Flywheel weight differ between the TR7 and the sprint.
I was told late sprints had a heavier flywheel. I can't comment on whether this is true or not, but all of the sprint motors I have aver had to bits have always had a lighter flywheel than is found in the TR7. TR7 flywheel is about 24lbs as standard.
Just be carefull you don't kill the performance with too heavy a flywheel.
Just something else to check.
Shaun
5-speed sprint?
Re: 5-speed sprint?
Yes, I had considered getting the flywheel lightened. I found out how heavy the TR7 unit is the hard way - dropped it on my toes..... 


Re: Update
It has been a while. To cut a long story short, the clutch jammed: the aptly named slippers slipped out of the carrier, which then wouldn't return to the original position. Another gearbox out job, which I didn't have time to tackle for a while, for various reasons.
Got back to it a couple of weeks ago. I decided to make some additional modifications, as I wasn't confident with the TR7 release bearing carrier, based on the experience described above. Ideally, something like the Sprint carrier - no chance of the fork coming away from the carrier due to different (better) design - although the Sprint carrier is too long for this situation.


As a compromise, I used the front of a TR6 gearbox to carry a TR6 release bearing - similar design to the Sprint and just the right length. I cut down the TR6 frontpiece, welded it to the front of the TR7 'box and smoothed down. Seemed pretty strong, and moves freely (without falling off the clutch fork).


I put the gearbox back in the car, started it up and.....I now FINALLY have 5 forward gears and reverse!
Got back to it a couple of weeks ago. I decided to make some additional modifications, as I wasn't confident with the TR7 release bearing carrier, based on the experience described above. Ideally, something like the Sprint carrier - no chance of the fork coming away from the carrier due to different (better) design - although the Sprint carrier is too long for this situation.


As a compromise, I used the front of a TR6 gearbox to carry a TR6 release bearing - similar design to the Sprint and just the right length. I cut down the TR6 frontpiece, welded it to the front of the TR7 'box and smoothed down. Seemed pretty strong, and moves freely (without falling off the clutch fork).


I put the gearbox back in the car, started it up and.....I now FINALLY have 5 forward gears and reverse!


- David6214
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Re: 5-speed sprint?
I'm impressed 

Previous owner of 42 Dolomite shaped vehicles, 14 Sprints, 12 1850s, 8 1500s, 3 V8s, 3 Toledos and 2 SEs
Re: 5-speed sprint?
I've been a bit slow reading this topic but there's a solution that might save others time in the future.
You can get a universal fitting combined hydraulic slave cylinder & release bearing, I read about them in Practical Performance car, think the guy that was building a diesel engined Westfield (!?) used one. Can't remember the manufacturer, will have to look it up, but think they were around the £75 mark which I thought quite reasonable.
Regards
Sean
You can get a universal fitting combined hydraulic slave cylinder & release bearing, I read about them in Practical Performance car, think the guy that was building a diesel engined Westfield (!?) used one. Can't remember the manufacturer, will have to look it up, but think they were around the £75 mark which I thought quite reasonable.
Regards
Sean
1977 1850 HL manual O/D
It moves.......!
First time for 4 years under its own steam.....
http://uk.youtube.com/watch?v=cSYQzds2TsM
It does go backwards as well.
http://uk.youtube.com/watch?v=cSYQzds2TsM
It does go backwards as well.


Re: 5-speed sprint?
Clutch hydraulics are simple, you fit a bell housing mounted internal co-axial slave cylinder.
Ken.
Ken.