1955 200R4 automatic transmission to Belair

by yaww

The 1955 Belair Hardtop Coupe urges me every year for a new project. This year is a long time in mind; But I decided to transform the transmission, which I couldn't dare to take a second hand.

The flat transmissions of the 1950s are particularly cumbersome and unfused in terms of 1st gear, because the gear ratio is 3.55:1; So you need to move to second gear very quickly. And the fact that the gear lever is behind the wheel and the gear range is long, it spoils your enjoyment in terms of driving. Senchromec and tail-front seals that constantly miss oil; In addition, the problem of mixing gears specific to the 1955-1956s (which wands can't drive your car) is also my motivation to switch to automatic transmission… Other options include using 1960 transmissions with a more suitable 1 gear ratio or reducing the differential gear ratio; but why do we have a pleasant automatic transmission when we're at the expense.

The resources I benefited the most from this transformation were summitracing.com (and technical support team), some drawings on the classicchevy.com site and product descriptions in the danchuk.com. Bowtieoverdrives.com is also the ideal source for those who think of the 700R4 and 200R4 transmissions.

The automatic transmission you're going to get, anyway, there won't be any new production. All manufacturers are regenerating their interiors by taking the old transmission boxes; therefore, it's better to buy it from a reliable location. They also classify Stage-Level 1,2,3 when renovating. 1 or Stock is preparing for vehicles used for daily driving, while Stage 2-3-4 models are being renovated with durable material for more aggressive and racing use. They also apply all production error corrections recommended by after-production manufacturers.

First, let's get to know our option

s:TurboHydramatic 350 and 400: There's not much difference between the highly popular 3-speed gearbox, which was used as TH400 in 1964 and then th350 in 1969; Th400 is heavier in terms of kilograms and there are very small differences in 1st-2nd gear ratios. The 3rd gear ratio is 1:1 in all transmissions, including the original manuals; therefore, it does not provide an advantage in terms of speed and fuel. You know, when we used to say, "Brother wants 5th gear" in new cars, that's because the 4th gear was always 1:1. You can get new one of these transmissions starting at 600USD from the UsA. SummitRacing's TH350 transmission is on sale for $600. The next economic model is the transmissions produced by TCI (approximately 1000 USD). In addition, many people on ebay.com are selling refurbished transmissions, if you can overcome the trust problem. 

TurboHydramatic 700R4, 4L60, 4L60E: These post-1980 transmissions are newer technology and similar. The biggest advantage is the 4th overdrive gear and lockup. With this transmission's overdrive gear, you can save up to 30% fuel, especially when using long drives. Prices start at $800. The 1st gear ratio of the 700-R4 is not ideal, especially for high-rate differentials (my differential 3.70:1) switches very quickly and to 2nd gear. There are technical problems with the first models of the 700-R4s, so choose new models called 4L60, which began to be produced in 1990. The turbine-connected (pump) gear of older models is 27 notches, and the new ones I recommend you buy are the 30th. Beware of the 4L60E model, it may be problematic to apply because it contains electronics. 



TurboHydramatic 200-4R (or 200-R4):

TurboHydramatic 200-4R (or 200-R4)
:200-4R has similar characters with 700-R4 excluding gear ratios; Overdrive and lockup features. It's compatible not only with chevrolet, but also to Buick, Oldsmobile, Cadillac and Pontiac. Since the tail part is monolithic, you need to remove the carat to interfere with the milestone gear. If you are going to replace your 6" tail TH-350 with 200-4R, you don't need to make any changes to your shaft or crossmember; the same lengths. The 200-4R's turbine-connected gear is 27 notches, so you should get a custom turbine. After all, this article was written for 200-4R; Because the ideal in terms of gear ratio and application is the 200-4R transmission (here I must thank Burak Ünal for changing my decision). Prices start at $900. I'm happy with the transmission I got from Transdepot.net for now. bowtieoverdrives.com, I think the most reliable seller, for those who risk paying a little more.


1. Gear gear ratios

2. Sump Shapes

What is lockup: The turbine, which acts as a clutch in automatic transmissions, combines oil pressure with the engine and transmission. This merger does not yield 100% like in the clutch, there are always losses between the engine and the transmission. These losses reduce performance, increase consumption (automatic cars therefore burn more gasoline) and the resulting heat increases the temperature of the transmission, shortening the life of oil and transmission.

When you switch to overdrive — i.e. 4th gear — the electric current to the transmission locks a separate balat inside the turbine with oil pressure, providing a 100% grip between the engine and the transmission. Your engine speed drops, your speed increases, you feel like there's a fifth gear. Lockup is controlled from the brain (ECM) in new model cars. We'll have to modify the 200-R4 and 700-R4s mentioned here with internal+external cabling kits (about $100) from bowtieoverdrives.com. You will turn on the gearbox's sump and change the 4th gear sensor, TCC solenoite and simple wiring as described. The 4th gear sensor will only allow your gearbox to lock in 4th gear. In addition, the lockup must be disabled as soon as you press the brake (as it stands), so you need to connect the external wiring from inside the kit to the transmission. There are two options when buying a kit here. The first is a relay that comes out of the kit to connect to the brake lamp, and the second is to replace the brake seal from inside the kit with the original. If you want the lockup to be disabled in gases for additional comfort, a "adjustable switch vacuum" can be taken in addition to the brake circuit, which interrupts the circuit according to the carburetor vacuum. $45 on e-bay. I say get a sucard plug while you're on the car.

When you browse the internet, you can see those who argue that lockup is unnecessary, but you won't find a reason behind it. Lockup is a technology with no drawbacks other than cost. Low oil pressure, wind resistance and high turbine heat can significantly reduce your life span of both oil and balata when driving through overdrive without locking. Let's remind you, both the transmission and turbine lockup should be featured.

Once you've removed your existing transmission connections, shaft, starter motor, ballad-printing and flywheel, you can start the installation of the new transmission. 


Flywheel Gear: Manual transmission vits (flywheel) clutch printing and pads. You now need a flywheel (flex plate) to match the turbine's bolt hole range (you can choose to match two different hole ranges called dual patterns). In addition, the number of teeth outside must be the same as the flywheel you will remove so that it can continue to work in line with your starter engine (Summitracing SUM-G100SFI). The 1955-57 Chevrolethas 168-toothed flywheel. You need to get a flywheel gear according to the engine's balance weight type (internal-external). Since my Chevrolet 1955 265 cuin engine is "internally balanced,"" I chose the appropriate fly wheel. In 1955-56, the starter motor was connected to the flywheel enclosure (bellhousing). When you change the transmission, you won't find a place to connect your starter engine, so you'll have to take Danchuk's #10100-coded adapter and connect the starter engine to your engine with this. You also need a flywheel saccna to cover your latest flywheel gear, scraper or Danchuk #2277.


Turbine (Torque Converter): After you decide the transmission, you need to make other choices. The part that provides the connection between the engine and the transmission by adjusting the oil pressure according to the circuit during take-offs; I mean, automatic clutch. Never buy it used, it is not possible to completely drain the oil in it; old oil and particles will obsolete your new transmission. The notch number of the turbine you received must be the same as the transmission, the bolt hole ranges must be compatible with your flywheel shaft (e.g. 10.75in). Grip value (stall rpm); in what era the turbine is fully grasped. Suitable for daily use from 1500 to 1700 rpm; it's suitable for higher-speed engines for higher performance purposes and increases your fuel consumption. The second data is turbine diameter (12, 11, 10inch). Usually the diameter will increase as the diameter shrinks. Also, if your transmission has a lock-up, the turbine must also be lock-up.

Before placing the transmission, gently fill up to 2 kg of oil into the turbine and place it in the transmission, make sure the pump gear is fully seated and the turbine is not in front. Connect the transmission of the TV cable before replacing the transmission again. The tire seal comes out of the TV cable, and if there is a gasket on the transmission you receive, do not try to install both gaskets 🙂

TV Cable (Throttle Valve Cable):TH350 and TH400 are controlled by vacuum and rocket wire from the carburetor, while on 200-R4 and 700-R4, the control head between the engine and the transmission is only on the TV. Adjusting the u wire that controls the pressure regulator in the transmission and the correct amount of withdrawal is directly related to the performance or garbage of the transmission; because the wire adjusts the timing of the gear change with the oil pressure of the transmission. If the TV wire is pulled too much, the oil pressure is high (good), but the gear changes are very harsh. If the TV wire is low, the oil pressure will be low, although it changes very enjoyable gear, your pads will be roasted very soon. You need to get this wire ready, one end is connected to the transmission and the other end is connected to the carburetor. However, you need to do a fine engineering in connection to your carburetor and keep the distance of movement given in the drawings. At bowtieoverdrives.com you can find many sets tailored to your carburetor and make it easy for you. TV Cable is the part you need to pay most attention to in this project, and will require a fine adjustment. A skateboard errand is coming on the cable where you can press with your finger and adjust the length of the wire.

Cooling and oil: Cooling is important for the performance and life of the transmission. With insufficient cooling, you can probably kill your oil and pads in a short time. You must connect the oil cooling inputs and outputs of your transmission to the cooling radiator with a record or pressure resistant hose. Some cars have a separate oil cooling circuit at the bottom or next to the water radiator. If your radiator is not compatible with this, you will need to connect an additional oil radiator. You'd also need to wear oil heat and monitor the transmission harar emanating from within the vehicle with a little modification to your gearbox. The place you connect can also work as an oil drain plug – if you don't have the transmission you're in- When you call CP8201 on ebay.com, you can get an indicator worthy of your classic with your customer for $30, including cargo. In normal condition, the oil temperature on the sump should not exceed 90 degrees (200F). In addition, your transmission will take approximately 12 liters of automatic transmission oil, but put 8-9 liters of insertion inside the turbine before starting. Please do not use cheap oil in your project that you have invested so much, carefully inspect the packaging of ATF oils, the minimum specification should be Dextron 3 (do not use Dextron 2 or 1). The heat resistance of cheap oils is low and can also damage your electronic circuits. You can find these oils in OPET or Castrol, it can also be in other brands. 

Connections: Your transmission will be connected to the front engine and from the rear tail to the chassis. There will be different modifications for different models here. For the connection from the tail section, you must have a profile (crossmember) in your chassis. If you're doing it for the 1955-57 Chevrolet, you need to connect the carrier profile to both sides of the chassis, which you can get ready (Danchuk #12564) or make (pictured) because there is no profile. You should also get the original ear to connect the transmission to the profile (Danchuk #977A). You may need to move your exhaust silencers. 

There's an important detail i've learned with experience here. If your engine is connected by my front-eared connection like 1955, the rear transmission connection unfortunately does not prevent the engine from relocating with torque, and the engine creates a dangerous situation by tearing your ears off in the medium term. To do this, you need to convert your engine into side-eared connections (unfortunately there are kits for engines only in 1958 and beyond), or additional connections to the chassis from there to the chassis of the transmission-engine connection (Danchuk #870). 



Shaft and skateboard: If the length of the transmission you insert with the transmission you remove is different, you will need to shorten your shaft and insert it if it is divided. You need to get a skateboarder (yoke) suitable for 200R4 transmissions (27 spine-gear) and shaft joint (type 1310 in 1955s). In any case, you will need to shorten the shaft; the length of the skateboarder does not matter. I preferred Summitracing AXE-T350-HP.


Gear Lever: Now give your gear seof P, R, N, OD, D, D2 and D1 gears. You're going to have to make a very complicated adjustment to the gears, both from the ground and the steering wheel. You should also get a Neutral Safety Switch (ClassicChevy.com #25-07) that controls your gear lights, preventing the vehicle from running in a gear other than P and N. For off-the-ground gears, the gear adapters are attached to the gearbox from the top. For arm gear, things are a little harder. You need to remove the entire steering pipe. If you can find it, buy the steering pipe and mileage of an automatic vehicle from the scrapyard. If you can't find it, you need to carefully distribute the manual pipe and adapt it to the automatat. To do this, i will outline what you need to do, you can ask the details by email. But you're going to have to rehearse a lot.



First, you should remove the connecting rings at the end of the gearshaft and boil only 1 of them into the pipe in the appropriate position. You need to open a slit over the steering pipe. It's going to be attached here with a gear screw. Make a ledge to the gear shaft, which will coincide with the slit you've opened, this protrusion will pass to the square and will last as you lower the gear lever. Again, make a metal part to the engine compartment of the steering pipe to lock the gear at Position P. The simky electrical connections must be made by the electrician. The customer can be adjusted where it is mounted, and after you start the tool, you can fine-adjust it. 

I recommend that you get an indicator for automatic gear from ebay, Danchuk or the scrapyard, because the original gear indicator assembly is coming on. You need to fasten a thin copper wire to the right side of the gearpipe and attach this wire to the mileage indicator through a thin slit that you will open to the steering pipe. As you pull the gear lever down, this wire moves in the slit, moving the gear hand. 

Pressure indicator: I don't think you can adjust your transmission correctly without a pressure indicator. Again, connect the pressure indicator from the bowtieoverdrives.com to the driver-side port of your transmission before starting first. Once the settings are complete, you will remove this indicator. This indicator will help you with the tests you need to do after the transmission conversion is completed. Note the pressures on P, R, N, O, D, L1 and L2 when the vehicle is at 1000 rpm after the first start. When you pull the TV cable a little with your finger, see the pressure increases, so you know there's no gap in the wire. Then repeat the pressures in the same gears with the help of someone, pulling the TV cable to the end without touching the gas wire. The results should be about as follows, below these values your transmission does not operate with sufficient pressure, it is at risk. If the values are above this, you can adjust and re-check according to your driving comfort. To adjust the TV cable, you need to scroll the adjustment bar back and forth by pressing the button (the pressure will increase as you slide to the driver's side) 


TV in normal condition pressure

TV full towed pressure

Park, Neutral @ 1000 rpm

55-65 PSI

115-135 PSI

Reverse (back) @ 1000 rpm

105-120 PSI

215-255 PSI

OD (4), D (3) @ 1000 rpm

55-65 PSI

115-135 PSI

D2, D1@ 1000 rpm

120-140 PSI

120-140 PSI


Mileage wire: Make sure there is a milestone connector connection hub on the gearbox you will purchase, or buy separately. You can also find the number of teeth in the belly gear gear you need to buy by entering your tyre sizes, differential ratio and type of gear inside the transmission with the online calculation in the bowtiesoverdrives.com. Before filling your oil, insert the gear and belly into place and fasten your milewire (I used the same wire). 

Once you've made all your assemblies and connections, you can now run your car. Complete the missing oil after the start, remember that you should look at the oil of the transmission while the vehicle is warmed and running. Once you've made sure everything's running without flowing, without making a sound, go on the drive and check the gear shift performance. Remember, if you change the TV cable setting, make sure you redo the oil pressure measurements. After all your settings are finished, you can remove the pressure gauge and insert the original plug. I wish you a lot of automatic and enjoyable…


Useful links:Assembly
, setting and testing instruction:http://www.bowtieoverdrives.com/Instructions/BOW%20TIE%20OVERDRIVES%20INSTALLATION%20INSTRUCTIONS%20GUIDELIN
ES.pdf200r4 picture assembly: http://www.classicchevy.com/assets/pdf/classicchevy/19-01.pdf

List of materials:

– 200R4 and lockup converter (transdepot.net, bowtieoverdrives.com
)- Lockup wiring kit
1- Pressure indicator: http://www.bowtieoverdrives.com/cata…BCAT&CATI
D=SA2- Heat indicator: http://www.amazon.com/Sunpro-CP8201-…3898023&sr=
8-3-TV wire: http://www.bowtieoverdrives.com/cata…SUBCAT&CATID
=W- Slip: http://www.summitracing.com/parts/AXE-T350-HP
/- Flexplate: http://www.summitracing.com/parts/SUM-G100SFI
/- Cross member
:http://www.danchuk.com/ItemForm.aspx…564&…Item i
&item=1003- Neutral safety switch: http://www.classicchevy.com/chevy-ne…1955
-1957.html- Indicator lens: http://www.danchuk.com/ItemForm.aspx…248
&Item=10248- Starter engine kit: http://www.danchuk.com/ItemForm.aspx…1
00&Item=10100- Transmission mount kit: http://www.danchuk.com/ItemForm.aspx…h
=870&Item=870-Gear link: http://www.danchuk.com/ItemForm.aspx…h=952&It
em=952- Cooling hoses: desired, flexible or hard li
ne.- Cooling radiator: if your radiator is old, good chance to buy new one with oil provisions(Or a seperate oil-cooler radiato
072- Oil bar: http://www.bowtieoverdrives.com/cata…BCAT&CATID=TA2
– Km. wire gear and housing:h
– 12 lt. Atf: OPET may be in Dexron 3 specification


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