The final drivetrain upgrade - Nissan Patrol Y61 axles (Patreon)

So far we've looked at the drivetrain starting from the flywheel, clutch disc and pressure plate, onto the BMW gearbox and now we're starting to look at where the power's going to end, the axles. This power isn't too much, but at least 600Nm to begin with. 

Axle choice is always an interesting topic when adding more power to old Land Rovers. Arguably the most common and straightforward choice is upgrading the internals of your Rover axles or changing them to a later style (e.g. Discovery 2). Ashcroft are considered the best of the best and for around £2k you can have new diffs (ATB or locker, pegged etc.), half shafts and CV joints. The other more affordable option would be to use the axles that are on the 110 now and replace half shafts if and when they break.

We want to avoid this, having broken three diffs in a 200tdi-swapped Series 2A

With a budget of £1500 for axles we can move away from standard and upgraded Rover options to different makes like Toyota and Nissan. It's worth mentioning that there are more convenient and purpose-built axles made specifically for high-powered Land Rovers (Such as Ashcroft's Force 9's) but these are generally way more expensive than I can afford. Long ago you could get a kit to transform the internals of the Salisbury axle to a 35 spline beast (Rover Tracks and McNamara made these) but they are incredibly hard to find now and likely very expensive.

Ashcroft 's Force 9 - Supposedly the best bolt-on axle if you can find or afford them! 

This is where the original idea to use Nissan Patrol axles spawned, I'd read that they were one of the strongest axles that could be fitted to a Defender within reason. I've done lots of research and have come up with a Pros and Cons list for standard LR vs Y61's.

Type 'Liwa hillclimb' into YouTube for some Nissan Patrol inspiration, mental machines! 

Standard Land Rover - !0/24 spline

Pros

- Readily available and cheap with good spares availability 

- Fitted as standard, can be easily upgraded with Ashcroft internals 

- Retains factory look, no need for wider arches

- 3.54:1 diff ratio good for low revs on the motorway 

- Full-floating design better for load bearing and half-shaft replacement 

Cons

- Ashcroft upgrades are expensive and often wont be given a guarantee when running 'high power'

- Half shafts are renowned for snapping under hard use/abuse e.g. sudden increase in traction 

- Diffs, shafts, CV's are relatively small compared to other medium to large 4x4's (Especially American kit) 

Nissan Patrol Y61 (H233B)

Pros

- Much stronger components, larger in every way and often don't break in competition with 37" and bigger tyres

- Better steering lock

- Better brakes

- Rear locker as standard on lots of Y61's

- Aftermarket upgrade parts available and guaranteed up to 42" tyres (RCV) 

Cons

- Much heavier than Rover axles

- Require brackets welding on and may be difficult to set up on chassis 

- Stance may be too wide for standard wheel arches (not very Sleeper-like) 

- Replacement parts more expensive and harder to get than LR equivalent

- Need to use 6-stud wheels

- Diff ratios generally higher (4.11, 4.7 etc.) so need faster LT230 to retain low rpm cruise

 - Less ground clearance

- Rear diff is in the centre (not offset like LR) so custom wide-angle propshaft may be needed to stop vibration

- Semi-floating design and swivel housings welded on as opposed to bolted on with LR axles 

Guess which one belongs to the Patrol...

There's a lot to consider when choosing which axles to use on Project Sleeper, each choice comes with many potential headaches and there isn't really a right answer but I'm definitely leaning towards sticking with the Y61's. 

Which would you choose?

P.S. Please let me know if this is too in-depth or wordy! Cheers, Fred.