speedo

Try using the correct combination of wheel/tyre for the car. 15" wheels shod with 185/65/15 tyres if saloon (sedan) or 195/65/15 tyres if estate (wagon). If you use a set of alloys from a 740 GLE you will end up with a superb combination which will enhance the comfort, hold the road like s**t to a blanket and look like a Bentley/RR into the bargain.

All the best, Peter.

700/900/90 Register Keeper, Volvo Owners Club (UK).

But that's no help for him since he has a '90 turbo which came with the 16" Hydra rims. Nice wheels they are too, and getting harder to find in good shape.

Yes they are in good condition but an odd size .LOOKS like I must pay the man or get the speedo adjusted .Question is can I change a cog \gear teeth on the drive somewhere to compensate my tire tyre size ?

Oh yes it is of help because the brake disc and callipers were made to fit into a 15" rim. All he has to do is swap with someone for a set of 15s and "Robert is your father's brother" ( old UK phrase "Bob's yer uncle" meaning job sorted.).

All the best, Peter.

700/900/90 Register Keeper, Volvo Owners Club (UK).

The speedo has an electronic pick in the diff cover that "counts" the teeth on a gear on the diff carrier. There's nothing to exchange easily. However, customization is very common with hot rodders and there's quite an industry to support this sort of thing. A quick search of the 'net turned this up at the top of the list.

At last an easy way to do it. Thanks for the link Mike.

All the best, Peter.

700/900/90 Register Keeper, Volvo Owners Club (UK).

Well if he wanted to lose the nice 16" rims. If they're in good shape I'd trade him my 15" alloys with a decent set of tires on them for the 16"s, best looking rims Volvo ever made IMO, and they improve the handling of the car over the 15s too. Tires cost a bit more but so what? Not like they have to be replaced weekly.

Speedometers are designed so that 1000 revolutons of the driven wheel equals one mile or one kilometer. This can be seen on the speedo face by the designation r=XXX or KXXXX. If the circumference of your wheel and tire combination can be matched with any other wheel combination available for the chassis then there is speedometer gearing avaialble for your car. Provided of course that the rear axle ratio in your car was also available in other versions.

There are five differential ratios for the US market:

3.31; 3.54; 3.91; 3.73; 4.10, and five different speedo ratios. The available combinations in your market should be similar.

Bob

That doesn't really apply to these cars though as they don't have a speedo gear, it's electronic and replacing the pickup wheel involves dissasembling the rear axel assembly.

That's why the speedometer gearing is matched to the differential ratio. The shutter wheel on the diff is the same for all models with an electronic speedo.

Bob

Is it? I thought that it was attached to the hemisphere, not the pinion?!?

If it's on the hemisphere (or ring gear, or an axle) it'll depend only on the tyre diameter.

Almost. According to someone on brickboards, there is a 12-tooth for non-ABS and a different one (48 or 96) for ABS.

It's on the axel, you're right, the pinion ratio has no effect, only the tire size.