[Mike harris]

My names mike, I have a samurai I run very large tyres

Have a fully float rear axle. I've just broken my 10th shaft, truck run large tyres

I don't want to do an axle swap so please just fully float upgrade ideas please

Anyone know a spool that fits or can be made to fit then custom shafts made?

Or does anyone do a kit? I don't have air lockers and don't want to head down that route, please advise,

Any help would be much appreciated

Some pics of broken shafts some 300m some have been chromo, I'm not sure of the material of the shattered ones, but it doesn't look much good.

[Mike harris]

Info I need is about lockrite or lunch box lockers

Can the side gears be changed for the Dana 30 ones? 29.5 shafts would need the spindles milling out, and custom shafts making, but I've already had lots made that have broke, just wanted to know from your experiance how much stronger they are?

Axle casing should be strong enough, I used to wonder if it was the case moving allowing the shaft to be twisted, but have always broken just on the outside of the side gear.

[alien]

How big are the tyres, and what reduction gears are you running???

If I had to hazard a guess, you're unlocked and undergeared and hitting shit full speed, which is what's causing a lot of the breakages =)

Gwagensteve's Hedgepig build is worth a look.

[Gwagensteve]

Check the thread in the rigs section. It’s a winch challenge car on 38’s.

[Gwagensteve]

Don’t have time to write a detailed response at the moment. I’ll get onto it soon.

[Mike harris]

38.5 mud treps, 6.5 trail gear tbox 5.38 diffs

Never use in anger, do everything at pretty much idle, I'm not interested in speed, we crawl if that doesn't work we winch.

Truck has twin lockers lockrite front and rear.

[Mike harris]

Any help would be much appreciated, I'm trying to by a Dana 30 axle to take part to look at sizes of the side gears and diff centre, and the shaft size to check will go through the suzuki side bearing.

[Gwagensteve]

Like I said, short of time ATM but perhaps you can help me with a couple of quick answers.

Are you obliged to keep the Sierra housings/centres because of the rules of your competitions?
How are you planning to deal with the spindle? A larger axle won’t pass through the suzuki spindle, so that raises issues that need resolving about spindle choice, wheel choice, brakes, and spline choice/pressure angle etc.

Have you experienced any ring and pinion failure? Be aware that dramatically increasing axle strength will force the failure up the drivetrain. Most likely that tiny 5.38 pinion will be the next point of failure.

[Mike harris]

Hi there, thankyou for your reply,

Yes need to keep the samurai housing, paid a lot for it and got lots of spares for these axles and I have custom wheels made for suzuki / jeep pcd

I'm going to change diff ratio to sj413 so 3.9 to one, this will make my high range box un usable but I only use low anyway, and I use 3rd and 4th gear currently.

The zanfi kit from Italy uses a 29.5 mm shaft, side gears for an arb, not sure which as they are a very low spline count, they advise you machine out the spindles 1.5 mm I think, so must be do able if they are selling the kit.

Dana 27 spline is what I heard tim hardy did many years ago, so I'm thinking of going down that route, has anyone fitted larger shafts into a samurai casing? I seen a few people to it to the vitara / sidekick rear axle with the larger diff, but the centre is very similar? I thought anyway.

I've had a fully float axle now for about 8 years not had issues up until I went into mud treps, 37, 38.5 boggers didn't have the grip or the aggression of the mud treps, they seem to bite and come to a stop, which I guess is how stuff breaks !

[tanshi]

I think you are going to waste alot more money chasing this line of enquiry than you will just getting rid of the zook diffs and putting something bigger in.

you could sell the stuff you have for a reasonable price, and the wheels, and trade off for toyota diffs. They are going to do alot better job than zook diffs ever will on 37 treps.

I understand the need to chase that dream but in the end you are asking for more from the zook diffs than they can give you.

[tanshi]

for what its worth I looked into this. H3 hummer arb airlocker side gears. 28 spline. cj7 spindles, and hubs with 27 spline drive flanges.

I know others are looking at 30 spline dana44 33.3mm hubs spindles and side gears with a machined locker to suit. This will give you 33.3mm axle shafts that will hold up but will be alot more expensive than it will be worth

[Gwagensteve]

Agreed.

I should have time to put in my 24c worth this evening.

[Mike harris]

Thanks for your advice, I completely agree a change of axle would be the best option, but that's not what I'm trying to achieve, I have toyota axles here in multiple cruisers and hilux's I own, I'd like to push the suzuki axle a bit more !!

Like I said housings have to stay has to be a samurai diff, so advice to get to that goal would be awesome.

So there are suzuki options, and there only what what I want to do, the expense or the modification required is no problem as long as there is some improvement

I was told about a guy on here who made a thread about a vitara housing with custom shafts 300m does anyone know if he increased the side gear size?

Does anyone know why tim hardy did all those years ago? Has it ever come to light his rear axle setup?

I'm grateful for any advice people are willing to share, it's cool people have experimented and tried stuff

[Gwagensteve]

My car runs vitara housings with 300m axles. They’re 26 spline and I can break them readily with 35’s. If I put the whole sidewall of the tyre on the ground I’ll take out an axle.

I don’t understand stepping up a tiny bit to 27 spline or something. If money is being spent on machining and axles the problem needs to go away, so the result needs to be a 50% + improvement. You’re getting away with what you have because you’re predominantly on a low traction surface. If you wheeled on high traction surfaces you wouldn’t get anywhere with that tyre- you’d be taking axles out every obstacle. You need some headroom. The difference in cost is going to be insignificant between it being a little bit stronger at 27 spline or something and bored spindles (ewww) and 31 spline and forgetting about the problem.

SJ centres are tiny. If you had a custom spool machined you could probably step up to 30-31 spline, but that won’t clear the spindle, and you’re stuck with tiny gears. Going to 3.9 will hold the pinion together at the expense of the transfer case. For a given task your loading the transfer and driveshafts ~40% more.

Boring the spindle seems like a dumb move. I measured it up and there’s no way a useful increase in bore could be achieved without significantly compromising the strength. Maybe Zanfi get away with it with small tyres on a Jimny but it’s not a solution for you.

I’m lightening my car and going from 5.12 diffs to 4.6. (Vitara rear front and rear) I’m also straightening my rear housing as it’s warped through welding and I believe that’s loading up my short side axle and weakening them. If that doesn’t work I’m not going to bother with some kind of hybrid centre, I’m going to put Toyota third members in it as they fit in a Vitara housing with a 3mm spacer on the mounting flange. Then I can run a full spool. I’ll probably go to unit bearings at the same time. I want to keep the same wheels all round so I need to keep the 5 on 5.5 pattern. I also don’t want heavy brakes and want to keep light housings.

I fully understand wanting to stay suzuki- It’s exactly what I’m trying to do, but I’m on 35’s not 38’s. You need a 30-31 spline axle and that’s going to wipe out pinions because you’re going to loose a lot of give in the axles. Bigger axles won’t twist as much to absorb torque spikes so that load goes into the gears and/or is otherwise transmitted upstream. It’s the same reason shortside axles fail much more readily- they don’t wind up as much to absorb torque spikes.

Notice I’ve largely avoided your question though about running a larger axle through the SJ centre. I genuinely believe it’s throwing money away (and lots of money at that) you need more gear strength and more spindle to end up with a reliable outcome. Boring spindles and incrementally increasing axle strength (at the expense of spindle strength) isn’t going to get the job done.

[Gwagensteve]

Oh, hardy ran a hybrid vitara centre ford rear axle spline . It wasn’t Dana based.

From what I’ve seen, he breaks driveline all the time. I don’t think that’s the gold standard.

[Mike harris]

I see exactly what you mean, I'm going to explore a few options, I might just order the zanfi kit to have a look at it and work out what spline side gears they've used, in the meantime il have some 300m shafts made to make truck usable I've lashed up some Tempory ones by grinding down a long shaft and pressing a flange on then welding around both sides lol ! Its usually the short shaft that lets go.

I'm going to have the next shafts made with a cut in them almost like a weak point for them to hopefully not break of in the diff.

I carry an x eng magnet in the car for fishing out the broken shaft in situ, I quite often remove it then carry on using the car.

[Gwagensteve]

Are you sure the housing is dead straight? The axle will break at the edge of the spline but it might be at either end. Ours have always broken at the hub end.

Across the group of us who have broken floaters some have had properly trued housings and some haven’t. Still always failed at the hub end.

Makes me wonder. It’s not the cause of your problem, but it might be contributing.

Fairly easy to check roughly by putting bare rims on the car and measuring edge to edge.

Out of interest, do you have a weight for your wheel and tyre combination?

[Mike harris]

I agree I thought that too but Yeh axle is straight I've checked a few times now suspecting it would be warped, I painted the shafts which are in it currently to see if under use it moved and would pick up and scuff the paint but it's all ok, both shafts sit perfectly in the spindles, when axle was trussed was held in a jig, tubes welded on the inside to stop warping during welding, and welding was carried out over about 4 hours, previous axles I've trussed have warped during trussing so learnt my lesson, I didn't truss the axle a man did for me who builds ultra 4 buggies.

The shaft I broke last weekend I think has broken hub end, in yet to take it out to look at it, my girlfreind was driving at the time !

[Mike harris]

Wheel and tyre are very heavy yes, not weighed them but I can barly lift them !

Again It's not used in anger, just crawls but i am fully aware about the loading and leverage they put on the axle and what the shaft is up against to turn them !

[alien]

What about figuring a way to bolt/graft on some portals and create some reduction at the wheels themselves?

[tanshi]

if money is no object, talk to jesse haines about some hummer portals. there are dudes running zook diffs on them with 42" stickys on rocks i believe.

[missmyljdaze]

tanshi wrote:

if money is no object, talk to jesse haines about some hummer portals. there are dudes running zook diffs on them with 42" stickys on rocks i believe.

no idea how good, or how much coin is needed to get them - but there is a company in India making zook portals [and cable operated lockers.]

[Gwagensteve]

If they exist there’s absolutely no way they’re going to be a solution for this car. The one photo of a portal on their website isn’t for a suzuki.

[Mike harris]

Thanks for info portals sound cool ! Wish they where an option !

My truck is already way to high as it is any higher and it would be ridiculous !

The idea of my thinking was to find an upgrade to my current setup without changing the axle casings, and wheels, that's all I want to do tonne honest, there the two components I'm not willing to change, happy to modify the casing as in the diff casing but not change it, so to be honest the options are limited as we have said.

I've got a jeep Dana 30 axle on the way to strip down and look at side gears and shafts, see how or if they could be made to go into a suzuki centre.

[Mike harris]

Last couple of shafts I've broke have been the long side, pretty sure I'm now down to one of each !

So I cut them down ground the end to a taper and then pressed on an old flange welded both side just to make the truck moveable,

[Gwagensteve]

I've spent quite a lot of time mulling this over and I just can't come up with a clean solution.

You could look into a Ford D44 front spindle/hub and adapt that to your existing rear housing. That will provide a 1.31" 30 spline axle. That will probably be adequate. The downside of the ford hub is it's very long and the hub is liable to damage but your rim with and offset should prevent that being a problem.

Warn offered (offer?) full float conversions for rear D44's on Jeeps that would also allow you to retain your 5 on 5.5 rims but with a more compact hub assembly. Front spindles from a jeep might also work.

A D30 axle won't add adequate additional strength. No way. At the moment you're clearly aware your axles are very fragile and I'm sure you drive the car thinking and axle will fail readily. Spending lots of money on a very small upgrade in axle strength (and no gain in gear strength) won't allow you to stop worrying about axle strength. The D30 axles will only be 15% stronger based on cross sectional area.

a 30 spline (D44/Toyota) axleshaft is 55% stronger than a Suzuki axle, like for like. That's where you need to be. Braking axles at of just off off idle is ridiculous. I'm generally loading up my driveline with the whole sidewall of the tyre on dry, firm ground when I take out an axle and I don't think that's acceptable. you're leaving too much of the potential capability of the car unexplored because the moment you generate traction you'll take out an axle.


I don't have access to my parts at the moment, but I'll have a look at a Sierra centre on the weekend. I doubt it will be possible to retain adequate meat through the carrier bearing with a 1.31" axle in a Sierra centre, even with a custom machined spool, but maybe, just maybe it's possible. Breaking a spool (well, most likely stripping the splines though the carrier bearing) though would be a bad day out.

[Mike harris]

Thanks for the reply very interesting stuff, I'm glad you guys are willing to offer advice and information very much appreciated, I've seen the warm hub and the float kit I built a Dana 44 up for a cj2a with them on years ago, very strong axles indeed !

I've just purchased a cheap kj jeep to use the front side gears as template for my machinist to open up spline of suzuki side gears

Well he's going to try for me anyway !

Needed the jeep side gears to work from and the spline to check once or if he can machine them. All depends how hard the side gear is.

Jeep came from central London was great fun in the traffic !

Literally got it cheap so il take side gears and shaft and scrap the rest.

Be interesting to see the size of the shaft 29.5 against my ones, hopefully if it goes to plan.

Il try this route exhaulst this option, then we will go down another route when this one fails

Be another route to test, 15% is an improvement I will also heighten the gearing to 3.7 or 3.9 samurai / jap sj413 will mean I can't use high range like I can now though, gearing will be too tall.

Got an event in few weeks time winch challenge so il see if I can pop some more of the shafts I have already then !!

[alien]

Next step is figuring out how to get portals under it and lower it to suit =) Can't wait to see your progress. Keep the updates coming.

[Gwagensteve]

Portal axled builds need to be able to get the front axleshaft above the crank centreline or the end result is a car that’s way too tall. That’s very difficult in a Sierra based build as it requires significant engine setback (or a very extended nose)

[alien]

Could you clock a portal on the end of the housing to 90 degrees so it's stretching the wheelbase instead of lifting it up? Obviously all sorts of leverage issues at play but maybe? I dunno.