/red=clean, brown/black= dirty/burnt and it will smell burnt too, if this is the case I`d recommend a MAJOR trans fluid flush inc torque converter. When was the last minor trans service?

 

[dirty hands]

if no trans error codes are present

needs the pan off and check

could be a mechanical fault
the over drive band or worn drive drum it wraps onto and behind the oil pump

 

[lanceb12013]

Thanks for the ideas and advice guys, might end up takin it to an auto trans mob and be done with it if I cant sort it out. Cheers

 

[st3r3otyp3]

Good job Guy`s you scared him off with your bands and drums, I was trying to keep it dead simple, straight out just check the quality of the fluid, number 1 killer of trans is HEAT number 2 is abuse/poor servicing.

 

[Jxfwsf]

Check for fault codes with the old paper clip method (free) will only work on v6 or 5.0L v8 and not gen III.

If none show up, put a new TPS on ($20-$30 on ebay)

 

[Pollushon]

The 4L60E has a single brake band and drum, if that was causing OD issues it'd likely be causing more noticeable issues with 2nd too.

I'd agree with keeping it simple, check for fault codes and your fluid condition first.