'77 280e 123

[mgburg]

Hello - I've dropped off our "new" 280E at a detail shop to give it the complete package - wax, engine wash, interior clean - everything ...-

What I need is a little info about the speedometer/odometer - the speedometer appears to be working just fine - I put my GPS on the dash and found that I'm only off by about 1.8 mph (high side) when I'm running about 70 mph on the GPS and about 72 on the speedometer - I'm not going to worry too much about that, but here's the rub - the odometer/trip meter is intermitent in its operation...sometimes it advances - but most times not ...-

What do I need to look for to get this fixed? Do I need a "new" instrument cluster? What?

Thanks!

[VLayton]

- the odometer/trip meter is intermitent in its operation...sometimes it advances - but most times not ...-

What do I need to look for to get this fixed? Do I need a "new" instrument cluster? What?

Thanks!


Someone who can re-attach the main brass drive wheel back to the top number wheel spindle.

Don't reset the trip while the car is in motion.

[mgburg]

Thanks Vince - A good speedo-shop should be able to do this without tearing anything up too bad?

[VLayton]

Thanks Vince - A good speedo-shop should be able to do this without tearing anything up too bad?

Yes.

I paid $150 in '98

A couple of years later I was qouted $90 with a removed speedo gauge IN MY HAND- that was the day I learned to fix them. Now my club members can get them for $100 for pull, fix, and replace. I've done 6-7 to date, only one has acted up, but I have no way of knowing if it was abused by the car owner (holding reset while driving (I guess I'd do a cluster handed to me for $75)

Warrantied (I wouldn't expect a warranty from most) until the NEXT 100k set. (if it still works after a few miles after turning the first number, I think my job was done, I doubt they could be PERMANENTLY fixed, perhaps by those better than I like a real VDO shop.

Best to you,

[Alex]

Don't reset the trip while the car is in motion.

Vince,

Is this a general rule on mechanical odometers?

[VLayton]

I don't know for sure, my guess is many of the VDO of the era are like this at least. I've only dealt with "W123" odometers- the cable turns the main spindle through through special plastic (spline?) gears, the main spndle has a brass gear that directly cogs to the trip meter, so when you hold reset it locks up those transfer gears and the weak point of the link is where the brass gear is supposed to turn with the spindle, which will just spin inside the center of the gear.

[mgburg]

Vince:

How difficult is it to remove the cluster and disassemble the meter to get to the gear(s) - I've done something like this to an older Chevy van MANY years ago - I'd hate to "tear" into this nice unit and get in over my head ...-

[VLayton]

How difficult is it to remove the cluster..-

Not hard at all, relevently, but must be done with great care

disassemble the meter to get to the gear(s) ...-

no harder than opening a motorized toy car, but actually fixing the slipping gear is not for greenhorns who are unwilling to risk permanent damage (my first was rough, but successful, I've refined my methods and tools choices since then)

- I'd hate to "tear" into this nice unit and get in over my head ...-

You may want to sit this one out, if paying for a professional is error it's at least on the side of caution

[mgburg]

Thanks Vince! I'll go the route of a pro...-

[pch2021]

the odometer shouldn't really be toyed with, however, saometimes the main gear drivng the trip gets stuck and at speeds under 10 mph, this CAN be reset. However, during normal driving, don't reset your trip. It can misalign the counting gears- the gears that turn the next number over, and thus, the odometer's funciton WILL degenerate.

[mgburg]

Thanks Guys! I've scheduled "surgery" for 10 Jan.'06 - hopes it's successful!