Lubricating Speedometer drive

[TimK]

After 30 years of running the speedometer cable directly from the transmission without use of an angle drive (I cut an access hole in the trans cover and ran the cable under the floor carpet to make a gentle bend), I decided to buy and install an angle drive. It lasted about 500 miles and broke. I removed the angle drive and reverted to my prior method of directly connecting the cable to the transmission. I was having trouble reinstalling the cable into the speedometer and removed the speedometer to see what was going on. I inserted a large flat wood drill bit to turn the drive and it was very stiff -- the cause of breaking the angle drive, I'm sure. I put a few drops of 3-in-1 oil on the edge of the drive socket and used an electric drill to spin in reverse. The drive freed up and turns with no effort. Is this a known issue and should it be lubricated periodically like this?

 

[Rob Glasgow]

I had the same issue when my angle drive broke 5 years ago. I installed a new one and it only lasted a few hundred miles before it gave up. I pulled the speedo and discovered it was very hard to turn. I cleaned and lubed the gears and reinstalled with another new angle drive. All has been fine for the last 10,000 miles. I probably should pull the speedo again and re-lube before long.

 

[CanberraBJ8]

I'm not so sure that it is the problem in total. I also went through a few angle gears. I think the quality of their build is a bit suspect. I ended up with a new cable, which although the old one seemed free enough to me when turning by hand, made quite a difference. With the angle gears I think I ended up dismantling a couple (the original, and the repo) and combining the best bits. So far so good.

 

[TimK]

I'm not so sure that it is the problem in total. I also went through a few angle gears. I think the quality of their build is a bit suspect. I ended up with a new cable, which although the old one seemed free enough to me when turning by hand, made quite a difference. With the angle gears I think I ended up dismantling a couple (the original, and the repo) and combining the best bits. So far so good.

Did you take out your speedometer and check the drive for freeness? I did not take apart the speedometer, I only put a few drops of oil around the circumference of the thing that the cable attaches to the speedometer -- some kind of little bearing I guess.

 

[CanberraBJ8]

I blamed the speedo first and oiled it. It was a little stiff I thought, however I have heard (can't remember where? maybe re speedos in 356 Porsches?) that the speedos shouldnt be oiled...

 

[TimK]

I blamed the speedo first and oiled it. It was a little stiff I thought, however I have heard (can't remember where? maybe re speedos in 356 Porsches?) that the speedos shouldnt be oiled...

that's what I thought too, which is why I asked the question, but it really changed the friction of the speedometer. I repeat, I did not spray any lube into the main body of the speedo, just around the bearing for the drive cable. I believe what I did was a good thing and hope it helps somebody else.

 

[CanberraBJ8]

Hey Tim

I agree - surely there are some sections of a speedo that do need some lubrication.

 

[Leo_Speichinger]

Their is a little washer (spacer) that goes between the angle drive and the gearbox threads and if is not installed when puting on the new angle drive it will break. It is listed in the Moss cat and is refered to in a sub note

Leo

 

[tahoe healey]

All good but don't use 3 in1 oil. It has paraffin which is wax and hardens with time. Use sewing machine oil or something like that. WD-40 is also not good for this as it evaporates.
TH

 

[Bob_Spidell]

It's been a while since I last had my speedo apart for, uh, 'maintenance.' The end of the cable goes into a shaft--it looks like a tiny camshaft with no lobes--that drives the magnet and its bracket. The bearings on the little 'camshaft' are what needs to be lubed--I used light lithium grease, after cleaning off the remaining dried and cruddy original grease.

For the life of me, I don't understand how applying oil to the end of the shaft would help free up these bearings but, if it worked, it worked--maybe enough of the oil worked it's way down to the bearings, which IIRC are deeper in the guts of the mechanism.

 

[TimK]

Their is a little washer (spacer) that goes between the angle drive and the gearbox threads and if is not installed when puting on the new angle drive it will break. It is listed in the Moss cat and is refered to in a sub note

Leo

I did use the copper washer -- that was not the problem...

 

[TimK]

Well, maybe it didn't work. Out for a drive today and the speedo quit. The cable connection to the speedo was very warm. Need to take it apart and see what happened. Healey's = drive 1/2 hour, work to fix what went wrong = 1 hour.