Speedometer Drive

C

campingstoveman

New Member
Gentlemen,

Last May when I bought my 1969 Series 1 3500 P6 it came with a non working speedometer, I traced the fault to the right angled drive on the Gearbox acquired a replacement and everything has been fine until this morning when I took the car to the garage for fuel. When I left the garage I found the speedometer was not working and have since found that the same fault has returned, the right angled drive square bowden cable has sheered in the gearbox.
I have spun the speedometer cable and it does not stick or catch and the speedometer also works ok. Any ideas please.

Martin P
 
The angle drives do fail on a regular basis, and if the previous one you fitted was secondhand it is quite possible that it only had that amount of life left in it.
The only other possibility is that something in the other angle drive or the speedo head itself is jamming up intermittantly.
 
Harveyp6,

Then I shall have to take the drive apart and make a new square cable to suit. The unit looks simple enough to take apart.
Will report on my findings.
The car had its longest run yesterday, a round trip of 130 miles, at motorway speeds apart from a slight wheel imbalance at 65mph it ran quite well. My SatNav provided the MPH.
I adjusted the tickover recently because I found it ticking over at 900 rpm instead 650 so need to balance the carbs as a flat spot showed itself when pulling away from junctions.

Martin P
 
Out of interest, did you reverse out of the garage ?
Just a wild theory but it may be when the cable is driven backwards that it binds and causes the problem.
 
Yes I did but I have had the inner out of the speedometer cable and its clean with no snags, I have lightly oiled it and it run through slow curves.

Martin P
 
Gentlemen,

Haven't got around to repairing the angle drive yet because the opertunity of buying a new one occurred which I fitted to the gearbox, twelve miles later with no reversing that is now broke so I can only assume its the speedo as the cable is free and no snags, does any body have a speedo unit for a 1969 series 1 3500 that is working they would part with please.

Martin P
 
campingstoveman said:
Gentlmen,

Is there any difference between a speedo for a 2000 or a 3500

Martin P
Click to expand...
Diff ratios and tyre sizes are different, so if the driven gears are the same then the heads must be different, if there are 2 types of driven gear (with different numbers of teeth) then the heads could be the same.

Looks like a job for someone with both parts books.
 
Additionally to the different TPM (turns per mile) that the two speedometers should be calibrated due to the differences in the final drive ratios between the 2000 and the 3500, the 2000 speedo will record up to 120 MPH while the 3500 should be up to 140 MPH.
Also the 3500 has a bigger fuel tank requiring a differently calibrated fuel gauge and different markings on the face of it in comparison with the 2000 type.
So, you should be looking definitely for a 3500 speedometer.

But if yours isn't jammed for good, if you feel inclined and you are handy with such delicate things you can remove it and lubricate the necessary parts giving a new life to it. There is also provision for adjustment to compensate for wear.


Demetris
 
You must log in or register to reply here.
Back
Top