Quark Posted December 13, 2008 Report Share Posted December 13, 2008 I have a non-overdrive 1971 import car and a dolomite sprint J type overdrive gearbox. Would it be easier to fit the overdrive to my existing box or fit the entire dolomite gearbox complete with overdrive? Quote Link to post Share on other sites
chris.gosling Posted December 13, 2008 Report Share Posted December 13, 2008 Hi Quark, I did this conversion last year, it's not difficult. Whichever option you chose, you're going to have to strip the gearbox because the sprint gearbox has a longer input spline than the TR6, and the mainshaft on the non-overdrive TR6 box is different to the overdrive gearbox mainshaft. What I would do, is use the input spline(constant pinion shaft) and constant gear from the TR6 box (because you know for sure that their helix angles match) mated to all of the internals from the overdrive Sprint box, all wrapped up in the TR6 gearbox outer casing. That way you get to keep the TR6 nose cone/clutch release bearing and carrier, and number stamped on the gearbox. You will need to use the TR6 output flange as the one from the Sprint is different. Just remember to take LOADS of photos as you strip and rebuild, I found them invaluable. You don't need any special tools. Good luck, Chris Quote Link to post Share on other sites
88V8 Posted December 13, 2008 Report Share Posted December 13, 2008 I have a non-overdrive 1971 import car and a dolomite sprint J type overdrive gearbox. Would it be easier to fit the overdrive to my existing box or fit the entire dolomite gearbox complete with overdrive? Depends how you define 'easy' http://www.tr-register.co.uk/forums/index....olomite++sprint Quote Link to post Share on other sites
Quark Posted December 13, 2008 Author Report Share Posted December 13, 2008 Hi Quark,I did this conversion last year, it's not difficult. Whichever option you chose, you're going to have to strip the gearbox because the sprint gearbox has a longer input spline than the TR6, and the mainshaft on the non-overdrive TR6 box is different to the overdrive gearbox mainshaft. What I would do, is use the input spline(constant pinion shaft) and constant gear from the TR6 box (because you know for sure that their helix angles match) mated to all of the internals from the overdrive Sprint box, all wrapped up in the TR6 gearbox outer casing. That way you get to keep the TR6 nose cone/clutch release bearing and carrier, and number stamped on the gearbox. You will need to use the TR6 output flange as the one from the Sprint is different. Just remember to take LOADS of photos as you strip and rebuild, I found them invaluable. You don't need any special tools. Good luck, Chris Thanks Chris - this sounds like good advice. Having done this, can you give me any advice on what new parts I will need? Quote Link to post Share on other sites
chris.gosling Posted December 20, 2008 Report Share Posted December 20, 2008 Thanks Chris - this sounds like good advice. Having done this, can you give me any advice on what new parts I will need? I did it on a (small) budget and only replaced what as needed. In my case it came to: 1 gasket set and gearbox oil, 1 constant pinion shaft bearing, the small roller bearings on the mainshaft and countershaft (4 in total) and the two thrust washers on the countershaft, 1 angle drive for the speedo cable. I replaced the two bushes for the clutch operating shaft in the gearbox casing, with four, to spread the load. I didn't buy anything until I had stripped the Dolomite Sprint box completely and inspected it. Top tip- the gearbox casing will fit in a dishwasher and comes up nice and shiny. Obviously I did this when my wife was at work! Chris Quote Link to post Share on other sites
SuzanneH Posted December 21, 2008 Report Share Posted December 21, 2008 I did it on a (small) budget and only replaced what as needed. In my case it came to:1 gasket set and gearbox oil, 1 constant pinion shaft bearing, the small roller bearings on the mainshaft and countershaft (4 in total) and the two thrust washers on the countershaft, 1 angle drive for the speedo cable. I replaced the two bushes for the clutch operating shaft in the gearbox casing, with four, to spread the load. I didn't buy anything until I had stripped the Dolomite Sprint box completely and inspected it. Top tip- the gearbox casing will fit in a dishwasher and comes up nice and shiny. Obviously I did this when my wife was at work! Chris Funny????????? Most men don't have a clue how to operate a dishwasher Merry Christmas Sue Quote Link to post Share on other sites
Quark Posted December 21, 2008 Author Report Share Posted December 21, 2008 Top tip- the gearbox casing will fit in a dishwasher and comes up nice and shiny. Obviously I did this when my wife was at work! Chris I understand the need for this subtefuge now, having once put a Triumph Bonneville engine casing in the bottom of the oven when my girlfriend was roasting a chicken. The crankshaft bearing dropped into the casing fine but the chicken wasn't so sucessful with a Castrol marinade! Quote Link to post Share on other sites
tell Posted April 29, 2009 Report Share Posted April 29, 2009 I did it on a (small) budget and only replaced what as needed. In my case it came to:1 gasket set and gearbox oil, 1 constant pinion shaft bearing, the small roller bearings on the mainshaft and countershaft (4 in total) and the two thrust washers on the countershaft, 1 angle drive for the speedo cable. I replaced the two bushes for the clutch operating shaft in the gearbox casing, with four, to spread the load. I didn't buy anything until I had stripped the Dolomite Sprint box completely and inspected it. Top tip- the gearbox casing will fit in a dishwasher and comes up nice and shiny. Obviously I did this when my wife was at work! Chris hii,chris.my,situation is as above,my tr6 is non-od,but i do have a sprint j type od box in the garage.i have never taken a box apart before,being a novice,the first thing ii noticed which is differant,the dia ,and length of the input shaft.after reading your review this gave my hope as the more i looked into this the more confusing and exspensive it become,to the point where i started looking for a tr od box ,the input shaft can be used from my tr,is the main shaft also a differant diameter,is the dolly a smaller dia.so many questions ,thanks tell Quote Link to post Share on other sites
Jersey Royal Posted April 29, 2009 Report Share Posted April 29, 2009 (edited) hii,chris.my,situation is as above,my tr6 is non-od,but i do have a sprint j type od box in the garage.i have never taken a box apart before,being a novice,the first thing ii noticed which is differant,the dia ,and length of the input shaft.after reading your review this gave my hope as the more i looked into this the more confusing and exspensive it become,to the point where i started looking for a tr od box ,the input shaft can be used from my tr,is the main shaft also a differant diameter,is the dolly a smaller dia.so many questions ,thanks tell Sorry Tell But cant resist it anymore..... Quark. Your some handsome devil you. Thats better Thanks Alot Guy Edited April 29, 2009 by Jersey Royal Quote Link to post Share on other sites
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.