Need Help Please!

[The Sandman]

My tranny started to act up recently. My car is a 97 (auto) with < 60,000 on it.
I always put the car in N at a stoplight then when I go it goes into 1st. If I'm driving like 35 or so I'll downshift into 2nd. Normally everything is fine. I noticed the problem when I tried to downshift and instead of going into ___ RPM for that speed, it dropped to a little over idle. I left it in 1st and took it up to like 3 grand and tried letting it decel but the RPMs dropped again.

Help pleez! :( :(

Edit -
I think it's the stall converter going bad ... ?
I can still accel fine I just can't let it decel in gear.

[ December 02, 2003: Message edited by: The Sandman ]</p>

[BillyCobin]

I'm not sure I understand what your saying.

So when you manually select a gear, you can't use to the transmission to slow you down?

[awesomeame]

if you want to shift, get an m5 :D

so when you downshift, your rpms go to idle, instead of going up, and slowing you down?

--matt

[3.4 slow to go]

Why aren't you keeping it in a drive gear at stop lights/signs?

How's the shifting cable/linkage?

[Wicked 3800 V6]

Why are you shifting so much? Prolly not the converter, but some sorta clutch band inside.

[The Sandman]

<blockquote>quote:</font><hr>Originally posted by BillyCobin:
I'm not sure I understand what your saying.

So when you manually select a gear, you can't use to the transmission to slow you down?<hr></blockquote>

That's what I'm saying.

I put it in N at stoplights because it saves wear on the tranny. If you leave it in gear the stall converter spins and creates heat - because you are not moving the heat doesn't get effeciently dispearsed... which makes your water pump work harder.. etc.

[BillyCobin]

It could be a lot of things...

Stuck valve in the valve body (4-3 sequence valve).
Damage to the spacer plate or gaskets.

Turbine shaft oil passages plugged.
Turbine shaft seal rights damaged.
Turbine shaft sealing balls loose.
Porosity in forward or overrun clutch piston.
Overrun piston seals cut or damaged.
Overrun piston checkball not sealing.

My guess is you either blew the piston seal on the overrun piston, or burned out the overrun clutchs. There are only two overrun clutchs, and they are quite a bit smaller than most of the other clutchs. They weren't ment for constant use and abuse.

Heat build up from sitting at a stop light is minimal, and the transmission has a cooler and was designed to deal with that. It wasn't designed to be constantly manually shifted though.

[The Sandman]

Hmm, fair enough.
What would you suggest that I do then?

[BillyCobin]

It's grounds for an entire overhaul of the tranny. Of course if everything else is working fine, then the transmission might go another 50k+ without any problems.

Check your tranny fluid, does it smell burnt? Are there any noticiable black specs in it?

If you ate the clutchs, there is going to be residue from them in the tranny, and the fluid will probably be burnt. If this happened, you should flush it and replace the filter soon.

If the fluid isn't burnt at all, then my guess it was a seal that broke. If you have good luck, it will just be a tear and the seal and it won't clog anything else up.

Just to make sure, this happens when you have selected a gear like 1,2, or 3, right? The overrun clutchs won't engage when you have it in OD, only when in gears 1-3.

[The Sandman]

<blockquote>quote:</font><hr>Originally posted by BillyCobin:
It's grounds for an entire overhaul of the tranny. Of course if everything else is working fine, then the transmission might go another 50k+ without any problems.

Check your tranny fluid, does it smell burnt? Are there any noticiable black specs in it?

If you ate the clutchs, there is going to be residue from them in the tranny, and the fluid will probably be burnt. If this happened, you should flush it and replace the filter soon.

If the fluid isn't burnt at all, then my guess it was a seal that broke. If you have good luck, it will just be a tear and the seal and it won't clog anything else up.

Just to make sure, this happens when you have selected a gear like 1,2, or 3, right? The overrun clutchs won't engage when you have it in OD, only when in gears 1-3.<hr></blockquote>


The tranny fluid was just changed ~4000 miles ago - I'll check it this weekend. Yes - you got everything summed up.

[mjparme]

<blockquote>quote:</font><hr> I put it in N at stoplights because it saves wear on the tranny. If you leave it in gear the stall converter spins and creates heat - because you are not moving the heat doesn't get effeciently dispearsed... which makes your water pump work harder.. etc. <hr></blockquote>

This is an interesting theory but I think the torque converter spins even when the car is in neutral. As far as I know (I am no expert though) if the engine is spinning the torque converter is spinning. The torque converter just serves the same purpose that a clutch has in a manual car.

Even if I am wrong and the torque converter does in fact stop spinning when in neutral I highly doubt any assumed affect that this has on the life of your engine/tranny is remotely quantifiable.

How does the tranny getting warm make your water pump work harder? The water pump pumps water no matter what. Also, I think you are putting more wear and tear on your car shifting it into neutral at lights all the time.

I have posted two links about torque converters and transmissions from howstuffworks.com. These may provide more insight:

http://auto.howstuffworks.com/automa...ansmission.htm
http://auto.howstuffworks.com/torque-converter.htm

[The Sandman]

Thank you.