Flex Plate; reuse or buy a new one?

[bsrosell]

(regarding '57 Golden Hawk w/ Flightomatic). Original flex plate looks good, no cracks that I can see at any of the bolt holes. Are these considered a 'wear item' that should be replaced upon rebuild, or do they go forever with the original (ie: properly aligned) bell-housing?
thanks!
Barry

[BobPalma]

As difficult as it is to install one when they go bad, it's cheap insurance to install a new one when the old when is in your hand. And you're not using up rare NOS parts; those can/could be easily reproduced in better material when/if necessary. BP

[bsrosell]

ok, thanks Bob. You actually addressed my unstated concern, "are the new plates as GOOD as the old ones?" I replaced a lot of things when rebuilding my Model-A Ford, thinking I was doing a good thing, only to find out later the original parts were MUCH better quality than the repros.....

[showbizkid]

This is one of those parts where microscopic stress cracks can occur over time, especially in a part that's 50 years old! My preference would be to replace it (unless you want to take the time and spend the money to Magnaflux it, which will likely cost more than a new part).

[rusty65]

Replace with new, save the old; you're one and done.
Just my .02.

[sbca96]

Be sure to use the proper alignment tool that fits inside the bellhousing
hole to center the torque converter on the crank/flex plate.

Tom

[bsrosell]

Tom, with my Model-A Ford, I simply used an extra transmission shaft for this. I assume that would work here too? (I have an extra FOM tranny torn apart....)

[PackardV8]

unless you want to take the time and spend the money to Magnaflux it, which will likely cost more than a new part.

FWIW, at the automotive machine shop where my heads and engines are done, we magnaflux test parts all the time. It takes seconds and costs very little. Ask around at independent machine shops.

On longevity trick I remember doing way back when on a drag car - we cut the center spider out of an old but magnafluxed good flex plate and welded it to the new flex plate, giving a doubled center.

jack vines

[PlainBrownR2]

I had one replaced in my Lark a couple of years ago. The one that came with the original drivetrain finally split and cracked. I wasn't going to lay down in the gravel and the snow to wrestle that transmission loose, so we brought it to one of our Stude shop guys. Anyway we bought a few of these flexplates which were still like new, but slightly used, and he went to the task of bead blasting the faces of the flexplates to smooth them out and remove the grunge, and then very carefully inspecting each and every one of the flexplates. On the surface the flexplates looked good, but at the microscopic level when the dirt was removed, a couple of them showed some problems. A couple of them were not usable due to some of those hairline cracks, but one of them was still in excellent shape, so it went in the car. Once that was done and the bellhousing was back on, it was checked out for alignment and the runout, and they were deemed as being dead on(age really killed the flexplate), so the car was buttoned back up.

[sbca96]

Tom, with my Model-A Ford, I simply used an extra transmission shaft for this. I assume that would work here too? (I have an extra FOM tranny torn apart....)

I can not say for sure, but years ago (before I went to a TH700R4 on my Hawk)
I was able to "borrow" it from John Myers. I have a drawing of it around here if
memory serves.

Tom

[52 Ragtop]

If I remember correctly, someone told me to double them up, and I did that on my 57 Golden Hawk. I also think new ones are available from some of the vendors. Rich?

Jim

[bsrosell]

yep, I've seen them available new, I was just wondering if that was a wise replacement or not, considering how many "perfectly good" originals I didn't use on my Model-A and wish I'd kept them due to poor quality of repros. Thanks.

If I remember correctly, someone told me to double them up, and I did that on my 57 Golden Hawk. I also think new ones are available from some of the vendors. Rich?

Jim