The Ford Barn

Admiral · 12-08-2020, 10:56 PM

OK, I’ll be installing a BorgWarner overdrive in my ’51 Ford and I’ve got a few quick questions about it. I’ve read both the service manual and the reference book written by Randy Rundle, so I know roughly 98% about it, but I don’t recall seeing answers to these questions in either document. (Maybe I missed them?

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Question 1: When overdrive is engaged (at speeds north of 28 mph), it’s not a problem to downshift into second gear, is it? I ask this because there may be situations where you need more power than the wide-open-throttle kickdown to direct drive provides.

Question 2: To disengage overdrive, do you have to be completely stopped to pull the control handle out, or can you just press the clutch and do it while driving?

Question 3: This may be the toughest one to answer. Since my car has the conventional three-speed transmission, I assume it also has the standard 3.73 rear end (though I haven’t torn it down yet to confirm). I know overdrive-equipped models had a racier 4.10 ratio for better low-speed pick-up. How well will 3.73 gears work with overdrive? I don’t mind a car with long legs for relaxed highway cruising, I just don’t want them to be too long. For reference, the engine will be a mildly built flathead V8 tuned for torque. It will have a 4-inch crank, boosted compression, a mild overbore, an Isky 1007B cam, a stock intake and a reworked Chevy distributor, nothing crazy.

Thanks!

12-08-2020, 10:56 PM	#1
Admiral Senior Member Join Date: Jul 2011 Location: Oakland County, Michigan Posts: 562	BorgWarner Overdrive Questions OK, I’ll be installing a BorgWarner overdrive in my ’51 Ford and I’ve got a few quick questions about it. I’ve read both the service manual and the reference book written by Randy Rundle, so I know roughly 98% about it, but I don’t recall seeing answers to these questions in either document. (Maybe I missed them?) Question 1: When overdrive is engaged (at speeds north of 28 mph), it’s not a problem to downshift into second gear, is it? I ask this because there may be situations where you need more power than the wide-open-throttle kickdown to direct drive provides. Question 2: To disengage overdrive, do you have to be completely stopped to pull the control handle out, or can you just press the clutch and do it while driving? Question 3: This may be the toughest one to answer. Since my car has the conventional three-speed transmission, I assume it also has the standard 3.73 rear end (though I haven’t torn it down yet to confirm). I know overdrive-equipped models had a racier 4.10 ratio for better low-speed pick-up. How well will 3.73 gears work with overdrive? I don’t mind a car with long legs for relaxed highway cruising, I just don’t want them to be too long. For reference, the engine will be a mildly built flathead V8 tuned for torque. It will have a 4-inch crank, boosted compression, a mild overbore, an Isky 1007B cam, a stock intake and a reworked Chevy distributor, nothing crazy. Thanks!