Hello all,

Since I upped the boost on my car last week, the auto box has been hesitant to shift up under full throttle, and as of last night, it just refuses point blank to shift to final gear, resulting in the car revving at the redline but not changing up.

Is this a clogged solenoid that an auto fluid change would fix, or am I looking at a rebuild/replacement?

Thanks for any help,

Brian

That’s funny, the same thing happened to me a week ago. Just had the engine rebuilt, new turbos and boost upgrade, within less than a day my box refused top change up past second gear. It would go straight into top if I took my foot of the throttle but as soon as I applied the slightest pressure it dropped back into second. I carried out the auto diagnostic and no faults were found. It was suggested that the extra boost pushed a near death box over the edge but since I was running the engine in I drove it very gently.

 

If you box is displaying exactly the same symptoms then I can tell you what I tried with no luck.

 

Checked and topped up trans fluid

Fitted new TPS

Re-adjusted throttle cable

Tested kick down switch

Even tried fitting a replacement control box from a friends Z.

 

At this point I conceded that the box had crapped out. Fortunately Andy p came along with a recently upgraded box for sale, which is currently being fitted.

 

Hope you have more luck than I did, sorry not to be of any help but it does seem like a strange coincidence.

 

Steve.

 

There is a diag page in the manual for this, although I can't remember which page right now.

 

When mine packed up I lost all drive, this was because the pump became blocked with crap (broken belts etc), therefore no pressure, no drive etc. Yours doesn't seem that drastic (yet).

Mine did the same, only was slipping in 1st off junctions etc.

 

Foot down to go and nothing, just revving then after a number of seconds probably as some kind of limp pressure built up I would slip into drive.

 

It's not a nice feeling when you're trying to jump off a roundabout junction and fuck all happens!!!

 

Classic signs of the auto going West!

 

 

 

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Mine started to do this too, revving in 1st and then would slowly move off and would not change up or down smoothly. Had the box taken out and they found a lot of aluminium filings in base of the casing. Cost me £1k to have it reconditioned now perfect.

 

 

Me Too. Also after an engine rebuild. Just packed up overnight, though after a frantic 1/2 mile the previous evening (perfect on the way home). Exact same symptoms - 1st 2nd perfect nothing after that.

 

I'm a mechanic and got involved 12 hours so far and nothing to see. I can say with authority that there is nothing to see either external, or internal to the box, thoughI've yet to take it out and strip it down. I would say the tech data in the tech section on this site is very good for checking out external/internal sensors (Serious note of thanks to the authors of this site).

 

Without knowing what's wrong with mine (at component level ideally) I'm not about to spend the £1200 that I've been quoted for a box. It's my experience (with other vehicles) that auto boxes do not just stop without warning, or if they do you find bits in the sump. Not so with this.

 

Did you have yours repaired Brian? I think I'm going to out mine as is.

 

 

NB. I think the slipping in first issue is an entirely different issue to the one that Brian originally posted.

 

That to me is a conventional worn out clutch issue (autogearboxes have wet clutches just like bikes). Symptomatic of simple wear and tear.

Hi Richard,

Regarding, my autobox, I've given up on replacing/rebuilding it, and have opted to convert it to a manual, which is apparently less problematic.

I hope you can sort out yours, from searching on T.T.net, I have been told that it is a line pressure solenoid that causes this problem and that the part is relatively inexpensive.

I hope this helps!

If any of the gears are slipping then the "clutch bands" are shagged and the tranny REQUIRES an over-haul. Sorry, thats the truth of the matter.

 

If the gear change characteristics are shot but not slipping then you are in with a chance. Its likely to be the TPS or the LINE PRESSURE SOLENOID!!! (particularly if the low gears are red lining before changing) These do not always appear as errors on the diagnostics! I've experinced most of these symtoms with my auto box. I had my auto box completely recon'd and still had the low gears red lining before changing - LINE PRESSURE SOLENOID was faultly even though it tested out OK during the rebuild. The speed sensor can also cause these problems but you should notice it on the speedo too.

 

Do check the obvious though, like the fluid and do a diagnostics to check for other error codes.

 

Laterz

 

Andy