Front diff to cope with the power of an M57

[Mo Murphy]

So I have an old 10 spline Front axle. I expect this will struggle a bit with the extra power.

What do I need to do to make this stronger on a budget ?

I accept this will need to be 24 spline and that I will need Ashcroft shafts to match the diff to the cvs but I don't really want to go to the expense of another locker or atb if I can avoid it.

Any suggestions ?

I'll be running a standard 220hp engine map and a 6 speed autobox with LT230.

Mo

[Bowie69]

Honestly I'd leave it as it is, I've run similarly powered heavier vehicles with aggressive 33"s and not broken anything.

The autobox is kind to things, a lot less shock loading.

[Daan]

Fit a later 24 spline diff and ashcroft shafts. Cheapest way to upgrade. If you have 10 splines now, you have the strongest CV's. So just change the diff.

Don't be tempted to fit a complete 24 spline axle, as the shafts and CV's in these are very weak.

Daan

[uninformed]

There was a very small window of time, just before the transition to 24 splines, where Def’rs had 10 spline diff end and the hopeless 32 spline CV. Make sure you don’t have these. 
 

 

[Mo Murphy]

Thanks guys, I do indeed have and intend to keep the earlier stronger CVs and hubs, so it'll just be a matter of presenting Mr. Ashcroft with one of my kidneys for some HD half shafts and drive members. Interesting and reassuring that a standard 24 spline diff should be up to the task.

My thanks to you gentlemen

Mo

[Daan]

2 hours ago, Mo Murphy said:

Thanks guys, I do indeed have and intend to keep the earlier stronger CVs and hubs, so it'll just be a matter of presenting Mr. Ashcroft with one of my kidneys for some HD half shafts and drive members. Interesting and reassuring that a standard 24 spline diff should be up to the task.

My thanks to you gentlemen

Mo

No worry's, do we get to see the M57 install?

[Nonimouse]

Moseph

Go and look at Uncle Nige's you tube thing on diff strengths - it's interesting

I would stay with what you have. The engine you are running is more powerful, yes, but it's far smoother in it's power delivery. Coupled to this you have a modern auto box (6 speed?) that again delivers power smoothly.

Unless you drive like an utter tawt, it will be fine

 

[Mo Murphy]

53 minutes ago, Daan said:

No worry's, do we get to see the M57 install?

Of course, on my thread after Christmas 👍

[Retroanaconda]

Let me know if you want my old AEU2522 CVS as spares Mo, no use to me now I converted to the later type.

[uninformed]

You may end up finding that an Ashcroft ATB is a good investment for your LT230 when the M57 is up and running. Given you’ll also want to do a high range ratio swap, that would be the time. 

[Bowie69]

1 hour ago, Nonimouse said:

but it's far smoother in it's power delivery

Made me realise being a nice 6 cylinder it should be very much easier on everything.

 

[smallfry]

Cheapest option would be a four pin diff centre.

You should hang your head in shame converting to diesel (or a bigger diesel) at this time.  Mr Kahn t will be choking on his breakfast. And the fumes.

Using the 6HP26 I guess ? If you have not bought the gearbox already, dont make the mistake of buying one from a car. You need one from an X5 or X3. 

[Snagger]

43 minutes ago, smallfry said:

  Mr Kahn t will be choking on his breakfast. And the fumes.

That’s a though that brings me much pleasure.

[smallfry]

1 hour ago, Snagger said:

That’s a though that brings me much pleasure.

Not nearly as much as it does me !

[Hybrid_From_Hell]

M57s are beasts and can blow up all parts of the drive train 😎😂😂

 

so I can give some sensible advice 

 

what’s the truck

gearbox

tyre size 

t box ratio 

what’s on front and rear axles so far ?

 

nige

 

 

 

[Mo Murphy]

OK Nige,

It's going in my 90

M57n with 6hp26x auto gearbox 

Transfer box 1.2 ratio with standard diff

33" tyres (255 bfg)

Rear axle has 24 spline pegged arb with standard shafts

Front axle is a bog standard 10 spline axle

Cheers 👍 

Mo

[Hybrid_From_Hell]

I need to run some numbers and I’ll be back with some ideas 😬😂👍

[uninformed]

11 hours ago, Mo Murphy said:

OK Nige,

It's going in my 90

M57n with 6hp26x auto gearbox 

Transfer box 1.2 ratio with standard diff

33" tyres (255 bfg)

Rear axle has 24 spline pegged arb with standard shafts

Front axle is a bog standard 10 spline axle

Cheers 👍 

Mo

That set up should give you pretty good Hwy cruising rpm. 
 

IMO a 24 spline diff will be fine. Ashcroft 24/23 shafts to suit your CVs. 
 

I think spending money on the LT230 may be more worthwhile. Personally I would not use a 1.2 out of a D2 or Tdci. Those Q gears are weak, generate more heat and they also reduced the quality of the centre diff gears from 98 onwards. They went ever further towards the end of the Tdci and changed the centre diff to a cast open design 2 pinion gear heap of carp 😞

[Mo Murphy]

Thanks for your feedback uninformed, I think the gearing will be spot on.

The transfer box is from a 1992 Range Rover so should be up to the task and will get some Ashcroft attention before being refitted 👍

I've seen some pictures of those diffs, fortunately my budget doesn't run to buying late parts and paying more money for cheaper parts isn't my thing 😆

Mo

[uninformed]

Your input gear might not be cross drilled ( I don’t think they were by 92?) you can do it yourself. Just grind a little off the surface first (only where drilling) to remove the case hardening, this will make drilling much easier. 
 

 

Edited December 16, 2022 by uninformed

[Mo Murphy]

Thanks, I have cross drilled input gears in my transfer boxes, they're cheaper than gearbox output shafts 😁

Mo

[Bowie69]

41 minutes ago, Mo Murphy said:

cheaper

 

1 minute ago, Mo Murphy said:

cheaper

I'm sensing a pattern  

[Mo Murphy]

14 minutes ago, Bowie69 said:

 

I'm sensing a pattern  

But not Britpart 😉

I'm on an NHS wage Pete and the the whole conversion is going to see me in for £5-6k, so I don't want to be spending money foolishly 😉👍

Mo

[Bowie69]

Absolutely, certainly wasn't a criticism!

[Snagger]

5 hours ago, Mo Murphy said:

Thanks for your feedback uninformed, I think the gearing will be spot on.

The transfer box is from a 1992 Range Rover so should be up to the task and will get some Ashcroft attention before being refitted 👍

I've seen some pictures of those diffs, fortunately my budget doesn't run to buying late parts and paying more money for cheaper parts isn't my thing 😆

Mo

92 RR should have had a Borg Warner transfer box, not an LT230.