dual range hydromatic, I'm confused.

Unknown
Unknown
edited November -1 in HUDSON
I recently put a dual range hydromatic in my wasp and found first off that the car would shift way too soon and I would be in fourth gear in about 100 ft. 1st to second would happen so soon that the car was barely moving. It shifted too soon but very smoothly.



So I started adjusting the throttle linkage to the transmission so that with a wide open throttle the throttle lever on the transmission would be in the kickdown position. It worked but the shifts became very harsh and when I slowed the car down it would really bang into 1st . Also the shift from second to third would be very long and the engine would over rev.



Then I started adjusting the throttle linkage back again the other way to soften the shifts and that seems to work but I still get a hard shift down into 1 st gear. If I go too far the kickdown doesn't work.



Any ideas on how to adjust the transmission for smooth shifts and proper kickdown?



thanks Jim

Comments

  • RL Chilton
    RL Chilton Administrator, Member
    Jim-



    Did you install a repro tranny mount or use an original?
  • Ol racer
    Ol racer Senior Contributor
    FYI

    There is an adjustment procedure outlined in the MOTORS Manual. You are on the right track. The TV Rod with no travel at all will shift real quickly. Adjustment depends on weather its a rebuilt unit or a used trans that had set. ( I just removed a dual range that sat for yrs and it would skip 2nd & 4th gear)....
  • Unknown
    Unknown
    Your first setting was WAY wrong. Look up setting throttle pressure in your shop manual. You need to after warming up motor put 1/4 inch drill bit thru linkage crossover. then loosen both nuts on throttle rod. Then push throttle rod all the way to the rear, then run lock nuts down finger tight. Next you want to back lower nut off two turns, tighten upper nut down ,shortening the tv rod. Then road test, you still may need to shorten rod to get shifts later. Also check manual about gas pedal stop setting. Good Luck Lou Cote
  • Unknown
    Unknown
    Rl, I used an original tranny mount from the donor car from which I got the transmission. I did modify the throttle set up a bit so as to switch the linkage from a single carb to the twin h but as far as I can see its got the same geometry that an original one would have.



    Lou, I haven't seen any instructions on the gas pedal stop settings.
  • Unknown
    Unknown
    Was This Car A Stick Shift Before??? Sounds Like You Have A 4/ten Rear End Ratio. Bill Albright
  • Unknown
    Unknown
    Hi Bill, yes I forgot to mention that I changed out the rear to a 307 and it also made quite a difference in the shifting, thanks for bringing that up. It does still shift quite well exept for a hard downshift from 2nd to 1st. I've tried adjusting the linkage but now I've gone too far and no longer have kickdown. I feel I'm close but not quite there yet.
  • Unknown
    Unknown
    Although proper adjustments are a must, it took me a bit of time to get used to how the old Hydra-Matics shift. Lots different than an automatic with a vacuum modulator or a new one that is electronically motivated. Finessing the accelerator while driving can net some interesting results, too.
  • RL Chilton
    RL Chilton Administrator, Member
    Dave53-7C wrote:
    Although proper adjustments are a must, it took me a bit of time to get used to how the old Hydra-Matics shift. Lots different than an automatic with a vacuum modulator or a new one that is electronically motivated. Finessing the accelerator while driving can net some interesting results, too.



    Original mount is good. Repros have too hard a rubber and will cause a violent downshift from 2nd to 1st. I also had quite a bit of road-testing to fine tune the linkage. Hydramatics are quite different than say a more modern day 700R4, etc. Shift points are very different. They can also be varied by staying in the throttle a little harder . . . tranny will shift later. I tend to keep it out of 4th around town by leaving the gearshift in 3rd and not using 4th at all until I get to the highway, and manually shift it into 4th at 50 or 55 mph.
  • Unknown
    Unknown
    I must say though, now that the transplant is done with the higher speed rear end, the car is a delight to drive. After reinstalling the carpet with its sound blanket the car is nice and quiet as well.

    I drove over to a cruise hangout the other night and some of the guys asked if I was driving an electric car as they couldn't hear a motor. I opened the hood and showed off the twin H carbs and air cleaners and heard a lot of wows. It definately is different from all the belly button cars that are usually out.
  • Unknown
    Unknown
    RL if this tranny ever gives up I would seriously consider a 700 or 200 r4 overdrive tranny. With the 307 rear end and the overdrive tranny a guy could cruise all day at 80 mph and the engine would just be purring along. With all that torque it would eat the hills.
  • Unknown
    Unknown
    Jimalberta wrote:
    RL if this tranny ever gives up I would seriously consider a 700 or 200 r4 overdrive tranny. With the 307 rear end and the overdrive tranny a guy could cruise all day at 80 mph and the engine would just be purring along. With all that torque it would eat the hills.



    Hope you cruise right down to the 2009 Nationals. Ron
  • Unknown
    Unknown
    I'm waiting till the 2010 when they are in Spokane ,Washington, that's more my neck of the woods.
  • Ol racer
    Ol racer Senior Contributor
    The Hydromatic was/is quite a Transmission... I am told by older Tranny Repairmen that the same Unit in Cars was also in Trucks, school Buses, and off Road Equipment with just the addition of deeper oil Pan...(What other Automatic could equal that claim back in the Day) Hydro helped make B&M famous with their Hydro Stick drag set-up shifting many Supercharged racers for years. The Hydro was virtually indestructable when propery maintained but its one downside is the extremly heavy weight....



    Parts are still available to rebuild Hydro's (www.autotrans.us) Dave Edwards, and a few Trans Shops will do the rebuild. I understand one of the best Person currently is Gus Souza, (630 231 7764) who rebuilds and ships Hydro's Worlwide.
  • Unknown
    Unknown
    Here's some interesting reading on the subject:



    http://www.hyperionparts.com/Rolls_Royce_Bentley_Mechanical_Support/HydraMatic_Transmission.html
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