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View Full Version : 6 bolt flywheel differences (turbo vs N/A)



Shadow
12-11-2011, 04:53 PM
Been a Long time since I worked on an 85 and older trans and I'm 99% sure but figured I'd post this up as "good info" anyway, since I searched and found Nothing on the subject.

15 years ago or so I had a customer with an 85 turbo Daytona that had a bad vibration at idle and i'm pretty sure (not 100%) it vibrated up into the rpms with throttle. After a bunch of obvious diagnostic, and knowing the car had just got this problem after having a clutch installed, we went after the clutch/ PP as posssible culprit.

Turned out that someone used an N/A 6 bolt flywheel to replace the turbo flywheel. Since the older mtrs where Externally balance by the flywheel/ ring gear (this is what I was told at the time) it shook being missmatched.

Sure enough, we found that there were two different part #'s and a pretty big difference between the two flywheels. We put the right one on and problem solved.

So, here I am with an 85 that's being converted to 5 spd and I need to make sure I put the right flywheel in there!

I have both 6 bolt flywheels and I'm 99% they go like this Turbo = part#4329179 and has smaller "ring" on the backside AND takes the larger PP bolt pattern.

N/A = part#5222680 and has much larger (thicker) "ring" on backside and has smaller PP bolt pattern.

Someone want to confirm 100%?

Also, was the 2.5 Ever available with 6 bolt flywheel? (that could throw another wrench in there!)

Cliff Ramsdell
12-11-2011, 07:28 PM
Bob,
There are two different flywheels but it has nothing to do with balance and such since all 2.2 motors were considered a neutral or zero balance motor.

The difference was the clutch size, 215MM of an N/A application and 230MM for a turbo/minivan application.

Motors were built with no consideration for the final transmission application either stick or automatic so the balance would not have been a consideration. All the early motors, up to '86 were also built with the heavy rods like the ones used in the TII motors but were not a full floating pin, just pressed.

Hope this helps,
Cliff Ramsdell

4 l-bodies
12-11-2011, 08:49 PM
Yes Rob the 6 bolt turbo flywheel has the larger PP bolt pattern for sure. My parts book says 85 turbo flywheel is part # 4348314. That is for turbo and H & K cars too. N/A smaller PP bolt pattern # is 4348312.
86+ N/A vehicles part # 4338874 and turbo and vans used 4338872. (8 bolt)
Part# is probably different than cast # on flywheel due to assy. (with ring gear).
Todd

---------- Post added at 06:49 PM ---------- Previous post was at 06:46 PM ----------

No 2.5 ever came with 6 bolt flywheel. TD 2.5's came out in 86 and lasted thru 88 model year.

Shadow
12-11-2011, 10:36 PM
K, thanks for the replies guys and that gives me enough to do what I'm doing now. And ya, casting #'s, Not part #'s :banghead: Wierd though, because I distinctly remember changing the flywheel on that Daytona all those years ago and the vibration dissapeared?

Although, I would have to have changed the clutch/PP to the larger bolt pattern and I don't remember doing that??

Maybe someone dble drilled the N/A flywheel OFF and that was the whole problem? Strange......