1964 clutch replacement

[Albert P.]

1964, 327/365 currently has 11" clutch; needs to be replaced. Any problems with replacing with original size 10" clutch? Thanks.

[Albert P.]

Re: 1964 clutch replacement

Can anyone help here? Thanks.

[Larry M.]

Re: 1964 clutch replacement

Al:

Some flywheels are drilled for both 11 and 10.4 inch clutch covers. If yours is this way, then it is no issue. If it is not, you would probably have to buy a new flywheel with this dual bolt pattern.

Depending on the condition of the old flywheel, you will probably need to at least have it resurfaced and rebalanced, so buying a new one is probably not that much more expensive in the overall job costs....and labor is about the same either way.

But if you have an 11 inch clutch setup that works okay now, why change to the smaller size? Pedal pressure may/will likely be greater for the 10.4 inch unit also.

Larry

[Joe L.]

Re: 1964 clutch replacement

Al:

Some flywheels are drilled for both 11 and 10.4 inch clutch covers. If yours is this way, then it is no issue. If it is not, you would probably have to buy a new flywheel with this dual bolt pattern.

Depending on the condition of the old flywheel, you will probably need to at least have it resurfaced and rebalanced, so buying a new one is probably not that much more expensive in the overall job costs....and labor is about the same either way.

But if you have an 11 inch clutch setup that works okay now, why change to the smaller size? Pedal pressure may/will likely be greater for the 10.4 inch unit also.

Larry

Larry and Albert-----

The use of a 14" flywheel with a 10.4" clutch, assuming the flywheel is dual-drilled and can accommodate the 10.4" clutch, gains you virtually nothing. So, even if you could do it, there's no reason to; if you're going to stick with the 14" flywheel, then stay with the 11" clutch.

If you wish to convert to the original clutch set-up, you'll need to replace the flywheel, pressure plate, friction disc AND bellhousing. For the sake of originality, this might be the thing to do. From the standpoint of FUNCTIONALITY, you won't gain a lot, mostly just a bit quicker revving engine. In fact, the 11" clutch might be better from the standpoint of street driveability.

[Tom P.]

Re: 1964 clutch replacement

Larry and Albert-----

The use of a 14" flywheel with a 10.4" clutch, assuming the flywheel is dual-drilled and can accommodate the 10.4" clutch, gains you virtually nothing. So, even if you could do it, there's no reason to; if you're going to stick with the 14" flywheel, then stay with the 11" clutch.

If you wish to convert to the original clutch set-up, you'll need to replace the flywheel, pressure plate, friction disc AND bellhousing. For the sake of originality, this might be the thing to do. From the standpoint of FUNCTIONALITY, you won't gain a lot, mostly just a bit quicker revving engine. In fact, the 11" clutch might be better from the standpoint of street driveability.

Joe has provided the CORRECT answer!
Overall, for functionality, the 11in clutch is the better one to have (I have ZERO clue why Vettes went to the smaller flywheel/clutch in 63!).
And as Joe pointed out above, if you want to return the car to original configuration, you'll have to change out those parts he mentioned, PLUS, the starter (153 and 168 teeth flywheels use totally different starters)!
And if you do change from the larger to the smaller flywheel/clutch/bell housing, trust me, your current big bell housing (444 or 621 style) is worth 10 times more than the smaller bell housing! EVERYONE is always seeking the big housing and almost no one wants the smaller housing (403 style)!

[Joe L.]

Re: 1964 clutch replacement

Joe has provided the CORRECT answer!
Overall, for functionality, the 11in clutch is the better one to have (I have ZERO clue why Vettes went to the smaller flywheel/clutch in 63!).
And as Joe pointed out above, if you want to return the car to original configuration, you'll have to change out those parts he mentioned, PLUS, the starter (153 and 168 teeth flywheels use totally different starters)!
And if you do change from the larger to the smaller flywheel/clutch/bell housing, trust me, your current big bell housing (444 or 621 style) is worth 10 times more than the smaller bell housing! EVERYONE is always seeking the big housing and almost no one wants the smaller housing (403 style)!

Tom-----


Yes, I don't know why they went from the 14" flywheel to the 12-3/4", either. I suppose the reason was to gain a bit quicker revving engine but, in the process and OVERALL, more is lost than gained.

For some reason, flywheel and clutch size "alternated" among Corvette generations. C1 was all 14"/10". C2 was mostly 12-3/4"/10-3/8" (except 66-67 L-36, L-68, L-71, and L-72). C3 was mostly back to 14"/11" (except 68 small block, L-88, and 70-72 ZR-1). C4 was back to 12-3/4"/10-3/8". C5 was back to 14"/11". I believe that C6 stayed the same as C5, though.

[Albert P.]

Re: 1964 clutch replacement

Thanks for the education.

[Albert P.]

Re: 1964 clutch replacement

Discovered 10.4" clutch when taking it down; problems I found: diaphragm fingers (2 of them) were overlapping and the clutch lower rod was worn about half way through where it attaches to cross shaft. I replaced with a LUK 10.4" clutch, I get about 2" freeplay at the pedal but is woking fine; it seem that the LUK product is very good (so far anyway).

[John H.]

Re: 1964 clutch replacement

I replaced with a LUK 10.4" clutch, I get about 2" freeplay at the pedal

Albert -

Use the threaded swivel adjustment where the pedal pushrod attaches to the top lever on the cross shaft to set the pedal free play at 1" to 1-1/4".

[Albert P.]

Re: 1964 clutch replacement

Thanks John, I've got that adjusted to where the lower nut is at the end of the rod and the least amount of free play I can get is about 2". Seems to be releasing properly, and I get no reverse grind.