whats thebest hydro?

-55 cad because of the front planetary ratio evenly spaces the ratios and you dont fall out of your power range on the 2-3 shift like most all hydros.
-i cant quite remember on the input shaft but i think its the length.
- the bell housing must be flat pan and the right depth. 54 cad is the only one that will work right in my recipe for me.
-i am using the big cad cover and an olds flywheel they bolt up perfectly

 

curious about the ratios of 2nd and 3rd, thought they were 2.63:1 and 1.45:1 respectively. What are the 55 Cads?

 

The first to second shift spring will increase the shift point, but beware of your engine RPM's when doing this, don't want to throw a rod!

The pump spring, aka pressure regulator spring will definitely beef up the shifting and should speed up dump and fill of the small coupling, but you may also need to adjust the TV rod a little.

A dual range (single coupling hydro) is a great transmission for street rides, but for your needs you may not be able to easily fit it to your engine. 61-63 Pontiacs had different bell housing patterns, and after that were BOP. So yours is a BOP and it is going to be somewhat difficult to adapt to the early dual range units. (I am presently doing that and it might be costly. (55 Pontiac dual range hydro to Dauntless V6) The only fortunate thing about this is that Pontiac v8's from 55-60 had the two top bolt holes in the same location as BOP pattern, so at least there is a starting point. I'll keep you up to date with that aspect.

Right now you are probably wise to stick with your DC hydro. They could be beefed but not too much. Again I don't like sprag clutches, a weak link in my mind. Reasoning why your trans is holding up is because the main fluid coupling absorbs most of the torque (as does the earlier hydro). It is not a torque converter therefore it can only transmit torque to the transmission at 1 to 1 and no more, so you save the transmission.

Quick story: Put a 54 Olds hydro behind a built Olds 371 in a 62 Nova. One day I got on it bigtime going around a corner and snapped the rear end spider case in two. The hydro was totally intact and still going strong.

 

same as 55-56 pontiac i dont have a resource for the exact ratios here at work i have it at home.

 

Nah, he jumped past the 350 and 400's and into 4L60 land. LOL

 

1st 4.08
36%
2nd 2.63
41%
3rd 1.55
36%
4th 1.0
this is the closest 2-3 shift you can get in a 56 and older hydro
55 cad and 55-56 pontiac

 

Thanks backyard. That first gear is a real stump puller. That third gear is a little higher than other hydros. Can't wait to try my 55 Pontiac hydro with Dauntless V6 and see how well it gets into 3rd.

 

Hey you good *******s seem to know a bit about the hydro. I have a '54 olds 98 (in pieces) and a '55 Cad, stock 331.
The Cad has a mean ker-thunk from 2-3., My trans guy has adjusted the TV rod , so it does it at lower revs, but it's still annoying.
What's wrong, and is it a major to fix? I hear it's quite a common fault?
Any help appreciated, because i'm not sure we have any Hydro 'perts here in Kiwiland.

 

My 54 Cad did that back in the day. If you have already adjusted the TV rod correctly then the the transmission is going from 2 to 4 then back to 3. Seems to be common in Cads, might try looking at governor and see if it is up to specs. The G2 port of the governor controls the 2-3 shift and the 3-4 shifts(I believe, will have to check) that could be giving you troubles. Only other thing would be valve body issues with spring pressure of 2-3 and 3-4 shift valves.