Trans shifting issue

[crazyTJ]

This '04 Aveo is giving me grief, i recently replaced the coil packs due to en engine misfire, that fixed that, but the transmission has an issue with shifting out of first gear.

What it does, from a dead stop, it will take reving the engine up slightly before it sorta grabs into first gear and takes off, once it's going, all other gears work just fine, only from the complete stop is the problem happening.

question, are there some speed sensors on this thing similar to other import models that may have gone bad? or is it something alittle more major (which i really don't want to know)

The fluid was recently changed with no help there and there are approx. 130k miles on the engine/trans combo.

any info on this would be greatly appreciated.

Thanks

[Davescort97]

Welcome to AF!

When it's in reverse does the engine rev up before it grabs that gear, too? Normal time lag between the shift of the lever and feel of the shift engagement is .9-1.1 seconds on the Aisin Warner 80-40LE transmission. If it takes longer than this with engine rev-up you probably have insufficient line pressure. If it does it in both low and reverse this is the problem. If the problem is line pressure the fluid pump isn't creating enough pressure from the onset. This is the internal pump on the tranny not to be confused with the torque converter. Once the engine runs a little faster, the pump creates enough pressure to engage the low/reverse clutch pack and go. When you changed the fluid did you use type IV fluid, Mobil JWS 3309 or GM specified fluid part #88900925? Any other fluid is not reccomended. Usually when this happens the pump is weak or the filter is clogged. Did you change the filter or just drain the tranny with the plug?

[crazyTJ]

never really paid much attention to it going in reverse, i'll check that out later today or this week and get back with ya. thanks.

[crazyTJ]

reverse is fine, only the forward gear (1st) just acts like it's in neutral at idle, then you hit the gas and the motor revs just a bit, then grabs, similar to the feel of low fluid levels.

I personally did not change the fluid, father did, and he said there wasn't really a "filter" in there, more of a screen that just got cleaned.

I'm gonna tear into it more this week after another vehicle repair is completed and see exactly what the deal is.

[Davescort97]

The line pressure is good. You don't have to change the pump. I hope you can connect with someone else that can do you some good. I'm thinking the forward clutch is slipping, but I don't think that is the case if it doesn't do it all the time. Thanks for coming back and letting us know. Git R Fixed.

[BlazerLT]

Did you check to see if the fluid level is fine? Did he use the right fluid?

Sounds like there is a pressure drop or a lack of fluid somewhere.

[johnnyfidgets]

i would tack out the matt and see if it helps if so then look into changing the hose of you and your back to new.

[Davescort97]

Sounds like good advice for me.