Which axle upgrade route to take

[James86004]

I was teaching my wife how to drive the Dormobile. It is not an easy vehicle to drive. It is manual transission, and there is no synchromesh on 1st and 2nd gears, so you have to double clutch it. No power steering, so it takes a lot of effort to steer. Kelly only has about 10 hours of time in her life driving manual transmission of any type. So, in the rocky place we were in, we were jerking all over the place, and that was too much for the weak 10 spine axles. Something broke completely in the rear, and something broke partially in the front. There is still front-wheel-drive, but there is an awful banging every wheel rotation coming from the left front. You see the steering arm on the left side vibrate a lot when it happens. We were towed out of the backcountry by some wonderful AZLRO folks.

So, I am thinking of changing the transmission to a Series 3 full synchromesh. Or maybe something else.

For the axles I have several options.
Salisbury rear, upgrade front.
Series Trek Toy conversion.
Take the 24 spline axles from the RRC I am parting out, weld leaf spring mounts on them, and install them. (this is by far the cheapest option)
Or
Install RRC axles and put Toyota diffs in them.

The last two are appealing because they give me some real nice disc brakes, and a tighter turning circle.

 

[Mercedesrover]

Well, ya-all know my vote.

Really though, it depends what you do with it and how hard you wheel. Being a 109 I wouldn't think you're doing much rock crawling but also being a 109 it's pretty heavy.

If you're on a budget, this is how I'd go:

Front: You probably just broke an axle u-joint. Replace both u-joints and leave it alone. There isn't much trouble for most people up front and you probably only broke the joint because the rear had failed first and you were asking too much of it. If you did break either the inner or outer shaft at the joint, they're cheap if not free to replace.

Rear: Pull out one of your RRC diffs and buy yourself an ARB locker and the ring-gear spacer for it. Install your 4.7 R&P into the new-style housing and run a set of 24-spline axles.

This set-up will be strong enough for most people and is relatively cheap. You'll spend may $100 up front and about $1200 in the back and will be getting a locker to boot.

jim

EDIT: Another option with the rear is to find a 4.7 T-100 diff, install it in your housing and run a set of 30-spline axles. Cost would be around $800. You could also install a locker in that diff for a total of around $1500. A little more work but you'd have a bullet-proof rear axle. I really want someone to do this conversion. If you decide to go for it, I'll knock $50 off the 30-spline axles for you.

 

[Alaska Mike]

My suggestions are based on the weight of your vehicle and my own Jeep background.

For the transmission, I would consider a truck transmission like the T-18, SM465, or a similar box over another Rover transmission. If you don't want the granny 1st, there are versions of the T-18 with a 4:1 1st gear. It would be the last transmission you would ever need to install. You would be limited to custom builders like Timm Cooper, Ike Goss, or maybe Jim Young, but they do good work.

For the rear axle, I would consider that Salisbury or one of Jim's Toyota conversions. If you're still running the 4 cylinder, you're going to have to do a gear swap on those RRC axles anyway. I just barely avoided the siren call of disc brakes myself, and with the extra Dormobile weight I expect that it is extra tempting. Isn't the RRC axle wider? I would be interested to see how the lighter Rover housing would hold up under the weight.

 

[revor]

If you desparatly want Disc's I'd do the Rangie axles and plan on converting at least the rearend to toy. You could also change to a Scout ll steering box and eliminate the steering problem and the steering relay. You will have wider axles that offer more stability as well.

On the other hand if you can live with the brakes and the steerig I'd do Series Trek..

The salisbury offers only a small gain over the rangie axle in terms of axle shaft strength, to really make good use of the massive diff you'd need to go with 35 spline axles, that can add up fast but you could get rear Disc's out of the swap.

 

[James86004]

Thanks for your input you all. 3 replies and 3 different answers! :jumping: That is great for the creative juices.

I should add that it is powered by the 2.6 liter Euro 6, which has much more torque available at the lower rpms than the 4 banger. The torque peak is at 1800 rpm. Also, the vehicle fully laden weighs 5200 lbs, according to the scale at the Ina Road Landfill.

 

[revor]

Aren't we helpful?:sombrero:

 

[Alaska Mike]

I think there is a general consensus:

• You need stronger axle shafts in the rear. 24 spline at least
• A better R&P would be nice too
• The front axle is probably sufficient

You have access to a set of axles that might work well and provide greater stability. Even with the V-6, I'm not crazy about the idea of running 3.54s. Then again, I'm going to run 3.54s on my Rover with a MPFI 4 banger, so it wouldn't hurt to give it a shot. Like I said, those disc brakes are pretty tempting...

 

[James86004]

The hard part about the Range Rover axles is the steering. Others who have done this swap report the track rod wants to go through the leaf springs, so you have to move it. Also, my Dormobile is right hand drive, my Range Rover is left hand drive, so I wil have to change something. I am a mechanical engineer, so it is not insurmountable, just more work.

 

[Alaska Mike]

Interesting. Shame you couldn't just swap housings and have everything bolt together with a little axle shaft machining. Reengineering the steering arms is something I don't feel comfortable with, especially since the RRC arms are cast on the swivel housing. Is this an ABS RRC? That might make for some more fun.

With those obstacles, I'd echo the others and fix the front and beef up the rear axle in some manner. Usually simple is better. You could always do a Torrell Industries disc conversion in the future.

 

[James86004]

Okay, I have had some time to sleep on it, and talk it over with my wife. If she can't drive the vehicle, she wants to sell it. If we lived anywhere else in the world, we would probably buy a D110 and swap the Dormie bits over. Here, D110s are a little pricey.

We talked about what we want to do with our vehicle. We want something that will take us to remote mine sites, is small, and is a self contained camper. Something that lets us cook and eat inside when the weather outside is lousy. We don't want to deal with a trailer or a roof top tent. The only other thing we can think of that would fit the bill is a Toyota Tacoma with a Four Wheel Camper on it. There are some very strong family political reasons not to get the Toyota, so that rules it out.

So, I am going to have to put some money into the Dormobile drive train. My wife really wants the disc brakes, because she has memories of going down Black Bear Pass in Colorado in our old Series III. That was where we discovered that the transfer case likes to pop out of gear on long, steep descents, and she remembers our brakes starting to smell, although I don't remember that.

I am going to make a few phone calls to get some more information.

James

 

[Yorker]

You could also swap Toyota Landcruiser axles under it completely replacing the LR axles. Depending what year you chose you'd get disc brakes too- a swap to rear discs is cheap. FJ40 & 55 axles are essentially the same width as LR axles, FJ60/62 are slightly wider which could be an advantage on side hills. FJ80 axles have been swapped under some series trucks- I don't know what is involved if you use them.

You'd have to deal with 6 lug rims- which may or may not be an issue for you- they could no doubt be changed to LR bolt pattern too.

Around here I can get a set of TLC axles complete from drum to trum(or disc to disc) for $300 or so. Even with the fabrication and new brake parts it still is a pretty cheap swap here (NY).

 

[Yorker]

http://forum.landrovernet.com/showthread.php?t=136252

whoops wrong link... I meant to post this:

RR AXLES to Series:
http://forum.landrovernet.com/showthread.php?t=109506&page=4

http://forum.landrovernet.com/showthread.php?t=131792&highlight=range+rover+axle

 

[TeriAnn]

Something broke completely in the rear, and something broke partially in the front. There is still front-wheel-drive, but there is an awful banging every wheel rotation coming from the left front.

I suspected this was going to happen soonish knowing that you folks actually use your Dormobile off road. Pretty much every Dormobile I know that gets used off road got switched to a Salisbury rear though most have stock fronts.

I'm running about 550 pounds heavier than you. Of course I carry 2 more fuel tanks (extra 22 gallons) and a 15 gallon built in water tank plus the heavier Salisbury.

As Keith mentioned your front problem might be a broken U joint. Or it might be a broken tooth in the 4.7 diff. If you broke a diff tooth I suggest converting to the much stronger 4.75:1 ring & pinion set. Font Axles are not often a problem. I only broke 1 axle & 2 R&P gears up front during my first 20 years of driving my Land Rover (four cyl engine). A year into my V8 I remove a twisted but still intact front axle (the other side to the one that broke earlier) when I went to replace a broken 4.7:1 R&P gear set.

My front new has a used set of Seriestrek 24 spline axles, 4.75 R&P in a Trutrac diff sitting inside a early RR carrier.

Considering that you are on a very limited budget I suggest just fixing what broke in the front and if it was the R&P upgrade to the 4.75 ratio. It should be plenty strong for your Euro 6.

The front discs sold by Rocky Mountain are about the least expensive conversion you will find. I'm still quite happy with mine They will work with whatever axle you put into the Rover axle housing allowing you to have front discs without solving the coiler steering arm leaf spring interference problem. Your truck has power brakes right?

The rear Salisbury vs RR diff is a tough one. The Salisbury is the same width as stock & the RR diff will give you a slightly wider track. Either way I agree a ARB in the rear would be stronger & I would suggest the stronger 4.75 R&P Jim's Toy conversion looks good but I think you need to do both front & rear to get the same R&P ratio. Jim? What's the closest ratio you can get?

Steering. Maybe its time to convert to LHD power steering? Series rigs are one of the easiest to convert. I think the hardest part might be mounting the power steering pump. The parts you need for the conversion should be readily available used and for not a whole lot of $$ since they are parts that just don't break and there is no real parts market for them.

Timm Cooper has evidently been using P-38 RR power steering boxes for a couple years new with great success. One from a wrecking yard might be easier to find than a Scout II box. You you really want to stay RHD, there's always a used P-38 RHD box from a UK wrecking yard.

Stay away from a 3.54 R&P unless you are planning to convert to a LT77S with LT230 transfer case. The LT230 has very different ratios than a Series box which explains the very different R&P ratios. A bell housing would be the stickler on an LT77S conversion

A SIII box would need to be custom built with a 6 cyl/Series I bellhousing to fit your engine. I think it is quite doable but I don't recall anyone doing it previously. I can't think of any reason why a six cyl bellhousing could not be fitted to a SIII gearbox.

I don't know anyone with an adapter that would allow you to use an American truck gearbox with a Series 4 or six cyl engine.

Of course if $$$ were no object I would suggest a International harvester NGD 3.0E engine (185 HP @ 3800 RPM, 325 lb-ft @ 2200 RPM) A short bellhousing R380 gearbox from Ashcroft, LT230 transfercase into Jim's Toy front & rear axles.

Or use RR classic front & rear axles while converting your front suspension over to coils.

Of course, like me you are on a tight budget so I suggest:

1. Stock front axle assembly, upgraded to 4.75 R&P if you broke yours and the front disc brake conversion sold by Rock Mountain (unless you solve the RR classic into Series steering interference).

2. RR classic rear axle assembly if you add front disc brakes, Salisbury if you do not. Convert to ARB diff and 4.75:1 R&P as you can afford it)

3. SIII gearbox with a six cyl bellhousing. Remember the key to longevity of a SIII box is to hesitate just slightly in the middle of the 'H' whilst shifting.

4. Source a RHD P-38 steering box & maybe a power steering box & mounting bracket from a six cylinder Rover car.

Good luck!

 

[Alaska Mike]

Honestly, you have the best small platform for your goals, within a human budget (let's not go all Earthroamer here). The basic bones of the vehicle are extremely adaptable to all sorts of combinations, which will make your Rover into something uniquely tuned to your needs.

Now's the time to examine your budget, spend some time at TeriAnn's website, and decide if you will be keeping this vehicle forever.

Just a few thoughts (these are all my opinion, so take them for what they're worth)-

• The 2.6 doesn't have the best support in the world (parts, knowledge)
• Rover transmissions aren't the beefiest in the world
• Rover axle components aren't the strongest in the world
• As you mention, disc brakes are nice

To swap any one of those components would be an expensive proposition. A replacement engine would require motor mounts, possible cooling mods, and transmission adapters. A transmission would require adapters to both the engine and the transfercase. A transfercase (which I would keep if possible) would require a transmission adapter. Axles would require modification for gearing and very likely braking (master cylinder...), as well as the spring perch and driveshaft issues.

Are you sold on all-Rover components? A diesel or fuel-injected engine of european or US origin coupled to a US truck transmission might provide a balance of durability, serviceability, and economy that the Rover components would have a hard time matching.

If you had the budget, what would be your ideal?

 

[greenmeanie]

Chevy 292 with TBI mated to Ford NP435 and High ratio transfer case. It'll be fun altohugh a 350 would be cheaper. Scout PS with home built column and spam can pump. Currently going with 3.54 diffs in Rover axles but expect to move to Jim's 4.10 hybrids. All in a 109 sw.

I've got a spare 6 cyl box sitting in Phoenix if you need it.