Lotus Europa Community
Lotus Europa Forums => Garage => Topic started by: buzzer on Saturday,April 14, 2018, 05:03:59 AM
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Trying to get my speedo to work today. TCS 5 365 box.
Speedo cable rotating in reverse :headbanger: :headbanger:
Any ideas!!!!
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Explain "Speedo working in reverse"
It is turning the opposite direction?
Is it an original box?
Original speedo?
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I thought that only happened in the Southern Hemisphere.
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If it is a Renault gearbox, and not a Lotus gearbox, don't they rotate different ways, as the gearbox on the Renault is mounted the other way around?
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The drive rotates the wrong way looking at the front of the drive cable when in the drivers seat it rotates anti-clockwise when driving forwards.
I did rebuild the gearbox and it all looked like the manual.
Lotus europa speedo. New speedo cable and new drive gear from Banks. Don’t know if the box is the original box
[size=0px]I thought that only happened in the Southern Hemisphere.[/size]
[/size]
:FUNNY:
In the Renault I thought they were driven a different way but the basic same internals.
The car has 5 forward gears before anyone asks.....
So it really confusing. What am I not seeing
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New speedo "drive" gear:
The plastic driven gear?
Or, the metal scroll gear on the pinion shaft?
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For the car to go forwards, and the drive cable to go backwards, both drive and driven gears at the cable joint would have to be reversed. Not very likely.
I think you need to compare what you have got, with what is standard and works correctly, which means taking the car to someone who has similar but standard.
I have a gearbox out and speedo drive cables with the gears, up here in Norfolk if that is any help.
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The new gear was the metal pinion gear that the speedo cable fits into. And I got this from Banks europa.
I’ll dig out my pictures I took of the gearbox internals and speedo drive before I assembled it and post them for comparison.
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I know it's a stupid question, but are you sure it is going around the wrong way, because when you look at the speedo cable, it is a mirror image of what it is going in to the speedo itself.
There is no possible explanation for the cable going backwards.
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The speedo drives all turn the same way. It's the ring and pinion that are changed to get the different rotation directions for the half-shafts.
All the speedometers I have worked on are direct drive. The cable turns a magnitized drum which turns a spring loaded drum with the indicating needle attached. So the cable turns in the same direction as the speedo needle.
On a Europa, with the speedo cable end pointed towards the driver, the inner cable should turn clockwise.
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Checked again this evening definately the inner cable is rotating anti-clockwise when driving forward. What could I have done wrong when assembling the gearbox. It’s totally baffling.
Will pull the speedo cable from the box and pull the pinion shaft next.
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"The car has 5 forward gears before anyone asks....."
You're sure?
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Yep 5 forward gears 1 reverse. Driven it. And the engine is in the back before I get asked that!
The only thing I can think is if I had a wrong nylon speedo drive gear (if there is such a gear) on the end of the driven shaft and the speedo pinion gear not fully engaged it could be driven backwards. Going to check that next when I take the pinion gear out I should be able to see the gear on the end of the driven shaft.
I’ll take a video too of it going backwards!
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The scroll gear on the pinion shaft only goes the one way. Some scroll gears are not handed but, even if you flip them, they still go the same way. Not sure what is up.
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Maybe your speedo is reminiscing, and wants to go back to the 70s.
Time travel in a Europa, instead of a De Lorean.
There must be a logical explanation. Time to contact Mr Spock.
So far you have defied all logic.
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Yep it must be something like that. I wondered what that extra module on the dash was ... must be a flux capacitor!!
I am doubting my sanity :headbanger:
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I think you've found a wrinkle in your space-time continuum!
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And dear SH of Cambridge is sadly no longer around to work out what is happening.
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Ok, I have taken the rear of the box off (I can do this in situ as I have a removable rear crossmember) Here are some pictures of the speedo drive gear.
As the speedo drive gear (lower shaft) rotates clockwise when looking at the back of the gearbox.
What is strange is the speedo pinion gear gears are angled differently from the diagram in workshop manual and this was supplied by Bank.
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According to this photo, that's the wrong gear:
https://jbcollier.smugmug.com/Lotus-Europa/i-XZdsKjq/A
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Yep the wrong gear. Interesting I got this from Banks.
So my options are:-
1) live with it and get a 90 degree converter than also changes the direction of the drive
2) change both gears
3) electronic speedo conversion
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Well actually just checked the uk SJ sportscars website and they have this pic
which is the same orientation that I have.
Confused totally now!! :headbanger: :headbanger:
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Yep the wrong gear. Interesting I got this from Banks.
So my options are:-
1) live with it and get a 90 degree converter than also changes the direction of the drive
2) change both gears
3) electronic speedo conversion
4) Buy a big rear view mirror and learn to drive in reverse.
5) Change the cams and starter motor and get the engine to go around the other way.
Presumably Lotus gearboxes have different gears to Renault gearboxes, as they must rotate in different directions.
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Now I realise this may be heracy but......I broke my speedo when I “ gently coaxed it to zero” during my restoration. Replacement is very expensive and recon takes 6 weeks. So I installed a GPS speedo. It took 5 minutes and is superb. I will replace the Smiths speedo one day but this was a very quick and easy temp solution.
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Smiths also makes an electronic speedo that you can drive with a GPS antenna. The fonts and styles have changed a bit so it's not an exact match for your other Smiths gauges, but it's not too far off.
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I might be driven down the GPS route, but spent time and money sorting out the standard stuff
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The worm gear would have to be wrong to drive backwards.
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Unfortunately, 90° speedo adapters rotate in the same direction in and out.
Let's go back to basic questions.
Is this a 365 gearbox from Lotus, or from a Renault?
Has the gearbox had any major work in the past?
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The gearbox is somewhat unknown, but the casings i.e. the rear casing is the correct Lotus casing (I believe the Renault casings are slightly different) and I understand that the 5th gear addition was a Lotus specific addition.
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so you have never had the speedo working on it before?
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and presumably as your car was I believe the spare race car, the speedo may never have been used on that car, and you may have a specially built "blueprinted" race gearbox.
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Is the speedo cable a know quantity? No junctions or boxes inserted for a cruise-control or other gawd-help-us?
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Here's a photo into my 365-box. I was planning to change the o-ring and shaft seal, so now I might as well get it done! (Thanks for pushing me). ;)
It shows that my worm drive 'goes the other way' than your's does and hence will try to turn the speedo drive gear clockwise when viewed from the outside.
The second photo shows the speedo drive gear, it has 19 teeth like the one from RD. The one from SJ (it looks similar to yours) is for a 352-box.
I can't remember how the 352 worm gear and speedo drive looks, but it looks like you have such a pair. I also can't remember if the 352-drive meets the top or the bottom of the worm gear like the 365-box. Maybe there's convenient space there without the 5th gear. If the gears meet at the the top that would explain why the 352 worm gear 'pushes inwards'.
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Peter,
I think you’ve nailed it!!!
By some fluke I’ve ended up with a 352 speedo drive gear and a 352 pinion gear. The gearbox when I got it was missing the speedo drive pinion and sleeve so I guess at some point as it was raced the box was rebuilt with some 352 bits including a 352 speedo drive gear when it didn’t matter. The 352 takes its drive off the top of the box. Problem solved, I just knew it had to be some wierd coincidence.
Now have to sort what the answer is. I’ll talk to Richard in the morning.
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Does this mean the 352 box rotates in a different direction to the 365 box?
Does the Renault engine rotate in a different direction to the Lotus Twin Cam engine?
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The pick up on a 352 looks like it’s on top of the worm gear instead of beneath as on the 365. So the boxes rotate the same way just the speedo pick up is a different configuration
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I told you the worm was wrong several posts back!!
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The worm that turned................. the wrong way.
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Roger,
Yep, but it was the only answer, but Banks supplied a 352 pinion instead of a 365 pinion and I happened to have a 352 worm installed.
now have to sort out the best/easiest solution that won't cost a fortune.
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Smiths make speedos that work from a hall effect generator. I'd have to dig for the numbers but there is a sensor from a Ford that just drops in. It doesn't care which direction it turns.
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Yes I've seem them, in fact looked them up this morning. I have a VDO hall effect speedo in my Westfield that works well.
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Update. Couldn’t source the right drives. But sourced a reversing 90 drive from a uk company called speedy cable. Fits on the rear of the speedo and is a nice nest bit of kit. A side effect is the speedo cable had a better run and loops nicely to the back of the speedo.