The Courier Issue 380
Posted by lisa moran on Saturday, March 10, 2012
With the Lancs area not having a meeting in December there is little to report on for this months Courier.
But in January's mag i asked if any of you had any projects on the go that I could report on in the area news, so to get the ball rolling:
Mr Petty's gearbox swap. Dennis' gearbox in his Vitesse had started to grumble during last years outings, and he had acquired a non overdrive box from long time member and Triumoh Guru'Bill Stuart', with Bill saying 'all you have to do is swap over the long output shaft out of your box into this one to convert it into an overdrive box'. Note those words 'ALL YOU HAVE TO DO'.
So between Christmas and the New Year break we decided to have a go at it. At this stage it's worth noting that neither Dennis nor myself had any experience of gearbox repairs or modifications, but Chris Manville, who was also helping, had.
10am Thursday, the car was in the garage, up on the stands and the three of us pulling bits off like a shoal of piranha and in three hours we had the old box out. At this point Dennis and I started to realise the work involved stripping down a gearbox. First you need a 'dummy'shaft, 165mm long, to insert into the layshaft as you push out its support shaft: not a problem, we will use the support shaft out of the old box and cut it down to size. The purpose of this dummy shaft is to keep the needles of the two bearings in place but allows the lay shaft to drop down inside the casing which i turn lets you take out the input shaft and main shaft, that is once you have pulled out the bearings at each end of the casing. With this done on the new box, we did the same with the old box as we planned to transplant the whole main shaft (which is the over drive long shaft) into the new box. At this point we have our first problem, there is a small roller bearing that joins the input and main shaft together, this had obviuosly failed but in doig so had knackered the bearing diameter of the main shaft that we needed to use, now this shaft is usuallya one piece item but in our this shaft had been repaired at some point by inserting this bearig diameter (lucky or what). So all we needed was a hardened and ground steel insert 0.500" diameter x 1.7" long (a trip to work, and sorted). At this point we had been at it for six hours and we were assembling the new gearbox with the main shaft of the old box. Three hours later on and we still couldn't line up the lay shaft so we called it a day at 7pm.
10am Friday, (minus Chris the gearbox expert!!!!!!) and starting again trying to align the lay shaft and after another two hours we decided to literally swap all the gear set of the new box main shaft onto the extended main shaft of the old box. With this done we were back once again trying to align the lay shaft and would you believe it the support shaft slid straight in like a good un. To end the day we assembled the overdrive and the bell housing.
11am Saturday. All we have to do now is put the box back in the car. And four hours later Denis was on a test run.....result!
So when someone tells you 'ALL YOU HAVE TO DO' think twice. But the truth is now we know how to rebuild a gearbox, something I had previously been a little scared of myself. It just proves that nothing ventured nothing gained.
If anyone else has a short tale to tell, lets be having it.
Thats all for now
Kev
But in January's mag i asked if any of you had any projects on the go that I could report on in the area news, so to get the ball rolling:
Mr Petty's gearbox swap. Dennis' gearbox in his Vitesse had started to grumble during last years outings, and he had acquired a non overdrive box from long time member and Triumoh Guru'Bill Stuart', with Bill saying 'all you have to do is swap over the long output shaft out of your box into this one to convert it into an overdrive box'. Note those words 'ALL YOU HAVE TO DO'.
So between Christmas and the New Year break we decided to have a go at it. At this stage it's worth noting that neither Dennis nor myself had any experience of gearbox repairs or modifications, but Chris Manville, who was also helping, had.
10am Thursday, the car was in the garage, up on the stands and the three of us pulling bits off like a shoal of piranha and in three hours we had the old box out. At this point Dennis and I started to realise the work involved stripping down a gearbox. First you need a 'dummy'shaft, 165mm long, to insert into the layshaft as you push out its support shaft: not a problem, we will use the support shaft out of the old box and cut it down to size. The purpose of this dummy shaft is to keep the needles of the two bearings in place but allows the lay shaft to drop down inside the casing which i turn lets you take out the input shaft and main shaft, that is once you have pulled out the bearings at each end of the casing. With this done on the new box, we did the same with the old box as we planned to transplant the whole main shaft (which is the over drive long shaft) into the new box. At this point we have our first problem, there is a small roller bearing that joins the input and main shaft together, this had obviuosly failed but in doig so had knackered the bearing diameter of the main shaft that we needed to use, now this shaft is usuallya one piece item but in our this shaft had been repaired at some point by inserting this bearig diameter (lucky or what). So all we needed was a hardened and ground steel insert 0.500" diameter x 1.7" long (a trip to work, and sorted). At this point we had been at it for six hours and we were assembling the new gearbox with the main shaft of the old box. Three hours later on and we still couldn't line up the lay shaft so we called it a day at 7pm.
10am Friday, (minus Chris the gearbox expert!!!!!!) and starting again trying to align the lay shaft and after another two hours we decided to literally swap all the gear set of the new box main shaft onto the extended main shaft of the old box. With this done we were back once again trying to align the lay shaft and would you believe it the support shaft slid straight in like a good un. To end the day we assembled the overdrive and the bell housing.
11am Saturday. All we have to do now is put the box back in the car. And four hours later Denis was on a test run.....result!
So when someone tells you 'ALL YOU HAVE TO DO' think twice. But the truth is now we know how to rebuild a gearbox, something I had previously been a little scared of myself. It just proves that nothing ventured nothing gained.
If anyone else has a short tale to tell, lets be having it.
Thats all for now
Kev
