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Q: Vehicle is shaking bad, loss of response, slows down when off accelerator almost like it has an engine brake. Starting to lose pwr

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I changed the transmission fluid and filter,degreased the engine and did the timing. Put it back together with the proper torque specs. I added dextrin 2 and Lucas transmission additive. I took the car out for a drive, everything was fine, shifting gears very good and responsive, but once I got on the freeway (55+mph) the car was shacking very very badly. I thought the wheels were about to fall off. I got it home, next time I took it out for a short spin the shaking was still there, but at an even lower speed (40 mph). I checked the timing, it was fine, CV axles seem alright, the bushings are all good aswell. So, I took the car out for one last putt this time the car was shaking at (15-25mph). I've looked over the transmission the only thing I found odd was a black ground wire that wasn't attached to anything, but it looks like it hasn't been used in a long while. It just seems very strange that this happened right after changing the ATF and filter. Do you think it could be a faulty transmission solanoid? Any suggestions?

My car has 300300 miles.
My car has an automatic transmission.

Hello, thank you for writing in. Shaking typically is a result of an engine running issue. Did you add any fuel additives? These will clean the engine and cause the debris to comes loose. You may be feeling the result of the engine degreasing. If the electrical connections were contaminated, soaked, or shorted out during that process, you would experience similar symptoms. You should start by checking the spark plugs and make sure they are not wet or contaminated. Secondly you will want to scan the vehicle for diagnostic codes and check if any other electronic device that is monitored is detecting an issue (not all codes turn on the check engine light). With some further inspection on the engine’s electronics, you will likely find something was messed with during the engine cleaning that you did. For more diagnostic help, contact our service department to schedule an appointment.

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