Odd ATX questions....

[SolidState]

The transsmission in my 94 ATX has been acting up for a while. The description of my problem could get long, so I will list them.

1) I don't seem to have 4th gear. Unless there is absolutely NO throttle, then it shifts into 4th until the slightest amount of throttle is applied.

2) Shifts hard. All shifts are hard and lurchy, but they aren't slipping. First to second, second to third. When letting off the throttle and allowing it to go down into forth, it is smooth, but slow.

3) Shifts hard into gear when coming out of neutral or park. I really jolts the vehicle.

Now this is where is gets interesting. If I reset the car by unplugging the battery and draining the EEC, the car shifts like a champ, and 4th gear is a go. It'll actally shift properly into OD and hold it without signs of going out of gear. Until you turn it off once.

However, the car 'races' when in OD. The tach moves ahead, and the then falls back, and I can feel the car surge as it falls back.

My speedometer also gets a little flaky at times. I can see it dancing.

Any ideas, guys? sorry for the long post, but I wanted to give you guys as much into as I could. I have ordered a new VSS, but I dunno if this is my problem.

Thanks

 

[Mike Kopstain]

VSS is your problem bubba... I hope you're a contortionist. Email me if you want some details.

 

[93nighthawk]

I agree with Mickey on the VSS, do a search on the forum, you will find lots of posts on it. Also you might want to check your motor mounts. If they are really bad, that will cause the problem of shifting from park to D.

Eric

 

[Mr Anonymous]

I disagree slightly. Since you are also seeing speedometer problems, I suspect one of the speedo gears (which also drive the VSS) is probably toast. The speedo drive gear & shaft can be removed (albeit difficultly) with the tranny in the car, but the main drive gear requires complete tranny disassembly. If you feel adventurous you could pull the drive gear & shaft and inspect/replace them, but if they are OK then then you're probably looking at a rebuild. frown

 

[Mike Kopstain]

Agreed, but I have seen some VSS's bind up and free similar to a binding speedometer cable. That could be it. SHOooo I believe the VSS is driven off of the final gear is it not? If that is the case, that is not removable without removing the transaxle. Maybe I read your post wrong.

Teg, the absolute first thing to do is check your codes. Everything you want to know is there. From there check the VSS with a Multimeter.

~ Mike

 

[SolidState]

Thanks guys.

To clear a couple things up, the car shifts out of park or neutral fine when I reset the car.

The speedo needle has only danced once or twice, after running the car pretty hard, and it was really hot.

Another little problem that I encountered tonight was under really light throttle, the car slowly went all the way up to 6000rpm before shifting. It shifted fine, but waited too long to shift. I figure this might be TPS related.

Thanks alot again, guys. I will contact you soon about how to replace my VSS, mike. Interestingly, what appears to be my heat shield over the VSS (down on top of the tranny under the back off the intake manifold...tin like cover) is all damaged and crumpled...

Cheers beer

 

[SHOfun 93]

Heck when I did mine last week, my heat sheild wasn't even by the sensor itself. And when you see how close the sensor is to the manifold, you will agree how easily that the high heat of the headers can start to wear on a VSS quickie style.

 

[SolidState]

I don't doubt it...

After reading the Factory Manual on CD, it states the following about the VSS:

Symptoms:

Harsh engagements, firm shift feel, abnormal shift schedule, unexpected downshifts may occur at closed throttle. Torque converter clutch will not engage.

The first four symptoms make sense, but I was wondering about the TC. I was told once that losing 4th gear might be a sign of a bad TC, so if the TC isn't engaging properly, could this be why 4th is racing?