Guest daytona Posted September 30, 2011 Share Posted September 30, 2011 I would like to find some rear end gears for my 1930 Cadillac anything below the 5.08 that I have now. I am installing an overdrive but would like to lower the revs even more. Link to comment Share on other sites More sharing options...
Matt Harwood Posted October 1, 2011 Share Posted October 1, 2011 I don't think you'll need lower gears with the overdrive, especially given the rarity, price, and installation headaches you'll run into tracking down a set that is only incrementally lower (such as the 4.75s in my car). Remember that your tires are probably 30-32 inches tall, so it's not like putting 5.08 gears in a modern car with a 25 inch tire. The tall tires are part of the reason for the tall gears.Use this to figure out your engine revs: Engine RPM CalculatorYou're using a Lloyd Young overdrive, correct? That will give you a 30% reduction in engine speed. For example, at 60 MPH, my '29 Cadillac with 32 inch tires turns just 2000 RPM with the 4.75 gears. Completely acceptable, and 60 MPH is the very fastest I'd ever want to drive the car given the limitations of the brakes and suspension that were never designed for interstate travel. It's actually happiest at about 52 MPH. Your 5.09s will not be notably different (the calculator gives me 2240 RPM at 60 MPH for 5.08 gears and overdrive on 32 inch tires), and you'll find that the car isn't very happy going much faster than 60, no matter how much gear you do or don't have. Essentially, the engine will think it's going 42 MPH when you're going 60. How does it seem at 42? Probably pretty good, no?Hope this helps! Link to comment Share on other sites More sharing options...
Guest daytona Posted October 1, 2011 Share Posted October 1, 2011 Thanks Matt. Yes I have spoken with Lloyd (great guy, sounds like he is 50 not 91!!) I will be getting my parts down to him a week after Hershey so he can install the overdrive. You have convinced me not to get any other gears as I would just like to go 55 without beating the engine to death. With my car the engine does sound and feel stressed out at about 42mph so the overdrive should get me to 55mph with low enough revs. Lloyd is not currantly doing the whole installation, his best helper has left and he is starting a new guy, so I will have to do the reinstall and wiring. Link to comment Share on other sites More sharing options...
Matt Harwood Posted October 1, 2011 Share Posted October 1, 2011 I'd be happy to help you with any trouble spots on wiring and hookups. It took some experimenting to get mine working correctly, but the difference it makes in the car is amazing.The single most important thing I've experienced is to make sure the cable on the freewheeling mechanism has full travel so it can fully engage and disengage the freewheeling. If it only goes partially, it won't work at all. Also route the cable as short and direct as possible to reduce binding and make it easier to move.E-mail me as you have if you need tips or some assistance. Lloyd is good at remote diagnosis of the electrical problems, too. Link to comment Share on other sites More sharing options...
alsfarms Posted October 4, 2011 Share Posted October 4, 2011 Hello, I have read with interest of the overdrive install in a 1929 Cad. I am doing a 1930 LaSalle Roadster and would consider the same overdrive. Would one of you guys share a reference for Lloyd? I would also like to see a few after pictures so I can determine if it is really want I want to do. Does this conversion give much gear whine when the overdrive in engaged?Regards,Alan Link to comment Share on other sites More sharing options...
Matt Harwood Posted October 4, 2011 Share Posted October 4, 2011 The overdrive is nearly silent, and certainly inaudible above the standard noises that the '29 makes. If you look at my photo albums, you'll see an album of overdrive photos, including how it looks installed in the torque tube. Most non-experts won't notice anything amiss, since it looks like all the other big, metal parts under a car, but those who know will recognize it immediately.You may also be interested in this:http://forums.aaca.org/f169/vintage-cars-overdrive-308008.htmlLloyd's contact info is: 614-837-7832. He's in Hershey as of yesterday, so give him until next week. Link to comment Share on other sites More sharing options...
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