Snow Dog

iTrader: (3)

i posted this in the vette forum too, but i thought maybe i could get a more informed answer here in the trans section.

the car is a 97 vette, minor heads/cam, had a 2.73 now has a 3.42 and TCI breakaway. the TC and gears were installed recently and now the car has a weird vibe from about 2100-2500. it only vibrates in that range and it will only vibrate when gas is applied. so if your coasting its not shaking. it will do this in neutral as well as drive. havent tried reverse yet. i tried disconnecting the TC from the torque shaft that stopped it so i thought the TC was unbalanced. i even rotated the TC on the shaft still the same. TCI felt the same and sent out a new breakaway, but the problem didnt go away. so now i have no idea whats causing this. the new TC is not as bad as the first one, but its still there. the TC slid right in no problems. replaced the pump seal while in there too. im stumped as to what would cause this. any ideas or tests i can try. the TC works great except for the vibrating issue now. Thanks

Suprfun

iTrader: (2)

If you removed the torque tube from the engine (and even if you didn't) when you installed the converter you need to be sure and preform the following procedure:

THIS IS DIRECTLY FROM A 97 CORVETTE MANUAL also it assumes that the propeller shaft hub clamp bolt is loose from the uninstall.

Important: the following steps must be preformed in order to provide proper alignment of the propeller shafthub, the propeller input shaft and the propeller input shaft front bearing.

1. Start and run the engine at idle until normal operating temperatures are reached. (Idle or drive for at least 10 minutes)

2. Turn off the engine and allow the powertrain to cool to room tempereture.

3. Raise the vehicle.

4. Tighten the propeller shaft hub clamp bolt.

5. Tighten the propeller shaft hub clamp bolt to 96 foot pounds.

This whole procedure can be found in the 1997 Corvette Service manual
book 3 Transmission/Transaxle on page 7-269.

Hope this helps,
Mark

Snow Dog

iTrader: (3)

nope never took it loose or moved it once the tranny was disconnected from the torque tube. all i did was unbolt everything from the torque tube lowered the trans with the rearend out of the way switched conveters and pump seal. then bolted everything back up. didnt force anythind didnt draw anything in with bolts. everything went together smoothly. thanks for the reply and info

ive been in contact with TCI more today. and my trans guy. they both agree that its got to be something with the TC and not the trans itself. so i dont know. i even tried putting washers on each of the TC bolts in order one by one and it didnt help. so i dont know. im completely stumped.

Hyper Chick

Mine did it real bad. It needed tuning. I had the TM deleted and the shift/lock up points changed. The TC was locking up too early, so it felt like a manual in too high of a gear. It kinda "chattered" or vibrated. After tuning, never had another problem

Snow Dog

iTrader: (3)

interesting, but the only problem is that it goes away at 2500 instantly. ill look into the TM setting though. i now they are altered a little but not deleted. the shift points are unchanged at this point. thanks for the reply.

Hyper Chick

That's exactly what mine was doing. 2000 - 2500 rpms then nothing at all. I think it was more the shift point and lock up points than the TM. Hope it helps!

Snow Dog

iTrader: (3)

yes it does im going to look into it more tomorrow. do you know what you changed yours too? because my shift points are not changed, at least i believe its not

Snow Dog

iTrader: (3)

oh wait. this problem occurs in neutral as well as drive. did yours do that? thanks

Hyper Chick

I don't remember what my shift points were changed to because all of them were. WOT and part throttle. I don't think mine suddered in neutral either. It's been too long ago. Sorry

jimmyblue

iTrader: (11)

Some people get lucky with just rotating the converter 120
degrees on the flexplate and bolting back up. Whether it's
voodoo or not, the other two orientations might get you
somewhere you like better.

Snow Dog

iTrader: (3)

yeah ive tried that unfortunately. the other part that sucks is that ive got a third converter in there now. not even a TCI and it vibrates too. not as bad but in the exact same spots again. so i think the stock units gonna go back in to make sure it does shake too. im so lost on this its not even funny. talked with a GM tech today about it and he feels theres no way i damaged the torque tube or shaft some how and that its got to be an inbalance in the TC somehow.

for the record i simply pulled the trans off the end of the torque tube. the book says drop the tube also. i didnt see any reason too so i left it in.

Snow Dog

iTrader: (3)

no problem thanks for the input chick

DAVE AT YANK.

From dave at yank the factory puts a white grease on the pilot of the factory converter where it goes into the torque tube this grease gets very hard overtime.If you dont get all that old grease out of there when you put the new converter in it could bindup in the torque tube and cause a vibration.Also tci paints there pilots on there converters i would remove the paint and put a light film of grease on the pilot when you put the tci unit back in.

Snow Dog

iTrader: (3)

hmm good idea Dave. i always lubbed the pilot with either bearing grease or simply some trans fluid to allow it to slide in. ill check out the grease. my next step is to put the stock TC back in and make sure the vib is the other TCs. after that its prolly back to one of the after market ones.

Snow Dog

iTrader: (3)

ok what about this? would a TC that works on an LT1 work for an LS1? i ask because the same TC is used from 93-2000 according to TCI. i would think there would be a balance issue between the two engines. anybody have any ideas on that?

DAVE AT YANK.

No they will not interchange they are diffrent height converters a ls1 wont even fit a lt1 93-97 and 98-02 are not the same converters.

Snow Dog

iTrader: (3)

but is that right for the vettes? i checked into my theory some more and it doesnt seem to hold up, appearently the vettes used the same converter for a very long time. C4s and C5s used the same.

anyone else have any ideas?

K9Kev

iTrader: (28)

Just had the same troubles with my conv. install. Mine vibe was worse than yours thou. I could feel it in neutral as well and all the way up thru the gears until around 130 MPH....then the road likely washed it out.
Sounds bizzare but, after the third converter, I got it all solved. I guess mine was just out of balance vert's. What a P.I.T.A.
Oh, and no...I never had vibes when in reverse.
Just wanted to chime in...Good Luck,
Kev