hi i have just bought a 300zx twin t h reg and my auto box is playing up the car drives fine but it does not want to go into 3rd and 4th gaer in my auto box but first and second are fine it stays in second and does not even change to 3rd or 4th shall i do a auto box diagnostic check or what please guys help me

Hi, I had the same problem. Probably due to a sticky shift solenoid. I was told it would need a new/recon box so I had it converted to manual. If I thrashed the nuts off it in 2nd it would occasionally change up.

 

You could try checking some of the sensors are working correctly - TPS is known to cause dodgy gear changing, also speed sensor. If it's had a km/mph conversion check all the connections are good and your speedo is displaying correctly.

 

RobH

check the level of the fluid first - make sure its right. Then do the diagnostic.

IF that shows nothing check the TPS for proper adjustment and that the voltage change is smooth.

 

The other thing that can make a difference is one the throtle cables in the engine bay - I think its the left hand one should only have 1-2 mm of free play in it - this can make a difference. But dont overdo that one as i can prevent the car starting up.

 

After that you may need someone to look at the box for you.

If you mean its stays in 2nd whilst in Drive, then try disconnecting the battery for an hour and then try agin. For the some reason the autobox ECU has a wobbly and needs to be reset.

 

Did anything happen when this fault showed up? Mine did a similar thing after going through a car wash. I expected the worst but it was simply a fuse!

 

Let me know how u get on.

Hi, I did exactly the same, i brought the car not realising it had a knackered box, being a mechanic i tried a few things myself, i replaced the shift solenoids, i stripped and cleaned out the complete valve body assembly etc, the diagnostic showed no faults, i like Rob H went for the manual conversion, it cost £1500 at Zedworld and i'm well happy with it, i went this way cos i didn't want to shell out £1200 to put the auto box right and have to do it again in 18 months as i have a receipt for a recon box supplied and fitted 18 months earlier.

 

If you decide to look into the manual conversion i would highly recommend Zedworld, great job and Jeffs always happy to help.

 

 

Baz

hi guys thanx alot for your help . what does tps mean and also another problem i drove the car and after a while all the gears started to slip and parked the car up and started it from cold and it was driving normaly 1st 2nd not switching into 3rd and 4th but fter a few minuites as soon as the car got warm all the gears started to slip even reverse ..........if any one can give me some advice that would be great through forum or if you have a contact number i can call u on thanx..........

Harry, from your last post it sounds as though you have none or very little AT fluid in the box! I'd stop driving it now and get it looked at.

hi the gear box oil and filter was changed 2 months ago how do i check too see if it is too low thanx

when i go over anything rough on the road the whole car judders it feels like it is going side to side some body has said it is the rear driveshafts ...........

That could also be worn out shock absorbers. Quite common.

thanx but how do i check the shocks .. also i jacked up the car and there was a little play in the rear wheel from side to side ....im getting a gearbox fitted 2morrow cant wait but want to get it all sorted its a good motor thanx.....

:rolleyes:

Play in the rear wheels is ralted to the Hicas arms - they are about 50 quid each from Nissan and not a big job to do - cant remember the exact name for them - I had mine done a few months back - that also is a common problem - but not a big one - my symptoms for that where the rear handling a bit funny round corners - but I've also heard it for your problem too. Any decent 300 mechanic will diagnose that one for you.