Defender Front Axle 10 to 24 Spline Conversion Maxi Drive Halfshafts & Detroit Truetrac Upgrade

g’day I’m Brett i’m at M.R. Automotive in
Redcliffe Queensland home of Maxi Drive products i’m here to have my front axle
completely rebuilt to improve strength reliability and off-road traction
performance so let’s take a look now at some of the upgrades i’ll be doing on
the front axle it will include a conversion of the axles from 10 spline
to 24 spine Maxi Drive units the installation of a Detroit TrueTrac
limited slip diff changing from the later CV’s to earlier one tonne
Landrover a AEU2522’s which are the strongest Landrover ever produced and
also changing the drive flanges to Maxi Drive drive flanges which are made from
better quality materials so let’s go through now each of these components now
I’m upgrading from the 10-32 spine which I have originally in the Land Rover
front axle which one the worst combinations produced by Land Rover and
I’m changing to a 24-23 spline Maxi Drive unit now these are manufactured
from aircraft material known as high tough nickel chrome moly steel and heat
treated to 1550 MPA so they work out about 50% stronger than the original
Land Rover axles so let’s take a quick look at the before and after to show you
the differences between 10 spline and 24 spline half shafts so this is the
original 10 spline unit and this is the upgraded 24 spline so not only is the
actual shaft diameter bigger than the 24 spine but there’s more surface area
around the spine region so we take the measurements it works out
at 28.23mm for ten spline and 31.6 for a 24 spline so
it’s significantly bigger as well as the stronger material ten splines have a
history of the splines twisting or the ends sheering off in the Diff due to the
depth of the ten splines it significantly reduces the maximum
diameter or the core diameter of the shaft which is where the weakness is
introduced the 32 spline CV end has the smallest diameter of all the shafts and
is typically prone to the splines shearing off due to their fineness or
the end snaps off in the CV this is a table of the half shaft and CV
combinations they were produced so you can get an idea as to what combination
you are running in your vehicle the county’s up to mid 20L axle code had
10-23 My late 200tdi had 10-32 the weakest spline combination produced from
around 300 TDI onwards it changed to 24 32 but if you want the absolute
strongest shaft you have to go aftermarket to MaxiDrive Ashcroft
Kam and among a few others to a 24 diff end 23 CV end most 200 TDI’s should
be able to convert to the earlier county or Ashcroft CV’s easily but for 300tdi
onwards it’s best to use an aftermarket CV from Ashcroft or similar which have a
later style CV built from stronger materials but with a 23 spline input for
the aftermarket shaft now the difference in the material strength between
standard 10 and 24 spline half shafts is actually pretty minimal it was the
design of the spline area which is typically where the failures occur
you can find the graph on Ashcroft transmissions website showing breaking
tests they did with the short 10 and 24 spline half-shafts showing that they
both break around the same amount of force applied although the amount of
twist each can handle before failure is quite different but by converting to
aftermarket half-shafts you’re getting far superior material
strength and the stronger 24-23 spline combination this table I made shows the
measurements of the shaft diameters you can see these 32 CV end minor
diameter is only 24.9 millimeters which is the smallest
diameter of all the shafts compare that to the Maxi-Drive 23 CV end shaft minor
diameter of 28.5 millimeters which is still larger than
all of the measurements of the original ten spline shaft the CV’s are being
changed from the later RTC6862 to the earlier County one tonne
army-style AEU2522’s which are the strongest Landrover ever produced you
can see clearly here the difference in the shaft diameter inputs the 32
spline and the 23 spline I’m also upgrading the drive flanges to
MaxiDrive drive flanges which have a bit more spline area and made from
stronger materials and can be used for oil lubricated systems with a better
sealing design with the steel cap now I’m replacing the land rover 2 pin
diff as its the pin which is a two pin diff only has a single pin it’s prone to
cracking or snapping and the spider gears can also crush and break off the
housing can also wear out and where the pin fits in it can ovalate and the pin
can flog around inside so this is being replaced with a Detroit TrueTrac
limited slip diff the Eaton Detroit Truetrac is an
automatic torque biasing limited-slip differential I chose this unit as it is
a simple design using gears not clutch packs it has no electronics or Airlines
and doesn’t need special oils the unit requires no maintenance it will
transfer up to 3.5 times more torque to the wheel with greater traction when the
opposite wheel is spinning thus helping to drive the vehicle forward the
downside of the design is if one wheel lifts completely off the ground and has
no resistance it acts like an open diff but the unit can be tricked with some
left foot braking to provide resistance which will then help the wheel with
traction continue to move forward the differential is made with three helical
worm gears and a side gear on each side when traction is lost the helical worm
gears are forced outwards into the carrier producing friction it’s this
friction which reduces the spinning of the spinning wheel and helps divert more
torque to the wheel which still has traction I chose this over a full
locking differential as it’s used 100% of the time to provide greater traction
compared to the two percent of times I may actually need a full locking
differential I’ve had a Detroit TrueTrac installed in the rear axle for the
last three years and it has performed flawlessly I’m quite certain it has
helped me not get bogged on a few occasions so the downside of this
upgrade is I have strengthened the rest of the drive line so it will send strain
to the weakest link which would now be either the ring and pinion or the
gearbox and transfer case which are more expensive to fix obviously but I think
this is unlikely as I am running standard tires in my style of driving
it’s typically touring outback areas I’m not doing rock crawling
I’m not typically going any really challenging tracks I’m just exploring so
this should give me plenty of reliability and I doubt there’ll be any
issues with failing components as I have already rebuilt the gearbox transfer
case in all the rear axle has already been upgraded to MaxiDrive units
so I think this is a rock-solid upgrade. Okay my initial impressions just after
the drive home the steering is a lot more firmer in the return to center as I
come out of a corner I can feel the wheel wanting to come back a lot more
strongly then what it previously did but that seems to be fairly acceptable
and also before I got the conversion done I jacked up my front wheel I
grabbed on the wheel and I turned it and watched the prop shaft and I could move it
from about 12 o’clock to around 1 o’clock positions so there’s a fair bit
of slop play before the prop shaft will begin to move I’ve just done the same
thing and I can literally move it about one centimetre and the prop shaft moves
so a lot of drive line slop has been taken out which should be a really good
thing the price it came in to around 4000 Australian dollars for the complete
upgrade which included the diff the axles drive flanges CV’s and all the
labor and other parts the bearings sealing kits oil I feel that’s a fairly
reasonable price because I’m thinking about reliability in remote areas so I
can’t afford to break down in the middle of Australia particularly when I’m out
exploring Western Australia which is what I hope to intend to do fairly soon
the distances are too vast and the cost of recovery to get someone out all the
way to collect my car and get me back to safety is just way too much for it for
instance if you break down in the middle of the Simpson Desert you can expect to
pay a starting recovery cost of ten thousand Australian dollars and that’s
just the starting cost you have to have that money available before they’ll even
turn on the engine on the recovery truck to come out and get you so I think 4000
now is much more better than spending ten thousand dollars later plus the costs of repairs to the car and plus the danger to my life and those who come
out to rescue me which could be you know three four five days drive to get to
where I am depending on where I’m exploring at the time so that’s for
reliability and safety I’m happy to spend that money now
now please remember that I am a Landrover
enthusiast not a Landrover expert so the information I’ve presented in this video
although I’ve tried to research it the best I can and present it as far as I
know as accurately as I can there could always be some incorrect information so
do your own research and check all your own part numbers chassis numbers against
the specifications for different parts so a special thanks to Blake and the
team at M.R, Automotive for completing the conversion and for allowing me
access into their workshop to do some filming. Thanks for watching. Please
subscribe if you enjoyed this video. Visit my website for Australian travel destinations, vehicle preparation ideas and gear
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39 thoughts on “Defender Front Axle 10 to 24 Spline Conversion Maxi Drive Halfshafts & Detroit Truetrac Upgrade

  1. One of my final upgrades on my Defender before I set off on my round Australia trip number 2. It will take a lot of worry off my mind knowing the whole driveline has now been upgraded or rebuilt. To equip your vehicle for touring Australia, visit

  2. 50% stronger! That means they'll only break half as much. Lol. As a child I remember labouring up Wilson's Promontory, popping end shafts, and nearly going over the edge because the brakes were no good either! Christ I hate Landrovers. 😉

  3. Nice upgrade, worth the peace of mind! Have you ever thought of rotating your snorkel intake around!

  4. great job, especially discussing the technical details in laymans terms!

  5. Great video and well researched. The Deserts of WA will become addictive and you’ll return many times, as there is just so much to explore.
    I bet you a beer that you will change the diff out to a switchable locker in the future. ??.
    Keep up the good work.

  6. Thanks! I still have an open front and rear diff. I've gotten everywhere people said I couldn't go without a locker. With some careful and technical driving. And the winch. I've wanted to go didn't the helical lsd track front and rear for a long time. People said it horribly affects handling. Thanks for proving them wrong. And the tip about the drive line slack. Well. That's the icing on the cake. Thanks bret. ??

  7. watched as promised Brett!! good reasoning and motivations on account for reliability!

  8. Nice upgrade … Ashcroft do there own LSD which is on my hit list. Great to see someone else fitting what I have planned! Hope to hear more about it when you get some time on rougher/trickier spots!

    Interesting point regarding the return to centre. I wonder why exactly??

  9. Very nice upgrade, you will no doubt, have more confidence in your travels

  10. I converted my Range Rover to 24 splines after blowing up my rear diff. 10 splines suck. My Range Rover has been converted to a GM 6.5 Turbo Diesel with 450 foot / lbs of torque. Its doubtful the 24's will hold up very long. Next up will be Dana 60's and 35's

  11. Nice upgrade, but, bloody hell it isn't cheap. That is a lot of $$$ for just a front upgrade. It will never break though.

  12. Great setup! I´ve a question:
    Would´nt it be helpful, if the drive flanges stay original, so that they are the weakest point?
    If they break, they are not expensive and would be very easy to replace.
    Thats the main point I always see in upgrades, exspecially if someone starts the upgrading at the engine side.
    Stronger drive flanges, stornger halfshafts, stronger differentials, stronger propshafts, stronger gearbox etc.

  13. I personally would've gone with lockers but it is personal preference & as ya'll say you do little to no real offroad 4wheeling, which I do a fair amount of. I'm also to frugal to pay labor rates & don't trust mechanics these days anyway, and do all my own work. That said I do like your choice of parts & am sure ya'll will have thousands of miles of great touring ahead of ya'll. Very good review & really like all the details, great video Brett.

  14. Nice upgrade Brett should serve your needs really well. And great video like always mate ?

  15. Logical upgrade but that price… OUCH!

    Considering a lunchbox locker upgrade for my front diff… 4K would get me a whole replacement vehicle or a new transmission LOL ?

  16. Nice up-grade cobber. I had units like that under the front of my '95 Tanami Edition Defender. Put it in for a service here in Gympie, and it came out WITHOUT the HD units in the front. Never trust an Apprentice. Love your work, Cheers for sharing. Atb, Brett

  17. Good update. I have Ashcroft ATBs in front and rear for approx. 60kkm now. Just perfect……since its a TD4, I kept the org. shafts. Why detroid instead ATB's from Ashcroft?

  18. i have a 2001 defender 110 county with a lot of backlash and have been thinking of doing this upgrade for a while what is the weight of all the parts roughly as i need to get them shipped to NZ

  19. Always love your videos
    But needing $10k for a recovery in the Simpson Dessert is just BS.
    We use him heaps for work when we take test vehicles out there.
    Yes he is very $$$, but not $10k before he starts. That's utter rubbish.
    He will ask for $2k before he gets going.
    There is a fella on the Gibb River Rd that has asked for $6k before he left…
    $10k seems like one too many campfire stories to me

  20. Hey Brett awesome video .. it rear still 10 spline ? I also wanna do the changes like this on my front diffs you links where I can purchase each of these stuff ? Rear I have put a Detroit true trac but it's 10 spline ..

  21. Getting to know how to fix your vehicle in the bush is vital to reliable and safe travelling remote areas. Your new system is not 100% bullet proof.

  22. Sounds like the kind of driving I'd like to do, no serious off roading, but just being able to go some places that might be risky without 4×4.

  23. When you changed your CV’s, did you get the original LR or aftermarket type like Britpart?

  24. That's the beauty about being able to fix your own vehicles. Labor will eat you up in fees and if you did break something out in the desert it's not really a problem as long as someone can bring you parts

  25. Great video mate, really informative – I'm going to do pretty much the upgrades since my wheel bearing failed on me over the weekend.

  26. Hi. Great video. I have a question. I have the Detroit Tru-Trac in the rear of my 94 Range Rover county. I have never experienced any problems. As my Range Rover has rear Traction control, which helps trigger the properties of that differential. I noticed a vast improvement in the sand with the rear application. I want to install the same Tru-Trac in the front of my Vehicle. Now that you have had it installed for some time, can you tell me your impressions of the unit in actual operations? Specifically on sand, as it pertains to traction and steering control. Further did you notice anything peculiar, or quirky about it? and in general what were your impressions with highway driving after you have had more kilometers to evaluate that aspect. I really want one but wish to gain your acquired knowledge on the subject. Thank you very much..great video as always. I still want to come there and search for gold in the outback.

  27. Can you please tell me how you got on with the function test as per eaton manual please? Preload on my front makes it almost impossible and permanently locked?????

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