Loren

Thank you for the charts! I have had a couple of vehicles with Overdrives in them. I personally think the flathead Plymouth benefits the most from them. There is a certain charm about a flathead Plymouth and the Overdrive transmission only adds to it. The governor does exactly what it’s name implies, its in control. The only gear that is really locked out is reverse. You can’t use Overdrive in first gear because you can’t windup the engine far enough to trigger the governor. Second gear isn’t that easy to trigger either. I’ve done it but its not easy and you’d probably select high gear anyway rather than bother. The governor measures drive shaft speed and not road speed and most of us are not going back to a 4.30 final drive ratio like the factory supplied in Overdrive cars. So in truth you’d likely never use 2nd gear Overdrive. The drive shaft speed vs road speed will vary with the final drive ratio you have of course, so the governor trigger speed is going to be higher with a 3.73 vs 4.30 final drive ratio. When you consider the weight of a flathead Plymouth and the fact that its being pushed along with around 100 hp, they do pretty good! I read a road test of one and it managed a quarter mile in 22 seconds, about the same as a Porsche 924! So they are in good company ( even if there are more flathead Plymouths running around now than Porsche 924s lol )

The benefits of a diaphragm pressure plate are reduced pedal pressure and increased gripping strength. An added bonus is when it reaches its end of life, the pedal pressure goes up noticeably. However you might need two similarly equipped vehicles to detect the change because it takes place over such a long time. When you see a lot of cars with diaphragm clutches you can tell the one that needs a clutch with one press on the pedal. Just as with a spring clutch they will slip if you don’t adjust them as they wear.

Here’s my two cents: 1) The Chinese throw out bearings from AB are noisy. 2) Get that flywheel machined ( you were probably going to do that anyway ) 3) Have your pressure plate, clutch disc and flywheel rebuilt by a local “Friction Materials” shop and get an American T.O. Bearing from them Anything that does not require a core is Chinese made. Suppliers love not dealing with cores and buying at low prices. I am not saying you can’t get really high quality Chinese stuff, but not many outfits sell it and you will have to pay more for it. ( remember they have the bomb so they know how to make high quality stuff ) I think you will find rebuilders that can save you some money and give you great quality. 4) Lastly if you want to you can put a 10 inch clutch in your car. That’s what the Taxis had.

There's an old joke told by Rodney Dangerfield about dinner at his house. "You don't brush your teeth after dinner, you count them!" Well, I am going through an Overdrive transmission and I decide to try the only optional gear set for the 1940-54 transmission. At the same time I am building a 1939 Ford V8 transmission and a Studebaker R10 Overdrive ( very old school, mounted in the middle of the torque tube ) to replace the hated T5 in my Model A. My Dad said he had a set of Lincoln Zephyr gears and I thought I try them at the same time. Well a Lincoln Zephyr gear set is 3 gears and if you want a NOS set they are astronomical in price! ( there's a set like I thought I had for $2,895 on eBay ) Turns out what I had was two of the correct gears and a cluster for a 1955-56 Ford with a 272 V8. When I looked at a gear chart from Van Pelt Sales and counted the teeth nothing made sense. Hence the Rodney Dangerfield joke. It took a phone call to Mac Van Pelt to identify what I had. Back to the Plymouth: At the time my cars were built ( 1949 & 52 ) the speed limit was 55 mph and the closest thing to a freeway in Los Angeles was the Arroyo Seco Parkway ( aka Pasadena Freeway ). Which is kind of laughable as a "Freeway". Anyway that's why the old cars had 3.90 rear ends and 3 speed transmissions. When Chrysler went to column shift ( largely so a 5 passenger car could suddenly become a 6 passenger car ) They tried the one year only second gear ratio and thought better of it for 1941. Turns out that 1940 second gear ratio was highly regarded with the "Boy Racers", it making the mopar gear box more close ratio. Not only were there lots of factory gears sold as replacement parts, the after market made them too. There's plenty of them for sale on eBay for less than $300! That seemed to me like a cheap experiment. So here we go counting teeth again. The 1940 Cluster Gear ( aka Transmission Countershaft Gear ) is part number 853-885 and has the tooth count of 32-25-19-14 Whereas the 1941-54 tooth count is 32-23-19-14. Second gear is the only different ratio and thus you only have to change two gears. The 1940 second gear is part number 692-687 and it's tooth count is 23. The 1941-54 second gear tooth count is 25. Enter the Overdrive: The Plymouth R10-G1 Overdrive will shift into 2nd Overdrive plus the top gear overdrive making it actually a 5 speed. When new, the cars were delivered with 4.30 rear end gears giving them lively acceleration....to 55 mph. Now days as the song says "I can't drive 55!" My 49 came with a 3.73 rear end and with Overdrive that car is really happy at 55 mph and 70 sounds like 55 used to. When I installed the Overdrive I swapped the speedo gear from my old transmission which has 17 teeth and the speedo is close ( p/n 652-848 ). With a tire size change and I would change to a 16 tooth speedo gear P/N 652-846 which is also useful with a 3.54 rear end ratio ( there being no other smaller tooth count speedo gears ). One fly in the ointment: Between the loose needles used in the cluster gear and the thrust washers it's a challenge to assemble the countershaft. Chrysler had a solution for the dealer mechanics, the Miller Special Tools C-578. It is a short rod slightly smaller in diameter than the countershaft and only as long as the cluster gear with the thrust washers. You assemble the cluster gear with grease ( to hold the needles and washers ) with the tool inside. After all the other parts are installed you invert the case and the cluster falls into place. Then you push the counter shaft in and the tool keeps everything aligned until the counter shaft is in place. The same method is used by locksmiths changing the pin combinations. Only one problem, try and find one! SO...I am going to make some from plastic rod stock which will work even better than the metal one did. If you enjoy using your brain and working little issues out, the old car hobby is the best! Have fun!

I have a 49 Business Coupe and I retained the vacuum wipers but added a dual chamber fuel pump. The top section produces vacuum at the moment you need it when pressing down on the gas pedal. Most electric wipers require 12 volts and have two speeds. The vacuum wipers have infinite speeds. Since I plan to keep the 6 volt system this was my old time solution.

The story of the VW dates back to 1925 when Dr Porsche had an idea for a "people's car". The early version had a 2 stroke engine in it as I recall and it might have been air cooled. When Hitler started building the Autobahn system it was felt the 2 stroke wasn't up to the job so they hunted around for another engine. Tatra had a flat four air cooled engine that was well proven so the Germans arranged for a license. I have actually seen a Tatra flat four and it looks like a VW on steroids! Much bigger and stronger in every way. However, the war got in the way and Volkswagen never paid Tatra. After the Soviet Union fell and Eastern Europe no longer had to deal with the Iron Curtain, Tatra sued VW for royalties on it's contract and won. VW at the time was expanding by acquiring smaller auto makers and Tatra became one of them. I have no more information than that and I would only be guessing as to this car's identity.

As I said before I have two Delta Mark Tens on my 6 volt cars. They work as expected. But they are very very rare and if you find a negative ground version you have to have it changed to positive ground. I wasn’t sure if it would work but I put an Overdrive transmission in my Business Coupe and it worked just fine. The ignition interrupt works imperceptibly. If someone can’t find a part you are talking about, why even mention it? So when I discovered the Winterburn CDI, I thought I would share. I have not yet received it from Fred but I am excited about it.

Hi Rich, point taken on replacement parts. I used use a lot of Mallory Ignition parts, however they have fallen off and certain things you just can’t get anymore. At one time ( when they were in Carson City ) I used to get them to make custom distributors for me, those days are long gone. I bought a Dyna-Flyte dual point breaker plate for my Plymouth because it uses a more common Mopar V8 point set. So I have been thinking ahead. One of the main complaints I have about electronics is they are voltage sensitive. Drop the voltage too much and it either fries the electronics or they just don’t work. If you’re committed to 6 volt, you don’t have very far to fall when it comes to voltage drops . lol Fred Winterburn’s CDI will fire the plugs at full power with voltage as low as 3.5 volts. Also he makes one unit and it doesn’t care if the power is positive or negative. I have no idea how he does it but I like it.

Years ago I drove a 2 stroke SAAB 93f to work everyday. The oil was mixed with the fuel and being a 2 cycle it fired the spark plugs twice as often as a 4 cycle engine. So anything that promised better plug and point life was worth investigating. At the time there was several CD ignition boxes on the market, with the Delta Mark Ten being the most successful. At their high point they employed 500 people in Grand Junction, CO. Of course later on with emission controls their market dried up and the owner retired. Delta made their boxes fully assembled or as a kit and sold them under the Archer and Heathkit brands besides their own name. I got the full story from a fellow who had built many of them and now repairs them. There are two models the one with a switch to convert the system back to the Kettering ignition without changing wires was called the “B” model and only came in 12 volt. My Plymouths are 6 volt and I have never seen a compelling need to change them to 12 volt. Well maintained a 6 volt system works just fine for me. Your mileage may vary of course. So because nos point sets are running out, I decided I wanted a Delta Mark Ten to lengthen the life of my plugs and points. Just try and find one in 6 volt! If you do find one it might not be Positive ground, so that means you need my guy to switch it over. Well I did in fact come up with two for my cars and I can tell you it was an adventure! Since Delta Products went out of business decades ago, the technology in them has not progressed at all. It seems there are other people making CDI boxes for racing and specialty applications. I kept hearing about a fellow in Canada whose Dad had patented the first CDI. He makes them as a cottage industry for the collector car guys ( 4 cylinder Porsche guys love them ) and he has never stopped improving them. Fred Winterburn is his name and he seems to be a really nice guy. According to him the 6 volt version just got the latest improvements. One thing I like about them is the switch which is 3 position CD-on, off, Kettering-on. No wire changes. Fred’s research found that by limiting the voltage sent to the coil he could get all the current to jump the spark plug gap instead of spilling out everywhere else. I am no engineer so I have to take his word for it. Anyway after reading what the Porsche guys had to say and a few others plus his website I bit the bullet and ordered two of them. He’s building them right now and will ship them at the end of the month. I have one of Langdon’s Stove Bolt ignitions but I’m not going to convert my cars to 12 volts to use it. I understand they are not being made anymore. HEI maybe very good but I think the Winterburn system has some better features, such as the voltage limiting circuitry and the fact you don’t have to re-engineer the car around the ignition. Of course in a post-apocalyptic world after an electro-magnetic pulse the HEIs will be toast along with the alternators powering them. My tube radio, generator, 6 volt Plymouth will likely run fine. lol More to come.

I have a 1949 P17 ( 3 passenger business coupe ) it came stock with a 3.73. I found a 3rd member from a 1956 Dodge V8 with 3.54 gears that I plan to install right after I do some rust prevention. Previously I installed an R 10 Overdrive and that really made a difference! The 56 Spider gears fit the axles I have so I don’t think you’ll have any problems there.

Ford ditched cast iron pistons with the Model T last built in 1927. The Model As all had aluminum pistons. Chevrolet kept them until 1953 or 4 as I recall. General Motors sold the tooling to Toyota and that engine came back to America in the Land Cruiser. Chrysler had engineers who were wise to the problems of reciprocating weight and had moved to aluminum pistons early. The issue is really about long vs short stroke. The fuels that were available during each automotive era had a lot to do with the design of the engines. The war changed the thinking about compression ratios and fuel octane. High torque slow speed engines were desirable before the war and high horse power high speed engines became possible afterwards. The metric that limits long stroke engines to low rpm is piston speed. During the travel of the piston up and down, it has to speed up from a dead stop at the bottom and the top of the stroke to a peak speed in the middle, slowing back down to zero. That peak speed in the middle of the stroke is what limits the engine's rpm. A long stroke engine will have a higher piston speed than a short stroke engine of the same displacement at a lower rpm. Thus the advantage of Over Head Valves is better breathing at higher rpm and higher compression, all made possible with better fuel. A short stroke ( smaller than the bore ) went along with it. There was a time when engine data pages included piston speed as a specification. Now days most engines are short stroke and piston speed isn't even mentioned anymore.

From what I've read in the early days of NASCAR stock meant stock. So that would mean the Pettys used Plymouth rods and rod bolts. The forging numbers were right there for all to see. The biggest cheater of all time, Smokey Yunick told a story of why his Hudsons ran so well. American race tracks all turned left at the time and all car engines turned clockwise when looking at the front of the car. This meant the torque of the engine pulled to the outside of the turn and reduced the traction and cornering power of the car coming out of the corner. His cheat in this case was to change the camshaft so that the engine ran counter clockwise and thus the engine torque pulled to the inside. It gave his drivers a significant advantage coming out of the turn into the straightaway. The driver could apply power sooner and harder. He never said if he even bothered to tell the driver. Chrysler racer Carl Kiekhaefer could smell a rat and protested Yunick's Hudson often. He knew that camshaft was somehow suspect but not what was wrong with it. After Yunick threw a fake tantrum one day and broke the cam in several pieces, he picked one of the pieces up and handed it to Kiekhaefer and said "Here's all you need to check it yourself!" Of course he could check the profile but not the direction of rotation. When I read that story I wondered how the NASCAR "experts" and an engineer of Kiekhaefer's calibre could miss what Yunick had done. Looking at a camshaft you can tell which way it is supposed to turn by the arrangement of the lobes. The rule is Intake follows Exhaust. Chain driven cams turn with the crank and a gear driven cam turns the opposite direction. Put a gear driven cam in an engine with a chain and it will run counter clockwise. Twin engine boats can have engines that turn opposite directions to counter the torque on acceleration. Now before you jump to the conclusion Lee Petty did the same thing, I can tell you he didn't. Photos of his car coming out of a turn show it leaning heavily to the outside. Also the Plymouth had a hypoid ring & pinion which couldn't be "flipped" to turn the right direction, like an "on-center" R & P can. Petty didn't mind the frequent tear downs because they came with a protest fee which was intended to pay for a set of gaskets and a little more. I am certain he tore the engine down every race. Yes he abused them but they only had to last at most 500 miles. NASCAR rules said the parts had to be stock. They did not say how you were to assemble them. To get more oil pressure to the rods you could be "sloppy" with the installation of the cam bearings. Put them in with half or more of the oil hole covered by misalignment with the galley.

I don’t know about steering wheel splines, sorry. I do know they rarely change.

To get where you want to go consider the old adage, “If it works don’t fix it.” Your car is an assembly of components that do certain things. Only touch the stuff you know is bad or not working. Replacing a part or assembly that you aren’t sure about won’t make the whole car any better, it just wastes your money. If a part is out of the car, then one of two things is possible 1) the part needs service or 2) somebody borrowed the part and didn’t put it back. Old Plymouths can be destroyed, but for the most part they are long lived and reliable. They are transportation cars and they do their job very well. Take it slow and enjoy your car and the learning curb you are on.

I question why anyone would want to change the rear end in a Plymouth. I can think of lots of reasons why one shouldn’t bother. The original is a good design and perfectly adequate for a flathead powered Plymouth. If the motivation is to lower the engine rpm on the highway, then there are much better ways to do it. You could install an Overdrive transmission. That turns a 55 mph car into a 70 mph car, with a whole lot less work and you will not have bastardized your collector car. A rear end that lowers engine rpm on the highway will kill your already bog slow acceleration. An Overdrive does not because it adds another gear and the rest stay the same. The advantage of a Plymouth Overdrive ( Borg-Warner R10-G1 ) is that you remove your old transmission, install the Overdrive transmission using the same linkage and speedometer gear and drive shaft ( if you have the long transmission. Or shorten it 7 inches if you have the short one ) add the wiring and you are done. No messing around trying to adapt a driveshaft, brakes and speedometer drive. You’re done in an afternoon.

An Ak Miller joke I was in Ensenada to participate in the La Carerra Classic race and it was drizzling. Ak Miller had his famous roadster parked near the entrance to the hotel and was chatting with other notables like Carrol Shelby. As I walked in he gave me the weather report, “Chilly today and hot tamale!” And you know he was right!

No offense taken. I am a week or two from having mine apart and then I can be on more solid ground. My experience has been solely on the Gemmer box. Professionally the cars I worked on were all rack and pinion setups and that is a different kettle of fish altogether. The one in my car is in very good shape, it just leaks. Perhaps I am missing something and will be able to see it right away. Its always easier when you can put your hand on it.

The last kit I bought for my 29 Model A I got from Macs to rebuild a 1953-56 F 100 pickup box. The price was $299.99 and it came with everything I needed. To adapt the pickup box to a Model involves lots of engineering and machine work…way too much to describe here. But I learned a few things, the steering gears were made by Gemmer for Ford for U.S. models and Ingersoll for Canadian models. I would be curious if one of our members has one loose that they can see if it has a name cast on the side. If Gemmer made them its likely the parts could be made to fit. The parts I have seen sure look like the F 100 parts which are readily available. Sounds like a worthy project for investigation.

Okay lets try to state this another way. A worm gear is essentially a thread. In a steering gear that thread is curved to the radius of the sector’s movement. The roller on the sector is not really a nut or even a half nut. It basically contacts the worm with one of its three teeth on a very limited area when everything is perfect. Start getting wear or damage and the other two teeth start getting involved. Only its more complicated than that because of helix angle of the sector. One of the out board teeth will be over center and the other will be under center. Add to that those outboard teeth are in contact with the adjacent teeth on the worm and because the center tooth is worn ( or in contact with a worn worm tooth ) it is putting them out of position. Someone wanting to adjust out the wear will screw down the sector adjustment and that makes the whole thing worse. Bottomline: The way to fix it is a new set of worm, sector roller, bushings and bearings.

Yes it is the whole thing. I don’t need one so I didn’t investigate further but one could ask if they could ( for a fee of course ) send you just the differential carrier. They seem to want to work with their customers. I spotted a rare 6 volt positive ground Delta Mark Ten CDI in a photo and inquired about it. They set up a buy-it-now auction and emailed me when it went live so I could buy it and not violate ebay rules. A carrier should weigh about what an O.D. Transmission does and the shipping for me was only $95. Bottomline, stuff is out there if people will look for it. What I have seen is crazy ads for odd parts, yet they show you the whole car from several views. The idea being to start a dialog with buyers so they will inquire about other parts. You’ve got to love this hobby!

If the middle part of the worm is worn so much that the teeth are binding rather than turning the sector that would explain the behavior you are describing. The only fix would be to change the worm and the sector roller. The problem is the vertical sector shaft requires an oil seal to keep the oil in. Once the seal dies nobody ever checks the steering gear oil and it goes metal to metal. There is also the possibility of something bent. I had a Mercedes that had a steering gear that just did not feel right. I tried adjusting it and finally I saw the imprint of the right front upper ball joint in fender liner above the wheel! The 90+ year old driver must have clobbered a curb. Once I changed the steering gear it was much happier.

Here we have lots of opinions all have some merit. I personally favor keeping the stock rear end. Its a good design and changing it won’t give you more power or reliability. I just saw a fellow asking for help figuring out what kind of brakes his car had because no one told him when he bought it. On axle ratios if you are going to drive highway speeds you’ll want the lowest numerical ratio. The lowest numerical ratio in the stock rear axle is 3.54 ( I have heard of a 3.23 but have never seen one ). The 4.1 ratio you have usually came in cars with an Overdrive transmission. That is a super desirable item so take a real good look at that car. Overdrive with a 3.73 is a real good combination. If anyone is looking for a 3.54, French Lake has one in a 56 DeSoto on ebay. You might ask if they have an Overdrive as the last one I bought from them was $250 plus $95 shipping. Anyway that’s what I’d be doing. Overdrive transmissions should be left in gear out of Overdrive when parked and the parking brake kept in good condition. I found a solution to the iffy parking brake issue. Speedway Motors has a special valve that gives you 4 wheel parking brakes. You push down on the brake pedal and pull on a knob that holds the brake pressure.

I am out of town right now but I know its in their catalog. The counter guys can look it up.

Usually the ratio is stamped on the flat under the filler plug. The exact location, orientation and size of the stamps does vary as they were hand stamped.

I have two Model A Fords, a 29 and a 31. The 31 has a Gemmer box from a F 100 pickup. The thing is not adjusted right, its too tight. The 29 had a very worn out stock steering gear and after evaluating it I found it hopeless. 29-30 Model As use the gas tank for the top mount of the column. If your steering gear is bad then cracks form in the tank leaking fuel on the driver’s legs. Happily this one is the only model that has a separate gas tank from the cowl so I didn’t have to paint the whole car to fix it. Not to dive too deep in Fords, the steering gear in my 49 P17 is pretty much the same design. The sector goes downward instead of sideways but they work the same. What I have learned from the F 100 Pickup Gemmer box is that the tapered roller bearings are the first and most important adjustment. Tapered roller bearings require some preload ( more when new ). Most of the slop you get in the steering is from a lack of preload on those bearings. However, make them too tight and it will steer like my 31. Hard to turn and the spring back after completing a turn is not quite right. Sector adjustment on the top is not the way to remove slop. In fact I’d say leave it alone. If you look at the gear and sector, it is basically a “worm gear”. The worm is curved to accommodate the arc of the sector. The worm of course will wear at the straight ahead point ( in the middle or smallest diameter ). So if you monkey around with the sector adjustment to get the slop out while going straight the gears will be too tight at full or near full lock and they might even stick there in extreme cases. If you had the steering gear out of the car on the bench you could easily try it to see what I am saying. If you can detect any minute movement when pulling or pushing on the steering wheel, then those bearings are way out of adjustment. I am sure at the factory they used dial indicators and spring scales to adjust them. The first thing I did when I got my P17 was put some lube in the steering gear. Now the pittman arm is covered in oil….the seal leaks. So I resolved to replace the seal and adjust the preload on the tapered roller bearings. The price for a seal from the mail order suppliers is $35. NAPA sells a CR ( formerly known as Chicago Rawhide now owned by SKF ) seal for $12 and change. Yes it is in their catalog. I’ve got all the sheet metal off the front of my car and I had planned to replace the seal and take pictures and describe how it should be done. Take the pittman arm off, then the bolts from the sector cover. There is a T slot in the top of the sector which is engaged with the adjustment bolt. Do not loosen the adjustment! Just get the cover free from the housing and push the sector up until you can slide the cover off the sector. You can slide the sector completely out. Disconnect the horn wire from the relay ( on my 49 its a bullet connector ) and remove the cover from the steering shaft bearing. There are paper gaskets there that are the adjustment medium for the bearing. Be careful with them! You can remove one of the bearings and have a look at its condition. You can also see the worm gear from above. Very carefully separate one of the gaskets from the pack. There are three thicknesses. Try removing the thinest one first. Put the gaskets and cover back on and check the steering effort. Too tight, put the gasket back in. Still loose try putting the thin one back in and take out a thicker one. ( yes its that close ) Once you’re satisfied change the seal and drop the sector and cover back in. You can bolt everything up and add some lube. Take a drive and if you still think your steering is too sloppy you can try one space on the sector adjustment but that’s about all I would do. I assume the factory knew what they were doing. A couple of thoughts on alignment. Radial tires perform better with more caster than the old cars specified ( 7 degrees is mentioned ) Also the old Plymouths had very little if any toe-in. Most late model cars have much more. Toe-in contributes to holding straight line steering. So if you can give your alignment guy the factory specs and ask for a little more toe-in you might just eliminate the wander. I can almost guarantee the alignment guys will only set the toe.