Dyno Testing a Re-Manufactured Automatic Transmission And Why It’s Important

Posted by on Tuesday, November 20th, 2012

Everyone knows that replacing an automatic transmission can be labor intensive and a general pain in the you-know-what. Modern vehicle manufactures try to fit as many items in the cavity of a car as possible, and as cars get smaller they get more crowded. This makes replacing an automatic transmission difficult. The last thing you want to do is replace a defective transmission with another defective transmission. Hence importance of dyno testing.

Transmission Dyno


If you have a transmission dyno in your shop, dyno testing is fairly straight forward. However, not many independent shops do. The dynos are expensive and are usually only affordable to larger shops, such as those that specialize in re-manufactured transmissions.

Dyno readout


The dyno is a machine that holds the transmission and drives the front pump with a powerful electric motor via a special adapter. The dyno also has a number of pressure gauges that help monitor the line pressure and other pressure readings in the transmission. As the electric motor comes up to speed (along with the front pump that it’s attached to) the transmission starts to generate line pressure. Readings on the gauges are compared with minimum factory specifications. The electric motor also drives the input shaft. The transmission can be run through the gears manually, assuring that all the clutch packs are being applied properly. Kick down functionality and vacuum modulators can be checked at this time, too. Electronic solenoids can also be checked at this time to assure that they are working properly.  A technician will also use electronic testing equipment to check the resistance in the solenoid. More modern transmission dynos will include a computer and monitor to help aid in the testing process.



After the technician runs the transmission through all its tests he will usually look for leaks and recheck the torque specs on all the bolts. If the transmission does not pass any of the dyno testing, it will be torn down and gone through again.



Dyno testing guarantees that a remanufactured transmission works properly. Time is money and you can’t afford to waste either so make sure the transmission you use to replace your customers original transmission has been dyno tested.

 I highly recommend you replace your customer’s transmission with a re-manufactured transmission. A remanufactured unit will include major alterations and upgrades designed to make them both stronger and more durable. A re-manufactured transmission will also include a much better warranty: three years compared to an average 90 days for a rebuilt transmission. In the rare event that a re-manufactured transmission fails within the warranty period, they will cover your R&R cost to replace your customer’s transmission. And remember, the companies that re-manufacture transmissions are very easy to contact. They are just a quick phone call or email away.

2 Responses to “Dyno Testing a Re-Manufactured Automatic Transmission And Why It’s Important”

  1. [...] swaps should not be something you steer away from. Just make sure to dyno test your newly installed transmission, to make sure everything is working properly. A new transmission, or remanufactured one, can [...]

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