Speedo is doing my nut in!

[10 inch Terror]

Hi all, I've just fitted a new speedo unit and it's reading slow. Before I fitted it I connected the cable and ran it up with my Dewalt drill. It went up to 50mph very smoothly with no jumping or juddering. Once I fitted it and connected the drive from the front wheel it reads very slow and doesn't kick in until I'm doing at least 30mph. I 100% sure it's the drive from the hub at fault could anyone give me any pointers please? Cheers guys Pete.

[wack 63]

Try the drill on the end of the cable to rule that out before checking the drives.

[10 inch Terror]

Try the drill on the end of the cable to rule that out before checking the drives.

I don't understand that. Could you explain please? Cheers Pete.

[rosscla]

Grip the end of the cable in a drill and use that to turn the cable. If it does the same then the problem is in the head not the wheel.

[Muppet]

cut 5mm off end of y outer cable an try it again,

[10 inch Terror]

Grip the end of the cable in a drill and use that to turn the cable. If it does the same then the problem is in the head not the wheel.

I've already done that before I fitted the speedo and it was fine. If I put a small Allen key in the drive coming out of the hub and spin the wheel it spins fine. I'm stumped on this one.

[vRSG60]

It's a nightmare, take a look at my thread here
I've given up. My speedo was rock steady at almost the correct sped until I fitted a new drive. 3 drives in a month later and I've found one that doesn't chew up after 50 miles but the speedo is all over the place. Off the scale at 40 mph.
My drill will only get it up to around 20 mph.

[Daggs]

Grip the end of the cable in a drill and use that to turn the cable. If it does the same then the problem is in the head not the wheel.

I've already done that before I fitted the speedo and it was fine. If I put a small Allen key in the drive coming out of the hub and spin the wheel it spins fine. I'm stumped on this one.

Having had a similar nightmare over a period of some years I have some experience on this issue.
You have checked the speedo operation using the drill method. But you need to try it again with the speedo in situ.
Assuming that works o/k, the trouble lies with the drive.
No1 Ensure you have sufficient cable entering the drive (wheel end) This can be adjusted by trimming back the outer a little at a time.
No2 Don't be fooled by the allen key turning in the drive as you spin the wheel. Like this, there is no resistance or pressure on the drive. It often appears to be working, until you re-assemble with the cable in position. Sometimes if the brass elongated nut arrangement is worn it allows the worm to push away from the gear-wheel.
The plastic drives are often not man enough and jump all to readily. I can only suggest you buy the best available (speak to Scooter Restorations, they may be able to advise)
If you are happy with the quality of the drive (wheel and worm) You then need to ensure the gear-wheel is positioned onto the hub in the optimum position regarding how it meshes with the worm.
If all of this fails to rectify the problem................I'm f*cked if i know............

[10 inch Terror]

Ok the speedo works fine in situ going by the drill method. I see what you are saying about the Allen key method. All the drive components are from MB so they are probably the best available? I'm going to take it all apart hub end and have a look to see any obvious problems. I'll report back in a bit and thanks for all your comments thus far..

[rbgaz]

buy a garmin gps lol sorted