Shift......VROOM...is it what I think it is??

[fldcar]

I have been noticing lately that under EXTREMELY LIGHT acceleration my tranny is doing something wierd....the 1st to 2nd shift is fine but the second to thrid is when it happens....when it shifts it revs up a bit (about 1500 rpms) Under hard or moderate acceleration it does not do it at all. The car has 82000 miles on it and it still shifts smooth as silk. Is my tranny going or do I need to adjust the band. I hope it is just in need of a band adjustment. If so how do I do it? Thanks I really hope I don't have to buy a new tranny now, I was at least hoping to make 100,000 miles. Tim

[Beav]

If you hit the search button you can usually find the information you're seeking. I'll help ya out this time, since I'm such a nice guy and all....

Adjustments

If engine speed increases abruptly on 2-3 shift, or if there is a delay of more than 1 second on a 3-2 kickdown, excessive clearance between reverse clutch drum and band may exist, adjusting screw should be rotated clockwise. If there is a braking action on 2-3 shift, excessive small brake band clearance may exist and adjusting screw should be rotated counterclockwise. Adjust brake band as follows:


Using socket tool No. 398603610, to hold adjusting screw in place, loosen locknut.
Loosen or tighten adjusting screw within 3/4 turn, to properly adjust band, then tighten torque to 19-21 ft. lbs. If slipping occurs on a 2-3 shift, excessive small brake band clearance may exist. If transmission shifts directly from 1st to 3rd, excessive large brake band clearance may exist. Adjust brake band as follows.
Using socket 398603610, to hold adjusting screw in place, loosen locknut.
Torque adjusting screw to 6.5 ft. lbs., then back off adjusting screw 2 turns. Torque locknut to 19-21 ft. lbs.

Around the shop we always comment that brevity of instructions indicates more difficult labor. As simple as the instructions seem the job pays 1.8 hours...

[fldcar]

I looked and found the band adjustment screw on the top of the tranny, but how in the heck to you get to it. It is way back under the firewall.....Is the special socket mentioned designed to go back in there?

I also have a question when it actually does come time for my tranny to be replaced........I have read alot that the tranny fluid cooler in the radiator was poorly constructed and eventually plugged up leading to the death of the tranny.....What if I were to buy a radiator from the dealer for a 97 Svx......Would'nt that help to solve the problem when the new trannyis installed?

Oy! Stop work. Flare under light acceleration ONLY means that you have a bad/misadjusted TPS. You can try readjusting it (I'm not sure which way you turn it; trial and error) or replacing it. Mine does that too when it shifts around 1700 rpms or less. Just accelerate faster, it's cheaper

[Mr. Pockets]

Originally posted by gcookaustin
Oy! Stop work. Flare under light acceleration ONLY means that you have a bad/misadjusted TPS. You can try readjusting it (I'm not sure which way you turn it; trial and error) or replacing it. Mine does that too when it shifts around 1700 rpms or less. Just accelerate faster, it's cheaper

I disagree with this, so please provide me with some supporting information.

As I understand it:

Since the ATF pump is driven by the engine, fluid pressure is relative to engine speed. Under light acceleration, the transmission shifts at lower engine speeds and therefore lower fluid pressure. As the clutches in the transmission wear, it requires more fluid pressure to make shifts. Thus the long shifts under light acceleration and why they firm up under hard acceleration.

That's how I understand it, anyway.

I'm not saying that a bad TPS can't cause these problems - I just don't understand why it would, nor why you conclude that this is the only cause.

Oh. Well, I don't understand it either, that's just what svx_commuter said and his TPS was faulty; caused those low-rpm flares until he replaced it.

[Beav]

That's entirely possible, but don't discount the fact that an out-of-adjustment band takes more time to engage and has greater potential for slippage.

[fldcar]

I think I will stick with the band adjustment and see if that helps. But does that special tool that was mentioned fit way down in there to adjust it. The screw itself is way down on the top of the transmission under the firewall. I don't want to mess with the TPS because I have had bad experiences withthe adjustment of it in my 2.2 Legacy.

[svx_commuter]

The reason the TPS can effect the 2-3 flair is that the TPS also controls the line pressure. Unplugging that resistor by the battery increases line pressure and if that's the problem at low rpms' light throttle then the slip will go away.

The other reason the TPS screws up the shifting is that it makes the TCU think your closing the throttle when you really just pushed it down a little to open it. So that the line pressure drops some. The TPS is an important item and not to costly to replace.

The TPS did fix my problem for a long time. However, after a trip to the drag strip I have develeoped a light throttle 2-3 flair agian. Only now it is at a slightly high throttle setting, going up a small hill. Before it only happened going down a hill

So Beav........ That band adjustment is for the light throttle flair problem and not slipping under a heavy acceleration? Maybe that's my problem now. I have read thru the procedure and it sounds like a trial and error adjustment. Any tips? Howabout that special socket? What makes it special? Got one to loan out?

Oh..... This latest flair started after I drag raced four runs. Could that have something to do with it?

[Mr. Pockets]

Originally posted by gcookaustin
Oh. Well, I don't understand it either, that's just what svx_commuter said and his TPS was faulty; caused those low-rpm flares until he replaced it.

Right, and his explanation is above. I just have a problem with you repeatedly telling people that a bad TPS is the only cause for a 2-3 flare.

Originally posted by gcookaustin
Flare under light acceleration ONLY means that you have a bad/misadjusted TPS.

I guess you misunderstood what I said; what I meant is that if the flare is under light acceleration only and not under heavy acceleration then I thought it was the TPS. I didn't mean that that could be the only problem resulting in the flare.

[Beav]

No, I've never seen the tool, but I'm certain that I'll be able to come up with something in my toolbox that will work. Actually the next time I change oil I should be swapping out a little ATF too, so I'll probably do it then.

Nobody can be 100% of the cause from this distance, however the band adjustment is considered a maintenance item (at least it used to be) and inexpensive if you do it yourself - *correctly*. TPS sensors take a lot of wear and tear over the course of their lives and it could very well be that your's is acting up. It's just that the band adjustment could be the cause and is supposed to be adjusted periodically anyway.

[MoreIBNR]

Ah - back to high school English class. "Only" should have been placed before the word "under," where it would modify "under light acceleration" instead of where you put it where it modifies "means."

This English lesson was brought to you courtesy of the Philadelphia public school system.

Originally posted by gcookaustin
Oy! Stop work. Flare under light acceleration ONLY means that you have a bad/misadjusted TPS. You can try readjusting it (I'm not sure which way you turn it; trial and error) or replacing it. Mine does that too when it shifts around 1700 rpms or less. Just accelerate faster, it's cheaper

[svx_commuter]

Originally posted by Beav
That's entirely possible, but don't discount the fact that an out-of-adjustment band takes more time to engage and has greater potential for slippage.

Okay the adjustment for the band is visable from the driver side right by the fire wall as fdlcar says. I wil have to reach thru a bunch of hoses and wires to get to it. The lock nut looks pretty big and the adjusting bolt has a square top.

The service manual I have has a different write up and it is for on the car maintenance.

If I tighten the bolt a half turn and then drive it will that be okay?

I talked with a tranny shop I trust today and he will not do it. He says that if it is starting to slip the lining is gone and tightening will not help. Any thoughts on that? He said the lining on the brake band is very thin. Also most cars do not have an external adjustment any more.

just get a 5 speed