Maxi drive axles strength

[TUFRR]

I have just stripped my rear Maxi Drive apart and found that BOTH axles are twised on the splines at both ends of each axle.

Has anyone else had this happen?

I was led to believe this locker was low klm and had an easy life in a near stock Rangie and the rest of the internals are undamaged.

I also have a Mac Namarra rear locker that i have stripped down
This locker is around 8 y/o and has been in a Rangie with 33's then 35's
and was powered by a warm 350 chevy and the axles are dead straight.

[landy_man]

i assume you baught the MD locker and axles 2nd hand... what did they look like before you put them in.

[DiscoDino]

TUFRR,
So you're saying that these two axles were under the same stresses and the MD gave whereas the MN did not? If we're not comparing apple to apples, you just added more spice to the confusion!

[landy_man]

mate.... i love the mockies

[Strange Rover]

Maxi axles are made from Hy tuff and jac mac are made from EN25 or EN26 (carnt remember)

So a while ago I asked maxi how good his axles are and how they compare to jac mac and he says something like both his material and jac macs have very similar yield strengths (both will start to twist and similar loads) is just that the hytuff is a lot more ductile and tougher (meaning it will deform or twist more before the thing actually breaks.

Ask jac mac how his axles compare to maxi and he says that his axles are the best and are made the same way that they make big truck axles. Say to him that maxi used to make them out of the same material (EN2?)and had failures and that since he changed to the hytuff that his axles are a lot stronger and jac mac says that thats because when he made his from EN2? he wasnt heat treating them properly and thats why they were failing.


SO .... my view is that maxi axles are made from better material that isnt necessarily any stronger but they will twist more before ultimately breaking than a jac mac. In either case I think that the material strengths are similar.

The biggest difference IMO is that the jac mac axle is designed much better. See how (from the pic) that the jacmac axle is machined down along its entire length to the minimum diameter of the splines where as maxi axles are machined to the same dia as the maximum spline diameter. What this does in the case of the jacmac axle is that the loads from the splines is introduced into the length of the axle more smoothly and evenly. The maxi axle has a much higher stress concentration at the ends of the splines where it turns to solid axle.

Now because the jac mac axle is a smaller diameter along it length the axle is a lot more flexible and so will handle bound up wheel loads better and shock loads better because the axle has more "give" because its more flexible. Now the strenght of the jac mac axle isnt any less because of the smaller diameter because the weakest point is always at the splines.

Now the maxi axle can handle the increased stress concentration at the splines because its made from his hytuff which can deform without cracking.

If the jac mac axle was made the same way as the maxi axle then it wouldnt be very strong cause it would be prone to cracking at the ends of the splines (like the good old 10 spliners do) and failing.

So which is better - very hard to tell cause I think they both perform very similarly for different reasons - jac mac has the better design and maxi has the better material.

IMO jac mac makes the best selectable locker in the world and do amazing things with rover diffs. jac mac can build a much, much strnger diff for your rangie than maxi could ever hope to do.

But comparing 24 spline to 24 spline axles they are both very similar.

Sam

[landy_man]

is Sam the man or what....

your knowledge never ceases to amaze me

thanks for all the info

[DiscoDino]

Hat's Off to that Sam...Hat's off.

[TUFRR]

Thanks Sam

I'll pull my Front locker down on the weekend and if the Jac Mac axles are not twisted i think i'll stick with his lockers Front and Rear and put the maxi in the Wife's Rangie.

[rangemann]

how much is jac mac paying you sam?
i'm sold.
but also cause i reckon you truck looks like a beast, so you must know what you're talking about

[Strange Rover]

Thanks Sam

I'll pull my Front locker down on the weekend and if the Jac Mac axles are not twisted i think i'll stick with his lockers Front and Rear and put the maxi in the Wife's Rangie.

The twist in the maxi probably wont worry it (because of the ductile hytuf ability to deform without cracking). If the jac mac axle had a twist in it like that then chances are that it would have small cracks at the start of the twist in the spline and would break off fairly easily.

Thanks for the compliments guys I guess I have a good interest in this strength and breakage and stuff and is probably why I run mog axles.

Sam

[Strange Rover]

how much is jac mac paying you sam?
i'm sold.
but also cause i reckon you truck looks like a beast, so you must know what you're talking about

It could almost be like that but it isnt the case. Have bought a bit of gear off jac mac which is funny bacause everyone up here uses maxi drive stuff (his shop is only 30min from my place) and maxi is such a great bloke to talk to and jac mac can be a bit difficult to talk to at times.

Sam

[TuffRR]

I certainly agree with Sam on this one. I have a Maxidrive in the back and McNamara in the front and have no complaints with either.
I think if Jack brushed up on his customer service skills, McNamara would be a lot more popular. At least his website somewhat makes up for it.

[Slunnie]

Sam, I assume then that the Maxi would be stronger again if he machined the axle down to the minor diameter of the splines also? Is this something that perhaps could also have been the reason why the earlier Maxi's were having failures when using the EN2? material where the JacMac's were not? A bit of speculation hey! I'd be interested to know why Maxi doesn't do this. Another thought is how would fatigue failures differ (I assume theoretically) between the 2 axles with the differing flex in use and ductillity of materials?

[Strange Rover]

Sam, I assume then that the Maxi would be stronger again if he machined the axle down to the minor diameter of the splines also? Is this something that perhaps could also have been the reason why the earlier Maxi's were having failures when using the EN2? material where the JacMac's were not? A bit of speculation hey! I'd be interested to know why Maxi doesn't do this. Another thought is how would fatigue failures differ (I assume theoretically) between the 2 axles with the differing flex in use and ductillity of materials?

Very good points. I think the maxi axles would be better if he machined them down a bit although I guess this would cost more to make this way. Also a lot of people believe that if the axle is bigger in dia then it must be stronger. This isnt necessarily the case because in this situation a thicker axle puts larger loads on the splines in shock load conditions (a spinning wheel hits something solid) and bound up wheel conditions (when one tyre is forced to do say 1/2 revolution while the other one doesent turn). In both these cases a more flexible axle is easier on the splines. Obviously the bigger the diameter of the splines the better and you really only want to neck the axle down to the min dia of the splines because if you go smaller than this then you are reducing the overall strength under constant load conditions for the shock load and bound load conditions.

Interesting comment about a poorly designed EN2? causing maxi failures - could definately be a contributing factor.

Fatugue strength of both axles again comes down the the same thing maxi's better material vs jac mac better design. It also would be a hard one to call.

An interesting point is that some axle manufactorers that use very strong allow steels (like 4340 or 300m which are very brittle and therefore can crack and fatigue badly) will actually neck the axle down further than the minimum diameter of the splines for a short region after the splines end so that the spline loads are introduced into the body of the axle as smoothly as possible reducing stress concentrations that could cause cracks to start.

For hard core 4wding axles they generally dont neck the axle down this far (they generally just make them like jac mac) because long term fatigue strength isnt as important as the one time overload strength. They still machine the axle down to the minimum spline dia to get the most flexible axle without reducing overall strength.

Flexibility of an axle is also the reason why full floater axles are so much stronger than semifloater axles. A full floater axle can be skinny along its entire lenght to produce a flexible axle where as a semi floater starts off very thick at the wheel end and tapers down to the splines to resist the bending forces of the wheel and therefore is very stiff by comparison.

Sam

[GURU]

G'day,

Sam this is excellent infomation you are giving, much appretiated.

But now I don't know what I want to buy, I did want Maxi's but maybe the Jac Mac is going to be better.

As I plan to be doing alot of rock crawling I understand the Jac Mac would be better as it would withstand the shock and bound of crawling through rocks, but under extreme situations they may break where as the Maxi may twist but not break........ hmmmm

[Bodge]

Its a great discussion...

-- Tech
-- Service

Now how do they compare on price?

[mickrangie]

Had a chat with Sir JacMac the other day...

For the JacMac air locker (unit only) $1300
For the Vac locker he said it was about the same price as the air locker....

I tried asking him a few times but he just mumbled

He also told me that he should have a kit ready in a few weeks that uses Nissian CV's and stub axles!!! would tell me how much they were

Maxi Diff lockers are about $1600 last time I had to but one.

HTH

[HSV Rangie]

Jacmac make 2 diff locks to suit RR.

1: uses the rover R&P with either vac or air locking.
2: Complete new bolt in housing using toy R&P with 30 spline axles.

1: around $1,300.00
2: Around $2,800.00

Michael.

[Bodge]

Jacmac make 2 diff locks to suit RR.

1: uses the rover R&P with either vac or air locking.
2: Complete new bolt in housing using toy R&P with 30 spline axles.

1: around $1,300.00
2: Around $2,800.00

Michael.

So you have to buy the axles and flanges on top of Jacmac's locker prices?

[HSV Rangie]

No idea about the 1300 one but axles and flanges come with the hypoid set up 2800.00
Michael.

[landy_man]

and I assume with the Toyota R & P you can choose your ratio

[Strange Rover]

Jacmac make 2 diff locks to suit RR.

1: uses the rover R&P with either vac or air locking.
2: Complete new bolt in housing using toy R&P with 30 spline axles.

1: around $1,300.00
2: Around $2,800.00

Michael.

So you have to buy the axles and flanges on top of Jacmac's locker prices?

I think the $1300 one can be run with stock axles (in the same way as an ARB locker can) and Im sure he could make the option 2 to work with the stock axles as well.

Its only the Maxi locker setup that needs the custom axle where the locking dog runs on it.

Sam

[jessie928]

bloody hell

for those prices, why dont you guys just slot in nissan diffs, if your gonna use nissan CV's.......
f+r can be had complete for 600-800$ then just slap a locker in the rear!
Jes

[Strange Rover]

bloody hell

for those prices, why dont you guys just slot in nissan diffs, if your gonna use nissan CV's.......
f+r can be had complete for 600-800$ then just slap a locker in the rear!
Jes

The price to do this doesent come close

$1300 for a jac mac locker - you wont even get an ARB air locker + compressor for that let alone shell out another $800 for the nissan diffs. And you still have to install them and buy wheels etc.

Jac mac can build rover diffs way stronger than nissan diffs so why bother swapping in something weaker. Stock for stock a nissan diff is better but when you start looking at upgrades you carnt buy a thing for a nissan diff.

Rover diffs are where its at. The only diffs that have more aftermarket support are Danas and you can build a rear rover to the same spec as a 35 spline d60 and you can build a front one to D44 spec with a 8in crownwheel (toyota) or an easier option is the toy crown with toy longfields. Both these combos are way stronger than any built Nissan diff.

Sam

[DiscoDino]

So Sam,

I'm JUST about to order the MD set of axles F/R, 4.11s, 4.3 RC kit, AEU2522 CVs, and the accompanying stuff...now I am about to reconsider.

Since I'll be importing the whole lot from Austrailia, what do you advise I run? I can easily slap in Mog axles (have a set that I can purchase cheap), or even 2.5Rockwells (in the yeard for a future project), however, I want this Rover to be for comps and the likes, necessitating the use of Rover differentials.

Your advice would be?
BEST SET-UP:

[Strange Rover]

So Sam,

I'm JUST about to order the MD set of axles F/R, 4.11s, 4.3 RC kit, AEU2522 CVs, and the accompanying stuff...now I am about to reconsider.

Since I'll be importing the whole lot from Austrailia, what do you advise I run? I can easily slap in Mog axles (have a set that I can purchase cheap), or even 2.5Rockwells (in the yeard for a future project), however, I want this Rover to be for comps and the likes, necessitating the use of Rover differentials.

Your advice would be?
BEST SET-UP:

Very tough question.

What you have got there is the best setup that Maxi can build.

Now if you went jac mac setup you would have something like jac mac 30 spline axles, hypoid centres (that run 8in toy crownwheel and pinion) with 4.1 gears (or 4.3s or even the 4.88 are quite strong), longfield toy CV joints and jac mac lockers.

Now I think the jac mac option would be a lot stronger because of the toy 8in crown and pinions are a lot (jac mac says 3 times stronger and I tend to believe him after what my toy mates do to their axles) and the toy longfields are lots stronger than the rover 110 CVs (again from what my toy mates drive)

If you go by what the US guys do the Maxi setup will be marginal with 35in tyres and the jac mac setup is good for 38s.

In either case you will still break stuff.

The maxi setup you will easily break the crown and pinions in one time overload conditions. And the landrover CVs will eventually fatigue no matter how carefull you are and you will also break them in one tme overload conditions as well. The problem with breaking the CVs is that you will almost always loose the inner axle as well. Guys in Aust running this setup break cvs and crownwheels all the time in winch challenges - you hear of at least one major breakage per competition out of say 8 rangies that compete (please correct me if Im wrong here guys cause this is just my opinion)

Now I dont know of anybody that is running the full blown jac mac setup including running the longfields. But basically this is equivalent to the absolute best setup that the US toy guys run with the exception of running a low pinion in the front (as opposed to running a high pinion but jac mac doesent offer this option). This setup on a toy would be the same as full alloy shafts all round, full floater rear axle, longfields and V6 centres (which are stiffer than the 4 banger ones). Have a look at what toy guys running this sort of setup get up to. You are talking warm 350 chevs, dual transfers (better than 100:1), ARB or detroit lockers and up to 38in tyres. Now these guys do still break CVs, inner front axles, and some crownwheels but they do make the rover guys look very weak.

If I was going to do everything and spend $$$$ then I would go the jac mac route but there are ways of doing pits and pieces more cheaply such as using toy 3rd members and redrilling the rover housing etc like myself and a few others have posted about here. It also looks like a short side front toy axle is the correct lenght for this conversion as well.


I would still get the maxi 4.3 gearset for the transfer though!!

Sam

[Britswed]

Gday DiscoDino

New to the Forum but have been watching this discussuion with interest!!

Until now didn't know alot about Mac stuff??But thanks to Sam(gday Sam)that is changing

We have been running Maxi's for awhile & also sell a few as well,so far to date only had two failures one in a mates car where the long rear axle twisted when the crown wheel & pinion let go(due to his lady keeping the foot into it lol) and mine at round 3 with over 500,000km on the original crown wheel & pinion said enough is enough.The axles on mine showed no signs of twisting yet!!!But agree with Sam would prefer an axle to give abit!!! Would much prefer to break an axle than a diff

In the front i run a ARB air locker with Maxi axles & flanges with the heavy duty cv's so far since going to the bigger cv's have not had a breakage,but when i was running the other cv's with disco axles as Sam said it would chew out the axle as well.

Mal at Maxi also replaced my mates axle free of charge,his customer service is great

Cheers Malcolm

[DiscoDino]

Thanks guys, that was a nice explanation.

Sam, your points are well understood, and it seems that for tougness, JMN is the way to go.

The 4.3 RC kit from MD is a DEFINITE thing I'll be getting, so that is a constant.

Another variable in my decision making is abundance of spare parts and ease of trail fixing (I live in Lebanon...MD/JMC is NOT round the corner unfortunately). If you are telling me that the weak link with the MD is the AEU2522 CV, then that is actually GREAT, as the Lebanese Military use them, and there are a LOT of them VERY VERY cheap (~55USD), and changing one is not THAT hard. However, if you are telling me that each time one blows it takes the inner axle with it, that is a bad thing, but at the price these are at, its not THAT bad, and I'll order a spare set from MD.

The rear axles of the MD are also interchangeable with the stock ones (same size), and a spare set is not that expensive.

On a whole, I do understand that JMC is the STRONGER option, however, Toyota parts a extremely RARE in Lebanon, so MD "may" be the better option for me, especially that I already have both ARBs RD56s (unless I can also reuse them with JMC?)

To tell you the truth, I have a VERY bad vibe about JMC simply becuause they have never replied to my emails (ok, maybe once), and they don't seem to be too friendly, whereas Mal/Paula and I have corresponded very frequently, and he even called me up once to ask me whether or not we are good to go (I was still debating on the rear Salisbury swap...). THAT, my friends, is a key reason to go for MD and not JMC...unfortunately...

Thanks again...Sam, any input on the above would be VERY helpful.

[v8grunt]

sorry to put in a wammy, but the photo of the axles look much like they are maxidrives old axles whick where made from en25, they were only somewhere between standard axle and hituff in strenght. i have broke one of mals old en25 axles, broke it at the outside part of the lockinf dog spline. so you should check if they are infact hituff.

glen

[Strange Rover]

sorry to put in a wammy, but the photo of the axles look much like they are maxidrives old axles whick where made from en25, they were only somewhere between standard axle and hituff in strenght. i have broke one of mals old en25 axles, broke it at the outside part of the lockinf dog spline. so you should check if they are infact hituff.

glen

Doesent matter if the pic is of an old maxi axle - he still makes them the same way.

EDIT - he still machines them the same way!! except now he uses hytuf.

Sam