Automatic Gearbox Additive?

Arkwright

Inactive
I have a 300zx TT which has just had a second hand replacement autobox fitted. The box was from a reputable trader and was fitted by a reputable garage.

It is holding in 3rd gear and doesn't change again until I lift my foot off the accellerator and then plonk it down again. No one seems to know what the trouble is.

A couple of days ago I spoke with an old man who used to repair gearboxes and has now retired. He said that the use of a particular additive would clean the valves (whatever) inside the box as one was probably sticking. However he could not rememeber the name of the product. He advised going to a gearbox specialist who may be able to supply this product. To date my son has taken the car to two such specialists who have refused to even look at the car when he says what it is never mind offer advice!

Does anyone know what this product may be?

I have obtained a tin of Wynn's automatic transmission stop leak & conditioner this purports to:
.stop & prevent leaks in auto transmissions
.smooth & quieten gear changes
.prolong the life of transmission components
.revitalise rubber seals
.prolong the life of auto transmission fluid.

I am reluctant to add this in case it is the wrong product.

Has anyone any suggestions? (manual conversion has already been suggested)
 

Gio

Well-Known Forum User
Hi Derek, this is a known problem on these autoboxes. It's mentioned quite a lot on the other place. I don't have enough experience on autos (only had one for 2 weeks) to comment on details or what the fix is. Maybe Mr F?

As for the manual conversion, lots of people claim to get it right but ...

If you look down this page, there are a few options http://tech.aus300zx.com/Engine-Drivetrain.html

and here's an autobox diag http://www.twinturbo.net/ttnettech/autodiag/autodiag.html

Me - I stick to if you want an auto, buy an auto; if you want a manual, buy a manual etc. It seems to me that doing a good conversion to proper spec is more hassle / less good than fixing the auto. But then, I think everyone knows how I feel about stock :D
 

Nidge74

New Forum User
Can't see that it would do any harm, based on your description.

If it was me, and I don't suggest that I am the brightest bulb in the box, I'd try it anyway, and if things do go wrong, there's no excuse not to do the Manual Conversion. :)
 

tel240z

Club Member
Hi Derek I Am No Professor On Autos But Here Goes .
It Sounds Like To Me That The Box Is Not Getting Enough Vacuum That Could Be Why When U Lift Your Foot Of Up Goes The Vacuum
Next Gear Sellected That Is Of Course If The Car Has A Vacuum Pipe To The Box. Or If Its An Electronic Box As Bmw Use It May Be Thinking Of Engine Braking Mode This Means As U Pull Away Sharply Then Let Off The Throttle It Stays In Alow Gear To Give Engine Braking A Quick Short Tap On The Throttle Should Take It To The Next Gear Thought I Would Let U Know All This As It May Help
 

Arkwright

Inactive
thankz for the input guys. We stuck the Wynns in today and my son has taken it for a blast and says it's now running ok. We'll see how it iz after the weekend.
 
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