On Sat, 22 Feb 2003, at around 21:08:03 local time, William Davies <[EMAIL PROTECTED]> wrote: > >----- Original Message ----- >From: Michael Hargreave Mawson <[EMAIL PROTECTED]> > >> Alternatively, is >> it physically possible that a single gearwheel has been replaced with >> one from a GT6, to give a quieter/smoother cruising gear? > >In a word - no.
Splendid - that rules that possibility out, then. > >> John? Are you there? Is there a speedo drive gear that could have >> been fitted to a 1500 gearbox that would give a 9% *low* reading on the >> correct speedo? And which speedo drive gear should I replace it with? > >I don't think John's on this list, though he's a regular on the >spitfire-enthusiast yahoo group and (as you know) the Herald group. Thanks for that. I unsubscribed from the spitfire-enthusiast group some time ago, and the question would be off-topic on the Herald group, so I'll drop him a private e-mail. > >> Ah, well, you see, I did have a problem with the original speedo in this >> car, and fitted a replacement, which I then calibrated to the rev >> counter (assuming a stock gearbox). The magnet *is* tired, and it >> required a 7-9 mph tweak at rest to give a "correct" reading at speed. >> "Correct" in this instance meaning 18 mph per 1000 rpm in fourth. The >> speedo still reads 18 mph per 1000 rpm, so it hasn't deteriorated any >> further over the last year. > >This would make me even more confident that the fault lies within your >speedo. I can supply an almost limitless supply of used speedos, or it >should be possible to have your original unit recalibrated. As long as >I know roughly what the error is I'm inclined to live with problems >like this, I am too - but I'm still not convinced that I know what the error in the speedo is. The rev counter is totally separate from the speedo, and I presume that it is more-or-less accurate. *If* I have a standard gearbox on the car, then I have recalibrated my speedo correctly to show 18 mph per 1000 rpm. However, given that the odometer is reading low by nearly 9%, something about that *gearbox* has to be non-standard, doesn't it? The gearwheels themselves and/or the speedo drive gear. Until I can work out whether it is just the speedo drive gear, or whether I have a GT6 box on there, I won't know whether my speedo is reading 9% low as well as my odometer. Logic suggests that it is just the speedo drive gear - but the evidence of my wife's car's speedometer suggests otherwise (not that I trust Mazda not to have "enhanced" the performance of that car by making the speedo read high...) Given that it is not possible to put GT6 gearwheels into a Spitfire gearbox, is there any easy way to tell what gearbox I have from a quick visual inspection? Is there a number stamped anywhere?? ATB -- Mike Ellie - 1963 White Herald 1200 Convertible GA125624 CV Connie - 1968 Conifer Herald 1200 Saloon GA237511 DL Carly - 1977 Inca Yellow Spitfire 1500 FH105671 /// [EMAIL PROTECTED] mailing list /// Send admin requests to [EMAIL PROTECTED] /// or try http://www.team.net/cgi-bin/majorcool /// Archives at http://www.team.net/archive /// Send list postings to [EMAIL PROTECTED] /// Edit your replies! If they include this trailer, they will NOT be sent.
