1990 Z32 AT stuck in 2nd gear

[Corvidae]

So I ended up selling my first Z32 (1990 NA) to my sister. She loves the car and it was running great for several months. A few weeks ago, she called me up to say that the transmission wouldn't shift. It was drivable, but needed to be "forced" into lower gears in order to get any kind of acceleration at all. She took it to a shop to have it looked at, and they quoted her 4K because "the transmission is just worn out and needs to be replaced." I told her that was BS and had her bring it down so I could take a look at it. I just got the car from her the other day, and have been doing some diagnosis work since then. I'm not a transmission guy, so I'd like other people's input before I take it someplace. Here are the symptoms:

* Shifter brake lock solenoid apparently not working, have to engage the manual shift lock in order to get the car out of park.
* Shifter action feels smooth... no problems shifting between settings.
* Reverse seems to be fine.
* When forced to 1st gear, acceleration and throttle response are normal.
* When manually forced into second gear, the shift from 1st feels just fine. No hiccups, loss of power, etc.
* When the shifter is on Drive, the transmission seems stuck in second gear. It will not shift down to first, nor up to third (I hit 80 in second gear... about 5K RPM, was still in second).

Any thoughts as to the source of the problem? I'm guessing it's a sensor somewhere, considering that it runs perfectly fine in first gear, it just won't shift there on its own.

Thanks,

-Corvi

[nick1809]

check/change the transmission fluid. (then sell transmission and do a 5 speed swap. xD)

EDIT: then if she REALLY needs a new transmission, try Z1 motorsports. they WILL have one cheap.

[Corvidae]

That was done as part of her diagnostics. Fluid was a little low, but that has been fixed. Was the normal red color, no burning / discoloration.

Since it runs fine if you force gears, it seems to be something to do with the sensors that actually tell the AT to shift. I tried doing the diagnostics, but either the AT control module isn't responding or my memory is faulty and there isn't actually an AT light on the '90(no lamp on when the car starts and attempting to go into the AT diagnostic mode doesn't do anything).

I'd REALLY like to get away from buying a new transmission (Z1 has auto TT transmissions for 885 including shipping... would the TT transmission work in an NA? I know the reverse doesn't).

[snowfox]

hey
I have an exact same problem. on 1993 z32 at

car drives fine and I have no limit on revs. but when put in D it does not shift.
did you find a solution?

[Ace2cool]

I'd think it would be either tcm or a solenoid frozen up in the trans. Where are you? I've got an auto trans taking up garage space you can just have.

Fluid level all right? Noises? Shifter solenoid working?

[NolimitZ32]

These transmissions are used in a ton of vehicle but you cant give them away, have had one sitting in my garage for months.

[DCaff300ZX]

These transmissions are used in a ton of vehicle but you cant give them away, have had one sitting in my garage for months.

Agreed, when I did my 5 speed swap I/my Z guy had to just turn the core in to a rebuilder for next to nothing, they wouldn't pay more than scrap value for it so I could chuck it or give it to them- either way I wasn't getting much if anything.
PO, the AT in the Z32 is a known problem area and when old (and ESPECIALLY if the trans got a "power flush"), they simply fail and in several areas which combine for the types of issues you have, and I had which were slightly different. May want to ask your sister if she had the trans serviced, Nissan for whatever reason recommends this procedure which most Z32 guys know to avoid as it forces particles and grit back INTO the trans and it's guts, a really really bad idea on ANY old trans and well-known by many to be certain death for a Z32 AT.
Everything came to a halt for me when the AT permanently stopped shifting at all. Specialty fluid from a race shop and service there had extended mine's life before the failure for 2 years, but the shop stopped working for the public and a trip to another shop resulted in an accidental flush, and two weeks later the trans failed.
Point is that I myself would not be stubborn in any way about replacing the auto trans as I have never really read or heard of anyone able to resuscitate one other than rebuilding it, and if the truth be known, a 5 speed swap from a reputable source (or, DIY!) may and usually is cheaper (and is certainly better) than replacing the AT, especially if trying to use a used Z32 AT unless from a reputable source such as one of our mods here or elsewhere who took care of the trans correctly, and won't lie to you about it's condition or history.
My swap cost about 2 grand total, including buying all necessary parts and removal/installation, and which was about 500 bucks less than the best bid I got for AT removal and replacement.
Good Luck!

[snowfox]

Honestly the offer sounds really good however the car is in such a bad shape and I live in GA. Im guessing its a TCM or maybe the solenoid? it's most likely to be an electronic problem.I also don't have the transmission light on...so.... I might mess around with it

If you have any more ideas, let me know, Thank you.