best way to get prop bolts undone..

[Craven]

2cam70,
A stiffer crush tube will of course require more torque to crush, but it’s not a spring the energy imparted in crushing is dissipated in the process, probably in heat, leaving a passive correct length spacer only.
Force left in the system is just the 30 – 40 lbf-ft of required preload as implied from the workshop manual when tightening after seal change.

Best I can do in explanation.

[512BB]

2 cams wrote ' A thicker, stiffer crush tube will require more torque on the pinion nut to crush and to reach the correct preload on the pinion bearings than a thinner softer one will it not? More torque required on the nut means more tension in the assembly and more tension in the assembly means less chance of oil leakage between the flange and the pinion bearing inner race - correct or not?' NOT

Any two metal surfaces pressed together will seal without sealant if the force per unit area between them is high enough' ONLY IF THE 2 SURFACES ARE A PRECISION FLAT FINISH, and even then, you should probably use a dressing of some sort.

'I'm quite willing to be proven wrong because I like learning things' WELL LISTEN UP THEN

'Unless you actually have really loose pinion bearings (i.e end float) you are unlikely to notice increased diff noise from incorrect adjustment.' NOT CORRECT. As I stated somewhere else, I had a pinion nut come marginally loose at one time, and the diff whined like err indoors. I just tightened it up in situ and the diff stopped squeeling.

I think I have identified 2 cams, why you do not understand the sealing arrangements on an English diff. Just for clarity and to repeat myself, my writing in bold is just to highlight where I have added text. I am not shouting. My education in computing was not sufficient to allow me to change the colour of the text or any of that jazz.

You seem to think that just because you have 2 metal surfaces pressed together, they will form an almost oil tight join. They will not . The later crush tube measures 1.8mm thick, but there is a bevel on the inside of the end face. The early crush tube measures approx.1mm thick, but because of the bevel on the later tube, the contact thickness / area between the 2 tubes will be very similar. Further, the end face of the later tube is not a precision finish, and the end face of the early tube is like the Quantock Hills. Similarly, the face of the flange does not have a precision flat surface, and it is for those reasons that those 2 surfaces being pressed together, no matter how hard, could not possibly form an oil tight assembly, and a sealant must be used.

It should also be born in mind, that that area of the diff is completely submerged in oil, so any 2 metal surfaces that were to form an oil tight seal between them, would have to have been so minutely finely finished. Does that sound like an English diff made in the 1960's?

I hope that clears up this discussion and we can all be friends again

Leslie

[Hawksfield]

2 cams

You stated: Unless you actually have really loose pinion bearings (i.e end float) you are unlikely to notice increased diff noise from incorrect adjustment. The main effect will be reduced pinion bearing life (and oil leakage if you don't use sealant).

With respect are you saying that incorrect pinion preload (less torque) does not cause diff whine? As I have heard of many cases of a "nip up" of the pinion nut has stopped whine.

Tying to learn more