1st motion shaft needle bearing

[rogerguzzi]

Hello All

                We will settle for Pete's view on the marks!

I have done some more measuring so if the original one is 14mm leaving out the thick spacer and fitting the thin one next to the hub with the 19mm bearing would only give an extra 0.020" more end float?

Looking at the drawings and the manual this is not were the end float is controlled(it would destroy the bearing!)the extra 0.020" would still mean the rollers are on the bearing surface it could just float back and forth a bit?

Dave 

        Yes the spacers are hard(quick file test) so making an oversize one would be more difficult(I could do it but not sure its worth the effort?)

So what does the collective brain think?

Roger

 

 

[Pete Lewis]

Float is controlled by the bearing on the stem and mainshaft,

If the heat grows the case it also grows the mainshaft, not of any significance.

The od pump cam is located between the od   spigot and the mainshaft bearing how can this have any effect on the spigot??as shaft is supported at both ends  with the cam in between them ???

Any wobble on the stem  brg.  Is elliminated when the shaft locates in the flywheel spigot so its supported both ends.

Pete

[johny]

I still suspect that there can be quite a variation in how far the mainshaft protrudes into the input shaft which the original design can allow. Otherwise it doesnt make sense (unless the longer bearing wasnt available in those days) that Triumph went to all the trouble of uprating this bearing only to then make it weaker than need be.....

[Pete Lewis]

i would  hazard a thought that the case length and shaft length  was an open limit  thats + - .010"  tolerance on shaft to main brg.   would be more refined 

whos got the drawings ????  cov transport museum or gaydon ???

Pete

[rogerguzzi]

5 hours ago, Pete Lewis said:

i would  hazard a thought that the case length and shaft length  was an open limit  thats + - .010"  tolerance on shaft to main brg.   would be more refined 

whos got the drawings ????  cov transport museum or gaydon ???

Pete

Hello Pete

                 I think you may be right.

I suppose the best thing to do would install the main shaft then measure the nose of the shaft distance and work out how far it goes into the 1st motion shaft?

Roger

[rogerguzzi]

Hello All

               After a lot of measuring and putting a bit more chamfer on the inside of the thin spacer so it sits tighter to the 3rd motion shaft I think I have clearance?

Then I turned my attention to the scroll seal set up and I thought I can modify that and fit a proper lip seal as Triumph did on the later boxes

So after lots more measuring head scratching etc I have bought several lip seals with small outside diameters to save taking to much out of the sleeve but after machining one  it look a bit weak at the front(they are cast iron)

So I looked at my spare (rebuilt non overdrive box) and it is a later one with the lip seal!

What Triumph did is leave the shaft the same size as the bearing(less a few thou) and here is the difference they made it out of steel and longer?????

So I have a big lump of steel and a big lathe so I am going to make one to suit my smaller shaft(I could change them over? but its in now and I would like to keep the other g/box as a spare)its only done about 1000 to 2000 miles since Canley's rebuilt it.

Roger

[rogerguzzi]

Hello All

              I have just check the parts lists and the scroll type sleeve was the same on the 1st Spitfires? and fitted until G/box No 34!!!

I think it was changed for 2 reasons to stop leaks and possibly to stop the release bearing carrier from jamming as it comes right through the carrier sleeve not 3/8" short as the old one does when push right back!

So when operating even less supported!

Probably the difference between spring and diaphragm clutches? 

Roger

ps mine will be stronger because I will leave the bore smaller so it will give more wall thickness next to the flanges

[Pete Lewis]

there is one advantage of a scroll,    they dont wear out. !!

but dont like being parked on porlock hill !!

good luck with the machining

youre right about the throwout stand off between coil and diaphragm  all very different  depths 

Pete

[rogerguzzi]

Hello Pete

                    I am not to worried about wearing out at 73 1/2 !!!!!!

The seal will probably last longer than me?

I still wonder if the factory were getting complaints about clutches sticking as they did not spend money unless forced to!

I have rough machined it but it got too cold in the workshop and I thought as the old brain freezes I will make a c**k up!

Roger

ps I wonder what clearance to leave in the sleeve the less means it is thicker at the shoulder?

[Pete Lewis]

Minimal,clearance , the shaft cant move about unless the flywheel spigot  goes for a walk

Pete also  73.3

[rogerguzzi]

Hello All

               New clutch bearing support made with an oil seal fitted so fingers crossed it will work ok

It has taken me about a day and a half(that's a retired day 10 to 10.30 start tea and coffee breaks to warm up and lunch break plus walk the dog) so I suppose about 3 hours of proper work!

I was a lot of tuning as the lump of steel I had was about 1/4" bigger diameter than needed! still passes the time

You can see I have used a oil seal with a smaller o/d to save weakening it (seal not fitted)

Roger