I have a 99 Accord Ex, Auto with 122k. I just swapped engines. Now it sometimes make a clunk or thump when going into reverse. It goes into reverse fine, no clunk but sometimes after going backwards about five feet it clunks. It doesn't do it in any other gear. I replaced the forward transmission mount and big round engine mount on the right side.

The tranny has no other issues like slippage or rough engagement.

Any ideas?

 

Glad to see you are back on the road.....sounds like you didn't damage the trans.

I would inspect the rear mount to be sure it is ok.

 

No I didn't damage the transmission thank the Lord.

One good thing about a bad mistake is that you never repeat it.

I actually paid a guy 450 to reinstall the transmission. I did notice the rear trans mount doesn't look like it is aligned right.

 

Good to know the trans is ok.....bet you won't go back to that parts store

Check the mount, the alignment could be a few things.....busted mount, bracket not right, other mounts out of alignment as well?

 

Is it a 4-cyl or a V-6?

The shop manual talks about aligning & tightening the engine mounts in a certain order. Look that up, so all the mounts are sharing the load in the proper proportions.