Is there a difference between the flywheel on an firebird 87 2.8 automatic and an 89 camaro 2.8 5 speed. After swapping motors I get a very noticeable vibration at the tranny. I used my 87 flywheel on the 89 motor. Anyone?

 

There is a huge difference between a flexplate and a flywheel.

But in regards to your underlying question, there is no difference in balacing between the "87 and '89 cranks, at least there's not supposed to be. The '87 MY was teh first year of the internally balanced 660.

 

89 as far as I have read, is the cut off year. Part year was internal, part year was external.

Even if both are internal. That 87 plate/wheel was balanced per the 87 crank, not the 89.

 

Change from small journal to large journal was a mid year change, internal/external balancing was at the beginning of the MY.

Besides, with both being internal, the flywheel/flex plate won't care what year crank it's on. The flywheel/flexplate will be nuetrally balanced, in both cases.

 

IIRC 1988 was the year of the switch to the internally balanced crankshaft. The symptoms describe also fit a misbalanced flywheel/flexplate perfectly. Unfortunately this mistake will have already dealt its damage to the new engine; expect a reduced main bearing service life. Replace the flywheel/flexplate with a neutrally balanced unit before starting your car again.

 

This would make no difference. Internally balanced engines use neutral balanced flywheels/flexplates. The definition of neutral, fortunately, is not particularly capable of changing from year to year

 

ops, I meant external on that post. As well, if he put it back on the same engine, but wrong clock angle, same problem.

 

Yes, but then you'd have to drill out a few holes so that you could get the bolts to line up. The bolt pattern in the (even neutrally balanced) crankshaft is not a perfectly spaced cicurlar bolt pattern.

Also, it's my understanding that the entire 660 line up changed to the internally balanced design, with the introduction of the genII which was in 1987.

The symptoms do indictae a similar problem, but I have seen this happen even with the proper flywheel/flexplate. IIRC it turned out to be an ignition module or something screwy like that.

 

Whats the easiest way to get the plate off the back of the motor (without taking the motor out of car)?

 

pull the trans.

 

QFT!

 

 

https://www.thirdgen.org/techbb2/sho...61#post2643261

 

I guess that works, but it's actually Quoted For Truth.

 

That's what that post says at the very bottom.