[TR] HVDA 5-speed in TR6--speedo gear

[Rye Livingston]

Your odometer would be off as it's all run by the same gear in the speedometer.

I understand you don't want to get behind the dash and take out the gauge. For my TR3 I was having Palo Alto Speedometer rebuild mine along with the tach.   I'm running Panasport wheels with 205/60 15, which is smaller than stock, so I had them calibrate my speedometer.  Per their instructions I marked out x number of feet, I think it was 90 feet and a few inches, down in the street.  I then attached a paper clip to the end of the speedometer cable and pushed the car the distance and counted the number of revolutions.  I did it 3-4 times.  They took that number and put in the proper gear in the speedometer and now it matches my GPS when I'm zooming down the freeway.

Good luck,
Rye
PH: 530-FIND-RYE

On Feb 02, 2017, at 11:28 AM, Tim Gaines <mtgaines at presby.edu> wrote:

Thanks for the reply. I think my odometer is about as far off as the speedometer. In my calculations I took into account tire diameter and final drive ratio to get the number of revolutions of the tires per mile. The drive gear teeth (10 or 11) gives the number of teeth per revolution of the drive, and my Smith gauge is calibrated to 1120 revolutions per mile. I don't see anything that easy to change here. What am I missing? I now have the car on stands, and it appears to be easy to unscrew the one bolt holding the speedo driven gear in. If I can find the right replacement to hit the 2.5 gear ratio I need, I'd still like to avoid getting behind the dash.

Tim

----- Original Message -----
From: "Geo Hahn" <ahwahneetr at gmail.com>
To: "Tim Gaines" <mtgaines at presby.edu>
Cc: "Triumphs" <triumphs at autox.team.net>
Sent: Thursday, February 2, 2017 12:26:20 PM
Subject: Re: [TR] HVDA 5-speed in TR6--speedo gear

On Thu, Feb 2, 2017 at 8:13 AM, Tim Gaines < mtgaines at presby.edu > wrote: 

...my Smith speedometer reads slower by about 5-7 mph than a gps tells me... 

How accurate is your odometer? That (IMO) is the indicator of what recalibration (if any) is needed. There are several things that can cause the speedo to read high or low and fairly simple ways to correct some of them. 

I'm not saying you do not need recalibration - just mentioning there are several aspects to instrument accuracy. 

As for which end to work with - I would much prefer getting behind the dash and unhooking the speedo to getting into the gearbox. 

Geo 

---
This email has been checked for viruses by Avast antivirus software.
https://www.avast.com/antivirus


** triumphs at autox.team.net **

Donate: http://www.team.net/donate.html
Archive: http://www.team.net/archive
Forums: http://www.team.net/forums
Unsubscribe/Manage: http://autox.team.net/mailman/options/triumphs/ryel@mac.com
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://autox.team.net/pipermail/triumphs/attachments/20170202/fd411b0e/attachment.html>