Hi all,

 

I have an auto jap zxtt. All working fine now don't have top gear? I was messing about with the hold button but don't think that would do anything.

 

Any advice out there?

 

Many thanks,

zx-ice

sounds expensive to me

 

ive had a jap auto and a uk one

ive had to put gear boxes in both

about £1500

(have you cheaked gear box oil)

No I haven't. The engine has only been in the car for 2 weeks. It's going back today but do you think it's the gearbox for sure? Is there any chance it can be a fuse of stuck hold button or something?

 

Thanks

Some of the sensors are known to cause probs with gear changing in autos...TPS and vehicle speed sensor being the most common. Also, if it's a jap with a km/mph conversion it might be worth checking the convertor - can be wired out of the circuit to test.

 

Could be a sticky shift solenoid - quite a job to replace. Def. worth checking fluid level and quality though.

Fluid level or quality wont make any difference.

Hmm...by quality I meant condition. I'm pretty sure that bits of gearbox in your fluid can cause sticking of sensors and solenoids. Also incorrect level would cause incorrect pressures. This is info that was passed to me when I had autobox problems.

 

Mark you could at least say why you think these would not make any difference - I thought the idea was to share information?!

Sorry, I was being rude and unhelpful.

 

Low oil does give presure probs, but only in as much as it mostly shows itself as it will "fall out of gear", on corners, braking hard etc, due to surging of the oil. it also might only engage when you rev it, and then go in with a bang. If the car has got to top gear speed it has enough oil to do the other gears, and top will not take much, if any, more oil than the other gears.

 

As for quality, it would not effect just top, and in extreme, a gearbox would run on almost any fuid (even heating oil) for a short time before it cocked everything up, so if it works for the other gears etc etc.

 

Years ago, the yanks, once leaders in auto boxes said only change the fluid every 100,000miles. It does not go through the same process as engine oil, and I dont believe it "wears out" to anywhere near the same extent. Nor does it become polluted by the combustive process as in an engine.

 

Top gear on the Z is a clutch, and it is too small for the job, hence they fail. A good thing to try and do is take your foot off the gas pedal as it changes gear, ie into top, this make a lot of difference to the stress placed on the clutch.