plk21e Posted August 24, 2011 Share Posted August 24, 2011 hello i am fitting an overdrive gearbox and prop from a mk4 to my mk3 ,my question is should the sliding end be fitted to the gearbox or diff.will have to change the flange on the prop at the diff end as the bolts on the mk4 are larger dia. any help or advise would be appreciated thanks Iain Link to comment Share on other sites More sharing options...
BritsnSpits Posted August 24, 2011 Share Posted August 24, 2011 Sliding end goes to the gearbox. Link to comment Share on other sites More sharing options...
1967 MkIII Posted August 24, 2011 Share Posted August 24, 2011 mine's on the rear to the diff. Link to comment Share on other sites More sharing options...
JohnB67Spit Posted August 24, 2011 Share Posted August 24, 2011 According to the Triumph workshop manual the sliding joint goes to the rear ie the diff. That is for the Mk3 anyway. Link to comment Share on other sites More sharing options...
plk21e Posted August 24, 2011 Author Share Posted August 24, 2011 thanks for the info,i was thinking it went to the gearbox but i have a mk2 that needs loads of welding but with a non overdrive box and the sliding part is fitted to the diff Link to comment Share on other sites More sharing options...
plk21e Posted August 24, 2011 Author Share Posted August 24, 2011 just looked up the parts catalogue for a mk3 and shows overdrive with sliding yoke of propshaft at the gearbox Link to comment Share on other sites More sharing options...
drofgum Posted August 25, 2011 Share Posted August 25, 2011 Hi,There is room for confusion on this one. As plk21e notes, the parts catalogue shows the prop shaft installed with the sliding yoke at the front, both in the overdrive listing, and in the propeller shaft listing. However the workshop manual states that the propshaft should be installed with the sliding yoke or the strap drive, as applicable, at the rear. My Mk2 Spitfire has always had the sliding yoke at the rear. It hasn't been troublesome. Best of luck, Paul Link to comment Share on other sites More sharing options...
plk21e Posted August 25, 2011 Author Share Posted August 25, 2011 im gonna put it at the rear and try it ,but may be a few years yet before it is on the road Link to comment Share on other sites More sharing options...
sparky_spit Posted August 25, 2011 Share Posted August 25, 2011 There was a thread like this on here a year or more ago and the general consensus was that it should go at the rear. A poster, who works with commercial vehicle transmissions, explained why it goes at the rear. I can't remember the details but it something along the lines of absorbing the compression in the shaft caused by the axle/diff movement as near to the diff as possible; ie not having the full length of the prop plunging back and forth, but just the coupling and small bit of shaft before the sliding joint at the diff end. The difference in mass between the two must be pretty large and therefore you only want the smallest part moving in two directions (rotation and back/forth). More of a problem with a live axle car than a Spitfire/Herald I'd have thought, but that's the reason apparently. Link to comment Share on other sites More sharing options...
Velocita Rosso Posted August 25, 2011 Share Posted August 25, 2011 To the rear...as Professor Higgins has just spelled out ??) Link to comment Share on other sites More sharing options...
jms700 Posted August 25, 2011 Share Posted August 25, 2011 Quote:The difference in mass between the two must be pretty large and therefore you only want the smallest part moving in two directions (rotation and back/forth). More of a problem with a live axle car than a Spitfire/Herald I'd have thought, but that's the reason apparently.understand what your saying and makes good sence, but odly enough, in the mgb with the live rear axle the sliding yoke is at the gearbox end ( on mine any way ) Link to comment Share on other sites More sharing options...
JensH Posted August 25, 2011 Share Posted August 25, 2011 From an engineering point of view - shouldn't make a difference? Engine and gearbox moving too...But might be easier to access grease nipple at the sliding joint when mounted at the diff??? Link to comment Share on other sites More sharing options...
plk21e Posted August 25, 2011 Author Share Posted August 25, 2011 too late now flange has been fitted so prop can only go on one way ie sliding yoke to diff.just sold a MGB and the the sliding part was fitted at the gearbox end so i suppose you can fit them either end Link to comment Share on other sites More sharing options...
junkuser Posted August 26, 2011 Share Posted August 26, 2011 With a live axle, that end of the shaft is banging up and down which would increase wear rate in the sliding section if at that end so best to compromise and have it at the front and put up with having to move the mass of the propeller shaft with axle movement.No such problem with a chassis mounted diff so may as well put the sliding section forward to where it is less exposed to the elements was my thought but the other ideas put forward in favor of moving aft are valid so just what what you are happy with I suppose.I was interested that Triumph changed from the original, fixed length, shaft used in the Herald to various sliding section designs. Assume it was that they were never sure what length each car would turn out. (Don't know how to add a smiley here).The full roller sliding joint seems rather an overkill for the amount of length change that can occur whilst driving with a chassis mounted diff and would more likely result in notches at their contact position, preventing any longitudinal movement.Plain sliding joint will give greater bearing surface and lighter loading on the lubricant.Haven't tried the strap drive so don't know what disadvantages it had. Link to comment Share on other sites More sharing options...
.thumb.jpeg.b15b81ef10abeea1c3039ae03c4a9f3a.jpeg)
Recommended Posts
Archived
This topic is now archived and is closed to further replies.