transmission problems

[Nismo300Z]

I have a 1995 Z N/A with an automatic transmission. I've had it for over a year and ever since I got it, sometimes it will leak and smoke. I took it to 3 Nissan dealerships and all the times they have said it was something different. Each time I paid to get it fixed but it will still smoke. I could have bought a new transmission. Now they said it might be a vacuum inside sending too much fluid and it's over-flowing and burning off the exhaust. Can anyone help me out and give me a suggestion on what it do or what it might be? Please help me.

[NISTECH]

we just repaired a 93 convertable for the same concern. what we found on this vehicle was 2 problems. one was the pan gasket was leaking and burning off on the exhuast and it also had a leak from the speedo pinion oring seal. this car when driving on the freeway would clear the lane for a half a mile and drew some pretty hasty looks from other drivers on the road. I would say take a good look your self under the car and see were the fluid is coming from. The places it could come from are pretty limited. Front pump seal would leak from the bellhousing weep hole, Pan gasket, cooler line banjo washers located on either side of the trans left side is near the rear of the main body and the right side is near the front of the main body just above the pan, speedo pinion seal right side near the rear on the tail housing, and the vent located on top of trans would pretty much look like it is coming from the top of the trans if looking up into the tunnel. also near the right side banjo washer is the shift lever shaft into the trans.

[NISTECH]

oh and also from the output shaft seal

[Nismo300Z]

Thank you NISTECH. I didn't check to see if it was what you had told me because I haven't had the problem. This has happened before and then with out warning, it starts to leak. Did the same guy have this problem also? It always happens when I go on long trips.

[NISTECH]

no this car was spewing transmission fluid when we got it. the customer did not indicate any history on the problem. as a dealer tech we dont get to talk to the customer first hand much.

[Nismo300Z]

NISTECH, I was just thinking. Every time it has happened was from long trips. During the trips I use overdrive and cruise control. Could any of this be sending too much fluid into parts of the transmission causing it to overflow. I don't think it could be cruise control but I'm starting to think it's the overdrive. Could I be right about the overdrive or is it just a coincidence?

[NISTECH]

check your fluid level hot. it is likely it is coming out the vents on long trips due to it heating up. make sure once its warmed up that your fluid level is about half way between the 2 hot marks and not any higher. if at operating temp the fluid level is ok you may want to consider adding an after market oil cooler infront of the radiator to help keep the fluid from over heating.