vibration problem
Thread Starter
Le Mans Master
Joined: Oct 2000
Posts: 6,209
Likes: 33
From: Texas-out west
vibration problem
Ok, need help in finding vib source. Vibration felt in engine and rattles shifter at approx. 2500rpm and above, high revs, more vibs. Does it under load and out of gear and just reving engine. That makes me believe not in drivetrain, but in clutch forward area. Suggestions, ideas? Thanks.
Melting Slicks
Joined: Jun 2001
Posts: 2,429
Likes: 14
From: CA
Re: vibration problem (LT1driver)
LT-1, What kind of mods do you have on your motor? What type of ballancer do you have?
Also, you may have a weak cylinder.
Start with a spark plug change, & if you have access to a multimeter, check all of the plug wires for correct resistance. If it still vibrates, do a compressing test on each cylinder.
Good luck. :chevy
Also, you may have a weak cylinder.
Start with a spark plug change, & if you have access to a multimeter, check all of the plug wires for correct resistance. If it still vibrates, do a compressing test on each cylinder.
Good luck. :chevy
Burning Brakes
Joined: Apr 2000
Posts: 1,012
Likes: 0
From: Minnesota
Re: vibration problem (LT1driver)
I can give you a list of some of the things I tried to get rid of a vibration that I had at about 55 to 62 MPH.
1.Motor mounts\
2.Transmission mounts
3.Upper and lower differential mounts
4.Fan clutch
5.Water pump bearing
6.Rag joint
7.Tire balance--balance wheels on the vehicle--try switching tires around first, or borrow some
8.Balance tires with beauty rims on if so equipped,use tire weights on back so beauty ring snaps don't hit tire weights.
9.Balance drive shaft
10.U-joints inspect carefully--the upper one on the driver side half-shaft needle bearings were bone dry
11.Check tires for flat spot--a long period of storage can cause flat spot or slight separation
not all, just some of the things I went through
Good Luck
SEMPER FI--1970 Dave
1.Motor mounts\
2.Transmission mounts
3.Upper and lower differential mounts
4.Fan clutch
5.Water pump bearing
6.Rag joint
7.Tire balance--balance wheels on the vehicle--try switching tires around first, or borrow some
8.Balance tires with beauty rims on if so equipped,use tire weights on back so beauty ring snaps don't hit tire weights.
9.Balance drive shaft
10.U-joints inspect carefully--the upper one on the driver side half-shaft needle bearings were bone dry
11.Check tires for flat spot--a long period of storage can cause flat spot or slight separation
not all, just some of the things I went through
Good Luck
SEMPER FI--1970 Dave
Thread Starter
Le Mans Master
Joined: Oct 2000
Posts: 6,209
Likes: 33
From: Texas-out west
Re: vibration problem (1970 Dave)
Motor is stock 350 LT-1, not in tires etc. since it does it while parked and not moving. I will check motor mounts and trans, h2o pump, etc. next week. I checked compression, 190 all cyl, wires check good and are new, plugs changed several times and heat ranges, carb is right on, dist checks good, dist cap good, no movement on damper etc. Cam and lifters changed out, does same thing before and after change of cam. Will keep all posted. Thanks.
Pro
Joined: Jun 2001
Posts: 579
Likes: 0
From: Pflugerville/ Colllege Station TX
Re: vibration problem (1970 Dave)
I think i have the exact same problem in my 69. I get bad vibration in 4th gear only and between about 60-70. Did you ever figure out what the problem was.
