redsscamaroboy

iTrader: (7)

4L80 swap , what did you do for a Trans mount in your ride? Shim or no shim?
I have a crazy harsh vibration after the 80 swap that wasn't there with the stock 4L60 or the TH400 w/ brake. 98 Z28 in sig.
Only after the the 80 swap has this vibration popped up, same torque arm as the TH400 and the same Moser 12 bolt as all the transmissions.
Driveshaft was made by a local shop that's very good at what they do.
Any info you can share will be appreciated , I can't take this beast on the highway it's so harsh.

Thank you in advance

josh4ku

iTrader: (10)

So what did you adjust your pinion angle too. Wrong pinion angle can cause this. Do you not have an adjustable torque arm? If so you won't need any shims .

redsscamaroboy

iTrader: (7)

It does have an adjustable arm, I am new to owning the car. It belonged to a good friend of mine that past away and now I own it. I have known the car for years even worked on it with him before , but didn't have any part of the 4L80-E swap though.
You think the angle changes from the TH400 it had to be 4L80-E? I can get that checked . That's somewhere to start , thank you .

01ssreda4

iTrader: (96)

Check driveshaft angle.

Firebirdmuscle

iTrader: (16)

Check your pinion angle and get that straightened out if necessary then if it's still doing maybe have them re check the balance on that drive shaft. It could be off a little.

redsscamaroboy

iTrader: (7)

What is the range the pinion angle should be in?
Is -2 degrees the best?

ls6jay

Check tailshaft play. I heard some yokes can rattle in some older tailshaft housings.

forcd ind

iTrader: (7)

Make sure you have enough yoke in the trans
A lot of time on 80E swaps, the trans ends up pointing downward due to hitting the floor, and the angle is off to the rear
Meas the trans angle, and the rear angle-picture a straight line from the trans, and a straight line from the rear-they should be close to parallel with each other, maybe the rear down a couple degrees

redsscamaroboy

iTrader: (7)

I will check that, thanks.

I see what your saying , I will look into that too.
Thanks