How on earth... do I remove the speedometer cable?

Tofufi

Tofufi

Member
Hi all, I have a 3500 series 1, with the strip speedometer.

I need to remove my speedometer to replace the bulbs that light the gauges, and for this the Haynes tells me that I 'Disconnect the speedometer cable'. It has also recently begun making noises so I need to replace the cable really.

However, this is proving significantly more tricky than I had expected. I simply can't reach the speedometer connection through the glovebox to disconnect it. I can get a finger on it, but with no chance to undo it.

Any tips or hints? :)

Thanks,
Jim.

P.S. whilst I'm here... does anyone know the ratio of the speedometer drive on the gearbox for 3500 and 2000 models? Mine has a 5 speed LT77 conversion, and therefore the speedometer under reads. I was wondering if a 2000 speedometer, which only goes to 120mph, could make it more accurate (or, of course) further out.

Having mentioned the above, I'd guess I would then need to change the fuel sender and temperature gauge sections as the V8 has a different size fuel tank and different temperature sender, I believe?

:)

P.P.S. Apologies if I posted this in the wrong section, I wasn't certain which one would be best for this. :)
 
Hi Jim.
Hows things?
You cannot access the cable from the glovebox,you have to release the speedo cluster and edge it forwards,then you can get to it!
It is very fiddly,and you need to disconnect the battery first, then do it slowly incase you pull any wires off!
Dave
 
Take off the little strip which covers the warning bulbs. With a screwdriver take out the screws that hold in the instrument cluster. These screws have phillips heads. Do not lose these screws, the are listed in the parts books as "special screws" This means that they are a really odd thread type, and you will regret it if you lose them!

You can then disconnect the speedo cable. If the cable is original, it will have an extension on the part which screws into the angle drive. You can just undo it. If your cable has been replaced at some stage, the you may need assistance from small children, who have small nimble fingers to get to the nut and undo it. Most replacement cables do not have an extension on the nut. If there is a nut sitting down the shaft then it means that someone gave up trying to do up the nut at some stage, and just left the cable resting in there. This can work sometimes. Just pull down on the outer and it should dis-engauge.

Then slide the cluster forward some more. Take out the 2 screws which holds the saddle for the warning lamps on. These are 2 flat head screws which screw down into the top of the cluster. This way you can leave all the warning lights connected, and make it much easier to put the cluster back in.

I would find an appropriate screwdriver bit, which is a number 2 or number 3 square bit, I would put the bit in in a drill, and spin the speedo and see if it runs smoothly, in both directions. If it does I would assume that the speedo is good. If it runs rough, then I would take off the angle drive, and spin the speedo without the angle drive. If it runs smoothly then the angle drive is in need of replacement. The angle drive on the back of the speedo is a BG2410/00. You can turn the shaft on the angle drive, and see if it feels rough. Some speedo repair shops can repair these, sometimes you can drift out the coverplate, and grease it up internally, if the gears are okay. You should be able to spin the speedo with the angle drive installed, easily with your fingers, with the square bit. If it is hard to spin, then it may need lubrication, otherwise you will break the cable, or angle drive downstream, so to speak.


http://www.speedograph-richfield.com/ht ... tion_.html

You can purchase a new one on the above link. They also com up on ebay pretty regularly.

If the speedo runs smoothly through the angle drive, then the speedo cable needs lubricating. Use heavy grease sparingly. You do not want grease spinning up into the speedo. Pull the inner cable out from the outer, and run a bit of grease on it, as you feed in the cable. When you get to the bottom of the outer, spin it a bit, just before you go in to the angle drive, on the gearbox. The angle drive on the gearbox is listed as being a BG2401/04 for the 3500. The 2000 automatic has BG2401/00. I am not sure what the difference is, but if you can find a Smiths manual, then that may tell you. I do not know of these would work on the LT77 which you have, but maybe swapping to a BG2401/00 may help. I you had a fixed speed drill, and a cluster out of a 2000, and out of a 3500 you could spin both at the same speed, and see if the read the same speed.

http://home.comcast.net/~rhodes/speedo.pdf

The link above may be useful.

If you have the older type of speedocable installed, and it needs replacing, then you should get the inner cable made from a sample of the old cable. A good speedo shop can do this for you, just bring in the broken cable. That way you will not have to find small children for speedo replacement!

Make sure that there is no cable stub, up in the angle drive, on the back of the speedo. If a cable breaks, and then you replace it, you can end up pushing in that stub, and having very little of the new cable in. The new cable will work for a short period, then break.

The bulbs which light the gauges just slide out the back of the cluster, and are very easy to replace.

They smiths gauges for the 2000 are SM BF8101/03 early, and SM BF8101/03 A (late) for fuel gauges, and BT8101/02 early and BT8101/08 late (temperature gauge). See if these numbers match what are on your gauges. If they do, then they are the same, otherwise it would only take a minute or two to change them over.

James.
 
The original strip speedo cable should have a long extension which pops out just below the hole on the dashboard. If you were to take off the gear box end you would be able to pull the speedo forward and get in to it.

I thought when people did the LT77 swap they changed the diff to one from a 2000/2200??

Colin
 
Thank you all for your replies... much appreciated :).

I've eventually managed to remove the speedometer cluster, but I couldn't find the source of the noise. I've lubricated the speedometer cable and found the right angle drive was a little stiff, so that got some attention too. I suspect the job will be significantly quicker the second time round, when I know what I'm doing a little better!

I also managed to replace the duff speedometer bulb, although the gauges are still lit dimly even on full power on the dimmer switch (which seems to have little brightening effect for half of its rotation).

Dave, all is well thanks. Hope you are OK? :)

James... thank you for typing so much out, it made the job easy. :) I'll try buying a 2000 speedometer cluster and see how the ratios compare... chances are low, but it could work. :D The links you gave were particularly useful, and could help in the future. I'm not sure I am brave enough to dismantle my only working vehicle that far at the moment :)

Colin... I don't know what diff is fitted to the car. If this were the case, would it make things easier for speedometer calibration? I've got to admit, I've not found where the speedometer goes to the gearbox, only I have been told that it would get transmission oil everywhere if I were to remove the gearbox end of the speedo cable :)
 
Hi Jim

Given a working cable and gearbox end drive, the other approach to your problem is to have the speedo recalibrated. I've had excellent service from this chap: http://www.jdo1.com/ Its a bit of a confusing site but there are good instructions on how to provide the correct information if you look closely! He may even know which gearbox angle drive to order to correct (as are Richfield llikely to know if you email them). I'd make your own judgement on whether you're going to get a bath if you take the speedo drive off the box. Weigh up how high it is on the casing vs the oil levl plug for starters! Even if its well below, all you expose when you take it off is the speedo drive spindle running in a bush, so I would have thought the loss rate would be low.

Chris
 
Tofufi said:
I've got to admit, I've not found where the speedometer goes to the gearbox, only I have been told that it would get transmission oil everywhere if I were to remove the gearbox end of the speedo cable :)
Click to expand...

I can't see how you'll get covered in oil if you just remove the cable from the box, it's only likely if you remove the speedo driven gear and its sleeve, and even then you won't get floods of oil coming out, particularly if you've just raised the rear of the car to get under there.
 
If you want to pop over one weekend,give me a call,and we can bung it up on the 4 poster and have a quick butchers! :)
 
The differentials are numbered, with a nine digit number. The first 3 digits are the identifier, which conforms to the type of vehicle for which the vehicle was made.

425 - 3500 models.
471 - 2200 models.
401 - 2000 models with girling brakes.
400 - 2000 models with dunlop brakes.

I think that the 3500's had an extra pair of spider gears in the differential, I am not sure about the 2200. I don't think you would want to put in a 2000 differential, unless you like changing them.

Good luck finding the number. I tried to find the number on mine, and gave up. If you can get your car on a hoist then that would help of course. Its not much fun trying to find it underneath the car, lying in the dirt.

James.
 
You can tell the difference between all the diffs apart from 2200 & V8 just by looking at them, the Dunlop cars have different caliper mounts, and the 2000 is missing the extra strengthening ribs in the diff case where it meets the pinion extension. If you had the V8/2200 type you could then count the turns needed on the prop to get one turn of the rear wheels, 3.08 for a V8, and 3.54 for a 2200. I'm always a bit wary of using numbers alone seeing as the newest of these cars are well over 30 years old and a lot can have been played around with in that time. The numbers are stamped across the bottom flat part of the diff casing alongside the drain plug IIRC.
 
Thanks all very much for the help :)

I'll have to look into getting the speedometer recalibrated and work out what I've got. I have been told previously that the drive gear in the gearbox could be swapped for one from a different vehicle, and that this way I should be able to get something near-accurate.

I'm not sure how soon I'll be able to get on with it, but I'll try to remember to post back when I do :)

Dave, I may take you up on your offer of using the 4 poster ramp :D

Thanks again 8)
 
OK, it's my turn to pull my strip speedo to replace panel lights and maybe change panel light rheostat.
My warning lights all work but I have no panel lights at this time.
I can see the speedo cable extension sleeve through my glovebox. The manual is vague at this part.
How do I remove the cable from here? I assume turning the extension sleeve unscrews the cable from the angle drive?
Thanks for any help.
 
Now that I know removing the dashtop is relatively simple on the Strip type facia's, I'd do that as it makes it a bit easier. Harvey assures me he's never had to do that to change a cable or drive at all & I have no reason to doubt him. ;) But my inexperience tells me to do do it with the top off (& I never refuse a lady). :LOL:
 
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