The front axle case modifications are nearly complete. It has taken a couple of days’ solid work to remove all the brackets associated with the coil sprung suspension and fit the custom built spring saddles and refit the bump stops at the correct orientation (the saddles are set 90 degrees to the swivel pin axis and the tops of the bump stops are 5 degrees out of parallel from the saddles, diverging towards the front of the axle). The bump stops are reorientated to allow for the different angle on the Series chassis and because the axle does not rotate aft as the springs compress with leaf springs. As a result, the right bump stop ends up sitting higher than before. The bump stop’s top surface was notched around the diff housing to minimise this height increase, but a rise of about 5mm can’t be avoided. The left side stop was raised to match. Because the original sides of the stops had been removed to fit the U-bolts, reinforcing was added inside the stops in the same manner as on a Series axle to stop the centre of the bump stop buckling under contact with the rubber blocks. The combination of taller bump stops and taller spring saddles will significantly reduce the clearance between the axle and chassis, limiting axle articulation. In my case, fitting the third leafs to the front springs will help enormously, but I also have the option of removing the 1-ton spec spacer between the chassis and rubber blocks, though I think this will not be required once the springs have been uprated.
The saddles have been made from sections of 8mm sheet steel, consisting of a full profile plate for each side of the saddles, plates for each of the four facets visible on the ends of the saddle and a plate each for the underside, drilled with a 15mm hole to locate on the springs’ centre bolts. The left side saddle is simple, but the right saddle is a very complex shape. I made templates from card before transferring the shape to the steel, nibbling with the grinder until it fit correctly.
Not only is the steel plate thicker than the cast saddles used on the original axles, but the method of construction has allowed each face of the saddle to be welded to the axle from the exterior (as per the originals) and also from the interior, so they will be significantly stronger. This alleviates concerns about the increased forces from the disc brakes and increased moment from the taller saddles.
The Panhard rod brackets have been refitted to the front of the bump stops, too, with a little trimming to suit. They are slightly further inboard now to ensure they clear the U-bolts, which will require a few mm of shimming between the Panhard rod hanger and chassis when fitted with a standard rod or would use a slightly shorter set adjustable rod. The latter is tempting as they are available with rose jointed ends which allow rotational movement in all axis, so they don’t put any stress on the brackets as the alignment alters from suspension articulation. The brackets just need a diagonal brace to buttress them against the ends of the axle tube to make sure they will tolerate the Panhard rod’s lateral thrust forces in use – the original bracing formed part of the now absent radius arm brackets.
To ensure that these Panhard braces don’t foul the steering mechanism, the axle will be cleaned up and reassembled before the braces are fitted, checking the clearance of the swivel housing arms and steering rods on full movement before welding.
Hi,
I have a question you may be able to help with. I hae a series III 1974 landorver for 18 years now. I think I have hd experienced during the years similar ones that you have with multiple fixings and treatment to this creature.
Now somethig happened to the rear differential and the prop drive does not rotate the wheels. I have not opened yet the diff. case, but rad the haynes manual that advised not to fix any of differential probelms but rather buy a reconditioned one. Bein in israel this may be quite expensive. Any suggestions?
Thank you.
David
Hi David,
In all likelihood, you have broken a half shaft or drive flange rather than the differential, especially if it’s a Rover diff (the same shape as the front diff, fitted on both ends of 88″ Land Rovers but only the front of the 109). You need to remove the half shafts for inspection by draining the il from the axle and removing the drive flanges from the hubs (the circular disk held by six bolts). It’s usually the right hand side (shorter) shaft that breaks because it can’t twis as much as the longer left hand shaft. If the shaft has sheared where it enters the diff, the end piece may be stuck in the diff planet gear, in which case you’ll need to remove the diff from the axle to knock the remnant out before refitting everything.
If it is the diff, then it is quite reasonable for an amateur mechanic to rebuild. You would need a clean work bench and a few specialist tools, and the proper Land Rover Workshop Manual is far more helpful than the Haynes manual, but it’s not rocket science.
Good luck.
Nick.
Hallo, I just got myself a set of front and rear discovery axle. Planning to install it on a 110. Since the engine and gearbox cannot be salvage, I got a nissan td27 diesel engine and paired it with a Nissan safari gear box. Will the axles match the nissan engine and gearbox?
Any advise.?
My 110 is a 1986 model.
Doing the same axle conversion on my swb 2a 300tdi project.. Having read this it doesn’t look beyond my abilities… Thanks for the site its been an inspiration!
Any measurements or tips on getting the spring seats etc in the right place on the front axle? Beyond that you have already posted?
Cheers Jim
I’ll try to take some measurements tomorrow.
OK Jim, I took the measurements for the front axle saddles. They’re 29mm from the bottom of the axle tube to the spring top. The angles of the front and rear slopes are copied from the original saddles, it’s the bottom part that is extended. The driver’s side saddle needs to be cut around the diff housing, and the best way is to make a cardboard model and cut it to fit so you get a 3D template.
Now, this is fine for my 109 with parabolic springs and MoD spec taller shackles and hangers. If you use just the MoD shackles and a standard chassis, the extra height required for the track rod to clear the leaf springs will be different because the spring will be tilted. The saddle will not need to be as tall as mine, and so the lack of the 40mm lift at the front of the spring will be mitigated by the shallower saddles.
The coiler axle’s swivel pin castor angle needs to be the same 3 degrees as the Series axle. If you are using lengthened shackles and hangers like me, then you can copy the angle between the bottom of the saddles and the flats of the swivel pin assemblies to set the castor correctly. If you add longer shackles but not longer hangers on the dumb irons, then the spring inclination needs to be accounted for – measure the spring inclination from horizontal by measuring the angle of the slope from the spring bolts at the front and rear ends of the springs with the short and the long shackles and add that to the difference between the saddles and the swivel flats.
The rear axle is easy – just transfer the brackets from the old to the new at the same angle relative to the diff pinion. Remember that the lateral spacing needs to be measured from centre – if you measure them from the axle ends, allow for the extra length of the coiler axles. Only use a Rover rear axle on an 88″, as a 110 Salisbury axle’s diff casing will be in the way of the right leaf spring. It’s possible that you will have to use taller saddles and cut the inside of the right saddle, just like on the front, to pass around the Rover diff as it’s set further outboard than the Series’ axles – this isn’t an issue on a 109 because the LWB’s rear springs are set outboard of the chassis, not under it.
Now you see why I only give general methods of how to set yours up, not specific dimensions and shapes, because there are too many variables on how you do it and what parts you use.
Nick
Good morning Nick,
Many thanks for the extra info.. All snippets of advice always helpful.
One last question.. A few people have suggested that with the tdi engine, the p38 power steering and then the converted coiler axles and brakes that I would need to take the landy for an sva test as its heavily modified.. And may after that loose its reg and tax exempt status? This worries me a bit.. Have you had any issues with this?
Cheers
Jim
The DVLA rules are on their website. It comes down to a points system for components used, whether it be in a rebuild or “radically altered” vehicle. The points are as follows:
Unmodified original spec chassis, original or brand new replacement, 5 points;
Engine, 1 point;
Transmission, 2 points;
Steering system, 2 points;
Suspension system (allows service replacement of similar parts, including parabolic springs), 2 points;
Axles (both together), 2 points.
You need to score 8 points to keep the original VIN and registration. A rebuilt or modified vehicle may need a Vehicle Identity Check to make sure it has no stolen parts and is not breaching the above system, but this is less involved than an SVA test and really comes down to you having receipts for the major assemblies you have bought in, like axles, engines or new chassis. I was not required to do this with my 109; the DVLA were content with the original rebuild and new chassis without an inspection or even any paperwork checks, but they have apparently become more vigorous of late because of the amount of ringing of Defenders (stolen vehicles or transferring SII VINs to claim tax exemption), so it’s not a bad idea to call them and talk it through.
I have a Tdi, the coiler axles and brakes (note the brakes do not feature in the points system) and parabolic springs (which score the two points for the suspension). I can either replace the transmission or the steering system with a different type, but not both as I would run out of points. You will be in the same position – replacing your engine, axles and steering will be fine as long as you don’t radically alter the chassis to do it. So, P38 steering with a mounting plate or clamp system, or through the relay hole as a chap called Vinny did on his Lightweight (to be featured in this blog as a “reader contribution”) would be fine, but fitting RRC/Defender steering with a chopped about front cross member may foul the regulations as the chassis may be deemed to have been significantly altered from original specification.
This interpretation has worked for me – I had three phone conversations and two email exchanges with the DVLA which confirmed my interpretation at the time. However, I am no legal expert and the DVLA’s rules, or their interpretation of them, may have changed over the last ten years, and individual inspectors may have differing perspectives, so it’s worth double checking in writing (email) with them before you carry out all the work, at least for complete peace of mind.
Hello Nick,
I have referred to this blog many times over the past couple of years. My last project was an 88 2A for my wifes b’day. A full rebuild.
Currently I’m working on a ’70 109 2A. I am going with Disco diff / axles. Your posts have been very helpful. Thank you.
I have decided, after loads of reading to follow your guidance about the steering set up. I will leave the track rod at the rear and follow all your geometry advice, as I come to weld the spring seats and bump stops.
But, and don’t take this the wrong way… it is now 5 years since you did your conversion, and you have logged a good few miles I imagine. Looking back, are you happy with the decisions you made, particularly about the placement of the steering rods, ackerman angles and general steering “feel”.?
I have stripped the Disco axles of all the unneeded bits and have spent a good while grinding it all smooth ready to weld the new parts as per your set up. So I guess this is my last chance to change my mind.
I appreciate your input, and obviously I take it all as your opinion only, and won’t come back wingeing. Hey, I’m in New Zealand and we are not like that 🙂
I look forward to your comments,
Best regards,
Justin Wade.
Hi Justin,
The axles made a big difference. I got increased steering lock because of the swivels being further outboard, allowing much more turn before the tyres reach the springs than a Series axle while also reducing the driver force required by permitting the use of standard wheels rather than wider offset aftermarket wheels that upset the scrub radius.
The disc brakes were a bigger improvement than I expected, allowing better control under heavy braking so you can brake harder without locking up. It also means that the brakes are self cleaning and self adjusting, and very easy to service.
The only snag I ran into after the axle swap was the low slung right hand side engine mount being fouled by the front UJ under hard braking die to a combination of spring compression and axle wrap bringing the tilted diff nose closer to the very low Defender engine mount. I don’t know if this would be an issue with standard engine mounts or with standard leaf springs which are not only stiffer in compression but much more resistant to wrap. I made an arched mounting to get around the problem.
I later added PAS, but that was to make it easier for Helena to drive. I was very glad of it too – it’s a much better mod than you’d think, but it’s not necessary; the coiler axles alone will give exactly the same steering feel as the original if you set the castor angle at the same 3 degrees, just with a wider range. Add P38 PAS and you can turn the steering lock to lock while parked with your little finger, but road handling is exactly the same – the gearing ratio (steering wheel revolutions to road wheel deflection angle) is very similar to the Series manual system, so no nasty surprises. The two mods together make the 109 surprisingly nimble, turning tighter than a Defender 90 or any type of Volvo.
Nick
1974 Series III, I have access to a set of Discovery II axels. Can the original 2.25L engine with 4 speed overdrive handle to step up in Discovery II differentials?
Maybe downhill, with a following wind, when Venus is in Capricorn…
Unless the engine has been significantly tuned (high compression head, cam shaft, high performance manifolds, electronic ignition and either a high spec card or even a fuel injection system), then it’d be a waste of time and a terrible drive. The overdrive alone would be very worthwhile, and maybe the axles if you installed diffs with a 4.7 or similar ratio. Even with a moderately tuned 2.5, a Tdi or 3.5 carb fed V8, the 3.54 diffs and overdrive are too tall for combined use. You can use one or the other, but you’re going to find tall diffs a real nuisance on hills or town driving with that engine.