Top Tips On Transmission Adapters For Your Next Project

Posted by on Tuesday, January 29th, 2013

Have you ever wished you could replace the transmission in your car with a better one, but the transmissions available to fit your engine were all equally bad? Sweat no more. There are many different types of transmission adapters available to match up almost any engine with any transmission.

typical transmission adapter


Car enthusiasts who want more power in their newer vehicles are swapping out the factory transmissions for the tried and true older and re-manufactured transmissions. Adapters must be designed to take a couple important things into mind. First, and the most obvious thing is the adapter must line up with the bolt pattern for both the transmission and the motor. Second, they must take into account the thickness of the spacer as to not make it too thick, or the converter (automatic transmissions only) will not engage the pump drive. Third, on an automatic transmission they must be sure to come up with a solution for the torque converter hub to make sure it fits properly into the back of the crank shaft.

Let’s take a look at automatic transmission adapters.

One of the most popular swaps available is to mount a Powerglide transmission behind just about any other motor, regardless of size, make or model.  JW transmissions offer a complete new bell housing for the Powerglide. This requires the stock bell housing to be machined off.  Advance Adapters, ATI, Transdapt, TD Performance and Hot Heads are all companies that offer adapters for different types of transmission / engine combos. Other things you need to take into consideration when making a transmission swap is that you will most likely need a new transmission cross member and mount. You will also need a new shifter (I recommend a cable operated shifter from B&M or Hurst), new transmission fluid lines and most likely an aftermarket cooler.  Sometimes you might also need a special transmission pan for clearance reasons, or in the case that requires a different transmission pan, you can just cut, weld and modify the stock pan.

Transmission adapter components



Manual transmission swaps are much easier.

This is because the bell housing and manual transmission are two separate pieces. Getting a special bell housing is a fairly straight forward affair. Special bell housings are available from companies like McLeod, Quick Time, Lakewood, and Hurst Driveline Conversions. A new hole will likely need to be cut into the floor board to allow the shifter to come up into the passenger compartment. The bigger issue will be the clutch linkage. I highly recommend that when doing an odd ball conversion you use a hydraulic throwout bearing in place of a mechanical one. The hydraulic lines are flexible making the swap a very easy one. Some guys are even swapping their automatic transmissions for a manual, and if you know what you are doing, this swap can go fairly easy.


Transmission adapter for Chrysler flathead engine


Transmission swaps should not be something you steer away from. You have to be a great diagnostician and troubleshooter when your working on your customers transmission. Just make sure to dyno test your newly installed transmission, to make sure everything is working properly. A new transmission, or remanufactured one, can dramatically improve the driving characteristics.

A transmission will not last forever, regardless of how well you take care of it. If a decision has to be made to replace the transmission, I highly recommend you consider a re-manufactured transmission as your first choice. They differ from a rebuilt transmission in the fact that they are as good as a new transmission at a greatly reduced price and often include modifications and upgrades that make them much more durable. A re-manufactured transmission also comes with a much better warranty: three years compared to 90 days for a rebuilt transmission.

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