auto tranny doesnt know when to shift?

[ohfosho]

hey guys, i bought this nice car like 4 months back. i have fixed most of the problems so far. now only once in a while when driving normal, at normal operating temp, its shifts into 2nd near 2 1/2- 3 krpms...normal. then when im waiting for third at the same rpms again, it stays right there. eventually kicks, usually really hard when it shifts to third. then it will really shudder around third gear and then downshifting those 2 last gears.


other times it seems to shift hard...so i cant say that its slipping really?
im thinking that the fluid needs to be swapped out, completely clean the system, and put in some nice new, thin fluid (prolly syntetic, but i dont wanna pay for that much of it!). also the computer from a 95 auto sho would help too right?

im just wonding how many people have had this same type of problem, and what was the fix? (and try not to say 'new tranny time')

 

[TYSHO]

I had the same problems, but with more symtoms, when my battery cable was loose. I thought I was in for a VSS replacement!

 

[SHO#7]

You need to start with checking the codes. You sound like a possible few things here. First, I agree with a chance that you have a vss signal problem. It sounds like it works most of the time, but the signal may drop out at times causing the transmission not to know how fast you are going, and not making the proper shift.

Second, I have recently seen a rash of bad MLPS' or range sensors. They sit on top of the transmission and tell the car what gear you have selected. It may be getting a false signal there, making the car stay in gear thinking you have selected it to stay in second.

Third, you did not mention your fluid condition. This is always a tell tale sign. If it is shifting erratic and your fluid is nasty, it may be in the unit. There is always that remote chance that a bulletproof SHO transmission may need replaced. They are not what we call the strongest unit out there.

And lastly, I may also suspect your throttle position sensor. In a modern car, you have to realize that there is no kickdown cable. It is all done electronically. Meaning the TPS looks at how far you are pushing the go pedal and tells the rest of the car. You tps may at times say you are giving it more go than you actually are. Making the transmission stay in a lower gear to maxamize your acceleration. Then it gets a different signal all of the sudden and may cause a late hard shift.

I would check into all of the above, and start with looking for codes. Your search may end sooner than you think.

Mike

 

[ohfosho]

yeah i have been planning to pull the codes soon.

the fliud is nice and clean, not brand new, but looks and smells alright.
it is a 'quality renewed tranny that was installed at the dealer in 99

 

[LeddZepp8687]

I have the SAME exact problem. I am not sure what color my tranny fluid should be, but it certainly has enough fluid. I tried re-setting by pulling the batt. cables for 30mins and nothing. And as for pulling the codes....Ohhh god I hate doing the codes, i always loose track and such. But I believe it is gonna wind up being a bad VSS which is a PITA to install....

P.S. mine shifts leisurly out of 1st then it slams into 2nd, well actually it doesnt want to shift out of 1st.

Anyone know if this is a bad VSS????

 

[SeanMc]

Mine does the firm 1-2 shift as well, and has for over 130k miles. The shift is more noticable if you have bad motor mounts. Check'em out.

 

[ohfosho]

thanx guys im going to check my codes soon, its raining today, so i couldent.

just curious: how much does the VSS usually cost?

 

[LeddZepp8687]

25 bucks! I just got my new one!

 

[ohfosho]

now how does ur average driveway mechanic relace this part the easiest?