Thread: D2 Diff into a RRC

Originally Posted by Slunnie

I don't know that I'd get too hung up on getting a 35sp into the CV for a LandRover. You really don't want the outer axle to snap and I suspect that would become your fuse in that setup. The outer axle holds the D2 hub together with the bearing unit (unlike the Rover hubs) so if it breaks your wheel will come loose. I would expect 30sp into the CV to be doable if the star is compatible with the 30/30 Longfields. If you run the Rover setup, then you probably still want the outer axle to not snap due to the collateral damage it does when it breaks.

9" and 35 spline is what they run with 42's and 500hp flat chat on the rocks. To run that strength in the front I'm not sure that Rover is the gear you need short of one of those rare front Salisbury diffs.

So if you are going 30spline you can keep the stock RRC housing and run longfields and a custom 30 spline drive flange..but i think the toyo diff is a compromise.

I dont like the idea of a fuse, just build it all strong and dont drive like an idiot, ha

Originally Posted by blackrangie

So if you are going 30spline you can keep the stock RRC housing and run longfields and a custom 30 spline drive flange..but i think the toyo diff is a compromise.

I dont like the idea of a fuse, just build it all strong and dont drive like an idiot, ha

Yes, and I agree completely re the fuse, but ultimately something breaks. I just think that its better to be something else other than the CV if you have to drive it out, and most definitely not the CV if its a D2 axle..

I suspect that even a pegged Rover CW/P will break before 30/30 Longfields.

Originally Posted by Slunnie

If you could do it then to suit a 35sp outer then!

Ok so what parts other than the custom 35spl axles and custom 35 spline drive flanges would we have to make?

The housing it self is no probs LRA do them.

Originally Posted by Slunnie

Yes, and I agree completely re the fuse, but ultimately something breaks. I just think that its better to be something else other than the CV if you have to drive it out, and most definitely not the CV if its a D2 axle..

I suspect that even a pegged Rover CW/P will break before 30/30 Longfields.

Pegged ashcroft CW&P?

I'm not sure re parts, but I suspect everything would be custom, even the CV's. Bearing units also.

Re the diff, I think so, especially if you're looking at 300M axles. At the end of the day a spiral bevel pinion is just small, especially if you then go to 4.1x etc and the problem is made worse. Thats why all of the the strong diffs are either big, hypoid or both, and the more hypoid the better (ie your 9" which has a big pinion offset - and in turn a big pinion). The hypoid has a larger mesh area between the CW/P and also the 9" is a much stiffer design with the pinion support.

Pictured below - all CW/P are 4.11:1 for comparison: Toyota 8" HP hypoid, Rover 8.5" spiral bevel, below Ford 9" (internet pic). You will note that a Toy 8" hypoid sits right in the middle of design between a LR and a Ford 9". They were just never built properly from the factory and high performance builders use a solid spacer in the pinion rather than the crushable unit when building them.

If running longfields, flanges would be 30 spline, axles (if running 9") would be 30/35 spline. So apart from getting a housing made and axles, and modding the bronze bush in the swivel and boring the spindle out, the rest should be all bolt in.

Originally Posted by Vern

If running longfields, flanges would be 30 spline, axles (if running 9") would be 30/35 spline. So apart from getting a housing made and axles, and modding the bronze bush in the swivel and boring the spindle out, the rest should be all bolt in.

It may be even easier to try and find a Rover Style locker that can be broached to 30spline and run Pegged Ashcroft CW&P (we run stock rover ratios from memory due to the low gearing capabilities of the Chev 6speed 6l90 Auto)

Bit of clarification from Dave Ashcroft when asking 100% if 35spline or 30spline could be broached into the ashcroft 24spline diff.

He said

"Not 35 sp,

I don't know about 30 sp, I doubt it for 2 reasons, the 30 sp will not clean out the existing 24 sp and also if it did there wouldn't be enough wall thickness left on the journal diameter"

I have also spoken to Jac Mac (quite helpful if you show him the respect he deserves as a diff genious) and he believes his (now TJM's) Prolockers will work in the 30 spline scenerio..getting more info in a few weeks.

So, so far we have some info from an earlier post that ARB could work with 30spline using off the shelf parts.

Dave has said not sure about broaching the Ashcroft to 30spline but doubts it, have asked if he can supply blanks etc.

Jac Mac has said 30spline could be broached or use 30spline parts on his rover 24spline (but i need to confirm and get more info)

Does anyone know of a rover style upgraded diff ever being used with 30spline obviously coupled with upgraded CW&P and pegging?