Vibration when verter's locked...
 

My tranny vibrates when the verter is locked and I push the gas down about 1/4 throttle. It's almost like the tranny wants to downshift, but it doesn't. I had the car tuned with Edit today, and they changed the RPM lockup to 50mph, increase line pressure, and deleted TM. After all that, it was fine at first, but once I started driving home, it started up again. It's really annoying, and I have to find out what it is, because I don't even know if it's something that's messing up my tranny. Any help I can get would be great.

I would suggest dropping the starter and taking out the converter bolts,rotate the holes by one and put the bolts back in. Its not that hard. For some reason this has help more than a few with vibrations. You MIGHT find alittle info on it with a search. Tony

mine does the same...when its locked and i start to give it gas but not enough gas to unlock "flash" the PCM it will vibrate. i wonder if its bad?
it might be that there isnt enough throttle and the PCM wont flash the converter and unlock it so it bogs the motor...


J

could be the converter clutch starting to slip.

TTT, still need to know what parameters in Edit to change :(

If mine is locked and I give very slight acceleration it kinda feels a little rough. Not really a vibration but more of a bog type scenario. Doesn't bother me as I'd rather it stay locked and save the gas. At first it tripped me out a little though. But once again mine really doesn't feel like a vibration.

Why would you want the verter to lock up @50?? I would like mine to lock at like 30mph as long as it didn't affect the performance........but I also do alot of 35-40mph city driving so a locked verter would save me some gas.

Ive got a problem with my TCI 3200 converter at cruising speeds when i touch the gas slightly, it almost seems like its the converter locking up and unlocking the rpms will raise about 200 and then drop back down 200 continuously. Anyone found a solve for the problem yet? I also have problems hitting the limiter into 3rd gear, even after a recently performance rebuild.

Because all you'll do then is bog the motor with a complete lack of throttle response in traffic. Yeah, you might save gas but the car would be a total drag to drive.

When your gearing is rather low locking up at 35 will bog it down. I can see locking it there if you have like 4.10 gears or so. I like mine locking at 40 MPH. I could stand maybe 45 but as mentioned it saves gas.

It's just something my tuner tried, thinking it would solve the vibration problem. As far as you describing it more as a "bog" type of thing, I guess I can kinda see it, but it's more of a vibration for me. I know it's not speed or RPM dependent. It'll happen at any speed as long as the verter is locked.

If at any speed it is doing it then I'd try the turning the converter and rebolting it. If that doesn't clear it up then you probably have lockup clutch issues or improper balancing.

Yay, problem solved!!!

I had 3.73s installed last night, and as I was driving home, I noticed that my wierd lock-up problem went away.

I guess it had something to do with a big-ass stall and 3.23s, maybe it was bogging down or something. Everything's good to go now. Maybe the 3.73s just tighten it up that much.

So yeah, it's nice to be able to ease into the gas without fear of shaking my car apart :)

3.73s reduce the torque needed and that puts less stress on the lock-up clutch

More than likely it had to do with the pcm TC unlock settings. Either way, glad to hear the problem is gone.

Could have also been torque clutch shudder - I had the same type of feeling with my new Midwest 3500stall/2.5str verter. After talking with John @ HPA - he explained that the better clutch materials used are to aggressive for just plain DextronIII - He sent me (2) bottles of Midco Transmission Supplement (which is simply a friction modifier).

I poured in one bottle and the shudder went away completely. Glad to hear you got your problem solved - but if it comes back - try the friction modifier.

-Jay-

Jay,

Where can I get it? Any auto part stores?

The exact brand I used (Midco) was sent to me by John @ HPA (sponsor) I think that Midco is the parent company of Midwest Converters.

I have seen other brands such as Gunk Synthetic Highly Friction Modified Auto Transmission Supplement (P/N M1410HFM) at stores such as PepBoys or Advanced Auto.

States:
"A uniquely blended synthetic product designed to convert & enhance DextronIII fluid into a highly friction modified ATF such as Chrysler-ATF+3 or +4. Stops torque converter shudder instantly. Extends the life of the fluid. Keeps valves & govenors free. Softens hard shifting. Inhibits overheating & fluid oxidation. Protects & coats gears & pumps. Compatible with electronics, frictions, & seals."

-Jay-