Torque Converter Issues?

[sublime187]

First of all, I've had the ATF replaced via drain-and-fill method about 5k miles ago. Prior to this, I don't know if the fluid was maintained. Here is my problem. When driving at around 40-45mph, if I let my foot of the gas, there is an audible thunk that can be felt very strongly as well. It has nothing to do with gear changes. i could repeatedly press and release the gas very slightly at this speed and repeatedly get the same thunking. From other posts from around the internet it sounds like this may be a torque converter issue. Does this sound correct? Furthermore, what is a good plan of action to take to correct this, and is this something I can live with, without causing further damage?

[maxnix]

First of all, I've had the ATF replaced via drain-and-fill method about 5k miles ago. Prior to this, I don't know if the fluid was maintained.

First off, drain and refill only replaces some of the contaminated fluid with new ATF while leaving +60% of the contminated fluid and all of the detritus not in the pan in the tranmission.

You should have had a good clue to the previous maintenance by the appearance and smell of the old ATF. Did you not replace the interior screen filter, its O ring, the gasket and one-time use bolts so you could clean and inspect the pan and filter?

I bet your problem is either your third motor (transmission) mount or your driveshaft U joints.

Inspect and report back, please.

[Unnatural1]

All of the above is good advice.

It sounds like what your feeling is the TC going in and out of lock up. You should be able to feel this to a certain point. But as previously mentioned, I'd start with checking your engine and transmission mounts.

I haven't experienced any harsh engagement/disengagement from my Q but it is possible that the solenoid controlling TC lock up is sticking, possibly due to a lack of maintenance.

Also, I did not find any related TSB regarding this issue.

[Haitian_King]

First of all, I've had the ATF replaced via drain-and-fill method about 5k miles ago. Prior to this, I don't know if the fluid was maintained. Here is my problem. When driving at around 40-45mph, if I let my foot of the gas, there is an audible thunk that can be felt very strongly as well. It has nothing to do with gear changes. i could repeatedly press and release the gas very slightly at this speed and repeatedly get the same thunking. From other posts from around the internet it sounds like this may be a torque converter issue. Does this sound correct? Furthermore, what is a good plan of action to take to correct this, and is this something I can live with, without causing further damage?

Fantastic! Finally, somone with the same issue as me. I feel that same thunk and I don't like it. I've been suspecting my TC, but from what I can find online, I don't have the stalling, lack of power at 3k RPM, and other "trashed transmission" symptoms.

However, my Q is a 92 with just over 97.2k on the clock. I had a BG AT flush/exchange around this time last year. I'm very interested in getting to the bottom of this issue.

[Q45tech]

Luckily I've avoiding having to deal with wornout TC clutches since you get a new one with every Nissan AT replacement. I'm on TC #3 now.

[Haitian_King]

Luckily I've avoiding having to deal with wornout TC clutches since you get a new one with every Nissan AT replacement. I'm on TC #3 now.

So that's what that is? And the only remedy is to scrap the entire unit? Shucks.

Isn't it a bit early for something that drastic? Damn the previous owner. There's a pretty big gap in maintenance history (or lack thereof) between the first owner and myself. About 60k miles worth.