help/advice: Zepher trans to flathead Q

[hardtimes]

I have a ('39ish) zepher side shift trans. It looks like it will attach right up to the bell bolt pattern of a V8 flathead. It has 26 tooth gear arrangement.
Will this zepher trans just replace the top loader '39 trans or in your experience/opinion, it be easier to just switch the zepher gears into the '39 ford box ? If there are mods/problems switching boxes, can someone who has done this , give me an idea what I must do to use side shift rather than top shift ?
Anyone know how to identify the actual year zepher that this gear box came out of ?

[jimTN]

It will work just fine providing it has the lever type clutch shaft like a 39. If you are putting this in a stock vehicle, you will have to cut the transmission cover to match the gearshift lever location. I ran one of these in a 40 dirt track car and it worked well until a sideways lick totaled the frame and bursted the trans housing. It was always a conversation piece when we ran that car.

[rotorwrench]

I don't know if the lengths are the same or not. Lincolns usually have a different rear mount up. If it's different then the torque tube would need modification. The close ratio gears can easily be put into the Ford case but they work better with low rear axle ratios like the 4.11:1. Lincolns were heavy old buggers.

[hardtimes]

Originally Posted by jimTN

It will work just fine providing it has the lever type clutch shaft like a 39. If you are putting this in a stock vehicle, you will have to cut the transmission cover to match the gearshift lever location. I ran one of these in a 40 dirt track car and it worked well until a sideways lick totaled the frame and bursted the trans housing. It was always a conversation piece when we ran that car.

Hey Jim,
Thanks much for good info ! After you cut cover to match shifter location, did you use something like a Hurst shifter or something else you adapted/made ?


Hope you didn't get injured in that 'lick' !
Would you have any pictures to share of the vehicle ?

[hardtimes]

Originally Posted by rotorwrench

I don't know if the lengths are the same or not. Lincolns usually have a different rear mount up. If it's different then the torque tube would need modification. The close ratio gears can easily be put into the Ford case but they work better with low rear axle ratios like the 4.11:1. Lincolns were heavy old buggers.

Good point, I hauled the '39 ford out of storage today. Will start comparisons. From first look, year the rear mount is different.
I for one am happy that we were lucky enough to benefit from lincolns being so big/heavy. Else, they might have had a puny trans instead of the one that handled a big beast ! Regarding the tip on the 4.11:1, I'm lucky enough to have a QC and so gear changes have interesting results and easy.

BTW...those Zephers were torque tube too, eh ?
I imagine that a lot of guys knew of the Zepher's strength and used these trans back when.

[skidmarks]

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The lincoln is no stronger then the ford, just a better ratio.

You mentioned hurst shifter? The tooth count also makes me think you have a later 40 to 48 lincoln transmission. The 39 has a funky floor shift stick on the upper right side of the case. The 39 lincoln transmission also came stock with ford gears and not the desirable 25 of 26 tooth count

[hardtimes]

Originally Posted by skidmarks

The lincoln is no stronger then the ford, just a better ratio.

You mentioned hurst shifter? The tooth count also makes me think you have a later 40 to 48 lincoln transmission. The 39 has a funky floor shift stick on the upper right side of the case. The 39 lincoln transmission also came stock with ford gears and not the desirable 25 of 26 tooth count

Thanks much this info helps !
Yeah, it has 26 tooth count.
So, '40 to '48 has the desirable gears. Do you think that VanPelt would know what hear by the numbers on the case top ?
I mentioned Hurst shifter, because as you deduced it has the two shift arms on the left side. Back when young...50s, we used a Hurst floor shifter for the Ford side shifter trans. Been so long, just seems like my imagination..again !
Do you know if that same Hurst floor shifter setup would work on this zepher ?
If I switch the gears to ford '39 case, is the zepher case worth keeping in circulation ?

[Mac VP]

If this Lincoln gearbox has a nine bolt side cover (on the left hand side) with two shifter levers on that cover, you have a 1940-48 Lincoln transmission. Since the entire gearset will fit in a 1939 Ford toploader gearbox, it would make more sense to make this switch if your goal is to have a floor shift trans. As discussed many times in past forum threads, the L-Z gears are no stronger than the Ford gears.....just a higher ratio for first and second gears. No change of high gear ratio.

Technically, the Lincoln gearbox will bolt up to the flathead V8 and fit the clutch disc okay. The clutch release shaft and arm would probably need to be changed (depending on what chassis you’re installing it in). The bigger problem would be the shifting mechanism and linkage.

The back of the Lincoln gearbox case is the same as the Ford so the appropriate rear bearing retainer and rear support could be swapped onto it. There is a Lincoln universal joint, but it’s interchangeable with the early Ford u-joint.

Here’s a picture of the unique 1938-39 Lincoln Zephyr trans.
http://www.vanpeltsales.com/FH_web/F...939LZ-case.jpg

[skidmarks]

I would put it in a 39 case for floor shift. The floor conversions are clumsy and with the 39 box you dont have to cut the floor for shifter clearance.

The lincoln 40 to 48 case doesnt have much value

[rotorwrench]

The later Lincoln transmissions were R10 overdrive types so they are a lot different.


A lot of folks put those old Lincoln gear sets in their cars for bragging rights only to find out that they are limited for top end. With the right rear axle ratio, they get off the line really well but they run out of steam as the rpm maxes out. Current highway speeds would have the rpm at very high levels. If you mate them with a taller rear axle that first gear is like a granny gear. This is why Lincoln went to the R10 overdrive so early in the game.

[V12Bill]

There were two Lincoln transmission cases. One for the three speed and one for the three speed with overdrive. The over drive was a bolt on .

[JSeery]

Originally Posted by rotorwrench

The later Lincoln transmissions were R10 overdrive types so they are a lot different.


A lot of folks put those old Lincoln gear sets in their cars for bragging rights only to find out that they are limited for top end. With the right rear axle ratio, they get off the line really well but they run out of steam as the rpm maxes out. Current highway speeds would have the rpm at very high levels. If you mate them with a taller rear axle than first gear is like a granny gear. This is why Lincoln went to the R10 overdrive so early in the game.

Maybe it is just the terminology, but I would state it the other way around. The Lincoln gears are like a modern "close" ratio transmission, so less rpm change between gear changes. To work well they require a lower rear gear ratio. Your final gear ratio is the transmission gear X the rear axle ratio.

So with a 28 tooth gear (2.820) and say a 4:11 rear axle the final drive in 1st gear ratio would be 11.59.

With a 26 tooth Zephyr gear (2.33) and the same 4:11 the final 1st gear ratio would be 9.58.

Using a 3:50 rear gear paired with a 28 first gear the final drive would be 9.87 and with the 26 first gear the final drive would be 8.16, which would be similar to a 2:89 rear axle gear with the 28 tooth 1st gear.

I my terminology these would not be a granny gear condition, but would lug the engine down to the point it would be difficult to drive.

It can get even wilder with the 25 tooth first gear! It is 2.120, these type of gears when used in the early Fords were primary used for race applications when they were wanting to keep the engine in a tighter rpm range.

[rotorwrench]

I was thinking of it bass ackwards. The first gear is more like starting out in second gear. It would be harder on the clutch to get started. With 4.44 rear gears it would be closer to a granny but it might still work. It would be humming some pretty good rpm at 55 though.

Most guys used the 4.11 gears with them back in the day. They would have been good for racing off a stop light but would be winding pretty well at over 70 MPH. At 90, it would likely be maxed out. This was when rear axle shafts were breaking more than they should.

[Tim Ayers]

You guys are losing me with the maxing out RPM comments. Are you talking about 2nd gear or 3rd? Regardless of ratio, 3rd is still 1 to 1.

What am I missing?

[JSeery]

Maximum rpm is maximum rpm (what we would refer to as redline) regardless of the gear the transmission is in. Using Zephyr gears is a confusing topic to say the least. It always has been. There is a 1955 article that discusses their use, but it is a little lone. I will see if I can post it. The fact that 3rd gear is always 1:1 is part of the issue. To use the Zephyr gears you need to run low rear axle gearing, but then in 3rd gear you are stuck with the low rear axle gearing! Everything is a trade off. Close ratio gearing allows for quicker acceleration, but it requires the lower axle gearing to work well. For starters you need an engine that you can run at higher rpm for any of this to work (in a race type application). You kinda work backwards, you calculate the maximum rpm you want to be running at the finish line (normally around the peak hp of the engine. Then you determine what rear end gearing gives you that rpm and that is the rear axle gear you run. Then using close ratio gears in the transmission you are attempting to keep the engine between maximum torque and maximum hp as you go through the gears. This also requires lunching at an rpm range around maximum torque, thus the busted axles. So, you want to launch at max torque rpm and then shift to 2nd gear at maximum hp rpm. The goal is that the rpm range will not drop below the maximum torque rpm and then again accelerate to maximum hp rpms. Then a shift to 3rd gear again want to rpms to drop to around maximum torque and then accelerate to maximum hp rpm at the finish line.

Most hp increases to an engine shift the torque curve to a higher rpm range. So with a hopped up engine you need to keep the engine in a higher rpm range from start to finish. That is why these type of engines and gearing are difficult to drive on the street. It is not easy to lunch at say 2500 rpm at a stop light and then drive it with the engine is the 3k to 5k range!

[JSeery]

Speed Mechanics Sept 1955

The truth about Zephyr Gears
Weight-power Ratio Important Factor In gear selection

By ED MARTINDALE, Mameco Engineering, Balboa California

MOST SPEED MECHANICS have two burning desires concerning their cars: to boil along at good top speed and to accelerate rapidly. Although engine soup-up will provide additional pep, without proper gearing neither desire can be achieved.
The stock cogs in gearbox and rear end are designed to give a car in stock form acceptable performance. Because the maximum torque developed by the engine is puny compared to the weight of the car, mechanical advantage must be obtained through leverage to move the car and this is accomplished with gears. By multiplying the torque available at the flywheel through speed reducing gears, 300 pounds feet of torque can become as much as 3000 (or more) pounds feet at the driving wheels.
So much confusion exist about gear ratios that clarification of the meaning of terms might prove valuable at this point. Four-to-one is a high ratio, but a low gearing. When used between the engine and rear wheels, it reduces wheels speed to one quarter engine speed and at the same time, (because of leverage advantage), increases torque available at the wheels by four. Two-to-one is a lower ratio but higher gearing: Wheel speed is half engine speed and torque at wheels is twice that available at the engine.
The rear end gear ratio affects the car's top speed and can limit or expand the engine's potential power output. Top speed however, is not necessarily increased when a higher-than-stock gearing is used and many, who substituted a 3.54 rear for a 4.11 for more speed, learn this the hard way. Acceleration through the gears is affected by the overall ratio of transmission and rear end gears.
That it requires more force to overcome the inertia of a body at rest than to keep it moving is a well-known law of physics. The additional force required to move a car from a standstill is made available by transmission gears. Low overall gearing also permits the engine to rev close to the rpm point at which maximum power is developed for good acceleration.
Theoretically a perfect transmission is one in which an infinitely variable gearing is produced, such as in Dynaflow. Unfortunately power losses usually prove to be a disadvantage that is not overcome by theoretical advantages. One of the best gear-box bets is a four speed unit, fitted with close ratio gears, that allows selective gearing of engine speed to wheel speed under a variety of driving conditions. In American gearboxes, the use of three forward gears usually requires a wider spread between ratios and consequently power is lost during shifts and elapsed acceleration time is greater.
As a general rule gearing changes accomplish very little in the stock car. Earlier we mentioned that top speed and that substituting a 3.54 rear, for instance, for a 4.11 for more speed does not result in a gain of 10 mph or so. Usually the stock car's gearing is chosen so that top speed is reached at about the rpm point that the engine develops its maximum hp. Gains in top speed are made with changes in rear end gearing when the engine is reworked to pull more power.
The standard Ford-Mercury boxes have a 28- or 28- tooth main driving gear. The Lincoln Zephyr box carried a 25- or 26-tooth main gear. The lower ratios available in the Zephyr first and second, produce a higher gearing and permit a higher maximum speed in first and second, without changing the speed possible in high (or direct). In addition, Zephyr ratios are closer than in Ford-Merc boxes. As a result of Henry Ford's feeling for standardization, Z gears are interchangeable in most Ford and Merc boxes.
Despite the fact that, among Ford-Merc owners, Lincoln Zephyr gears have been widely used, it would be unwise to order a set for your own rig without a thorough study of your needs and your equipment. Z gears should not be regarded as a cure-all. Unless you've souped or lightened your rig, they will not appreciable improve your car's acceleration, for the higher gearing requires more power from the engine or a lighter wagon to drag. With Z gears it will take a heavy car longer to get going from standstill than when equipped with stock cogs.
In a lightweight chassis, however the Z combination usually spells success and the advantages of Z conversions are most noticeable when used with souped engines or with stock mills capable of handling the load. Combining greatly increased engine output with a light chassis almost always demands the use of Zephyr gears.
It should be obvious that knowledge of your engine's capabilities is necessary to correct analyze the elements that determine proper gearing. A tachometer (discussed in August SM) can be helpful in experimenting with various tire sizes in search of more perfect gearing. If a higher gear will give you more speed, a larger tire size will duplicate this effect. If you obtain the same or a higher reading on the tach, with speed improvement, higher gearing will be of benefit. As it's less expensive to test gearing with borrowed larger tires than to purchase a number of ring and pinion sets, keep experimenting with tire sizes until no further improvement is found.
Determining proper gear ratio can be done, with some rough accuracy due to our omission of wheel slip and wind resistance factors with the formula: Gear ratio = Engine rpm X tire diameter (in Inches) divide by mph X 336 (a constant *). Double check answers thus found against specifications of quick moving cars with similar modifications to those found in your car. The more time you spend checking for the right gear, the less heartache you'll have on road or drag strip.
Zephyr gears can be installed in any (except V-8 60) '32-'48 Ford or in '39-'50 Merc transmission case with little difficulty although some years are a tighter "squeeze" then others in installation. It is impossible to change just one gear in Z conversion; in some models ('40-'48 Fords and '40'50 Mercs) only the cluster gear with rear thrust washers, main drive gear and second gear must be replaced. In other models, it is necessary to make an almost complete parts-changeover.
Boxes built before 1940 were "floor shifters" and later model were "side shifters." Some but not all, speed mechanics think it wise to change to a floor shift box if extensive power modifications are to be made, The floor shift box has a reputation for greater strength that is increasingly appreciated as power is upped.
In the '32-'36 boxes only a few of the original parts are retained in a Z conversion, but in the interest of reliability all parts are usually replaced. The parts changes required on early Fords are: the cluster gear and thrust washer; main drive gear; main shaft; second gear; synchro-mesh assembly (and second gear thrust washers on some models) low and reverse idler. For the proper combination, check all parts needed against a late Ford parts catalog for the current stock numbers.
In '37-'39 Ford and '39 Merc boxes, the above parts (except low reverse idler) are replaced. The '39 second and high shifter fork is used in converting all '37-'39 boxes.

[Barn Junk]

There were different kinds of racing back in the 1950s with the flatheads. Rodders were adapting to different situations with the different gearsets. Straight line drag racers had tracks of 1/8, 1/4 and even 1/2 mile. Circle tracks were usually shorter but required slowing for corners. The Lincoln gears were closer ratio so could stay in the higher HP curve easier. Everybody was looking for a little advantage to bring home the trophy or bragging rights. Zepher gear sets could be bought over the counter at the local auto parts stores for very reasonable prices.

[cas3]

nice article jseery, thanks for posting. i wasnt alive in the early days of drag racing, but my understanding is the lz gears were sought after for street racing between stop lights. so, you had tall enough gears to get to the next light in 2nd, thus eliminating one shift, and since the old fords do not speed shift well, that was a game winner. again, i am the youngster here! what do the old guys say on that theory?

[hardtimes]

Originally Posted by Mac VP

If this Lincoln gearbox has a nine bolt side cover (on the left hand side) with two shifter levers on that cover, you have a 1940-48 Lincoln transmission. Since the entire gearset will fit in a 1939 Ford toploader gearbox, it would make more sense to make this switch if your goal is to have a floor shift trans. As discussed many times in past forum threads, the L-Z gears are no stronger than the Ford gears.....just a higher ratio for first and second gears. No change of high gear ratio.

Technically, the Lincoln gearbox will bolt up to the flathead V8 and fit the clutch disc okay. The clutch release shaft and arm would probably need to be changed (depending on what chassis you’re installing it in). The bigger problem would be the shifting mechanism and linkage.

The back of the Lincoln gearbox case is the same as the Ford so the appropriate rear bearing retainer and rear support could be swapped onto it. There is a Lincoln universal joint, but it’s interchangeable with the early Ford u-joint.

Here’s a picture of the unique 1938-39 Lincoln Zephyr trans.
http://www.vanpeltsales.com/FH_web/F...939LZ-case.jpg

Thanks for the picture Mac. Mine is '40/'48.
Question: When I make the gear switch from Zephzr box to '39 ford box. Do you have all the 'stuff' that may be needed / sloppy , to make it right again ?

[hardtimes]

Originally Posted by skidmarks

I would put it in a 39 case for floor shift. The floor conversions are clumsy and with the 39 box you dont have to cut the floor for shifter clearance.

The lincoln 40 to 48 case doesnt have much value

GOOD reasons and reasoning , thanks ! That's what will happen.
Disclosure:
I have a '39 double detent top loader in my '30 roadster with B engine. I have an alum adapter made specifically to adapt the '39 and the 'kit' came with 3 or 4 adapters to make it easy job. And, it has the 26 tooth Zephyr gear set in it for a dozen + years now. Guess I'll have a 'backup unit'.
Some of you guys may have known a guy, Joe Mac, who part owner of the old ford store in LA area. Last he lived was in Corona. Just before Joe died , he and I finished rebuilding the '39 that's in my ride. He had a single family dwelling , maybe four bedrooms. Most were made into trans parts holding rooms. Quite a sight that was ! He's the same guy who imported the lot of Russian B engines, an nos block from that resides in my ride also !