Thread: For Don Shilady

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Don, 2 words. Throttle Valve. A simplified explanation is, The throttle valve (located on the side of the tranny) controls the internal transmission pressure based on the amount of opening at the throttle (or carb) and essentially tells the trans when to do what. From the clamping pressure in the clutch packs to upshifts / downshifts and when to allow overdrive.

If this was not at least close in adjustment, you would've smoked the trans by now. A friend thought that this connection was the old "kickdown" linkage. So he left it off and went for a quick testride. We had to tow him back after 2 miles!

Like you, I think your transmission setup is good.

My AOD uses this same technology and I have mounted a pressure gauge in the dash so I can monitor the trans pressure, by adjusting the linkage length at the carb I can control the pressure in the trans and change shift setpoints.

Gee Whiz, Rodger thinks it is OK and so does 34-40! I am going to include a picture for Jerry out of respect for his experience. I am reluctant to change what seems to be working but when I took the air cleaner off for a picture I noticed the dangling cable. Maybe when I tromped the accelerator I forced the set nut to slide? At present the engine idles at about 1000 rpm. This is the second transmission for this car and the first one locked up due to rust after standing for about five years "dry" in my garage. I took it to a shop that was initially very interested in my car and very helpful. They played around with the first transmission for several weeks with various detergents and pressure tests. Finally they got it to shift through all four gears so I know from their pressure tests that the shift points are determined by pressure. Although the shop got the first transmission to work they talked me into purchasing a new Monster 700R4 and set it up for me with extensive road testing. Now that engine and transmission just went over 1000 miles and unless Jerry can say something full of special insight I don't want to make any unnecessary changes. I do wonder about the dangling cable with the set nut on it. I had to pressure the shop to finally release my car after they had it from February to May 2013 so I will have to go to another shop if there is really something wrong, but I am happy with it running now. Today on a 150 mile trip in my 2008 Impala (V6, 4-speed auto) I watched the tach a lot. In the Impala the tach varied a little more than My Model A but pretty much behaved in the same way as my 700R4. The tach would go up with acceleration but without any large jerkiness over shifts. I think it is OK as is unless Jerry has some keen observation. Yes the Monster trans is set for a very fast shift from low to second and often chirps the tires on that shift. Sooo what does Jerry say about that dangling cable, did the set nut slide out?

For Rodger I did the stall trick and the stall occurs right at 1600 rpm.

Don Shillady
Retired Scientist/teen rodder

While I am glad I took off the air cleaner to see the "dangling shift cable" I already had an appointment this morning for Va State Inspection and I took the car to "Performance Transmission" in the nearby Hanover Air Park. This is a one man shop with Bruce Orlandi who maintains a very neat shop with three lifts. Bruce runs a Cavalier with a 706 cu. in. aluminum block and twin 750 cfm Dominator carbs. He spotted the dangling cable as due to the flimsy aftermarket socket jumping loose when I did the acceleration tests and the cable popped back into place. I have a lot to learn about the 700R4 and I note that my setup includes a Summit accessory to make the OD shift automatic. I tried to understand every aspect of my roadster build but the installation of the 700R4 was limited by a restriction of my observations after the manager of the first shop limited my access to the shop interior claiming I asked too many questions. That shop was interested mainly in treating me as a "customer" restricted to the waiting room just reading magazines. Eventually I got my car out of that shop but there is a gap in my understanding of the car with respect to the 700R4. So far Bruce at Performance is much more informative.

Don Shillady
Retired Scientist/teen rodder