940 Auto won't change gear
 

Hi all,
I've recently purchased a Volvo 940 Saloon automatic which was running fine until recently when it stopped changing gear. The garage seem to think that it's the rear speedo drive in the diff as it's not working. The speedo hasn't worked since I bought the car 4 weeks ago either.
I was hoping someone can shed some light on this for me, as a new speedo sensor will cost me £130ish.
I desperately need the car on the road asap as I use it to run my elderly mum around as well as myself. Also she is booked into several car shows in the up and coming months.

Many Thanks in advance,
Aaron.

The speed sensor in the diff has nothing to do with the gearbox as the gearbox is hydraulic not electronic. If it is a 1991 or 1992 car it is a common problem with the speedometer not working. The solder joints on the PCB and speedometer probably need redoing and the capacitors are probably blown and leaking.

I'd recommend you find a garage used to dealing with proper cars not modern computer cars.

Have you checked the oil level, the linkage is moving underneath correctly and is the kickdown cable adjusted correctly and still on the throttle spool. It is more likely to be an issue with one of those or dirty oil or worst case the gearbox itself.

My mates 940 blew up its gearbox after issues going in to 3rd and 4th.

It's a 1994 2.0L Turbo Wentworth saloon Auto. If that helps any.

Does it have a button on the side the shifter and the quadrant marked 1-2-D-N-R-P or no button on the side and 1-2-3-D-N-R-P?

Also does it change any gears at all, eg 1st to 2nd to 3rd but not 4th?

Like Luke sys, the speedo is irrelevant and that garage has no clue!

Yes it does have the button on the shifter.
It will change gear (just about if i fiddlewith the throttle) on the flat but not with any load on i.e. uphill.

That's the AW71 box then, from your description i'd go with that Luke suggested, someone has over-adjusted the kickdown cable or it has snagged on the throttle drum on the inlet manifold.

The garage have said the gearbox oil level is fine so they are stumped as to what it could be.

It was driving fine until I gave my mate's Volvo a jump start then it started going funny.

Did you rev the engine while jump starting? :thinking:

How did the garage check the oil level?

My 1998 940 was exaclty the same with it hanging on to low gears when accelerating. I adjusted the kick-down cable which has a little brass ferrule crimped on it up at the throttle spool end.

Although the measurements looked ok, (IIRC it's 1-2mm from the cable stop), I eased it out another half mm of so & the car drove completely differently and much more relaxed.

It's back under cover at the mo as I have a coolant leak on a cylinder head blanking plug but that's another story!

I hope you sort it.