Driveshaft condition

[Badwolf]

1 hour ago, Colin Lindsay said:

More people have died in bed than ever died in Triumphs.

An awful lot of people can't do what you do in bed...in a Triumph....well not without NHS intervention!!!

[Colin Lindsay]

Just now, Badwolf said:

An awful lot of people can't do what you do in bed...in a Triumph....well not without NHS intervention!!!

You mean snore?

[Badwolf]

Whatever????

[NonMember]

He means sleep, as any RBRR entrant will tell you 😛🤔

[sulzerman]

Just noticed the second driveshaft the supplier sent has knackered threads!😡 The hub had already been removed by a clown, looks like they hit it with a big hammer!

Sent photos to supplier and waiting for response, not happy as I have fitted a new uj☹️😡

[Pete Lewis]

the threads are apart from the lead in is shallow the main part for the nut are quite distorted

a die nut may recover some what , and depend on how far on the nut goes .

certainly not the best solution its done a lot of on's and off's in its previous life 

its not just scrap but heading that way

Pete

 

[sulzerman]

Quite annoyed they sent me stuff like this,😡👎

[johny]

ok they should have told you but I think thats pretty mild damage for a 50 year old item. If thats all thats wrong with it Id file the end threads to a taper (the nut goes well past them) as the metal should be soft and get it installed👍

[Wagger]

On 30/05/2022 at 09:51, johny said:

Are you sure Pete? That has a bit of a whiff of possible urban myth about it and Mr Google cant find me anything☹️ 

This is one for a metalurgist or physicist. However, the metal used would have been a bit special. Like piano wire, good in tension, not in shear. Predominantly, each side gets twisted and the structure remains as a twisted helix in tension, unless you drop the clutch in reverse quite often. So, if you swap sides, you create a shear force on the structure, NOT a good idea.

Vitesse ones are more beefy, but I will not tbe tuning my 2.5 litre Vitesse anytime soon.

[johny]

I didnt realise there was a difference between the non doughnut halfshafts fitted on the different models (apart from length on the later Spitfires of course) so good to know👍

[johny]

Im not so sure thats right now as it looks like part number 128135 short driveshaft was used on all Heralds, Spitfires/GT6 (those with short & non rotoflex axles) and Vitesse (non rotoflex) so looks like it wasnt beefed up at all from the original 34.5bhp all the way to 95bhp (cant find torque figures but probably even more frightening)😬

 

[Wagger]

One can worry too much. I used to wonder what would happen if a rabbit tried to run through the spokes of my push bike, then motor bike. That never occurred, but I did hit a stone aged 9 with the front wheel. The front of the bike went skywards, wheel turned and the bike went at right angles into a ditch lined with stinging nettles. Gyroscopic action involved somewhere.

30 minutes ago, johny said:

Im not so sure thats right now as it looks like part number 128135 short driveshaft was used on all Heralds, Spitfires/GT6 (those with short & non rotoflex axles) and Vitesse (non rotoflex) so looks like it wasnt beefed up at all from the original 34.5bhp all the way to 95bhp (cant find torque figures but probably even more frightening)😬

 

Torque on 2 litre approx 115 lb/ft. 2.5 litre approx 130 lb/ft. Rotoflex maybe safer depending upon where the shaft shears. However, the rubber donuts do not like high torque. There are CV joint mods.

Heralds never had rotoflex. Mk2 Vitesse and some GT6's. Cannot remember which, but Mk2 I believe.

 

[Pete Lewis]

you can multiply the torque ( apart from efficiency losses  ) by the axle ratio  

so a 2ltr Vitesse at 115 lbft and a 3,89:1 diff gives the shafts more like heading to 447Lbft at max torque 

all excluding 948  H ,V6 V1 spit 1-111 and Gt6 1-11 used short shaft 128135

the long shafts used on late non rota Gt6 lll  and late spit MklV and 1500

there were evolution of the inner short outputshafts where the dia was increased 

i even  sheared one of those back in the 60s in my rusty 948Herald

my 64 Vit6 had the bigger ones off hand  dont know when this mod took place but quite ealry on 

Pete

[Wagger]

On 02/06/2022 at 16:00, johny said:

ok they should have told you but I think thats pretty mild damage for a 50 year old item. If thats all thats wrong with it Id file the end threads to a taper (the nut goes well past them) as the metal should be soft and get it installed👍

Try and find some thread files. That can be recovered. Did mine after distorting the LH side as it needed 150 lb/ft to get the hub off. The hub puller distorted the end of the shaft. If you ever do these, unscrew the hub nut flush with the end before using the hub puller. That will preserve the threads.

[Pete Lewis]

with the puller  there should be a cap to protect the threads but they get lost 

Pete

[johny]

9 minutes ago, Pete Lewis said:

you can multiply the torque ( apart from efficiency losses  ) by the axle ratio  

so a 2ltr Vitesse at 115 lbft and a 3,89:1 diff gives the shafts more like heading to 447Lbft at max torque 

Hmmm so a 3.63 diff would make a back wheel coming past me in my MK1 Vitesse more unlikely😃

[Pete Lewis]

yes  ,  Il drink to that  seems more suitable than worrying   Ha ! 

417 and live in hope   

3 wheels on my wagon comes to mind   

 

Pete

[johny]

That settles it then - I just needed one more reason to change the diff👍

[Pete Lewis]

look  just stop................ looking for any reasons    they arrive without any dreaming 

Pete

[Steve P]

3:27 in my tuned 2.5 Vitesse putting out around 170bhp,I went for the Jones/Bowler CV conversion.

Now what can I worry about?.

S

[daverclasper]

4 hours ago, johny said:

4 hours ago, Pete Lewis said:

you can multiply the torque ( apart from efficiency losses  ) by the axle ratio  

so a 2ltr Vitesse at 115 lbft and a 3,89:1 diff gives the shafts more like heading to 447Lbft at max torque 

Hmmm so a 3.63 diff would make a back wheel coming past me in my MK1 Vitesse more unlikely😃

I'm not knowledgeable enough to understand the implications of torque, though I gather it can stress components?.

My Vitesse (standard engine, as far as I know), has a 3.27 diff, OD box, fitted by Canley, before I bought it.

I gather the diff, is a bit low geared ideally?.

Any driving style that is better to not stress my drive train (I am a bit of a plodder, not high revs through the gear and high top speeds)?.

Should I be giving it more beans?

Not worrying about this (honestly) 

Cheers 

[Pete Lewis]

Dave the 3.27:1 is a higher ratio   ie less rpm input for a given output 

what you can have is the need to give it more beans in certain conditions as to get the torque needed at the wheels you have to give more input

a 4.11:1 is the opposite   this could explain why some 3.27 go bang as they have to transfer more torque 

depends on your countryside   hills need a lower ratio  motorways you get away with a higher ratio its a balancing act 

and this all depends on what torque your engine develops 

Pete

 

[daverclasper]

Cheers Pete, did know that , but must have had a confused moment, with what was higher/lower ratio. Bit like our cars, "musen't worry" (about my brain).

So, maybe, as a rule of thumb, try not to maul it?

[johny]

yes its not to straight forward is it Dave. In many fields 1:2 would be a low ratio so that 1:11 might be called a high ratio but in transport its the other way round. I wonder if it came from 1st gear (so called a low gear) but which has a high ratio while the higher gears, 2nd, 3rd, 4th, have progressively lower ratios arghhhh 

[Wagger]

4 hours ago, Steve P said:

3:27 in my tuned 2.5 Vitesse putting out around 170bhp,I went for the Jones/Bowler CV conversion.

Now what can I worry about?.

S

Is that a Quaife differential? The standard GT6 one is reputed to be fragile.