No more pretty looking final assembly, but I have been busy fitting various parts to work out how to build up the hubs and brakes.
The axle was drum braked, which is fine enough but it seems a shame to go to all the trouble of adapting the axle as I have and not fitting discs too. So, I set about getting cheap parts for the conversion. The calliper brackets were mentioned previously and save a fair bit of fabrication and welding.
I got a set of axle ends from a 200Tdi Discovery as a swap for some redundant parts I had in the garage. The idea was that these would match the Discovery 200tdi front axle I will be fitting unatlered, save for the suspension mountings. This would prevent any concerns over brake balancing.
Unfortunately, the Discovery hubs don’t fit the Salisbury stub axles – the Discovery hubs have their bearings much closer together than a Series or early 90/110/Defender hub, and the Discovery stub axle is correspondingly shorter. While the Discovery hub will fit onto the Salisbury stub axle, the outer bearing sits too far inboard to be secured by the hub nuts and washers, so the hub slides up and down the stub axle. Furthermore, with the hub seated inward against the seal land, the outer end of the long stub axle holds the drive flange about 5mm off the hub.
I then tried fitting the Discovery stub axles, included in that swap in anticipation of this problem. That turns out to be impossible; the manner in which the stub axles are located on the axle tube is completely different, even though the bolt holes all line up . The Defender stub axle has a flat flange with a rim that sits around the edge of the axle flange, while the Discovery stub axle has a wide protuberance on the mating face which locates inside the open end of the axle tube. The diameter of that protuberance is much larger than the internal diameter of the Salisbury axle tube, so the stub axle and axle tube flanges are held apart.
I did consider having the Discovery stub axles machined to make the protuberance fit the axle. Playing around with this idea and fitting all the components as best I could showed with a high degree of confidence that if the stub axles were machined to fit, then all the Discovery components would fit with the calliper brackets, callipers and discs aligning correctly. A trial fit confirmed that the Salisbury half shafts would push in far enough for the drive flanges to mate up with the hubs without causing trouble in the diff. There were some concerns with this idea, though. The first was that replacing the stub axles in future maintenance or repairs would require their being machined too, making the job costly and troublesome and repair on a trip very difficult. The second concern was that this would lose about 40mm of wheel track, which would look very odd compared to the front axle and lose some of the lateral stability on side slopes that this mod is partly for. The third was that the narrower wheel bearing spacing simply isn’t as strong when dealing with tangental loads from cornering, and combined with the different offset that my after-market rims have, may lead to premature bearing or stub axle wear.
So, how to retain the Salisbury stub axles? Basically, I needed another set of hubs that had the same bearing spacing as the drum braked Salisbury. The immediate thought is a 300Tdi Salisbury hub, but it transpires that these use the narrower pitch like the Discovery. The front hubs from a 200Tdi Defender or earlier 90/110 work, though (early Range Rovers may, too). So, I have now test fit the original stub axles with a pair of 110 hubs and discs from Rogers of Bedford’s stock of old used parts and they fit perfectly. The disc is just a little too deep and fouls the calliper bracket, while the callipers’ slots are also misaligned with the discs’ rotors, but 3mm washers between the calliper brackets and the axle flanges brings everything perfectly in line. The Discovery mudshields even fit without alteration and the old Salisbury shafts and drive flanges mate up at their original depths.
So, the 110 hubs will be cleaned up and fitted along with new calliper seals (and stainless steel pistns if these are rusted), new discs and pads (perhaps EBC, like I fitted to the Range Rover if the price is reasonable), new hub seals and mud shields (these Discovery ones are too rotten), and new bearings if required.
Do you have splined hubs for the Salisbury 4HA axle
Yes. All Salisbury axles use splines separate flanges, unlike Rover axles which use a combination of splined and integrated flanges. However, I am looking into welding the flanges to the shafts, as I understand is common practice in Africa, as it is supposedly stronger and reduces spline wear while also eliminating the need for the plastic cone. That would allow me to fit the alloy wheels’ plastic centre caps.
hi i was just wondering whats parts you used for this brake conversion as im looking to do it to my 110. and i want to have all the parts so its not of the road to long.
Hi Tyla
I kept most of the standard 110 axle. The hubs were replaced with front hubs from a 90/110 to accept discs without the need to replace the stub axles or half shafts and drive flanges as these older front hubs have similar dimensions to the drum braked hubs you’ll be removing.
The calliper brackets are standard parts for 300Tdi 110/130 rear axles. I used Discovery rear callipers, which are the same as 90 rear callipers, because I had access to a Discovery’s entire braking system, giving me a balanced set up for a max gross vehicle weight similar to that for a 109. I used standard D110 rear discs, and to get them to align with the calliper slots I had to make up spacers to mount the calliper brackets inboard from the axle flanges that they would bolt directly to on a 300 axle. Using 110 rear callipers, which you should do because of your higher MGVW and to balance the existing front discs, you will need to have the calliper brackets skimmed by an engineering shop to get the calliper and disc alignment – this is all because of the 300s having skinny (weaker) hubs. That is the only custom work you’ll need.
Remember to get the brakes tested by an MoT station on completion and to tell your insurers. Having and engineers inspection and report could be useful just in case of an accident, too.
Nick.