1997 Pathfinder Transmission Issue

[A1218]

So I was going somewhere this morning that was about an hour away. I was driving around 70mph most of the time and doing some short bursts up to 85mph at times. 40 minutes into the trip I had returned to cruising around 70mph and then decided to accelerate hard again.

The transmission did not drop gears and accelerate rapidly. The pedal was all the way to the floor and the rpms wouldn't pass 3000rpms. So I let off and decided to accelerate again and this time the rpms went high but not much gain in speed. Some jerking occurred and I pulled over as I knew it was a transmission issue. When the vehicle was slowing down from 60mph it felt like something was engaging and disengaging continuously. I turned around to go home and I took the local roads all the way back and it was shifting relatively fine driving up to 50pmh.

There's a slight whine noise when driving, like there is snow tires on. But very faint. I took it back on the road again just now and its driving pretty normal going up to 60mph and accelerating fast from stops and such. No jerking, or slipping. I did hear a clunk once around 55 mph when releasing the pedal and if I let the vehicle coast down a hill at its own speed I get a clunk noise when it shifts into 3rd around 15mph. Accelerating through the gear doesnt do that.

I tried switching the overdrive on and off and its working as the rpms change when doing so. Checked the fluid and its fine. I changed the fluid last month and last year as well.

All in all, its not failing to changing gears or banging. I did have a the transmission rebuilt 7 years and about 80,000 miles ago when the reverse gear failed and the vehicle wouldn't shift.

Could it be the torque converter?

I may have been getting some signs recently such as a shudder when the vehicle is rolling at idle speed. And it is worse when engine is cold (shudder decreases significantly after its warmed up after driving few minutes). As well as that slight howling noise when driving that I've noticed a few days now.

Im now at 184,000 miles.

[A1218]

Everything is working perfectly fine today so I’m not sure what happened.

Any thoughts?

TPS acted whacky?

[mdmellott]

Our R50 models are great marathon runners but are not really designed for wind sprints. I had loads of fun, back in the day, with my old '89 Mustang 5.0, manual 5 speed, cruising along at 65mph or so in 5th and then dropping it to 3rd with the pedal to the metal and rocketing forward while being pinned into my seat. Cruising at 70mph in the Pathfinder, automatic, and punching it to drop into 3rd and accelerate is a bit more work than all those old actuator valves in the transmission are designed to tolerate long term. They may be a bit sticky and slow to respond as they age but they will go the distance in the long run if they aren't too frequently demanded to act like a sprinter.

[Mike W.]

Our R50 models are great marathon runners but are not really designed for wind sprints. I had loads of fun, back in the day, with my old '89 Mustang 5.0, manual 5 speed, cruising along at 65mph or so in 5th and then dropping it to 3rd with the pedal to the metal and rocketing forward while being pinned into my seat. Cruising at 70mph in the Pathfinder, automatic, and punching it to drop into 3rd and accelerate is a bit more work than all those old actuator valves in the transmission are designed to tolerate long term. They may be a bit sticky and slow to respond as they age but they will go the distance in the long run if they aren't too frequently demanded to act like a sprinter.

I would argue that's all the more reason to regularly do fluid changes on auto boxes.