Front Drive Shaft Update

[Dokatd]

Anyone on the east coast have a stock front shaft we can borrow and return untouched? PM me if you have one handy. I'm having trouble getting time to remove mine for mock up.

 

[derek0343]

Anyone on the east coast have a stock front shaft we can borrow and return untouched? PM me if you have one handy. I'm having trouble getting time to remove mine for mock up.

I have mine front shaft free to borrow, But I'm in California.

 

[Dokatd]

I have mine front shaft free to borrow, But I'm in California.

Not sure shipping works out for that. But let's keep that option on the table.

 

[Clark Kent]

Here are my stock breathers. I replaced them with raised breathers almost 2yrs ago.

The silver cap is spongy like there is a spring holding it up. It is crimped in 3-4 places retaining it on the breather body.
View attachment 7915469

Inside the bottom of the breather you see what looks like a valve stem complete with a rubber seal. The stem doesn’t move when you bounce the silver cap, but you can push it open with a pick by pushing outward toward the cap. It springs back closed, but with very little resistance. Below are a few photos to give you the best a views possible.
View attachment 7915470

View attachment 7915471

View attachment 7915472

I cannot see any way to remove rubber and fix the breather.

Thanks @Tom109. Good pics.
That accords with the section schematic I posted. The spring sits between the cap and the valve which acts as a piston. The spring is calibrated to 0.5bar. The cap crimps would need to be removed to take off the cap and valve to get to the seal. Not a difficult job.
Is there a brand or markings visible on the cap?

 

[Tom109]

Thanks @Tom109. Good pics.
That accords with the section schematic I posted. The spring sits between the cap and the valve which acts as a piston. The spring is calibrated to 0.5bar. The cap crimps would need to be removed to take off the cap and valve to get to the seal. Not a difficult job.
Is there a brand or markings visible on the cap?

No markings on the cap. I’ll take a closer look at the body tonight.

 

[255/85]

I visited JRace in October and posted about their development work here and here.

The Grenadier is my first full-time 4WD (never owned an 80 Series or any Land Rover) so it's all new to me and I find the mechanics interesting - or at least novel. That said I would feel more comfortable with a part time kit if it eliminated the front prop shaft vulnerability - but why would it? Wouldn't there will still be the same front DS issues once the vehicle sees any track requiring articulation?

The part-time systems I'm familiar with generally employ much larger rear differentials than front because of the additional capacity needed and increased wear seen in on-road usage. In the second post you linked "Jay" mentions a problem with the rear axle that prevents a substantial GVM upgrade. Wouldn't that be more pronounced in a part-time system where the rear end would be taking most of the vehicle's load until center-locked? Wouldn't a part-time kit also require a larger rear axle set-up in addition to a the redesigned front shaft?

At 7500 US miles in we've got the tiniest bit of front pinion seal seepage. It's not enough to even drip. This makes no sense to me though. I have other vehicles with over 175K and over 200K miles respectively that are still dry as a bone. All the front pinion seal issues folks are having point to increased bearing wear as binding front CV joints strain the flanges. I'm guessing that the front transfer box output shaft and bearing are larger than the front differential pinion shaft and bearing so the deflection/wear/whatever is more frequent there?

 

[Dokatd]

The Grenadier is my first full-time 4WD (never owned an 80 Series or any Land Rover) so it's all new to me and I find the mechanics interesting - or at least novel. That said I would feel more comfortable with a part time kit if it eliminated the front prop shaft vulnerability - but why would it? Wouldn't there will still be the same front DS issues once the vehicle sees any track requiring articulation?

The part-time systems I'm familiar with generally employ much larger rear differentials than front because of the additional capacity needed and increased wear seen in on-road usage. In the second post you linked "Jay" mentions a problem with the rear axle that prevents a substantial GVM upgrade. Wouldn't that be more pronounced in a part-time system where the rear end would be taking most of the vehicle's load until center-locked? Wouldn't a part-time kit also require a larger rear axle set-up in addition to a the redesigned front shaft?

At 7500 US miles in we've got the tiniest bit of front pinion seal seepage. It's not enough to even drip. This makes no sense to me though. I have other vehicles with over 175K and over 200K miles respectively that are still dry as a bone. All the front pinion seal issues folks are having point to increased bearing wear as binding front CV joints strain the flanges. I'm guessing that the front transfer box output shaft and bearing are larger than the front differential pinion shaft and bearing so the deflection/wear/whatever is more frequent there?

There is not enough "bind" to damage bearings. It's just barely enough pressure to pinch the boot.

 

[Clark Kent]

The Grenadier is my first full-time 4WD (never owned an 80 Series or any Land Rover) so it's all new to me and I find the mechanics interesting - or at least novel. That said I would feel more comfortable with a part time kit if it eliminated the front prop shaft vulnerability - but why would it? Wouldn't there will still be the same front DS issues once the vehicle sees any track requiring articulation?

The part-time systems I'm familiar with generally employ much larger rear differentials than front because of the additional capacity needed and increased wear seen in on-road usage. In the second post you linked "Jay" mentions a problem with the rear axle that prevents a substantial GVM upgrade. Wouldn't that be more pronounced in a part-time system where the rear end would be taking most of the vehicle's load until center-locked? Wouldn't a part-time kit also require a larger rear axle set-up in addition to a the redesigned front shaft?

At 7500 US miles in we've got the tiniest bit of front pinion seal seepage. It's not enough to even drip. This makes no sense to me though. I have other vehicles with over 175K and over 200K miles respectively that are still dry as a bone. All the front pinion seal issues folks are having point to increased bearing wear as binding front CV joints strain the flanges. I'm guessing that the front transfer box output shaft and bearing are larger than the front differential pinion shaft and bearing so the deflection/wear/whatever is more frequent there?

Good questions.

Jay was looking at all possible options then working through the list. It was clear to him and anyone else that has done a study that a different driveshaft (only) is going to be an imperfect solution so he took an open mind approach. A part time 4WD conversion would have been very low on his list. There's the engineering and cost issues plus the market interest. Who would want it? I'll assume the potential for improvement is the reduced duty cycle of the driveshaft. It's no longer rotating all the time and when it is it's likely at reduced speeds off-road. The articulation and pinching problem still exists. But combine a part time conversion with a cardan style driveshaft and you have probably solved it but in a very complicated and impractical way. There will be driveshaft vibes but minimal at off-road speeds.
Part time conversion is not a simple solution and is probably in the trash basket already.

My fading recollection of his point about the rear axle was a weak area in the housing tubes. That was about weight bearing capacity for higher GVM approvals.

You have probably picked up that lift and GVM mods are regulated in Australia. The owner can do a little bit with tyre sizes and rims. SSMs like JRace can do quite a bit more with pre-approved kits. Beyond that, modifications need engineering involvement at the design stage then post-installation scrutiny and sign off after the bill is paid. There are still regs and limits to follow if the vehicle will be registered for on-road use. The vehicle also gains a modification plate to keep police and roadside inspectors happy.