Range Rover axles on Series IIa

[Toy-Roverlander]

I didn't plug the redundant outlet in the shuttle valve - the original was that way from the factory, with a single pipe running to the rear axle and another single pipe to the front cross member. The new valve arrived with a plug in the same port, and since I already had all the original T pieces, I decided dimply to rebuild the brakes to the original schemeatic just using brand new cylinders, copper-nickel pipe and braided hoses.

I'm using a Tdi engine, so it'd pull 3.54 diffs, but I don't want it geraed that high - it's between 35 and 40% higher final gearing than standard and is n ot only non-selectable, but also screws up low range. I have a Roverdrive which raises gearing by 28%, which is a bit less than I'd like for the engine, but it will have to do. I'll be swapping the 4.71 diff from my spare SIII Salisbury axle to the new rear axle before fitting it. A fiddly job, but I have the manuals and an accurate digital vernier, so should cope - I will be building up the new axles before the swap, so the vehicle should only be on stands a short time.

From what you said, it sounds like the small end of your master does one half of each front calliper, while the large end does the other half of the fronts, with the rear brakes plumbed into that large cicuit via that balancing/warning valve. My master looks alittle different, as does the Discovery's differntial pressure valve (I don't have that yet). I don't think the Discovery uses a balancing valve, though - I'll have to take a closer look.

Aahh, didn't know that was original. I hardly ever get to see the original things, usually it's all different. Non of the people I know have standard Series motors:sombrero:.

You're right with saying that 3.54 diffs will stuff up low range. They do give a 32% increase in high gear, just a tat more than the 28% that the Roverdrive will give you. But I must say. It's really nice to have the splitter gears. 28% increase is already very welcome indeed. At least you still got normal low range and no speedo recalibration.

Another option would be to use an LT77 gearbox with adaptor to fit it to the Series transfercase. Ashcroft sells these, don't know what they do in price though. But I think it could be cheaper than the Roverdrive. This gives you the 5th, overdrive, gear.Whoops, just saw that you've already got the Roverdrive. I don't know if this can still be used with the 5speed conversion. Could give you a very relaxed '6th' gear for on the flat roads.

I'm running 3.54 diffs in mine, but my Toy gearbox has different ratio's. My final drive in 4th high range is 3.54:1, compared to the 5.4:1 of a Series, that's a big difference. 1st gear low range is 34:1, standard Series is more or less 40:1. Not that much difference. And it makes it up with a bigger engine. Where, with a Series, you would need to rev it to get power, I can idle through. The 3B has got tremendous torque from just over idle. That compensates for the slightly taller gear ratio.

As for the brakes. I would go for a matching system. I've been told that a drumbrake M/C doesn't work with a disc setup because of residual pressure in the system (apparantly to keep the brake shoes close to the drum, but that's tha job of the adjusters, so I don't know if it's true or not). Normally, if you get a disc brake conversion kit they advise you to use a M/C from a 90 as this one has a disc/drum setup.

I just noticed the reply of Jsbriggs
I've got the setup that's pictured in the last diagram.

 

[Snagger]

Thanks, Jeff.

Both set ups are broadly similar - the front end of the master activates 4 pot-pairs, while the rear does 2 pairs. It's just hw those pairs are selected that varies. At the moment, I don't have the pressure reducing valve for either system, but given that the front axle is from a Discovery and I think I can get hold of a good Discovery pressure reducing valve, I'll most likley go with the standard Discovery brake arrangement. Schematically, it seems to be somewhere between the two, with twin front lines and a piston pair in all callipers operated by the scondary system like the RRC diagrams, but the piping around the pressure reducing valve seems simpler and more symetrical.

Nick.

 

[Snagger]

I worked out a whole load of gear ratios for SIIIs, based on standard transmissions with 7.50s as a baseline tyre (1:1 effective ratio). I lloked at all the likely mods to affect gearing, but not the gear box fitting a different transfer box. You can see them here: http://forum.landrovernet.com/showthread.php?t=156187&page=3

I did toy with the idea of fitting an LT77 to the series transfer box, but given that the Roverdrive wouldn't fit without a custom drive member, it doesn't seem viable. There's little benefit in fitting an LT77 with the Ashcroft kit, as the 5th gear of the LT77 is similar to a Series box with overdrive. It'd be a lot of expensive work with the only benefit being less oil leaks, but with the complication of many custom parts (bad on a trip). Replacing the whole transmission with the LT77, LT230 and 3.54 diffs is too much work to be worthwhile for me.

As for the brake MC issue, Series MCs shouldn't have any residual pressures (like you said, the snail adjusters are there to do that), but they may have very different cpacities which will affect the pressure they apply to the calliper pistons and the ratio between primary and secondary ciruits pressures with SIII dual circuit MCs. Don't forget, though, that most SIIs and SIII 88s have single circuit brakes, so that may be the initial reason for the advice to change the MC when fitting disc brakes.

 

[Snagger]

Koos, I just noticed you're still using the original steering (RHD, too). I was planning to do the same, but am a little concerned that the steering box will reach its limits before the swivel stop locks limit the steering movement. that would mean that hitting a pothole or stump with steering at full lock would allow the swivels to move a little more and damage the steering box. Have you tried steering from lock to lock with the front off the ground to check the swivels reach the stops before the steering box runs out of range?

 

[Toy-Roverlander]

Koos, I just noticed you're still using the original steering (RHD, too). I was planning to do the same, but am a little concerned that the steering box will reach its limits before the swivel stop locks limit the steering movement. that would mean that hitting a pothole or stump with steering at full lock would allow the swivels to move a little more and damage the steering box. Have you tried steering from lock to lock with the front off the ground to check the swivels reach the stops before the steering box runs out of range?

I too crunched some serious numbers to come up with the ultimate combo. There's one disadvantage with the Toy gearbox. 2nd low range is only slightly shorter than 1st high range. But there's not much that can be done about that. It's because of the 1.996 low ratio. The later transfer cases have a better low ratio but can't be swapped unfortunately. All I could do now is fit 4.11 R&P's, that would give me the original (well, LC's had 4.11 or 3.7 as standard so it's still a guess) LC ratio's. But it will raise revs on the highway. And as most of my driving is in our flat country this taller ratio is perfect. In the mountains it's a different story, it just means I'll be going a bit slower up the hills. I haven't had any problems offroad yet with the gearing being slightly taller. Quite often I'm not even in lowbox yet.


Sounds like a good idea to just keep the Roverdrive. Keeps it nice and simple. The only thing I can think of....is the gearbox strong enough for the torque of the Tdi? And not just strong enough for a little while, but strong enough to still be reliable after an x amount of miles? I'm not too familiar with them. I believe the very late SIII boxes were the strongest?

I could have mounted the 3B motor on my SIIa box but apparantly their limit lies at or around 160 lbs/ft. And the 3B delivers 167 lbs/ft, so that's slightly more. So I wasn't sure about long term reliability of the IIa box (imagine being in soft sand, fully loaded for expeditions and you can't give it some welly as you might break the box..... that's not a good thing).
So I opted for the Toy gearbox. Our friends from across the big pond fit big V8's in front of them, so they're quite strong. Their only weakness being the alloy transfercase. But I don't think my diesel will break that one.
It was also cheaper as I didn't have to buy a high ratio transfercase or a Roverdrive, nor did I have to buy the adaptorkit in Australia.


About the steering.
Nope, haven't tested it yet lock to lock. I'll do that. The thought did cross my mind whether the steeringbox would have enough range or not, but simply forgot about it as I had other problems to deal with at that moment.
I have read reports of people who say that the turning circle improves quite a lot and that the steering feels a bit heavier. Maybe the steering arms on the swivelhousings are shorter??
If the steeringbox does indeed comes a bit short, one can easily adjust the swivel stop bolts to match.


Anyway, I'll try it out and report back to you.


ps, here's an overview of my gear ratio's

TOYOTA H41 GEARBOX WITH 4.7 DIFFS High range Low range
first : :23.15 :45.37
second : :12.42 :24.34
third : : 7.14 :13.99
fourth : : 4.7 : 9.21



TOYOTA H41 GEARBOX WITH 4.1 DIFFS High range Low range
first : :20.19 :39.58
second : :10.83 :21.23
third : : 6.23 :12.20
fourth : : 4.1 : 8.03



TOYOTA H41 GEARBOX WITH 3.54 DIFFS High range Low range
first : :17.43 :34.16
second : : 9.36 :18.34
third : : 5.38 :10.54
fourth : : 3.54 : 6.94

 

[Snagger]

Sounds like a good idea to just keep the Roverdrive. Keeps it nice and simple. The only thing I can think of....is the gearbox strong enough for the torque of the Tdi? And not just strong enough for a little while, but strong enough to still be reliable after an x amount of miles? I'm not too familiar with them. I believe the very late SIII boxes were the strongest?


About the steering.
Nope, haven't tested it yet lock to lock. I'll do that. The thought did cross my mind whether the steeringbox would have enough range or not, but simply forgot about it as I had other problems to deal with at that moment.
I have read reports of people who say that the turning circle improves quite a lot and that the steering feels a bit heavier. Maybe the steering arms on the swivelhousings are shorter??
If the steeringbox does indeed comes a bit short, one can easily adjust the swivel stop bolts to match.


Anyway, I'll try it out and report back to you.

I know a few poeople who have been using series boxes for years behind Tdis or V8s, several of them are regular RTV trailers, and none of them have had any trouble yet, so it should be alright. I drive with gentle feet, engaging gears with low engine rpms so the turbo isn't spooled up, gently letting the clutch out and then easing the accelerator pedal down. It's the shock loads more than maximum torque that causes gearbox damage, and I am very careful to prevent shocks.

Regarding the steering, I thionk the steering arm on the coiler swivels may be shorter than that for the drag link on the Series axle. That will hopefully mean that the swivels rotate more for a given steering wheel/box movement, and may mean that the swivels do reach their stops first. If the steering is heavier, then this sounds likely.

I have 7x16 wheels which are much more offset than standard rimss, but I plan to fit 1-ton or Wolf rims to the new axles, so they should mitigate any increase in steering loads from the different gearing effect of the shorter swivel arms.

Do let me know what you find - adjusting the stops would protect the steering box, but would lose a lot of the increased steering lock available from a coiler axle, which is one of the pricniple reasons I'm planning to carry out the swap.

 

[Toy-Roverlander]

I too always try to prevent shock loads. I'm very, very sympathetic to the mechanical bits. No shock loads,keeping a steady throttle on speedbumps, waiting to accelerate as soon as the rear end stops bouncing, revving the engine up before coming of the clutch when downshifting to match engine speed to lower gear before engine braking. Slow gearchanges, engine braking. All that sort of stuff. It all helps making sure all components last as long as possible.


I had a look today at the steering.

I had the steering box centered in the middle so it's 2 full turns to the left and 2 full turns to the right. The wheels pointing straight ahead.

To the left was 2 full turns, so it can go to the end of the steeringbox range. It did give nearly full steering lock judging by the position of the swivel seal on the swivelball. I adjusted the stop a bit so that it doesn't 'botto'm out' in the box.

To the right it goes a bit further, looking at the oil seal again it gets very close to the end of the sphere where the tubed section begins, but for some reason with less turns, about 1 7/8's of a turn it hits the stopbolt.

So it turns slightly sharper to the right than to the left. Strange, as the steeringbox is centered. Maybe it's how the steering arms are setup on the relay and the box..

It does look like it's got more steering lock than a Series axle.

Just fit it, see what you get and adjust the stops back a tiny little bit.

If I remember I'll measure the steering arms on the coiler axle and the leafer axle tomorrow. Could well be that there's a difference.

I have 7x16 wheels which are much more offset than standard rimss, but I plan to fit 1-ton or Wolf rims to the new axles, so they should mitigate any increase in steering loads from the different gearing effect of the shorter swivel arms.

It took me a while to understand what you said here. Correct me if I'm wrong here. You're saying that you have the 7x16 wheels now, and that by going to Wolf rims the steering will be lighter but that will be offset again by the shorter steering arms. Right?

Are you planning on fitting wheelarch extensions? Wolf rims will stick out a fair bit. I believe they have the same offset as LWB rims, but are an inch wider. Don't know wheter that's half an inch each side or 1inch on 1side though.
I'm thinking about leaving it as it is now, with the wheels sticking out a little bit and no extensions. I just really don't like the look of them. And it only really shows how far the stick out when you stand behind or in front of it. Seeing it from a angle you would hardly see that they stick out.

 

[Toy-Roverlander]

I had a great idea today :victory:

I'm expecting driveline vibes from the front prop as the u-joints angles are way off now due to the diff nose pointing upwards.

As I need to have the front prop lengthened anyway, I might as well treat it to a double cardan joint.
Usually these things are fairly expensive...

But what about if......

I take the yokes of an old propshaft ( I happen to have an old front prop lying around), turn them back to back, make sure they're properly aligned and then weld them together. They both have that bit sticking out that normally fits into the diff or gearbox flange, so when put back to back there will be a 3 or 4mm gap in between the 2. Perfect for a good weld.
I'm sure this is strong enough. Normally they weld the tube shaft to the sliding bit or the yoke, and that diameter is a lot less than from the outside of the yokes.

So weld them 2 yokes together back to back, fit it in my front propshaft and send it away to have it shortened to the right length. I'm pretty sure that will cure any vibes. And it is a lot cheaper than buying the double cardan joint of the shelf.

 

[JSBriggs]

As long as the splines arent worn, its a great idea. I friend of mine has done that for a long travel slipyoke.

Another bit of trivia is that the leafer and coiler slipyoke splines are the same, so if you have clearance issues, you can use a RRC/Disco solid one as a starting point.

-Jeff

 

[Snagger]

Double cardan joints have a linkage between the two UJs to make sure they both deflect the same way and by equal amounts. Just attaching a second UJ in a pair of regular prop yolks will not work because the two adjacent UJs will be free to move independently of eachother - they well just drop and kink out of line. Discovery IIs use double cardan front shafts, so you could use one from a scrap DII, replacing the yolks and having it cut to length. However, unless you use 4wd at high speed, you shouldn't get too much trouble with the standard prop (corrected for length) - the prop is free to rotate as it pleases in 2wd, so shouldn't cause any hammering.

Yep, you worked out what I was getting at with my wheels and their influence on the steering - sorry for being as clear as mud. I have 235/85 on 7" rims, so not only are the tyres a little wider at the tread, but they're offset from the swivel pin axis. Those factors both make steering ehavier, but I'm hoping using the LR rims will bring the treads back in line with the swivel pin axis and mitigate the effects of the shorter swivel arm. My Metro steering wheel doesn't help, either, with its smaller diameter (it is more comfortable and does allow much more leg and elbow room, though). I already have Defender wheel arches because my existing sidewall protrude a little from the front wings (the rear axle has a slightly narrower track, so the tyre walls are flush with the tub panels).

 

[Toy-Roverlander]

Double cardan joints have a linkage between the two UJs to make sure they both deflect the same way and by equal amounts. Just attaching a second UJ in a pair of regular prop yolks will not work because the two adjacent UJs will be free to move independently of eachother - they well just drop and kink out of line. Discovery IIs use double cardan front shafts, so you could use one from a scrap DII, replacing the yolks and having it cut to length. However, unless you use 4wd at high speed, you shouldn't get too much trouble with the standard prop (corrected for length) - the prop is free to rotate as it pleases in 2wd, so shouldn't cause any hammering.

The way I thought it out it will be exactly like the front prop on a D2. By taking the 2 yokes and welding them together back to back you basically create the centrepart of the double cardan joint. In that centrepart you fit the U-joints to which another yoke bolts to the diff-flange and on the other side is the shaft that goes to the u-joint at the gearbox end.

Well, at the moment the U-joint at the gearbox hardly has an angle in it while the one at the diff does. My prop is nearly horizontal, and then it angles down towards the diffnose.
If u-joint angles are not very close to each other (and opposite) you will get vibration. I just don't know at what speed it would be noticable. And even if you can't notice it by feel, the bearings in the transferbox and diff will notice the effect of vibration.


I can't use a D2 one as the flange is different. When using one of these on other coilers with LT230 you need to swap the output flange as well for one from a D2. And in my case that means having to make another gearbox to propshaft adapter (remember, Toyota gearbox, Landy propshafts....)

 

[Snagger]

The way I thought it out it will be exactly like the front prop on a D2. By taking the 2 yokes and welding them together back to back you basically create the centrepart of the double cardan joint. In that centrepart you fit the U-joints to which another yoke bolts to the diff-flange and on the other side is the shaft that goes to the u-joint at the gearbox end.

It won't work. Take a very close look at a double cardan joint and you'll see the two UJ spiders are mechanically linked by an arm from one into a socket in the other to keep them operating at equal displacements. Your planned prop will kink and be well off ballance as the joined section falls under gravity/ centrifuge, throwing the second UJ and the prop off its rotational axis.

 

[JSBriggs]

I misunderstood what was being asked. Snagger is right about the DC shaft and how it functions.

I thought you were asking if you could lengthen the shaft by adding the spline section from a second slipyoke and welding them together, which you can. Cobbling together a shaft with 3 u-joints (but not a DC) wont work.

-Jeff

 

[muskyman]

gone

 

[Snagger]

I can't use a D2 one as the flange is different. When using one of these on other coilers with LT230 you need to swap the output flange as well for one from a D2. And in my case that means having to make another gearbox to propshaft adapter (remember, Toyota gearbox, Landy propshafts....)

I know LR use two different sized UJs for different applications. I really don't know if the UJs on the DII shaft are the same as those on a Series or Defender shaft, but if they are, you would be able to swap the yolk on plain UJ end. If the DC joint also hares the same dimensions, you could replace that yolk too, giving you a DC prop that will fit. It's worth a close look.