Speedo woes

[nemchenk]

First problem with my new Landy!

Driving back from its old home, we noticed that the speedo was way out -- it never seemed to register anything above 40, even when it was clear from surrounding traffic we were doing around 70, and jiggled a lot.

I've checked where the cable enters the back of the speedo, and where it comes out of the transfer box, and both seem secure. I've noticed that the outer plastic sleeve of the cable has melted off in one spot (about 5cm long) where it was near the exhaust.

On advice from two other Landy owners, I also took off the gearbox end of the rear propshaft, to make sure the nut behind that was secure (it is.)

Any other ideas? Someone said the tyres or diffs might be non-standard -- the tyres are 205/80R16s, and the difss... how would I know? Is there an easy way to tell?

Anyway, any advice would be appreciated!

Edit: Oh! And how much torque should I apply to the propshaft-to-parking-brake nuts? My Haynes book doesn't seem to list this...


Thanks!

 

[DISCVRY]

The cable itself may be broken or sprung. I would bet on broken. I can't remember, but I think you can disconnect the cable at the speedo end and remove the cable from the sheath. It should come out in one piece and not have any sprung or funny looking spots on it. If it is broken, (what I suspect), maybe only the top half will come out.

The speedo is probably acting weird as the two broken cable ends snag on each other while rotating. If the cable was just sprung, the needle would be bouncing all over the place.

-Reed

 

[bhodisatva]

Check also at the gearbox end, there should be three screws holding the speedo cable in place, if one of these is missing it can give similar symptoms.

 

[nemchenk]

Well, I don't think it was the speedo or cable -- I unhooked it from the transfer box (all 3 screws were in place), and tried it out with a drill. I could get it up to 70mph with the drill -- steady reading, no probs.

I wrapped some duct tape around it where the exhaust had burned off the outer sheath, oiled it with some light machine oil, cleaned up the end and the "socket" for it on th transfer box, and put it back together, making sure the three screws are tight.

Looking behind the proposhaft end, the large central nut is NOT staked -- I can see where it would be, but it isn't. No pin in rattling around there, either...

Gonna go for a test-drive and see if maybe it was just "cranky"....

 

[betobenz]

I've had the same problems. The speedo can be taken appart and theres a wound spring in there that controls tension on the needle. Heres how I THINK it works first the cable drives a wheel with magnets on it. That magnatize wheel or disk drives another disk which is hooked to the needle with the wound spring. So the cable driven wheel combined with this wheel hooked up to the guage needle is acting like a slipping clutch. The faster that wheel turns the more it starts to grab the wheel with the needle. Hence, the speedo needle starts to move towards 10mph 20mph etc.
Some sickness that a speedo will develop are where the cable goes into the speedo can dry out-you will see how the part that the cable turns in the actual connection in the speedo body could possibly dry out and jam. I put a drop of oil on it. also I've found it's good to leave the knurled connector that connects the cable to the speedo just a bit loose IE not fully finger tight. Try just doing these two things and see what happens.

My speedo acts strange at lower speeds in the cold. But as it works more it tends to work ok and fairly accurate.
My speedo was going wild and would peg it self past seventy when I was going about 20. So I took it appart and gently lifted the speedo neele over the stop by zero and wound back around so that the wound spring had more tension. It worked. It was some trial and error but it's ok. I also had a speedo jam-a mess-hence I learned to oil that part I mentioned above. This is very fussy work and even then no guaranteed results. The right way to do this is to have your speedo rebuilt. But for me, I think these speedo's are just this way and speending 100 dollars plus to rebuild it -well I think it will probably go back to doing the wild spins again. So for me I just did the above and it semed to do ok. When it does do the wild thing I've been known to give the speedo a slap with my fist and then it acts a bit better.

 

[betobenz]

I've had the same problems. The speedo can be taken appart and theres a wound spring in there that controls tension on the needle. Heres how I THINK it works first the cable drives a wheel with magnets on it. That magnatize wheel or disk drives another disk which is hooked to the needle with the wound spring. So the cable driven wheel combined with this wheel hooked up to the guage needle is acting like a slipping clutch. The faster that wheel turns the more it starts to grab the wheel with the needle. Hence, the speedo needle starts to move towards 10mph 20mph etc.
Some sickness that a speedo will develop are where the cable goes into the speedo can dry out-you will see how the part that the cable turns in the actual connection in the speedo body could possibly dry out and jam. I put a drop of oil on it. also I've found it's good to leave the knurled connector that connects the cable to the speedo just a bit loose IE not fully finger tight. Try just doing these two things and see what happens.


My speedo acts strange at lower speeds in the cold. But as it works more it tends to work ok and fairly accurate.
My speedo was going wild and would peg it self past seventy when I was going about 20. So I took it appart and gently lifted the speedo neele over the stop by zero and wound back around so that the wound spring had more tension. It worked. It was some trial and error but it's ok. I also had a speedo jam-a mess-hence I learned to oil that part I mentioned above. This is very fussy work and even then no guaranteed results. The right way to do this is to have your speedo rebuilt. But for me, I think these speedo's are just this way and speending 100 dollars plus to rebuild it -well I think it will probably go back to doing the wild spins again. So for me I just did the above and it semed to do ok. When it does do the wild thing I've been known to give the speedo a slap with my fist and then it acts a bit better.

 

[betobenz]

I've had the same problems. The speedo can be taken appart and theres a wound spring in there that controls tension on the needle. Heres how I THINK it works first the cable drives a wheel with magnets on it. That magnatize wheel or disk drives another disk which is hooked to the needle with the wound spring. So the cable driven wheel combined with this wheel hooked up to the guage needle is acting like a slipping clutch. The faster that wheel turns the more it starts to grab the wheel with the needle. Hence, the speedo needle starts to move towards 10mph 20mph etc.
Some sickness that a speedo will develop are where the cable goes into the speedo can dry out-you will see how the part that the cable turns in the actual connection in the speedo body could possibly dry out and jam. I put a drop of oil on it. also I've found it's good to leave the knurled connector that connects the cable to the speedo just a bit loose IE not fully finger tight. Try just doing these two things and see what happens.


My speedo acts strange at lower speeds in the cold. But as it works more it tends to work ok and fairly accurate. The Speedo does come appart easily but it's easy to mess it up so if you dare read on..

My speedo was going wild and would peg it self past seventy when I was going about 20. So I took it appart and gently lifted the speedo neele over the stop by zero and wound back around so that the wound spring had more tension. It worked. It was some trial and error but it's ok. I also had a speedo jam-a mess-hence I learned to oil that part I mentioned above. This is very fussy work and even then no guaranteed results. The right way to do this is to have your speedo rebuilt. But for me, I think these speedo's are just this way and speending 100 dollars plus to rebuild it -well I think it will probably go back to doing the wild spins again. So for me I just did the above and it semed to do ok. When it does do the wild thing I've been known to give the speedo a slap with my fist and then it acts a bit better. Hitting it is a lot more rewarding that pouring for hours over springs and magnet wheels. I have a box of old speedo parts just in case though. I'm keeping my eye out for a NOS one or rebuilt onee or perhaps I will buy a couple of old ones and take my chances.

 

[antichrist]

The rear output nut doesn't have to be just scure, it also has to be torqued correctly. Also, the housing for the worm that drives the speedo cable is shimmed, though I've rarely seen that to be the problem. However, if the PO had the gearbox out, they may have incorrectly fitted it.

Tom Rowe
Four wheel drive allows you to get stuck in
places even more inaccessible.