I'm knackered - Spitfire overdrive conversion.
Discussion
Ten years ago I moved from the UK to NZ, and brought three overdrive gearboxes with me.
As my daughter is twenty, I obtained an NZ built Spitfire Mk III a few months ago - to some extent because it was easier and cheaper to get a complete car here rather than to restore a UK one (brought with me ten years ago, rust problem). The Spitfire has obviously been appropriated by said daughter, I doubt that any NZ cars had overdrive as original - and this one was no exception and still had the original box (at least a gearchange rebushing kit had been fitted).
I was told my mission this weekend was to fit an overdrive - the mission was mostly successful - in that the gearbox is in and works - but as with any job like this it's the unexpected bits that take all the time.
The new gearbox is a close ratio (Marina 1800 gearset), which needs a fine spline driven plate. Doesn't exist in NZ, supplied by Canley Classics. Overdrive is a 27% J type, from some long extinct Volvo. Dave at Canley also supplied various other bits I thought I would need.
Old gearbox came out OK, propshaft was tricky as the exhaust was close, a big bar soon had that sorted. I'd forgotten how heavy even a non overdrive box is, but I just managed to get it out and chuck it on the ground.
Had a diversion at this point as the heater isn't working - so it was out with the old heater from the UK car (another mission involving hammers and screwdrivers) - changing a Spitfire heater has to be one of the worst jobs ever. By 6.30 on day one the new heater matrix was sort of fitted, but it started drizzling and the Chateaux cardboard started calling. But I had managed to change the driven plate.
Day 2. SWMBO came to help. Got heater back in - wish I was a contortionist. Cast iron bellhousing fitted to overdrive box - HEAVY or what - two of us trying to get the thing into place when I realize the overdrive is fitted with a 5/16 bolt rear flange. Yes, I know this is correct but the propshaft from the UK car is a non overdrive 1500 one (CV joint type). I'd already fitted a small flange to the back to go onto the diff, so the front had 3/8 bolt holes - no can change. Fortunately a Vitesse J type O/d box I have in stock had a big flange fitted so it was a matter of changing them over. More hernia inducing lifting and I'm staring to think what have have I started.
Anyway - flange changed and a two person job to get the overdrive box roughly back into place. Either I've weakened overnight or the box has gained some kilos, but it's even HEAVIER. The usual copious grunting - long bars, cursing and swearing - and the "thing" slips into place - YES! Install the plethora of bellhousing bolts, small issues with the overdrive mount (from UK car) and suddenly it's time to convert the gearchange (add cut off switch arrangement). I have to say that all the stuff from Canley is much better than in my day - albeit with a small issue with the extended shaft for the gearchange - a hole has been machined slightly out of line so I couldn't get reverse. I had to twist the gearchange shaft to compensate - I'll let Dave know as the twist solution is not obvious.
So, it's all in place - four forward gears, one reverse. Then I need to get the overdrive switch working. Cowling, switch and wiring rescued from UK car, and fitted to NZ car - another mission as the steering has to be partly dismantled (good job I don't do this for a living) - another hour or two.
Eventually it's test drive time - some sort of water leak from the heater - but OK for a blast round the block.
Despite being stood for ten years the overdrive and gearbox work first time (thanks Mick), and synchro on first is very useful. Son goes out for a drive - daughter goes out for a drive - SWMBO goes out for a drive - thumbs up all round. The vibration from the knackered prop UJ has gone, and it's great to have an overdrive switch to play with after ten years.
All in all a successful weekend, wish I had remembered to bring an alloy bellhousing or two with me, would have made things a bit easier!
Now it's just a question of refitting the tunnel etc - I don't have the adapter for fitting the angle drive so I've left the speedo cable off for the moment - no real hardship as the speedo stopped working some time ago.
Day 2.
As my daughter is twenty, I obtained an NZ built Spitfire Mk III a few months ago - to some extent because it was easier and cheaper to get a complete car here rather than to restore a UK one (brought with me ten years ago, rust problem). The Spitfire has obviously been appropriated by said daughter, I doubt that any NZ cars had overdrive as original - and this one was no exception and still had the original box (at least a gearchange rebushing kit had been fitted).
I was told my mission this weekend was to fit an overdrive - the mission was mostly successful - in that the gearbox is in and works - but as with any job like this it's the unexpected bits that take all the time.
The new gearbox is a close ratio (Marina 1800 gearset), which needs a fine spline driven plate. Doesn't exist in NZ, supplied by Canley Classics. Overdrive is a 27% J type, from some long extinct Volvo. Dave at Canley also supplied various other bits I thought I would need.
Old gearbox came out OK, propshaft was tricky as the exhaust was close, a big bar soon had that sorted. I'd forgotten how heavy even a non overdrive box is, but I just managed to get it out and chuck it on the ground.
Had a diversion at this point as the heater isn't working - so it was out with the old heater from the UK car (another mission involving hammers and screwdrivers) - changing a Spitfire heater has to be one of the worst jobs ever. By 6.30 on day one the new heater matrix was sort of fitted, but it started drizzling and the Chateaux cardboard started calling. But I had managed to change the driven plate.
Day 2. SWMBO came to help. Got heater back in - wish I was a contortionist. Cast iron bellhousing fitted to overdrive box - HEAVY or what - two of us trying to get the thing into place when I realize the overdrive is fitted with a 5/16 bolt rear flange. Yes, I know this is correct but the propshaft from the UK car is a non overdrive 1500 one (CV joint type). I'd already fitted a small flange to the back to go onto the diff, so the front had 3/8 bolt holes - no can change. Fortunately a Vitesse J type O/d box I have in stock had a big flange fitted so it was a matter of changing them over. More hernia inducing lifting and I'm staring to think what have have I started.
Anyway - flange changed and a two person job to get the overdrive box roughly back into place. Either I've weakened overnight or the box has gained some kilos, but it's even HEAVIER. The usual copious grunting - long bars, cursing and swearing - and the "thing" slips into place - YES! Install the plethora of bellhousing bolts, small issues with the overdrive mount (from UK car) and suddenly it's time to convert the gearchange (add cut off switch arrangement). I have to say that all the stuff from Canley is much better than in my day - albeit with a small issue with the extended shaft for the gearchange - a hole has been machined slightly out of line so I couldn't get reverse. I had to twist the gearchange shaft to compensate - I'll let Dave know as the twist solution is not obvious.
So, it's all in place - four forward gears, one reverse. Then I need to get the overdrive switch working. Cowling, switch and wiring rescued from UK car, and fitted to NZ car - another mission as the steering has to be partly dismantled (good job I don't do this for a living) - another hour or two.
Eventually it's test drive time - some sort of water leak from the heater - but OK for a blast round the block.
Despite being stood for ten years the overdrive and gearbox work first time (thanks Mick), and synchro on first is very useful. Son goes out for a drive - daughter goes out for a drive - SWMBO goes out for a drive - thumbs up all round. The vibration from the knackered prop UJ has gone, and it's great to have an overdrive switch to play with after ten years.
All in all a successful weekend, wish I had remembered to bring an alloy bellhousing or two with me, would have made things a bit easier!
Now it's just a question of refitting the tunnel etc - I don't have the adapter for fitting the angle drive so I've left the speedo cable off for the moment - no real hardship as the speedo stopped working some time ago.
Day 2.
Good work!
When I did it in the days before the internet nobody could tell me the correct length of the new prop or supply me with an overdrive prop so I had to have mine cut down based on measuring the new gearbox. I got it about 5mm wrong and had to make spacers to move the engine forwards!
Can I recomend a fibreglass tunnel? So much easier than the floppy cardboard!
When I did it in the days before the internet nobody could tell me the correct length of the new prop or supply me with an overdrive prop so I had to have mine cut down based on measuring the new gearbox. I got it about 5mm wrong and had to make spacers to move the engine forwards!
Can I recomend a fibreglass tunnel? So much easier than the floppy cardboard!
Hi John
Just found this randomly searching on spitfire overdrives. About 15 years before you wrote this I bought an overdrive box and prop from you and a reconditioned lead free engine for my mk2 just prior to taking it home to NZ! For some reason I returned to the UK about 10 years later and sold the car just before I left for $3000, little realizing it was worth about ten times that in the U.K. as they'd finally taken off over here. Mine was lovely but a search of its rego shows it has been cannibalized now, sob.
Are you retired from the trade now or would I be able to contact you when I next come home - determined to get another mk2 overdrive going?
Cheers
Just found this randomly searching on spitfire overdrives. About 15 years before you wrote this I bought an overdrive box and prop from you and a reconditioned lead free engine for my mk2 just prior to taking it home to NZ! For some reason I returned to the UK about 10 years later and sold the car just before I left for $3000, little realizing it was worth about ten times that in the U.K. as they'd finally taken off over here. Mine was lovely but a search of its rego shows it has been cannibalized now, sob.
Are you retired from the trade now or would I be able to contact you when I next come home - determined to get another mk2 overdrive going?
Cheers
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