Hot Rods Losing battle with Hydramatic

I bought a 1949 olds 303 and Hydramatic that had been sitting for 15 plus years, I freshened the engine up and it runs great but the transmission is giving me fits. It stays engaged while in neutral and it will not shift from low to reverse. Reverse works and the reverse park lock works.

I have replaced the front and rear seals, disassembled and cleaned the valve assembly twice just to satisfy myself that I assembled it correctly and adjusted the bands and tested that they engaged and disengaged.

transmission linkage is uninstalled, engine rpm 450 and the transmission has 70 pounds of pressure at idle.

is there something that I could have installed wrong while assembling the torus assembly?
Any other ideas?

 

All my Hydro manuals are out at the shop, and I won't be going out there until Tuesday, but will take a look then.

 

@PhilA might be able to help you out as he has had his apart many times.

 

Yes, Phil helped me with the band adjustments. I thought I’d throw a wide net and see what I get.

 

I have a 1950 Olds 98, and have almost the same transmission as you do. Perhaps I can shed some light on this.
Until 1951, the reverse gear was mechanically applied, meaning that it was sort of like a non-synchro mesh transmission. I have to stop at Lo for a few seconds, then move to reverse to avoid grinding.
With this in mind, does your transmission grind while trying to get to reverse? If so, I believe the front band may be out of adjustment, which would not stop the inside shafts from turning while stopped.

 

D2, that’s helpful, I’ll try waiting longer in low before shifting into reverse.

 

i've never worked on one, but i understand that there aren't a lot of technicians left that know how to adjust them. as a teen, that's one reason we drove stick shift cars...

 

I’m stubborn enough to keep trying till I get it. I just tried adjusting the front band again. According to the fatsco website you engage the band at 700 rpm and back it off when the engine rises to 900 rpm if there is no change the band is slipping. I got no rpm change, time to pull the pan again and see if I can find what’s wrong.

 

As you know Hydramatics prior to 1954 were not Dual Range and had the mechanical reverse engagement using the coarse 'parking' paul. Dual Range units had clutch applied reverse which of course is infinitely smoother. Low gear has both front and rear bands applied, no clutches applied. Shifting to reverse releases the rear band, keeps the front band applied and engages the parking/reverse paul with the shift lever. The rear band is involved in neutral also. It is applied with the engine off but released with the engine running. Sounds like your rear band is not adjusted properly?

 

When I first disassembled the valve body that reverse parking valve was frozen up and not working but both it and reverse works now when started in the reverse position. I’m more concerned with not having neutral working which like you said may also be attributed to the rear band. Something definitely not right with the front band though.
Btw, I spent a lot of time studying your Rube Goldberg throttle linkage when working on mine, pretty ingenious.

 

Thanx! I was surprised that it works!!!!

 

Dual Range hydramatics first appeared in 1952 models. 1951 was the first year to have hydraulic applied reverse. 1950 being the last year for mechanical reverse.

 

Another thing is that Lo range can be set up for 1st or 2nd gear start. In the case of the 2nd gear start the front band is released, only the rear band is applied. As mentioned, you need to check the rear band adjustment.

 

A few years ago I had mentioned that the reverse cone clutch would periodically stick. I have only had that happen to me on my 54 Lincoln. The symptoms were that when in a forward drive range the car would not move. Reverse worked, but even neutral felt like the car was stuck in a gear.
In the Paul Marsh hydramatic manual there's a procedure to get the reverse clutch freed up.
It lists that you shift to Lo then to Reverse, then repeat 4 more times. Of course you will need to keep the brakes on during the procedure.

 

You are right. Got my years mixed up. The first gear hold valve is the patent that put B&M on the map. In actuality, it was only really useful to mud boggers who rocked the car to get unstuck! As a racing tranny, the 1-2 shift needed to happen so quickly, most racers just started out in 2nd. In the fluid coupling the low gear was the equivalent of a torque converter.

 

But his doesn't have the cone clutch?

 

Have you checked your linkage adjustment? Seems to be pretty critical on these things. That and bad motor mounts can cause a lot of problems.

 

Probably true, but his symptoms sound a lot like the reverse unit sticking problems.

 

Thanks for those who gave their input, I found the reason why it wouldn’t go into neutral. I took apart the valve body assembly (again!) and found a burr that was holding a valve in place which caused the torus assembly to spin. Some 400 grit wrapped around a chopstick fixed it.

shifting from low to reverse is now possible with waiting 10 seconds and holding the brake but it ain’t pretty.

 

Sorry I just flat spaced-out and forgot to do some research when I was out at the shop Tuesday! But, at least it sounds like you're getting somewhere...