4 wheel steer diffs

[hellbilly_racing]

Hi,

I'm building a fun offroading vehicle based on 2 XJ Dana 30 axles under a jeep chassis. The power comes from a 2.8 turbo diesel so isn't too savage! The truck will be purely offroad and has a trailer to transport it around. Mainly used in the mud and gravel, so no rock crawling!

What I need is advice on diffs; in the past I have had good success with welded rear diff and open front, but I don't know if this knowledge transfers to a rear steering axle. Based on the stock spec Dana 30s, relatively low weight and power and the fact that it will run 35x12.5x15 mud tyres, what would you recommend for a low budget, non competitive, traction aid, both front and rear? I would be happy to weld the rear up if it won't have an adverse effect on rear steering, and would like to fit something in the front...

Thanks

[hellbilly_racing]

Doh! Sorry for other posts, Pirate4x4 was hanging for ages and not posting my thread, at least that's what I thought. Typical impatience, lol

[NetBSD]

if it steers, dont weld it, it will act the same as a locked front, wont turn worth a shit, go open or a selectible locker

[hellbilly_racing]

Ok, that's what I thought, but wanted to be sure... :)

What lockers can anyone recomend for the Dana 30?

[p575]

if you lock/weld a dana 30, and run 35 inch tires...your gonna go boom

[hellbilly_racing]

Ok, so I accept that the D30 is no D60, but I'm talking about low speed wheeling with a 140bhp turbo oil burner for power. I've been looking around and the soft locker option seems best for a steering axle. I have decided on 4.88 to get the ratio as low as possible and always have the option of upgrading to cromo shafts if breakages become a problem. I've seen lots of reference to XJs wheeling on 35s with 4.0 petrol lumps, and they seem to keep it together?

Any thoughts?

[GAredClaYJ]

This sounds interesting, make sure you post some pics up when you complete it. I kinda want to see this.

[jesster]

Ok, so I accept that the D30 is no D60, but I'm talking about low speed wheeling with a 140bhp turbo oil burner for power. I've been looking around and the soft locker option seems best for a steering axle. I have decided on 4.88 to get the ratio as low as possible and always have the option of upgrading to cromo shafts if breakages become a problem. I've seen lots of reference to XJs wheeling on 35s with 4.0 petrol lumps, and they seem to keep it together?

Any thoughts?

XJ's also have d35 or 8.25 in the rear.

d30 gearsets are tiny, don't know how long they will hold up in a rear application, but my guess would be not very long...

Little unit bearings in the back would suck too...

Its just a bad idea, might want to rethink your axle selection.

[ShaggyDoo]

It's not hard to break stuff going slow... That D30 rear with a turbo diesel isn't going to last long under anything heavier than a go-kart.

[Pietro]

Why would you need rear steer for a non rockcrawling application anyway?

That diesel doesn't put out much horsepower but I am sure it makes a decent amount of torque which won't last long with any small axles. Just think when it is bound up and you drop it into gear what will happen.

Stick with some larger running gear off a bronco or jeep waggy

BTW, if you used two front d30 axles off of an XJ, you would have the diffs on the opposite ends which would make some interesting driveline problems.

You could use a high pinion XJ frontend in the front of the buggy and maybe a low pinion CJ frontend in the rear which would then the on the same side as the XJ axle. You would of course have to convert one of the lug patterns.
Maybe use a D18 or land cruiser tcase (I don't know which ones are offset to the driver side. You would have to search. That shit is older than me!) I think the cruiser is on the pass side but the D18 may not be.

[hellbilly_racing]

Why would you need rear steer for rock crawling, even? How about better manouverability? I mess about in the woods mainly and some of it can be real tight and tricky.

If you really think that the D30 is a bad choice then it's made asking the question worth while. My other option is to sling a pair of Toyota pickup axles under it... Would you rate the toyota 8" over the D30? If so I'd appreciate the knowledge :)

The last thing I want to do is start asking for advice once I've made the key decisions!

I think it needs to be made clear that I'm not in the US but the UK, so don't have access to the killer axles and aftermarket that you guys do; sure I could open a check book and import a load of bits, but that sort of defeats the point of the thing! Point in case is that the Cherokee is easy to get parts on here and is really cheap, Jap stuff is sought after and commands a price, Landrover stuff is everywhere but I don't rate it and my personal favourite is the Daihatsu Fourtrak which is really tough, but no aftermarket, not even a locker :(

So, there you have it... I once ran a toyota Hilux on 38" with a 3.5 V8 and the axles just laughed it off, so I'd like those, but after seeing these XJs on 35s I thought it might be worth a look.

Armed with that information, what would you advice be now?

[Pietro]

I think if you ran the XJ/CJ axles, I would go much smaller in motor, perhaps a 4 cylinder jeep motor

I would rather run a samurai chassis with some home made exo body or something to keep it small

or

Use the XJ/CJ axles with a FWD car engine/trans. Pull the diff out of the trans and weld it. That way it is small and light, has a lo low range ratio (no high range though it wouldn't work for mud really)

[tennessee rockhumper]

the toyota axles would be a far better choice, especially with a set of longfields. the d30's dont have a chance

[hellbilly_racing]

There is one more option that I failed to mention, though it will either be prohibitive from a supply or cost stand point, but it is possible to source Volvo C303 axles in the EU; portal, sensible gearing, lockers and lighter than Unimog units....

I'm favouring the Toyota 8" idea, but what is the equation in real terms? Is a toy 8" equal to a D44? If I was to upgrade toy shafts I would bypass the longfields and go straight to the CroMo shaft/U joint kits, though I can't remember who makes them...

Thanks for the feed back so far, keep it coming :)

[theydontstop]

I think the new longfields are stronger at much greater angles than the older ones and u-joints too.....

[84xcabyoda]

my suggestion is to read around a little in the toyota section about the axles. with the longs in them they are comprable in break strength to a d60. the u joint conversion is not worth it for strength. my .02

the volvos would be first choice
toyotas second
dont think you really have a third cause the d30's will never last

[American]

Volvo portals would be :smokin:

DO NOT go d30. That is just dumb, I'm sorry. Atleast go d44 w/ those 35's, man!

[Rockhales]

the toyota axles would be a far better choice, especially with a set of longfields. the d30's dont have a chanceX's 2, 30R=:barf:

[Tjeepfreak]

The d-30 on 35's can be done I had a welded d-30 on 35's on my Tj but I just kinda wanted to see it blow up before I put the new axles in But nonetheless they held up for awhile, but I really agree with everyone else I would atleast go on up to d44's or something I'm sure other better axles can be had for cheap, I mean really atleast for the rear, ah hell with it I say Build it with welded d-30's at both ends and take video It should be fun to watch :nuke: :laughing:

[wheelerpeeler]

the toyota axles would be a far better choice, especially with a set of longfields. the d30's dont have a chance


Go with the toy with 30sp longs. I run them hard with good reasoltes.

[tennessee rockhumper]

If I was to upgrade toy shafts I would bypass the longfields and go straight to the CroMo shaft/U joint kits, though I can't remember who makes them...




longfields are way better than a cromo and ujoint.

i wouldn't consider any other axle upgrade for a toyota when longfields are available at a comparable price

[hellbilly_racing]

Thanks for your help and advice everybody...

I have taken everything said here and elsewhere and come to a rough decision!

I think that given the time and cost implications I'm going to do the folowing;

Build up a Toyota front axle with Longfields on stock shafts, with the option of going to cro mo shafts should I need to. Also some kind of soft locker.

Take a standard Toy rear axle and weld up the diff.

Locate both axles with a three link of my own design; symetrical front and back, with one locating arm pattern and one panhard rod size doing duty all round (simplification and standardisation of parts). Coil overs at each corner (10" Stroke).

The logic at the moment is this; I can put it together with conventional 2ws and coiled suspension. Then at a later date the built front axle will be joined by a simarly speced rear steering axle that will share the same brackets and bolt straight on in place of the solid axle. There are other ideas that I want to try out on this 4x4 too but the need for a good quality, reliable base running gear would allow me to concentrate on the R&D aspect without having to fix my junk whole time!

Your thoughts please.... :)

[hellbilly_racing]

Oh, and incase you're intrested; here's the donor vehicle...


http://img.photobucket.com/albums/v621/hellbilly_racing/F77.jpg


Now I know most of you won't of seen one of these before, and let me tell you, there's not many in this country either!

It's a 1988 Daihatsu Fourtrak F77 Pickup. The engine is a 2.8 Turbo Diesel, and is a really tough unit, probably stronger than anything Toyota ever made. The drive train is made by ASIN; the same people who do drivetrain for Toyotas of a similar age. The axles are fixed 3rd member style with 3.33:1 though 3.9:1 was available in the petrol. It has a 5 speed box with OD, a single piece married trans case with 2 speed gear reduction; hi 1.3:1 Lo 2.37:1. The front output is on the same side as a toyota pickup. The front and rear outputs are both bolt on flanges. As you can see the truck is leaf sprung. The chassis is mandrel bent 2x4x0.2" box section with tubular cross members.

For my own project I will be retaining the cab, as it gives it character and identity, and making up an exocage and roll structure over the rear bed. The chassis won't be used as I all ready have a buyer for that, but I have a front half chassis from a station wagon model, so all the cab mounts, engine mounts, steering box bracket, trans crossmember, ect are allready in place. Then I will make the rear out of box to suit the suspension arrangement.
The current drop side bed is to be removed and is also going to a new home! It will be replaced with a basic flat bed for the spare wheel and recovery gear. The bed will also house the radiator, to protect it from damage and blockage when wading in water and mud.
The wheel base is currently 112", so this will be shortened to 100", which is about the min without the rear tyre catching the cab.
Moving onto the drive train, the standard 2.8 and transmission will be kept as they are tried and trusted. The turbo may get upgraded to a more modern unit, to aid spool up and tweek the boost up a bit. I will also add an intercooler should space allow.

Any more questions or advice would be gratefully recieved :)

[Pietro]

First off, how did you go from wanting two steerable jeep axles (which would have had opposite dropped diffs with what you proposed) to a set of toyota axles:confused:

I think you need to figure out what the hell you are building before you ask for more advice. Being that axles are going to be dependant on the tcase outputs and vice versa, you need to gather what tcase you are going to use before you decide on what front axle you are using. All of a sudden, this extreme budget build is going to be very expensive if you need to purchase some custom adapter to make a tcase work with what axles you decide to use. So do you want 4 wheel steer or not?

You really don't need a set of 30 spline longfields to run 35's on a lightweight buggy that won't ever see rocks. Thats crazy. From the other post in the toyota section, the 30 spline birfs aren't going to fit the stock inner shafts which are 27 spline. At most, you will need a set of treated birfs from marlin or bobby if you are locking the front.

[hellbilly_racing]

I totally agree; although I think I need to ask advice before I fgure out what the hell I'm building...

Your right, there has been an about turn in the project, but only because of asking questions. I'd far sooner be shot down by you for asking dumb questions, then revising my choices based on new information, than being shot down for saying 'look at this I've just built' before being told where I went wrong and filling me with regret ;)

The truth is; yes I do want 4ws, but the research I'm doing has led me to decide to do it in stages. Basically put it together in 4wd 2ws mode, but with all the infrastructure there for a steering rear axle, rather than decide at a later date to cut the backend off and start again, hence why I will be building a well specced front axle and a literally standard spec rear.

The idea of budget is somewhat misleading, because I'm happy to put my hand in my pocket for something that I think is good value, regardless of cost; so it's probably more accurate to call this a value build up, where all money spent is due to careful consderation of application and available solutions on the market.... Basically, I'm trying to avoid BS'ing myself about what I need, because that will turn into a high budget build :)

I don't think I've ever mentioned running 30 spline birfs, and even if I do go with Longs (which I may) I will stick to 27 spline stock shafts.

Anymore, for anymore?

[Pietro]

there is no way to do cheap rear steer unless you want to use a front dana 60 (because they are available in both side drops) and using a offset rear output tcase (like the dana18 or land cruiser, or samurai but too small)

at that point, you will have a 1 ton rear with 8 lugs and huge brakes that is very heavy and wide and you will have a lot of money invested in a front toyota axle which is very narrow and six lug

the only cheap 4 wheel steer driveline I can think of is using a LC tcase off of an FJ cruiser (pass side drop both front and rear I believe or the dana 18) and use a GM dana 60 up front and a Ford dana 60 front axle for the rear

Both diffs will be on the passenger side. One problem is that the ford dana 60 is a high pinion diff meaning that the pinion will be driving the ring gear on the weak side when used as a rear axle IIRC. Shouldn't be a problem on 35's but will if you go to like 39's. You could try to find a low pinion Ford dana 60 front axle, I don't know if it exists, try searching. Ford is the only driver side drop front axle that would work, Dodge is pass drop fronts. You could use a set of dana 44s. A GM dana 44 or 10 bolt (which are plentiful) up front and a ford dana 44 used in the rear. You will probably have strenght issues with the dana 44 axleshafts in the rear if they use the smaller 260x ujoint though. Easily upgradable though.

regardless of what the toyota board says, you dont need 30 spline longs. everyone there runs them including myself because they have huge tires with rediculously low gearing and locked front axles. You aren't going to have any of that by your driveline description. Its a waste of money at this point. At worst, buy a spare set of birfs (you can get stock birfs anywhere, shit I've got a whole set of stock inners/outers and longfield outers/stock inners laying around, anyone else running longs will have extras). If you start popping birfs with 35's, then you may want to upgrade. Longfields are for rockcrawling mind you. Plenty of people ran 35's on toyotas back in the day with stock birfs and never really had a problem. They just won't survive on a rockcrawling rig with a 100:1+ crawl ratio.

[ROBULUR]

why dont you run the dahatsu as is it looks like some potential

[hellbilly_racing]

Right, I'd like to answer the last question first, as it is the easiest!

The stock Daihatsu parts are really strong and myself and some friends wheel them very hard, with CVs being the inevitable casualtys. The only problem is total lack of aftermarket representation... The hotest upgrade is the 3.9 diffs from a petrol; that's it! Everything else you have to make your self... At a later date I would like to look at the possibilty of manufacturing and marketing some simple stuff such as lunch box lockers and steeper diffs. But for now my time and money is tied up in my projects :)

Thanks for you advice regarding Longs; I think I might just try stock Birfs to start, maybe get some restraining rings machined up locally and sweat them on. Read my last post again though; while I accept that there is no cheap way of doing this properly, there is a value judgement to be placed on the whole project and all components in it....

The Daihatsu trans case has both outputs on the right hand side, like a landcruiser...

At the moment I'm really honing in on what my truck needs to perform and it would seem to involve the following spec:

Front Axle
Toyota 8" - stock shafts, Birfs or Longs, lunch box locker, Landcruiser HyPinion diff, 5.29 reverse cut diff, hub eliminators, home made hi-steer.

Rear
Toyota 8" - stock shafts, welded spool, stock 4cyl diff with 5.29.

Suspension
Daihatsu PAS box with crossover, 3 link and panhard front and rear, 10" stroke coilovers, 35x12.50R15 on steels

Of course there's a lot more beside this, like cage, winch, underbody protection, sliders, ect, but this gives a good idea of where it's going...

All thoughts and sugestions gratefully recieved...

[Pietro]

why link it? It sounds like what you are building is a flexy trail rig, you just need to add the crawler (maybe not if that diesel has some real bottom end nut)

[hellbilly_racing]

Yes, I want it to be flexy, but I also want it linked because I reackon there's as much work in fabbing up brackets for Hilux springs and shackles as there is in fabbing brackets and links for the coils...

The Daihatsu lump is all bottom end; it's no modern short stroke revvy diesel!

As for ratio, by my calculations I have shifted the gearing so that Hi 1st will be equal to low 1st standard; roughly a 40% reduction... Low first comes out at 45:1 with 5.29 diffs, which is more than acceptable for what I will be doing...

[hellbilly_racing]

Just looking through the Toyota threads and came across this truck, which is pretty much the format I'm looking for myself; minimal or zero overhangs, low CoG, Exo.

Obviously won't be exactly the same but gives a general impression.

http://tellico.off-road.com/wwwthreads_uploads/1330714-Pete%20Under.jpg

Which makes me think of another reason for links over leaves; shorter chassis....

[hellbilly_racing]

I'm thinking I should start a build up thread for this machine as it won't be long before I start getting into it again...

What catagory do you think it belongs in? Toyota because of the axles or General because it's a Daihatsu? :)

Will take some pics this evening on my way home as the truck is in the barn at my mother in laws.....

[Mudplugga]

Hellbilly
I've seen you on some of the Daihatsu forums I think ?

I agree that Yota axles are probably the best option.
I have a Dai' based trialer, well it uses the g'box and transfer box with Range Rover axles.
I've also got an old Yota LJ70 that's going to be chopped when I get time, and the diff offset is right for the Dai' drivetrain. They're strong 8" axles with LSD in the back. LJ 70's are on the Auto Trader site dirt cheap as well.

Where are you ? I'd like to see your creation when it's done.

Mudplugga

[hellbilly_racing]

Hi Plugga, you have probably seen me on Difflock, giving advice to Daihatsu owners.

Toyota axles were part of the original plan, but what with the abundance of dead cherokees around I thought I'd test the water...

I'm In Warwickshire, near Stratford... Yes; where Shaky comes from :rolleyes:

You can keep track of my junk when I start posting the build on here, and if your ever over we could go wheeling sometime?

If you trial then you probably know my buddy Matt Calladine? He runs the yellow Daihatsu axled suzuki trialier with an Allard turbo kit on the 1.3....

Great to hear of more people wheeling Diahatsu junk :)

[Mudplugga]

I thought I'd seen pictures of your truck before.

I'm up in Ironbridge, home of that other great tourist attraction, and trial with the Mid Wales 4x4 Club. We've got some of the best sites around :smokin:

Here's a link to our unnoficial web site

http://www.midwales4x4.proboards55.com/index.cgi

Mudplugga