Morning all,

Having recently fitted 15in vesa alloys to my 340 I have noticed the speedo is now erratic up to circa 60mph (was warned this might happen), and that the milometer has stopped working altogether. Is there a simple fix for this?

Many thanks

Roge1

I think it's probably a coincidence that fitting new wheels has done this, unless youve disturbed the speedo drive in the end of the passenger front wheel hub or something. What size tyres do you have? Because of the lower profile with larger 15" wheels the actual rolling diameter shouldn't make too much of a difference really

Steve,

Due to suspension rubbing, I have ended up with 175 55s on the front and 195 55s on the rear. I will take a look at the drive in the front pass wheel hub, just in case I wasn't as careful when the wheels were replaced as I hoped I was!?

Thanks

Roge1

Them tyre sizes wont be helping accuracy, I'm afraid - the correct size to get the closest rolling diameter on Vesa's would be 185/55/15 or 195/50/15, I'd go for the latter as its a much more common size

Tyre/wheel size will only make a difference to your speedo accuracy, unless someone has removed parts of the speedo cable end point in order to fit the wheels. Do they have a solid centre, ie no small cap that covers the centre? It could be pressing on the speedo cable end point and pushing it back into the hub.

If 'someone' warned you that might happen, they knew the wheels would damage your car.

Some cars with ABS do have an issue with some LP wheels/different sizes, but that is rather different to a simple mechanical speedo drive.

The little clip that holds the cable in the end cap may be deformed or missing allowing the cable to move further in. Happened the other week on my sisters car, the clip was deformed making it to wide to hold the cable properly.