free hit
counters
Speedometer repair - Interior/Exterior/Lights/Glass/ICE/HVAC & Other - The Lotus Forums #ForTheOwners Jump to content


Speedometer repair


Recommended Posts

Anyone pried into the guts of the Smiths speedo? My problem: it works for a few miles or less then doesn't register at all; when I back up even a few feet it starts working again going forward. I have a new cable.

 

Anyone experienced similar symptoms and corrected them? Thanks in advance.

 

Scott

Link to comment
Share on other sites


Upgrade today to remove Google ads and support TLF.
  • Replies 9
  • Created
  • Last Reply

Top Posters In This Topic

Top Posters In This Topic

Posted Images

I have mine in pieces at the moment, as I am converting it to a stepper motor drive( when I get to it someday) but the actual mechanism is pretty bulletproof it seems, so unlikely to be the actual problem you have. It is possibly the little gear that goes into the gearbox that is your problem, and a new cable does not fix it. It is a plastic/nylon gear which was worn in the middle section, which caused the problem. Mine was worse than intermittent, and spares are rare in Aus, and it seemed like an interesting thing to do at the time. I am having second thoughts, but it does mean I can easily do MPG calcs, and other fun stuff with microprocessor control. I have already replaced the failed Otter switch with temperature sensor and microprocessor, but that is another story.

 

If you need photos, or explanation of how it comes apart, just ask. There are various pages on the net too, but having just done it, I can say that they miss out some steps in the dismantling procedure, but it is pretty straightforward.

Clive

Link to comment
Share on other sites

If you wanted it done by someone else (and having previously lived in Seatte for a number of years I appreciate it's not very local for you), I used these guys a couple of years ago to fix my Excel speedo

http://www.jdo10.pwp.blueyonder.co.uk/

They did a good job, and it now works fine.

Link to comment
Share on other sites

Thanks for the replies.

 

Clive, yesterday I removed, cleaned, and inspected the nylon drive gear and the angle gear; both looked good. With my new speedo cable I'm confident the drive portion of the system is working well. Surprisingly to me, everything worked fine for the 25 miles I drove after that. If the speedo starts screwing up again I'll tear it down and will likely come back to you for advice.

 

Scott

Link to comment
Share on other sites

Clive

 

Pictures and an explanation would be great as a resource for other who may stumble across this thread... if you feel willing to share.

:)

It's getting there......

Link to comment
Share on other sites

A bit more local to you is Roscoe Instrument Repair located in Illinois. They were recommended by someone on the Vintage Lamborghini Yahoo mailing list so they should be used to oddball stuff.

S4 Elan, Elan +2S, Federal-spec, World Championship Edition S2 Esprit #42, S1 Elise, Excel SE

 

Link to comment
Share on other sites

Have a look at this too. It has lots of info.

 

http://www.tr3a.info/PDFs/speedo.pdf

 

I just found actually getting the guts out was a careful extraction with gently raising the lugs around the edge, and then it came apart ok.

Clive

Link to comment
Share on other sites

Thanks again for the helpful comments. It turns out that my confidence was misplaced; the problem was in the drive system, which I confirmed after removing the speedo and watching the cable end rotate (and then not) through the hole in the dash while driving. Specifically, the short cable between the transmission and angle drives. Apparently the cable needs to be jammed and 'screwed' into the angle drive shaft, at least that's the only way I found to mate the two. It's been working for 40 miles, and am hoping it keeps on doing so!

 

Clive, if you are considering going back to the original system I located a source for the plastic transmission drive gear in the US, for only $20. Dave Bean Engineering, 209-754-5802.

 

Scott

Link to comment
Share on other sites

GR338-GPS-06:

3-3/8" GPS Speedometer Gauge 200mph

  • Colors: Day - Black dial // White font

    Night - Numbers White Glow

  • Font Style: Muscle
  • Tick Style: standard
  • Graphic: -
  • Logo: -
  • Custom Text: -
  • Pointer: Black Blade White (Glows White)
  • Bezel: Stealth Black
  • Disc:
  • Notes:
  • Production Notes:

Price: $259.95

Qty: 1  

This is what I now have in hand as the LSD unit has no cable drive gear. Display even gives you 0-60 times!

post-13088-0-50953300-1399094941.jpg

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.




×
×
  • Create New...