Snagger

The LRM magazine, Britpart sponsored and conducted build showed the same problem with their new springs. Not a great advert for their products. They did the same thing once the fault was spotted. Shame they didn't repaint the spring eds before refitting - the scorched and blistered paint didn't look that neat against a galvanised chassis and newly painted panels!

I've had a quick peek around the front just now. There is no way that a link to the front cross member would work satisfactorily, shackled or not; it's just too short a gap and would result in a different set of wrap forces, rather than controlling the existing forces. What does look potentially feasible is a pair of rods connected by transverse bolts and bushings (I'm thinking of coiler trailing arms) to the axle, just outboard of the U-bolts, and rose (Heim) joints at the front end, bolted to the outside of the dumb irons through the upper spring bolt holes, the bolt of which will just clear the spring eyes inside the dumb irons. This will give rigid thrust arms to sold chassis mountings with free rotational movement for cross-axle motion and free pitch movement at each end of both rods for spring compression, but fixed length roughly parallel to the springs for anti-wrap control. It won't impinge on the spring bushes, will maintain the same axle axis at all suspension ranges and while being outboard of the springs, won't impinge on steering lock because they will be forward of the axle, where wheel/tyre steering motion is less at full lock (as it is the turn's outboard, lesser pivoting wheel that moves towards the front of the spring). I should even be able to buy off-the shelf brackets from YRM... I need to take a close look at the possibility of fouling the drag link on the near side, but that looks unlikley.

With the amount of spring distortion I must be getting to suffer the prop impacts that are occurring, the springs must be pronouncedly "S" shaped under heavy braking. There is no way that the Soren bar is going to worsen things and no way that the spring will distort more due to longitudinal compression over its arced length. The ladder bar may be more effective though, and won't place extra loads on the rear spring bolts or bushes (though the Soren bar may alleviate bush loadings because of the reduced rotation of the spring eye from preventing the S-bending). I'll have a closer look at the feasibility of a forward bar connecting to the front (steering relay) cross member once I have sorted the gear box and engine mounting.

That sounds similar in principle to what Fridge did on his rear axle. I am still hoping he'll contribute to this thread! No solution is perfect, but I still think the "Soren bar" is the most practical and elegant in this scenario. I'll try that first and see if the bushes take it. !N

I previously fitted 2.8:1 low gears in place ofhe standard 2.35:1, so low range is not so badly affected. I did look at 4.1 diff costs, but it's expensive. I'd prefer that ratio, though, as 4.71 is badly undergeared while 3.54 is overgeared to about the same amount. 4.1 would be ideal for road use in high range, and would also result in the standard overall low ratio with the gear sets I retrofit.

I've previously had the synchro spring failure - that's what prompted the gear box to be rebuilt 40k ago. And I have been using 3.54 diffs for about six months. It had occurred to me that they may be putting extra strain on the gear box, especially since steep hills in town have to be done in third gear.

I think something went through the gears to break the teeth off - there's a big impression of something at the root of each broken tooth.

Thanks guys. Food for thought. I like Soren's solution as it doesn't put strain on the chassis cross member, which wasn't designed for those forces, and avoids any contact with the sump or pulleys. I use Polybushes in my springs, so they should take the forces without much complaint and will be easy to swap if they don;t cope. I think I'll go that way first and see how things go - I can always change later. I'm not keen on the Willy's set up - my springs have too much camber anyway, but it puts a hell of a strain on those U bolts.

That's another benefit of an overdrive - 2nd, 2nd +OD, 4th...

Makes sense, or they'd probably have used the old system for the RR too.

If it's any consolation, mine broke its third gear yesterday - lots of heavy chattering in third and slight occasional chattering in neutral, confirmed but two whole gear teeth in the drained oil today. I have a Tdi too. Might just be too much torque in the long run - the box has probably done the thick end of 100,000 miles, with rebuild 40,000 ago and about 25-30k behind the Tdi.

That was very much the LR way at the time. Look at the late SIIAs and early SIIIs and you'll see technically incorrect door hinges, lighting, speedos, switch gear and so on. They would only switch over to the new parts once the old stock was depleted, and that was for all markets. The factory recon transmission I bought around 1996/7 has a Suffix A casing and thus reverse idler shaft and gear, even though the rest of the innards were Suffix D. They have always just used whatever was left over, not specifically palming them off on the old colonies. As for the wheel bearings, the idea was to rationalise the three different bearings in use - identical inner and outer bearings on the RR but two different sizes on the Land Rover, to one common spec across all vehicles for the obvious logistical and financial benefits. That RR spec bearing went onto the 1980 and later Land rovers, including the Stage I V8, and the Discovery nearly a decade later, and is still used on current Defenders. It was a factory stream lining exercise rather than a technical benefit.

It also sounds like seized calliper pistons, and they fal more often than servo units because they rust.

In other words, when the gear boxes needed overhaul, they were replaced with the then contemporary new units, and the axles were given the post 1980 rationalisation retrospectively, like I had don on my 109 axles. Still nothing unusual about either.

It could be a loose nut on the back of the main shaft, having broken the tab washer.

As Phil says, the MoD used the contemporary boxes. The only differences were the top filler plug in lie of the breather plate.

As I said in the first post, the first part of the solution is to make a new mount, which I can get away with because I have a Discovery engine giving me that space, and I already have a third leaf on the parabolics, all from Heystee, The oly way of stiffening the springs would be to ho to very heavy duty standard leaf springs, byt even that won't achieve a great deal.

I'd be interested in seeing how Soren connected the axle end of the control bar, but that is the principle I had in mind. It should work pretty well - when applying lots of driving power, the bar would be in compression, an when braking hard, it would be in tension. It wouldn't take any bending forces. By forming a triangle between the rear of the spring and the top and bottom of the axle, it should be pretty stable - triangles are the most stable shape you can get and are used extensively for structural systems because of that. A small amount of axle movement would still be imparted, but only from the spring side of said triangle lengthening as the spring is compressed and straightened. This would rotate the diff downwards, not up, as the apex of the triangle is floating with the axle by being on the spring eye - if it was on the chassis eye, it would rotate the diff up just as your suggest. I had been toying with the possibility of fitting the system atop the front of the spring, perhaps using the upper spring bolt holes in the 1-Ton chassis, but I suspect the spring eyes obstruct the hole and I think the drag link may foul control rods in that position. As for the Willys solution, that is also an option, but that's putting all the forces through the U-bolts and is still relying on the stiffness of those bottom members, so they need to be really heavy. Forming a triangle seems more elegant and avoids the extra U-bolt loads as the anti-wrap forces would be transmitted directly along the control arms in compression or tension. Only the rear spring bolt would carry etra loadings, and that would only be outboard of the shackles, so shouldn't shear the bolt.

Sounds like the pressure switch is sticking. When was the fluid last replaced? It could be dirt in the fluid or corrosion from water in the fluid.

I have found the source of the nasty noise that occurs under heavy braking of my Tdi powered, Defender axled 109. I had thought it was brake judder or even the tyres slipping n the rims, but no, it's the front UJ rubbing against the rhs engine mount bracket. The combination of nose dip and axle wrap causes the diff nose and front end of the prop shaft to move up, and given that the starting position is relatively high because of the axle swap and the Defender 200Tdi engine mount sits a lot lower on a Series vehicle than in a Defender, the combination is too small a clearance, even with my three-leaf parabolics and 1Ton chassis and shackles. So, part of the solution is to modify the bracket - luckily, I have a Discovery engine with Defender manifolds, so have plenty of space under the injection pump to move the span of the bracket upwards. The other part of the solution will be to look at controlling the amount of axle wrap. I am considering a very simple pair of arms that will connect from the axle bump stop pads to the rear spring eye bolts, forming a stable triangle. The straightening of the spring under compression will result in that side of the triangle lengthening, while the vertical and top sides of the triangle (the axle case and the anti wrap bars, respectively) will be constant, which will cause a small amount of axle rotation with the diff nose moving down under spring compression, but I think the effect should be small. Connecting similar rods to the front spring bolts would cause the diff nose to pivot up under spring compression, but would also foul the steering system's drag link. What I have in mind is a pair of scrap coiler trailing arms with the cylindrical bush fitted in a bracket welded to the axle and a new end fitted in place of the stud end that would attach to the spring bolt. Any opinions? Word of advice for those considering such mods - 12J/19J?Def200Tdi and coiler axles don't mix unless you come up with an engine mount that goes over the top of the injection pump. You can fit a Discovery 200Tdi or 300Tdi with coiler axles because of the higher injection pump. However, with parabolics greater wrap, and especially with standard mountings and two leafs, you're going to have to watch the separation of the diff nose and engine mount/injection pump under heavy articulation and braking.

Bad prop or bad diff.

I read it somewhere too, in an LR manual. It might have been their Worshop Manual. It's not in the Haynes manual, and no-one does it. Even my current gear box, which was bought new from LR as a replacement, wasn't sealed. I don't ever need to top up the gear box - the level only drops an imeasurable amount between the 10,000 mile service intervals (book suggests 12k) from sweating through the selector seals, no more than a soup spoon full. Anyway, I always advocate DIY rebuilds if you're competent to do it. Professional rebuilds never seem to work well or last - they put far to many worn, defective or poor pattern parts in.

Something missing from some manuals and just about every rebuild, even by LR themselves, is to use bearing seating compound on the rear bearing carrier when you refit it to the gear bx casing (not the visible one on the back of the transfer box but the one in the gear box secured with a huge circlip). This prevents the carrier spinning in the case but also stops the oil migration from gear box to transfer box which is so common as to be thought of as normal. Also make sure you use OEM parts wherever possible - a lot of the pattern parts are made of substandard materials or are dimensionally poor.

Well done.

Mine had no o-rings, so I used RTV sealant on the threads. It isn't elegant, but it works.