Save my car, LS1Tech!
Thread Starter
Joined: Jul 2007
Posts: 2,861
Likes: 4
From: Ringoes/Flemington, New Jersey
Swapped rears, practically same vibration
2 sets of wheels (one set was straightened and road forced with no issues)
its not flywheel/clutch related due to engine off in neutral and the vibration is still there...
I am thinking driveline angle
2 sets of wheels (one set was straightened and road forced with no issues)
its not flywheel/clutch related due to engine off in neutral and the vibration is still there...
I am thinking driveline angle
Launching!
Joined: Apr 2013
Posts: 225
Likes: 0
Before I wrecked my 97 z/28 6spd, for a while it did something similar at high speeds(i think 90-100+), and i don't remember exactly what i did to fix it. The most probable thing i can think of right now is (don't remember why) re-install the drive shaft with it being lined up differently.
Thread Starter
Joined: Jul 2007
Posts: 2,861
Likes: 4
From: Ringoes/Flemington, New Jersey
Like I said, I've put my D/S in multiple times... Same shake every time. Even after it was balanced.
I think it's the angle. I just haven't had time to diagnose it
Also, my rebuilt rear is for sale if anyone needs a 3 channel 3.73 rebuilt rear
I think it's the angle. I just haven't had time to diagnose it
Also, my rebuilt rear is for sale if anyone needs a 3 channel 3.73 rebuilt rear
Thread Starter
Joined: Jul 2007
Posts: 2,861
Likes: 4
From: Ringoes/Flemington, New Jersey
Transmission is pointing down 1 degree.... So I set the rear to point up 1 degree. It got better but it's still present. So I put the rear up more, it got worse... So I cranked it lower and it's still there but not as violent
Thread Starter
Joined: Jul 2007
Posts: 2,861
Likes: 4
From: Ringoes/Flemington, New Jersey
Fine tuned it by just winging the Torque Arm adjustment. It is not noticeable at ALL in gear/under throttle. but if you push the clutch in you can feel it. No where near as bad as before
Very interesting. I never knew our cars were that sensitive to pinion angle. I mean I know it's important, but didn't know that just the difference of a 2* range would cause such a vibration. I always thought of it as more of a traction tuning tool. On older cars I've ran anywhere from 0* to -4* without problems.
Thread Starter
Joined: Jul 2007
Posts: 2,861
Likes: 4
From: Ringoes/Flemington, New Jersey
I thought I measured it to the T... I am wondering if the T/A relocation crossmember has anything to do with it. I put the bushing on the 2nd set of holes from the top. IDK how to even tell which hole set to put it in...
If I remember correctly, I put mine in the top position on the TQ arm relocation crossmember. It's a full length UMI adjustable TQ arm, LT1/M6. Moving the front of it up shortens the instant center which should hit the tires harder. I pretty much had to move it up there so it would clear my Y-pipe. As far as the current pinion angle.....all I've done so far is eye-balled it to comfirm it is slightly negative. LOL Sad huh?
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welll went to the track there were two other lt1s and i asked if there cars vibrated and they dont get it at all till 110 they said bout their drive shaft having some kinda damper on it near the tranny??
like a rubber bushing?
do u guys
like a rubber bushing?
do u guys
I'll have to check my angles and see what they are, but my car is all stock susp. wise. Plus a stock balanced driveshaft with almost 192k on it.
I think they are talking about the dampner that is on the yoke of most 4th gen driveshafts. The stock steel and 2 diff styles of stock aluminum ones I own have them on there.
Thread Starter
Joined: Jul 2007
Posts: 2,861
Likes: 4
From: Ringoes/Flemington, New Jersey
I swapped the rubber one in, and i did use that plate yes. I used the plate on the OE rubber mount and another steel plate. lol just to push the trans up
Thread Starter
Joined: Jul 2007
Posts: 2,861
Likes: 4
From: Ringoes/Flemington, New Jersey
They weren't in when the vibration was present. I measured the trans output shaft angle it was pointing DOWN about 3 degrees. I put the plates in and it pushed it up to about 1 degree down still. so I set the rear to 1 up and it got better. I then cranked the rear down a little (which makes no sense) and the car doesnt vibrate at all in gear. You can feel it in neutral but its no where near as horrible
Thread Starter
Joined: Jul 2007
Posts: 2,861
Likes: 4
From: Ringoes/Flemington, New Jersey
Correct vehicle in motion over 70mph. Vibration doesn't change in neutral if the engine is revved or shut off. The vibration changes when I push the clutch in or shift to neutral (meaning, a driveline vibration)
