A/T doesn't like 4th gear at low speed/RPM

[munjal]

An odd issue came up with my '98 max last night ....

When cruising at low speeds around 40 mph and 1500 rpm....the car was ...sort of bucking....as if going in and out of gear.

However the issue immediately goes away when I give a little more gas and raise the rpm to over 2k rpm or higher...or turn off OverDrive and go into third gear....

Issue seem to come up after about 5-10 minutes of driving after everytime I stopped and parked the car somewhere.

I checked my fluid level this morning (transmission) and it seems fine, however I did see really small/fine bubbles on the dipstick...the kind I heard of when you have too much fluid in the transmission...don't know if this is the case or not.

I did replace the fluid about 5-7k miles ago, and earlier this year, on two separate incidents, I got a CEL code for Torque Converter Clutch solenoid, however in both cases the code went away on their own after a few days. I don't know if this is related

At the moment, I have no codes, (or lights really) but I have to borrow and reader and try to pull the codes anyways, if any exist in the system.

My Car specs: Stock to the bone 1998 SE, with 210K miles.

Only else comes to mind, is could this be a possible fuel issue instead of the transmission, since it only occurs at low RPMs after a few minutes of driving?

Also, I have not driven the car today to see if this issue has returned.

Any and all of your wise feedback is greatly appreciated.

[MinisterofDOOM]

Sounds like the torque converter is locking and unlocking to me. The TC clutch solenoid error code would support that theory.

In 4th gear, above probably 43-ish mph (not sure of the exact speed for the Max 4 speed, but it should be right around 43) when throttle is consistent (steady cruise, very little change in throttle position) the torque converter will lock a physical clutch to increase fuel economy. It's mainly designed for highway cruise efficiency. When the clutch engages or disengages, it can be felt...feels kind of like a very soft shift. If the solenoid is having problems, it could cause the surging you describe as the clutch locks and unlocks repeatedly.

Might want to just observe next time you drive to see if the surging is only present above 45 or 50 at steady cruise. From your symptoms, though, I'm pretty sure the issue is that lockup clutch. The solenoid probably just needs to be replaced.

[munjal]

Ya, it only happens in the 40~ish mph range.....once in a while when stopped and idling too......the only thing is I read for codes last night and I don't have the solenoid-related code anymore. I'm going to see if I can get a transmission shop to do a diagnosis for the solenoid pack for now ...since I don't know what else to check.

I will consult the FSM to see if there's anything in there too

[munjal]

More replies on the maxima.org forum here:

http://forums.maxima.org/4th-g....html

seems like a lot of people have this same problem