1956 Hydramatic flex plate spacers and starter

[Otto Skorzeny]

I just finished overhauling the Hydromatic transmission in my 1956 Cadillac. When dismantled, there were 3 spacers between the flex plate and the torque converter. An empty bolt hole seemed to indicate that there should have been a fourth spacer. Somebody probably lost one over the last 50 years.

I reassembled it using a fourth spacer taken from a spare transmission. The shop manual doesn't show pictures or say anything about this. I decided to look in the GM parts book that goes up to 1959. The listing for the flex plate says to discard  (throw away) the spacers when installing the new flex plate. In the same parts book also lists these spacers in case you need them. That seemed somewhat incongruous but one never knows when dealing with the General.

My question is; Was the new flex plate listed in the parts manual a different design and thus no longer in need of spacers? Did GM discover a problem with  the flex plate/spacer design that caused them to tell mechanics not to reinstall the spacers? What gives?

Next; what effect, if any, dl the spacers have of  the function of the starter? Will they move the ring gear into or out of the way of the starter gear?

If anybody can shed any light on this I'd be much obliged.

[Roger Zimmermann]

On my parts book going to 1958, the shims are listed for 1956 to '58 cars. On the Cadillac Serviceman from April 1956, there is a notice sying the the shims reduce vibrations and that they were installed from engine nr. 061172.
I saw these shims on each '56 - '59 transmission I overhauled.
On the part book going to 1965, the shims had to be discarded on 1956 to 1959 cars with the new flywheel # 147 4670. A change was probably done on spare parts, who knows...
At your place, I would fabricate one shim and install it.

Good luck,

Roger