High Speed Gears or Overdrive

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    I’ll assume that everyone has heard of Phil Bray’s passing. A friend remarked that the high speed gears which Phil supplied to the hobby might be at an end. Does anyone know about the future of the business, and the supply of high speed gears?

    Which makes me wonder, has anyone installed an overdrive on an Eight-cylinder Pierce? Just curious that if so, which brand you used and how you like it. And might you recommend an overdrive instead of high speed gears?


    PAS member Lloyd Young has done quite a few Borg-Warner overdrive installations in P-A’s. 1933-35 cars with the S-W Power Brake are a complex setup, but pre-’33 cars are a natural. This is the same unit used in 1936-38 P-A’s, but using a much safer solenoid control rather than the centrifugal so they can handle the application. The engage-dropout speed gets down to less than 25 mph, compared to 40 or more with the centrifugal arrangement used by Pierce.

    I have owned B-W overdrive equipped cars since the early 1960’s and have added them to a number of cars that were available as an option when new. There is no better way to add flexibility and lower engine RPM’s. One of the reason I got our first P-A was the standard overdrive in the 1936 1601. It’s part of the high quality experience!

    I put a Bray gear in my 1933 1247 because I wasn’t smart enough to figure out how to do the setup for the O/D from ’36-’38. In retrospect I wish I’d pursued the O/D option as this car is a driver, not a show car. The only advantage the gearset change has in my opinion is that it is invisible. The 30% reduction in engine RPM’s with O/D is far preferable.

    The overdrive can be used in 2nd gear as well as 3rd which allows low speed operation in town into 2nd overdrive with no lever change. Once engaged you will have engine braking down to 25 mph unless you flip a solenoid switch to deactivate. If you go this route I suggest getting a spare driveshaft to shorten and keep the original so that the car could be returned to original specs later if ever desired.

    Some of Phil’s gears had noise and setup issues. Mine had both. Phil used my original gearset to run comparison tests to determine that there were issues and did do some price adjustments after that for some members. I used the 3.85 in the ’33. It helped some, but from every perspective I wish I’d installed one of the old Phil Hill 3.54 sets instead.

    I believe Greg Long was doing a different brand O/D unit. You could check with him or he may post his experience. Whichever O/D is more cost effective is still a better investment than using a Phil Bray gearset unless you are after show points.

    Pierce-Arrow was a leader in using the O/D in 1936 along with Chrysler. Others used the European pre-selector route combining O/D. Think about this: What modern car doesn’t have overdrive for efficient operation?


    Hi all, This subject has over the years been discussed on The Message Board.I am about to try the Overdrive idea on my 1929 133. The unit I will be using is a Laycock model B. The same as the Jaguar & Austin Healey etc. It is bigger than the J Type which was fitted to Triumph & Volvos etc. I figure that The bigger unit will take the torque, Jags being 125 +++ hp. The Laycock Model A is similar.The solenoid activating unit is of course 12 volt & my car is standard 6 volt & works 100% AOK.. I think with a bit of engineering the B Type Overdrive can be adapted to do away with the solenoid & use a cable to the dashboard. I MUST remember to figure a fail safe way to avoid leaving it on when selecting the gearbox in reverse, otherwise the freewheel device in the overdrive unit will lock & break the unit!! Also the O/D unit will have to be off set to the left of the tailshaft centre line so as to clear the torque arm. 3/4″ would do it. Since the tailshaft will now be a split into 2 I do not see a problem. The O/D unit will be mounted on 2 new cross members. The front of the O/D unit will have a specially designed plate With the input shaft bearing & seal fitted to it. The input shaft will be modified to take a standard Hardy Spicer flange. This is ALL EXPERIMENTAL!! so it will take a little while to achieve. I will photograph the process & anyone interested can eMail me & I will send a zipfile of it. Maybe by Xmas!! I have done similar conversions on my other Vintage cars. 1924 Delage, 1927 lancia, 1925 Turcat Mery, 1925 Lorraine Dietrich. It works a treat on these as they have much less torque than a Pierce- Arrow. The Pierce I assume would pull a hi rear ratio without much of a problem. However an O/D unit gives the original gearing PLUS 2 or 3 extra ratios. This is the best of both worlds! Plus it is a bolt/bolt off conversion if you want to go back to original. Cheers



    I have fit several Mitchell overdrive units in Pierce arrows.

    I went with the Mitchell because it is a simple synchronized gearbox. No electic solenoids, no free wheeling, no issues.. Just either in direct: 1:1 ratio or overdrive, which for our applications is 26%.

    So for my ’33 836 with the original worm drive differential, a 4.28:1 ratio, the new final drive ratio in Overdrive is 3.17:1. I chose the Mitchell OD because of the ’33, ’34, ’35 stewart warner power brake system It has to have a spinning driveshaft to have brakes. An OD system with freewheeling would leave the car without brakes. The simple Mitchell OD is either in direct or OD. so unless you intentionally select a postion between gears there will always be braking available.

    My ’33 836 is a dream to drive with this OD, the engine easily pulls this gear ratio at 60-70 mph on all Michigan freeways, and even at lower speeds, 40-55 mph on secondary roads are no problem. The engine runs cooler and of course quieter.

    The Mitchell family has used this gearbox in a 1 ton pickup truck for 20 years, towing cars. Their pickup truck is a gasoline big block V8 truck.

    I looked at an open OD at the Mitchell shop in Colusa California. The gears are very robust, the shift forks heavy, the bearings large, and the box itself very heavy duty. The OD uses standard input and output yokes and U-joints.

    The only drawbacks are that there is some gear noise in overdrive, in m cars, a distant whine.. The noise level seems to be lessening as i put on more miles.

    The gearbox uses a mechanical shift, so either a cable or a shift lever with a push pull rod is needed to shift the OD

    On my ’33 836, I made a simple selector located under the front seat. It is not intended to be shifted on the road. I leave the car in OD 95% of the time.

    I have made NO attempt to do any noise insolation with the OD.

    The mounting is quite easy for anyone capable of steel fabrication work.

    I have installed three Mitchell OD units in Series 80 cars. The Series 80 cars have either 4.45:1 gears for most enclosed cars and open cars. In mountainous areas, Pierce equiped the cars with 4.88:1 gears. The Pierce literature states that there also was a 4.65:1 gearset available, But I have never seen one.

    With the 26% OD, the new gear ratios are : 4.45:1 x .74 = 3.29:1 . And the mountain gears 4.88 x .74 = 3.61:1.

    The resulting rpm drop makes for not only a higher max speed, but much less noise and engine wear and heat.

    The Series 80 installation is a bit more involved, because the Torque Arm front mount needs to be moved or offset to the right. The parking brake and rear brake pull rod needs to be moved or shifted to the left.

    I made a gearshift lever that shares the parking brake handle and slot in the floor boards, It works very well, and looks pretty much like a piece of original equipment.

    I prefer an overdrive over high speed gears. With an OD, the original gears are still there, and just one shift to OD will give you an additional 10-20 mph available if you wish.

    Greg Long


    The 1930 Model C sedan that I owned from 1996 to 2005 came with a Borg OD unit that generally worked fine, but had quirky kick down and reverse limitations that I didn’t particularly like. It conked out in the middle of a tour in the late 90’s, just when Phil Bray was developing his first Pierce ring and pinion sets. Arlo Boe installed one for me and it worked quietly and effectively for the entire balance of the time I owned the car, including our 3000 mile cross country trip from Minnesota to the Bartlett, New Hampshire meet in 1999. I know others had problems with some of the later sets, but mine always worked fine. That said, though, now that Greg has used Mitchells on his Pierces, I’d give that option serious consideration. I installed 26% Mitchell’s on both a 1918 Reo M-6 touring car, and also on a 1930 Model A Ford woody wagon. Both performed really well, and I much preferred the Mitchell mechanical lever shifting to the electronic solonoid set-up up on the Borg unit.


    I have the Mitchell in my Series 80 thanks to Greg and it runs fine.

    I have yet to use it on any PAS tours, but Jak, if you come up to Rhode Island this year for the 2014 Annual Meet, there will be at least one Series 80 with the Mitchell overdrive installed that you can test drive.

    Cheers to those in OZ!



    I looked online, where do you see them for sale? Ed


    Mitchell Overdrive is old school. Sue Mitchell uses email, but does not have a website.

    Mitchell’s main customer base is the Model A. They make a ‘plug and play’ OD setup for the Model A, torque tube, shifter etc. I’m sure you can find some in print ads in Model A Literature

    Sue Mitchell’s husband developed, designed, tested and extensively used the OD. They used to make a much larger one for use as an over or underdrive for big trucks and motorhomes. This Motorhome unit is about the size of a 5-gallon bucket !! It is no longer made.

    The unit I use is called the model 1000, it is an aluminum box, ribbed for cooling. It has a normal input yoke using a 1310 U-Joint, and a standard splined output shaft. You have to buy or get your own U-joints, output spline drive yokes, and adapters to the old style drive yokes on our Pierce Arrow cars.. I bought mine from wholesalers, and made my own adapters.

    The box is 10″ wide, 9″ long and 5.5″ tall. The input and output are NOT centered in the box, this is because the counter shaft or secondary shaft needs more room than the shift fork and push pull shift rod. See the photos.

    Mitchell Manufacturing makes the unit such that the shift rod is on the left side of the box when mounted, the vent and speedo cable housing are set up for this orientation. The determining factors are the vent [must be on top], and the speedo cable housing orientation, the cable must be above the centerline and lube oil level.

    On the Series 80, I had to ask Sue to make a few modifications to the vent and speedo cable housing, so that the box could be set up with the shift rod on the right side of the box. This allowed a direct push-pull rod shifter from next to the parking brake back to the OD shift rod.

    Sue was more than accommodating, Sue’s daughter who is a machinist in the shop also worked with me regarding the modifications.

    However. Sue’s son Steve, believes that the ONLY OLD CAR IN THE WORLD is the Model A, and fought the process of making any modifications. He basically said if I couldn’t make the OD unit the way HE made it, then I didn’t know what I was doing. [He didn’t design it, his Dad did].

    Anyway Sue and her daughter Cyndi made the minor changes, it just required drilling and tapping the opposite side of the case for the vent and rotate the speedo cable housing 180*, and move the drilling and tapping of the one ‘odd’ bolt for the speedo housing 180*.

    So if you want a normal OD, and want to have the shift rod on the left side of the box, get a normal Model 1000, if you want to have the shifter on the right side of the box, ask for the ‘Pierce Arrow’ version. I’m sure Sue still has the differences in my file..

    Don’t expect fast service !! This is their busy time, everybody decides once the weather warms up that ‘this year’ I’ll put in an OD.. Mitchell Mfg often is 3-4 months behind on Model A orders.

    Most of the Accessories for the OD are available from driveline and transmission wholesalers. I have names and numbers for a very good one in Fresno.

    Here are a few photos of my 836 installation and of a normal Model 1000 OD unit.

    You can email and request a paper brochure be mailed to you, or telephone and request one

    [email protected] 1-800-859-2088 Ask for Sue, or Cyndi. I highly recommend you DO NOT

    attempt to ask questions of Steve. He won’t be helpful.


    Here is the standard OD box, from the input end.

    Greg L


    Thank you Dr. Peter for your kind regards! Just a quick comment on the Laycock unit

    The “freewheel”” part of the Laycock O/D does not work like a normal freewheel. It does NOT at any time disconnect from the drive system. Therefore you always have engine braking. The Mitchell unit looks the berries. Plus it is USA available. You should be able to (If interested) in the Laycock O/D be able to source one via the Jaguar & Austin Healey fraternity. BUT remember that if you do get one to be SURE that the gearbox mainshaft is with the unit as it forms an essential part of the O/D unit & if missing is a VERY expensive item to reproduce. Cheers




    I’ve only seen one Turcat Mery in my life.It’s amazing that a P-A

    Society member would have one. Can you tell us a little about it and

    how do they perform?



    Scott, I will be at Warwick in July, I can draw sketches, demonstrate the Mitchell Overdrive etc if you will be there.

    Greg L


    I’m glad my question generated so much response. Thanks to all.

    I’ll add at this point that I did have a Mitchell overdrive in a 1926 Packard some years ago. The one advantage mentioned about it preserving the standard gear ratios is especially advantageous if you live in hilly country. (I’m near southern Vermont) The Packard had a big high torque engine as well, but there were times when I was glad to drop out of overdrive into standard ratios.

    The Mitchell was a nice unit. Well made. Slight gear noise but nothing to whine about (pun intended). I do wish they had a website for easier information, though.

    I was expecting that most Pierce guys would prefer high speed gears, but this discussion has been enlightening.


    Ok……I will chime in. I have no problem with the overdrive installed, but I would rather a high speed ring and pinion. First I don’t like the look of the extra shift lever. I see from Greg’s comment he uses the OD 95 % of the time. I think I would hide the shift lever under the car or hood as it is only used rarely. As a purist, having an extra assembly under the car also bothers me. I restored my 1936 1602 ONLY because it had a factory overdrive, otherwise I would have bought a 35 V-12 to restore as I like the body style better. I think the gear set is less expensive as an option and less work to install. I had only seen a gear vendor splitter / overdrive in the past, and the Mitchell is new to me. It looks like a good unit, and if in the market for an overdrive I would use it. I think there MAY be a safety issue with the splitter / OD units on the 33 to 35 Stewart Warner brake systems. If the unit has a neutral or non engaged spot there would be no brakes, and thus a very dangerous situation could develop. One also must remember that just because a Pierce can go 75 MPH does not mean it should. A perfectly restored and operating car can be driven at higher speeds, but a barn find car that has not been properly gone through could and would be very dangerous to drive if the steering, brakes, wheels, and shocks are not operating at 100 percent. My estimate is that 75 percent of the cars currently at the meets are below par on brakes, steering, and suspension. Many also have bent or out of true rims and old or very old tires and tubes. Thus a disaster on a improperly prepared car with an overdrive or high speed rear end could easily happen.


    The correct installation of a Borg-Warner unit on older P-A’s should eliminate the kickdown switch and simply use a toggle switch under the dash. When the kickdown circuit is eliminated you can use reverse with no fear. I have 3 cars that I’ve installed and set up this way. On my 1949 Hudson CV that originally came with O/D, I still eliminated the kickdown switch and installed a toggle. The cable lock-in/lock-out can be placed under the dash and not visible from beltline or above.

    As Ed points out there are serious pitfalls on doing a ’33-’35 O/D installation of EITHER type and I’m not sure about the Laycock. Use on my British sports cars that I had as transportation in the 60’s & 70’s was seamless and reliable.

    I’ll repeat my original comments that done properly ANY O/D makes for a more flexible driver. I can assure you that based on my experience, it is FAR less expensive that high speed gears. I absolutely wish I had gone with O/D on the 1247 because a combination of O/D and the S-W Power Brake unit would be nirvana! Our 1936 goes like crazy, the 1933 stops like crazy.

    On my 4 B-W O/D setups I’ve had one solenoid failure, that on the 1949 that was a high mileage 53 year old original. If it fails while traveling, you can merely use direct drive for the balance of the trip. Brand new 6 Volt O/D solenoids are available from Randy Rundle at less than the quoted cost of a rebuild.

    Why did Ed choose the 1936? That’s the driver choice.


    Edgar pointed out:

    >>I think there MAY be a safety issue with the splitter / OD units on the 33 to 35 Stewart Warner brake systems. If the unit has a neutral or non engaged spot there would be no brakes, and thus a very dangerous situation could develop.

    He’s right. With the Mitchell I used on the Packard, yes indeed you can find a neutral. If you do not engage the high/low gears fully and firmly, you are left in a neutral condition. This happened many times if I was a little too gentle with engaging or disengaging.

    As for going fast, I never used the overdrive to simply go faster, per se. I used it to get the engine rev’s down to a less-hectic level. Even at 35 mph, the engine sounded so much better in overdrive than without. And in those occasions when I needed to do 50-55, I believe it was alot easier on the engine to not have those long connecting rods thrashing about. Not to mention easier on my ears


    I also wanted to say that I agree that most cars out there are not in the best mechanical condition. I’d say that very few cars have had full engine rebuilds and every mechanical aspect assured to be perfect. I’ve owned several cars of various makes over the past 35 years and every one, without exception, required a proper full engine rebuild and the cure of a host of mechanical problems. And some of these were cars which I was assured were “rebuilt” or ‘perfect drivers”. To most people, I’m convinced, “restored” means a cosmetic restoration to make it look pretty with little or nothing done mechanically than to just make it barely drivable. The source of this is, I think, judging which only rate cars based on cosmetic condition. Unless you drive your cars, there is little incentive to invest into the unseen parts of your car. Many owners are not mechanically astute and are under the illusion that if the engine runs and the car moves, it is “drivable”. Not so.

    So if you are into speed, I agree that installing an overdrive may be a very bad thing by encouraging faster driving when your car may not be up to it.


    From my driving experiences in old cars, if you are on a tour,driving a 40mph car, or slower is just fine. You are with a group of other ‘speed impaired’ cars.

    But, Say if you want to go to friend’s 25 miles away, for dinner, and will be coming back after dark, driving an old car with dim and minimal rear lighting, and driving under the speed limit by 10 or 20mph. is just inviting to be rear-ended.

    So for me, being able to drive comfortably at 50-55mph instead of 40mph and being a rolling road-block is a safety issue. Having people not recognize that there is a slow moving car in front of them, then going into road-rage or totally stupid in order to pass you is incredibly unsafe.

    As for the in-gear or not-in-gear possible situation, yes it can happen, but I think I have to TRY to not get it in gear. I would not want to have a totally hidden, inaccessible shift in a car that needs to be in gear for the power brakes foot brakes to operate.

    And it needs to be said: the ’33, ’34, and ’35 cars with Stewart Warner power brakes ALSO have very good brakes using the parking brake or emergency brake handle, and the hand brake is applied to ALL FOUR wheels.

    I can almost lock the brakes on my 836 with the hand brake.. it certainly is not convenient, or ergonomic, but it is a very effective emergency brake.

    The question of safety of driving our old cars ‘at speed’ will be a discussion that can go on forever. I know that some cars are being driven with older tires, possible loose steering, marginal brakes, poor shocks etc..

    But just how good are the other cars on the road with us? Good tires ? Good shocks? Worn ball joints and tie-rod ends? And the driver texting their friends, with the sound system at 110 decibels?

    I think an old car, driven by someone ‘in tune’ with DRIVING a car, is not just pointing a power assisted., auto transmission’d, electronically controlled appliance down the road, distracted by the radio, programing a GPS etc. A person driving an old car is DRIVING the car, he or she can feel the road, feel the wind, feel the engine, and because of this is involved with driving. I believe that this makes an old car equally as safe as a poorly maintained ‘modern’ car driven by an uninvolved, distracted driver.

    Since this is a thread about High-Speed Gears vs Overdrive, I’ll get back on subject. The most recent vendor for high speed gears really soured that option for me, I’ve heard of many issues with these gear sets. And while the Mitchell is not silent in OD, it is silent in direct. The high speed gears were noisy all the time.

    When I had a ’27 sedan with mountain gearing, it was a rolling road-block, I regularly pulled over to let the lineup of cars behind me to pass when on 55mph secondary roads. This spoiled my enjoyment of this car, except when, once or twice a year i’m on a tour.

    Because of the road speed issue, I went looking and found my ’33 836 Club Sedan. It’s definitely a driver, and it has been driven, several thousand miles a year. But even with a relatively comfortable 50-55mph cruise speed, I still did not enjoy going on an hour drive in the car. But with the OD, 60-65 is comfortable, more comfortable than 55 was without the OD. And going someplace an hour drive away is not something I dread anymore.

    I do pay attention to DRIVING, I have two hands on the wheel, looking for passing traffic, driving DEFENSIVELY. Could a tire blow out? sure, would it be more dangerous at 65mph, than at 50mph? sure. But since I’m INVOLVED, I think I’m much safer than the out of touch person with one or two fingers on the steering wheel, looking at their smartphone, with the radio at 110 decibels. A blown tire in this scenario will end up with the car off the road and likely upside down. The driver is not aware until it is too late that the car has a problem then over reacts.

    I wish I was bringing my ’33 836 to Warwick, to demonstrate the car with the OD, but I will have my ’25 Touring car there, and it is also equipped with a Mitchell OD.

    Greg L


    I once owned a 1911 Hudson torpedo touring. The restorer had

    doubled the horsepower and added a manual overdrive without a

    neutral. In 1968 he had it air freighted to New York and toured

    back to S.F. with 50 other pre ’15 autos. He had a lead foot and

    65MPH was his cruising speed(75 was about tops, but it was

    comfortable at 65MPH).He had upgraded his brakes with ’55 Chevy

    hydraulics and he robbed a Cole V8(twice the weight of the Hudson)

    for its contracting manual emergency brakes. The overdrive made

    that car rapid(6 speeds forward).

    I once sold a 1913 M4 Franklin because every one I had toured

    with was a dog in the hills and cruising speed was wanting. The

    guy I sold it to took me for a ride after he had restored it and

    put in an overdrive. I was amazed at how flexible the car was. On

    his maiden voyage, he joined the 1976 Bi-Centennial Portland to

    Philadelphia Tour and cruised at 50-55MPH(it was 6 cyl.,240 cu.

    in.). The moral is: changing the gear ratio takes something away.

    Adding an overdrive only improves the car. If you are a purist,

    leave the car alone.


    G’day from the Land of OZ.

    Adding to this stream —As an engineering exercise I am fitting up a Laycock Overdrive unit to my 1929 Club Brougham. I also have a set of Phil Bray hi Ratio CWP gear sets. BUT I do not have 100% confidence in the Gear set after perusing some of the Messageboard streams on the subject. Hence the Laycock conversion first off the cab rank. A couple of photos to follow. Cheers to y’all


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