1996 Toyota Avalon transmission causes engine to "bang" backwards

Maintenance/Repairs
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1

Ray and Tom:



Do I really need a new transmission, as recommended by my Toyota dealer? I have a 1996 Toyota Avalon XLS with 230K miles on it. Starting at 191K miles, the engine itself started to bang hard backwards on the mounts when (1) the gas peddle is released quickly while traveling at around 40 MPH or more, or (2) when starting off in park, and shifting into reverse. I have asked a lot of questions and done research, but still have not gotten the exact fix for this - even after driving for 40K more miles! All I have done is change my driving habits to NOT take my foot off the gas fast, or to just park where I only have to pull out of a space to avoid shifting into reverse! Drives my wife nuts because I pass by the close parking spaces!!



Since I would like to have my 15 year old son learn how to drive with this car, I am concerned that teaching him the finesse needed to handle this quirk may be too much for him ? and me.



What do you think is wrong? The transmission has been serviced very regularly, and shifts very smoothly. Is there a solenoid that needs to be replaced? Motor mounts? Thanks in advance for your advice and wisdom, and helping us reach several hundred thousand more miles on this car!



Tim

2

This sounds more like bad engine mounts, same problem I had with my '96 ES300 (same basic car). They caused my radiator to crack at the upper hose, so it’s worth fixing it soon.

3

I understand the ES330 has the same engine as the Avalon. Reading into your reply, are you saying this symptom went away after replacing the motor mounts then?

I have thought about doing this, but wasn’t quite sure. I did replace the dog-bone mount which had definitely gone bad. Did you replace the trans shock as well? Thanks for such a quick reply!

4

Yes, the problem went away once the mounts were replaced (in '96 it was still the ES300). I’m not sure which exact mounts they changed out (I had an independent shop that I trust do it).

5

Thanks!

6

It;s possible that the tranny is a problem, but I bet it is the engine or trans mounts.

7

I think I will try replacing the 2 motor mounts and the trans mount. I may even change out the trans shock absorber, which looks easy to do. Start there and see if the symptoms go away.

Any recommendations for a DIY weekend mechanic on a motor mount project? Easy to do? Pitfalls to avoid??

Thanks!