Auto Gearbox NOT engaging reverse

[cikko]

Hi,

I have tried searching for this *allegedly* common fault - the gearbox works fine forwards but reverse cannot be engaged.

If it is as common as a "well known fault" according to anyone who I speak to, there must be a wealth of fix solutions out there...

I suspect there's nothing internal it drives fine forwards - so I suspect something like linkages need adjustment etc.

I came to the above conclusion after hearing from some people that the reverse WILL engage if on an incline or loaded up boot space...

The levels appear to be ok.... I wonder if I should go for a filter and fluid change first and see if that's the fix?

I dont wish to throw money away and if there is a fix it (ie selctor cables need an adjuster adding or new adjuster if they have them) then I'd rather do that and get straight to the fault!

Please - if anyone can help me avoid taking this to a specialst.....

Stu

[insanitybeard]

Being an auto box, to the best of my knowledge there won't be any external linkages as the control is all electronic, so if there is an issue it's going to be electrical- control wiring or module, or an internal gearbox issue. I'm not familiar enough with the auto boxes to expand any further I'm afraid.

[insanitybeard]

Ok, it appears that there is infact a cable (mechanical- not electronic) from the selector lever to the transmission, but this may only be for interlocking functions, it needs the input of somebody more familiar with the AG4/5 transmissions than I!

[Chrispb]

Hello 

How did you check the fluid level in the gearbox?

https://www.fordmpv.com/smf2/ford-galaxy-reference-library/galaxy-mk1-mk2-automatic-transmission-fluid-level-check/

Changing the filter on the AG5 is impossible without dismantling the box changing fluid is also time consuming and expensive as you will only get half the fluid out when draining so would need to be done several times with a drive in between to get the new fluid through the converter and valve chest.
Cost of fluid from Ford was at last count Ã,£21 a litre, the box holds 7 litres but you'll only get half of that out so bear that in mind.
I have been told by G/Box specialist to use Dexron 3 I have also used Mercon V which is a bit cheaper.

Have you checked for any stored fault codes?

A faulty solenoid could be changed in situ, other possibilities are broken brake band and cracked piston but I'm sure that affects operation of forward gears, would also require gearbox removal

[insanitybeard]

Chris, do you know what the selector cable does? I presumed most of the actuation in the 'box was done hydraulically/ electronically, but for there to be a mechanical cable onto the gearbox must mean there's some kind of mechanical actuation going on?

[Chrispb]

Chris, do you know what the selector cable does? I presumed most of the actuation in the 'box was done hydraulically/ electronically, but for there to be a mechanical cable onto the gearbox must mean there's some kind of mechanical actuation going on?

Hi Paul
I'm not a transmission specialist but as far as I know the selector cable attached to the top of the box provides the initial selected range as with other auto boxes.

[insanitybeard]

Thanks Chris, though I removed and installed a few auto boxes in my time I never had the training so never got involved in stripping them! I'll have to dig out my textbooks and have a read up! Is it possible a defective range sensor could prevent selection of reverse gear?

[billywizzo]

Hi
Not sure about what could be wrong with your gearbox but try WIMBLEDON AUTOMATICS on 020 8540 6624.
I used them to get a replacement gearbox on my galaxy (took half a day to replace) and been back to them for oil changes and they are very knowledgeable.

Would recommend them if you need any work done on your gearbox.


Bill