1950s Will 59 hydramatic fit in a 1958?

[D. Mailan]

Hi all,

My 58's transmission has been giving me issues. Will a 59 hydramatic fit in a 58?

I assume there would be no modifications needed. I know that the transmissions internally are slightly different.

Thanks,
Derick

[dn010]

According to the interchange book, only 59-60 interchange.

[60eldo]

59-60 are 2 different transmissions, 59 is bigger

[D. Mailan]

Yeah, like Jon said. The 59 and 60 are very much structurally different. I believe its impossible to put a 59 jetaway in a 60 due to the size difference to accommodate the lower floor on the 60.

But I am not sure if the 59 and 58 would be able to swap out.

[Roger Zimmermann]

I'm almost 100% sure it could be done. The main difference is the rear oil pump is no more included into the '59 transmission, but how often do you start the car by pushing it?
A '60 transmission into a '59 car will be OK, but the countrary will be a no go: the case for 1960 is narrower, the floor too.

[D. Mailan]

That what I thought Roger.

I am aware of the oil pump difference but that is not a concern. Like you said, how often do you push start a nearly 2 ton cadillac!!