Tranny problem - vibration??

[gimper]

Hello

 

I’m pretty new to the forum, in fact never posted but have browsed and searched it a lot and found a lot of nice information big thanks for all of that. Anyways I have a 1990 Cutlass Supreme International (sedan) with quite a high mileage 190k or so. I just got the Cutlass yesterday :-), so I’m now an owner of a W-body car.

 

Anyways I experience vibrations when the torque converter locks up. I also experience vibrations in OD (4 gear) assume the TC is locked in fourth hence causing the vibration. I have yet to experiment removing the plug to the transmission preventing the TCC to lock up the TC and thereby see if that is really the problem. (Will be back with the result – arrived home late yesterday hence didn’t do the test).

 

The engine is also somewhat vibrating while idle in P, N and D causing a rattle of the exhaust which is slightly dent due to the previous owner backing it into a curb. However the engine it self runs smoothly although I have to say the car feels under powered and slow compared to my 89 Bonneville SSE (3.8 V6 in that one).

 

Now to my main question, what is causing the vibration when the torque converter is locked? Since I’m an idiot when it comes to automatic transmissions my next question is how do I go around and fix the problem :-).

 

In regards to the car in general is relatively well maintained, there is a new alternator, master cylinder (with ABS system) along with a relatively clean engine bay. The front rotors are slightly warped (very light pulsing). The suspension is to my surprise very tight and there is no sag in the rear end (this is the big plus with the cars is very nice driving on country roads – the road holding is great).

 

I will naturally if I get the vibration fixed do a full service (new plugs, wires, filters, oil, anti freeze and so forth). Ah the trans fluid has probably seen it’s best days but it doesn’t really smell burnt and its still somewhat red. Will naturally change it but first need to see how to get the vibration fixed and it might be a flush by automation since I may dig into the tranny so to say.

 

Many thanks in advance, Gimper.

 

[Supreme Cutlass]

If the TCC is the problem, just leave it unplugged. Problem fixed.

[gimper]

:-), thanks but I kind of want to have it working since it will make quite a diff in mpg.

 

Thanks Gimper

[gimper]

Hello Folks,

 

Disconnected the plug to the tranny this morning and drove to work. The vibrations are gone now - in other words it’s a problem with the torque converter lockup. The big question for me is why does it vibrate when the lockup engage?

 

Grin, since I drove the car nicely home on country roads I didn’t really notice that there is no kick down what so ever. I guess I will do a search to see if I get any tip why it doesn’t kick down, don’t think it’s related to the vibration problem although it could all be due to a high mileage tranny.

 

Ah, when I disconnected the plug I had to lift the air filter box and the previous owner must have changed very recently since it looked more or less brand spanking new. Hence I have a feeling that the car has been fairly well maintained which is nice.

 

Any takers to why it vibrates, is it the torque converter it self or something else? Is there a good site for automatic transmission repair? I mean when you get procedures and how to go about restoring/repairing/overhauling it.

 

Many thanks in advance Gimper

 

[Regal_GS_1989]

It could be possible that the kickdown not working could cause the vibration that you are having. If the trans is shifting too soon, the torque could be bogging the engine down once it locks up.

[gimper]

Hello

 

Thanks for the input, sounds resonable since it shifts very early since the kickdown isn't working. We will try connecting the plug once I fixed the kickdown problem.

 

The reason why it's not working is that the TV cable isn't attached to the throttle at all :-) - ugh. The cable is there but the cable bracket that should link it to the throttle leveler is gone. Since I'm not in the US but in Europe it would be super if somebody could take a pic so I can see how that part should look like. Then I can go out hunting at the local junk yard for a something that could serve in it's place (so I can attache the cable again). Hopefully I can get the kick down working this week.

 

Big thanks Gimper

 

 

 

It could be possible that the kickdown not working could cause the vibration that you are having. If the trans is shifting too soon, the torque could be bogging the engine down once it locks up.