Heavy vibrations when engine braking in 4th gear?

[kicknurass4fun]

I just got done doing a clutch install in my car. Put in a SBR3500, very lightly resurfaced act flywheel(minimum resurfacing didn't need it), BG synchroshift 2 in trans, Redline shock proof in transfer case, and a new clutch fork/pivot ball. When I let off the gas in 4th gear the car vibrates like crazy only around 2000 rpms and lower. If its in any other gear it doesn't vibrate (haven't tried 5th yet). It sounds like the vibrations are coming from the middle of the car almost like it is a carrier bearing, but it never did this before i changed the clutch. When i accelerate it will vibrate like crazy only if i am in way to low of a gear and i can diffidently tell it is coming from the middle of the car. I haven't gotten on the car yet because i just put the clutch in and i would like to give it a little time still also because I'm afraid it will mess something up. I don't see how it could be a carrier bearing because it never did this before the clutch install. Any ideas would be greatly appreciated!!! Thanks

 

[Defiant]

See if your rear balance shaft is 180° out-of-phase.

 

[kicknurass4fun]

Would that happen if i spin the motor over the wrong way while trying to unbolt the flywheel?

 

[Defiant]

It's very likely your cam belt timing will jump.

 

[kicknurass4fun]

If the timing belt jumped on the cam gears the car wouldn't run good and my car runs fine. Is there a easier way to check if the balance shaft is out of phase other then basically ripping everything apart and performing a timing belt change. Thanks

 

[Defiant]

If the timing belt jumped on the cam gears the car wouldn't run good and my car runs fine.

Not if it jumped at the oil pump gear.

Is there a easier way to check if the balance shaft is out of phase other then basically ripping everything apart and performing a timing belt change. Thanks

Pull the inspection plug and insert a Philips screwdriver while at TDC.

 

[Mist3r Spool]

I'm confuzzled, you stated that you're having problems while braking in 4th gear...usually that means you have a warped rotor or maybe a tire is out-of-balance (which I am totally sure you know). You meant under vacuum, right? I know this post seems to be going in the direction of balance shafts, etc. but I just thought I'd point that out.

If you have the rear (oil pump) balance shaft out-of-phase, you will notice a lot of vibration between 2k-3.5k rpms and/or under vacuum. Unfortunately, the only way you can really check to see if it's not lined up is by pulling off the lower timing cover.

Remove the timing covers (you'll have to remove the crank pulley/dampener, drive belts, & waterpump/ps/alternator pulley.

Remove the spark plug from piston #1 (if you remove the rest of the plugs, it'll be easier to rotate the crank-but it's not necessary)

Insert a long screwdriver (or a rod or something similar that won't fall through) into the spark plug hole of piston #1 so that it sits on the piston.

Rotate your crank (using a 1/2" drive socket) clockwise until the screwdriver is at it's peak position (not moving up further/not moving downward). You may have to rotate the crank twice, to ensure the cams are at their proper marks (exhaust cam @ 3 o'clock and intake cam @ 9 o'clock and dowel pins @ 12 o'clock).

You may have to rotate your crank up to six times before your oil pump gear lines up (due to oilpump to b-shaft gear ratio).

If you can't get your oil-pump gear to line up-you know that's the problem. The timing marks are pretty straight forward.

 

[Defiant]

I'm confuzzled, you stated that you're having problems while braking in 4th gear...

Engine braking, not wheel brakes.