My transmission makes creaking and tinging noises like a hot exhaust cooling down whenever I put the car in park or put it under load in reverse. For a while I thought it might be the exhaust but it is definitely the tranny. Sometimes (infrequently) it will also thud when changing from forward to reverse or vice versa. Car drives fine and shifts smoothly. Fluid was changed last year on more-or-less scheduled interval. At this point I am trying to get ahead of future problems and looking for ideas.

I thought maybe the flexplate was loose but the shop says they are tight. Could be a cracked flexplate but the shop said they did not see evidence (they did not remove it). Possibly a failed tranny mount? Possibly a bad vane or three on the torque converter although I would expect other problems. Ideas?

This is the non-electronic 4T60 aka 440-T4 in my '85 SDV

Looking at it some more I am pretty sure the mounts are at fault here--when the transmission kicks, the engine is moved a little, which causes the exhaust to get torqued up, producing the sounds

It sounds like you may have found the problem. Another case of wimpy mounts.

If the sounds is indeed from the transmission, it most likely is coming from the sprag gear. The sprag tends to rear it's ugly head on these transmissions at around 150k miles and they usually make noise only in park or neutral. Once it starts to make noise, the catastropic failure is close and will occur if the gear seizes or lets go and sends debris through the rest of the transmission. Unfortunately, the transmission has to be removed from the car to replace this part. This part is one of the weak spots on this transmission.

Does the sprag problem make constant sound? Mine only makes noise when the park pin engages and the car rocks. It also makes noise in reverse. Probably makes it in drive too but I can't hear anything at speed

My experience with bad sprags is when the disaster was already done and I open the tranny and find a seized sprag and a bunch of parts in the pan so I can't say much about how it sounds exactly. However, people have told me that they hear some type of a whine while in park and the engine is idling.

Thanks for the info. I don't hear anything like that.

Maybe it could be some play in the CV joints on your front drive axles That usually shows up when turning sharp at low speeds, but any play can make a slight clunk when shifting from forward to reverse, or vice-versa.

I was able to get it up to the shop and the mechanic confirms that the front tranny mount is broken clean through and the engine mount is in a bad way. I ordered a set from rockauto (Anchor is cheap but it only has to hold a while) and hopefully this will fix it

I got the mounts and jacked up the engine, and near as I can tell the current mounts seem to be intact. What looked like tears before was actually just flecks of crud and there is no visible damage to the rubber at all now that they are clean. However there are shiny spots under the crossmember where the nuts used to be, but the nuts are now about 1/2" over on one mount. Also there is a brace from the right front mount to the exhaust and it was unbolted at both ends. Not sure the mounts are bad or if the mounts have just gotten pinched up. I decided to tighten the mounts and secure the brace, and it seems to have fixed everything. I suspect the loose brace was my exhaust sound,. The mounts may yet prove to need replacing though. So there ya go.