Speedo repair

[Tombutlercpa@cs.com]

I recently managed to get a Morris 4:55 pumpkin into my TC. It works very nicely. Thanks to all whose assistance made it possible. I guess its time to get the Speedo into shape. I have two issues: 1) Speedo goes out of whack after 60 MPH. The rate of speed indicated goes up much faster than the tach indicates (Tach has been tested against an electronic one and the tach is very accurate). 2) Speed indicated by speedometer is not in line with actual speed using a 4:55 pumpkin at any speed range. All help appreciated. [Non-text portions of this message have been removed]

[Sam Suklis]

Tom: It sounds like you're going to have to find the correct speedometer drive gear for the transmission. Will the one from the Morris fit? Otherwise, you'll have to find out if one is made for an equivalent ratio rear end for a TC. Sam SS

----- Original Message ----- From: Tombutlercpa@cs.com> To: mg-tabc@yahoogroups.com> Sent: Tuesday, April 30, 2002 5:44 PM Subject: [mg-tabc] Speedo repair > I recently managed to get a Morris 4:55 pumpkin into my TC. It works very > nicely. Thanks to all whose assistance made it possible. > > I guess its time to get the Speedo into shape. I have two issues: > > 1) Speedo goes out of whack after 60 MPH. The rate of speed indicated goes up > much faster than the tach indicates (Tach has been tested against an > electronic one and the tach is very accurate). > > 2) Speed indicated by speedometer is not in line with actual speed using a > 4:55 pumpkin at any speed range. > > All help appreciated. > > > [Non-text portions of this message have been removed] > > > > > Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/ > > >

[Chip Old]

On Tue, 30 Apr 2002, Sam Suklis wrote:

> It sounds like you're going to have to find the correct speedometer > drive gear for the transmission. Will the one from the Morris fit? > Otherwise, you'll have to find out if one is made for an equivalent > ratio rear end for a TC.

Two other solutions that may be less trouble: 1) Have the speedo recalibrated to suit the new rear axle ratio. Any of the usual speedo repair shops should be able to do that for you. Contact them ahead of time, because they will want you to gather some data for them ahead of time (typically how many times does the speedo cable rotate for each rotation of a rear whel). 2) Insert a small gearbox (similar in concept to the tach drive gearbox) between the cable and the speedo or between the transmission and the cable to adjust for the new rear axle ratio. Again, the speedo repair people can advise you on this, and you will need to gather the same kind of info in order to get the right ratio. -- Chip Old 1948 M.G. TC TC6710 XPAG7430 NEMGTR #2271 Cub Hill, Maryland 1962 Triumph TR4 CT3154LO CT3479E fold@bcpl.net

[Frank O_ The Mountain]

In a message dated 4/30/02 17:48:58 Pacific Daylight Time, Tombutlercpa@cs.com writes: >>

[i.thomson@talk21.com]

Although I will bow to greater knowledge Chip; wouldn't the average speedo repair place be thrown by the chronometric speedos which T types use? The reduction gearbox seems the better route to me, especially as I would be loath to trust my speedo to a place which doesn't know exactly what it's doing. I too have contemplated the alternatives, having just had Roger uprate my diff., but as I never look at the speedo anyway I will probably just ignore it. Ian Thomson. -------

>Two other solutions that may be less trouble: > >1) Have the speedo recalibrated to suit the new rear axle ratio. Any of >the usual speedo repair shops should be able to do that for you. Contact >them ahead of time, because they will want you to gather some data for >them ahead of time (typically how many times does the speedo cable rotate >for each rotation of a rear whel). > >2) Insert a small gearbox (similar in concept to the tach drive gearbox) >between the cable and the speedo or between the transmission and the cable >to adjust for the new rear axle ratio. Again, the speedo repair people >can advise you on this, and you will need to gather the same kind of info >in order to get the right ratio. > >-- >Chip Old 1948 M.G. TC TC6710 XPAG7430 NEMGTR #2271 >Cub Hill, Maryland 1962 Triumph TR4 CT3154LO CT3479E >fold@bcpl.net > > > > >Your use of Yahoo! Groups is subject to http://talk21.btopenworld.com/redirect.html?http://docs.yahoo.com/info/terms/'>[url=http://docs.yahoo.com/info/terms/http://docs.yahoo.com/info/terms/>

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[Chip Old]

On Wed, 1 May 2002, i.thomson@talk21.com wrote:

> Although I will bow to greater knowledge Chip; wouldn't the average > speedo repair place be thrown by the chronometric speedos which T types > use? The reduction gearbox seems the better route to me, especially as > I would be loath to trust my speedo to a place which doesn't know > exactly what it's doing. I too have contemplated the alternatives, > having just had Roger uprate my diff., but as I never look at the speedo > anyway I will probably just ignore it.

I meant a speedo repair shop that knows its way around chronometric instruments, like Vintage Restorations (John Marks) and some of the others that have been mentioned on this list. I wouldn't take a chronometric instrument anywhere near the average neighborhood speedometer shop. My personal preference would be the supplemental gearbox to alter the speedo cable rotational speed, because it leaves the speedo unmodified. Some local speedo shops *are* capable of doing this work. -- Chip Old 1948 M.G. TC TC6710 XPAG7430 NEMGTR #2271 Cub Hill, Maryland 1962 Triumph TR4 CT3154LO CT3479E fold@bcpl.net

[Donald Wilkinson]

Get Carl Cederstrand's book. Don TC7993

>From: i.thomson@talk21.com >To: fold@bcpl.net,mg-tabc@yahoogroups.com,mg-tabc@yahoogroups.com >Subject: Re: [mg-tabc] Speedo repair >Date: Wed, 1 May 2002 09:16:44 GMT+01:00 > >Although I will bow to greater knowledge Chip; wouldn't the average speedo >repair place be thrown by the chronometric speedos which T types use? The >reduction gearbox seems the better route to me, especially as I would be >loath to trust my speedo to a place which doesn't know exactly what it's >doing. I too have contemplated the alternatives, having just had Roger >uprate my diff., but as I never look at the speedo anyway I will probably >just ignore it. > >Ian Thomson. > >------- > > >Two other solutions that may be less trouble: > > > >1) Have the speedo recalibrated to suit the new rear axle ratio. Any of > >the usual speedo repair shops should be able to do that for you. Contact > >them ahead of time, because they will want you to gather some data for > >them ahead of time (typically how many times does the speedo cable rotate > >for each rotation of a rear whel). > > > >2) Insert a small gearbox (similar in concept to the tach drive gearbox) > >between the cable and the speedo or between the transmission and the >cable > >to adjust for the new rear axle ratio. Again, the speedo repair people > >can advise you on this, and you will need to gather the same kind of info > >in order to get the right ratio. > > > >-- > >Chip Old 1948 M.G. TC TC6710 XPAG7430 NEMGTR #2271 > >Cub Hill, Maryland 1962 Triumph TR4 CT3154LO CT3479E > >fold@bcpl.net > > > > > > > > > >Your use of Yahoo! Groups is subject to Href='http://talk21.btopenworld.com/redirect.html?http://docs.yahoo.com/info/terms/'>[url=http://docs.yahoo.com/info/terms/http://docs.yahoo.com/info/terms/> > > > >-------------------- >talk21 your FREE portable and private address on the net at >http://www.talk21.com > > > > > >Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/ > >

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[R. Zwart]

Who else, but John Marks would call you if you hadn't answered his two FAXs. I just wanted some 6 volt bulbs for the new new new new Rotax dash(s) he made for me... I have had a great interface with Vintage Instruments over the past three years. If he didn't have it, he found it; if he couldn't find it, he had it made. THANKS JOHN MARKS, BOB Chip Old wrote:

> On Wed, 1 May 2002, i.thomson@talk21.com wrote: > > > Although I will bow to greater knowledge Chip; wouldn't the average > > speedo repair place be thrown by the chronometric speedos which T types > > use? The reduction gearbox seems the better route to me, especially as > > I would be loath to trust my speedo to a place which doesn't know > > exactly what it's doing. I too have contemplated the alternatives, > > having just had Roger uprate my diff., but as I never look at the speedo > > anyway I will probably just ignore it. > > I meant a speedo repair shop that knows its way around chronometric > instruments, like Vintage Restorations (John Marks) and some of the others > that have been mentioned on this list. I wouldn't take a chronometric > instrument anywhere near the average neighborhood speedometer shop. > > My personal preference would be the supplemental gearbox to alter the > speedo cable rotational speed, because it leaves the speedo unmodified. > Some local speedo shops *are* capable of doing this work. > > -- > Chip Old 1948 M.G. TC TC6710 XPAG7430 NEMGTR #2271 > Cub Hill, Maryland 1962 Triumph TR4 CT3154LO CT3479E > fold@bcpl.net > > > > Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/

[R. Zwart]

JOIN THE VINTAGE MG CLUB AND YOU CAN CHECK THE BOOK OUT OR BUY IT FROM MOSS. JOINING WILL GET YOU OTHER BENEFITS. BOB Donald Wilkinson wrote:

> Get Carl Cederstrand's book. > > Don > TC7993 > > >From: i.thomson@talk21.com > >To: fold@bcpl.net,mg-tabc@yahoogroups.com,mg-tabc@yahoogroups.com > >Subject: Re: [mg-tabc] Speedo repair > >Date: Wed, 1 May 2002 09:16:44 GMT+01:00 > > > >Although I will bow to greater knowledge Chip; wouldn't the average speedo > >repair place be thrown by the chronometric speedos which T types use? The > >reduction gearbox seems the better route to me, especially as I would be > >loath to trust my speedo to a place which doesn't know exactly what it's > >doing. I too have contemplated the alternatives, having just had Roger > >uprate my diff., but as I never look at the speedo anyway I will probably > >just ignore it. > > > >Ian Thomson. > > > >------- > > > > >Two other solutions that may be less trouble: > > > > > >1) Have the speedo recalibrated to suit the new rear axle ratio. Any of > > >the usual speedo repair shops should be able to do that for you. Contact > > >them ahead of time, because they will want you to gather some data for > > >them ahead of time (typically how many times does the speedo cable rotate > > >for each rotation of a rear whel). > > > > > >2) Insert a small gearbox (similar in concept to the tach drive gearbox) > > >between the cable and the speedo or between the transmission and the > >cable > > >to adjust for the new rear axle ratio. Again, the speedo repair people > > >can advise you on this, and you will need to gather the same kind of info > > >in order to get the right ratio. > > > > > >-- > > >Chip Old 1948 M.G. TC TC6710 XPAG7430 NEMGTR #2271 > > >Cub Hill, Maryland 1962 Triumph TR4 CT3154LO CT3479E > > >fold@bcpl.net > > > > > > > > > > > > > > >Your use of Yahoo! Groups is subject to >Href='http://talk21.btopenworld.com/redirect.html?http://docs.yahoo.com/info/terms/'>[url=http://docs.yahoo.com/info/terms/http://docs.yahoo.com/info/terms/> > > > > > > > >-------------------- > >talk21 your FREE portable and private address on the net at > >http://www.talk21.com > > > > > > > > > > > >Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/ > > > > > > _________________________________________________________________ > Send and receive Hotmail on your mobile device: http://mobile.msn.com > > > > Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/

[Ray]

How was the Morris/Spridget pumpkin installed? I have been off the list..... Best, Ray