LR 110 Salsbury rear axle drum to disk brake conversion

[mongosd2]

Here's a list of part, with part number to convert a 110 rear brake conversion...I highly recommend buying all new parts. I had have quite the collection of crap sitting in the shop from trying to cob it together...

Parts are all readily available in the UK. Total for everything with shipping was under 600 bucks, here's the parts list:

FTC942 or RUB101740 HUBS (RRC 92-94) Hubs (I had a set)
FTC1725 HALF SHAFT LH
FTC1726 HALF SHAFT RH
FTC1740 STUB AXLE (2)
FTC3145 OIL SEALS (2)
RUC105200 DRIVE MEMBER (2)
RTC3129 WHEEL BEARING (4)
FTC3185 BEARING SPACER (2)
FTC3179 STUB NUTS (4)
FTC943 PLASTIC HUB CAP (2)
FTC2783 HUB OIL SEAL (2)
FTC3306 CALIPER BRACKET
STC1268 CALIPER RH
STC1269 CALIPER LH
FTC3846 ROTORS
DA4185 EBC BRAKE PADS

Bolts right up, no machining of the ftc3306...

 

[Snagger]

I managed to do it a lot cheaper with second-hand front hubs from a 90/110, new front discs, s/h but rebuilt rear callipers and new calliper brackets, but it was fiddly to work it all out.

I'd recommend you re-pipe those callipers; the existing routing looks very close to the coil spring (it could be an illusion, without any depth preception) and in such a position, any slight bending from contact with offorading detritus could push it into the coils where it'd be crushed or severed when the axle articulates. I've seen that before on a "professional" job, where a mechanic routed the pipe through the spring! The correct routing should drop down vertically close to the calliper until below spring plate level, then run along the back of the axle case at mid-height and then over the top of the diff. You could run it through the spring mounting bracket for off-road protection, but the pipe could easily be damaged when undoing the spring retaining nuts if servicing the suspension.

 

[mongosd2]

It just didn't make any sense to me to after gathering all the parts, from 3 different trucks, to do the conversion that way. Expensive, not really when you consider that brakes are rather important. If you've ever seen my D2, I will find a way of making anything work, but the mishmash of parts just really didn't leave me with a warm, fuzzy feeling...


The line's are done already, I didn't have the right flare tool at the shop when I did the install.

 

[Rovertrader]

Actually that is a great deal considering to convert a D-I to Def front brakes is over $500...

 

[Snagger]

It just didn't make any sense to me to after gathering all the parts, from 3 different trucks, to do the conversion that way. Expensive, not really when you consider that brakes are rather important. If you've ever seen my D2, I will find a way of making anything work, but the mishmash of parts just really didn't leave me with a warm, fuzzy feeling...


The line's are done already, I didn't have the right flare tool at the shop when I did the install.

I can understand your reservations, but it actually works perfectly. Not only that, but is saves replacing the 200Tdi (and earlier) half shafts and flanges with the much weaker 300Tdi types and allows you to retain the wide spaced wheel bearing set up of the original axle rather than the closer spaced and weaker narrow hubs. The brake discs are chunkier than the standard rear discs too, and that means they have a greater heat-sink ability. The only concern is that the clearance between the outer edge of the discs and the grooves in the callipers is fairly small (about 3mm in my case), so heavy corrosion would have to be cleaned off periodically.

 

[mongosd2]

The half shafts are just shorter, not any weaker. The splines on both axles (disk and drum) are the same length, so stating the newer flange is weaker really isn't true. The hubs are the same as the stock 110 front hubs, so the bearing spacing is the same. The lower profile flange also fit's under a alloy, if that matters.

You can use the drum half shafts with the drum drive flange if you want, but I needed a new half shaft so I went with the disk brake axle shaft and flange.

This is a direct bolt up...no spacers or machining of the brackets...

 

[Snagger]

The half shafts are just shorter, not any weaker. The splines on both axles (disk and drum) are the same length, so stating the newer flange is weaker really isn't true. The hubs are the same as the stock 110 front hubs, so the bearing spacing is the same. The lower profile flange also fit's under a alloy, if that matters.

You can use the drum half shafts with the drum drive flange if you want, but I needed a new half shaft so I went with the disk brake axle shaft and flange.

This is a direct bolt up...no spacers or machining of the brackets...

The 300 Tdi shafts have a smaller diamter for most of their length, widening at the splines and at the stub axle seal. The splines on the outboard end and the corresponding flange splines are much shorter, increasing point loading and wear, especially if you don't remove the stub axle seals and let the splines run dry. The loss in torsional strength from the thinner shafts is not significant, but the increase in failure rate of the outher splines is.

 

[mongosd2]

Not the ones I got..same diameter as the drum axle shafts, just 1/4" shorter and the splines are the same length...

 

[Snagger]

Curious - I got the parts from a scrap 300 axle to look at converting the good 200 axle I already had, and the shafts were not only shorter but thinner for the majority of the length (just the splined and seal sections matched the 200 shafts), and the drive flanges are definitely thinner with less spline overlap. The shafts and flanges were worn out through the spline wear that is so common to the 300 parts, and I didn't want to fork out a fortune on replacing parts when a stronger alternative was open to me using parts I already had. Anyway, the point is that the conversion is entirely possible through lots of different methods. The one method I have seen and disliked was the method I used but using standard 90/Discovery/RRC rear discs to match the callipers - to get everything to line up, you'd have to shave a fair bit off the thickness of the calliper mounting brackets as the rotors sit further outboard than front discs' rotors.

 

[AndrewClarke]

This is good stuff. Just a couple nights ago I was starting to research this topic, as my drum brakes need rebuilding (again, again, again, again). No matter what I do, they never seem to work right. I am in the process of placing a parts order to try once again to get them working well, and was just considering that maybe I should just do a disc conversion. I just priced up what I need to buy for my brakes, and it's up to $332 to get my drum brakes working well. I've never really been happy with them though, and this is probably the fourth or fifth time I've been into them for one reason or another in the last six years.

Because I don't even really understand the nuances of the different options, I feel out of my depth and wonder if maybe poorly operating drum brakes are safer than an inadequately understood disc brake conversion. I suppose I could pay someone else to do the work if that's an otherwise show-stopping concern for me.

From this post and others, there seem to be a dizzying array of options. I could use RRC, Discovery, Defender rear or Defender front discs. Some of these options seem to necessitate replacing my brake booster and master cylinder with one from a Defender or possibly a Discovery. Some seem to need new half shafts, and some don't. Some can be bolted on pretty much as-is, and others need machining and fabrication to work right.

The bottom line is that I need my brakes to work well and reliably, of course. I don't really have anyone I trust to do this work for me, now that I think about it, so that means I need to do it myself. That means I need something that's quite easy to source and repair, and is reasonably well documented so I'm not left wondering if the fact that it's 4mm off means I did something wrong, or I need to fabricate a spacer.

I've been amassing the list of links that have been confusing me, which I'll put below in case anyone else cares. I'm happy to get scrapped parts from a NAS Discovery or RRC, but I'd rather buy new parts from the UK and spend more if it means that what I have actually works without having to forge the trail myself.

Neither one of you mentioned that you replaced your brake booster or master cylinder. Did you both find that you had enough fluid and stopping leverage with the stock items?

Does anyone have a recommendation on the best route for me to take if I'm going to try to undertake this swap?

Thanks,
- Andrew.

http://forums.lr4x4.com/index.php?showtopic=11685
http://www.aulro.com/afvb/90-110-13...onversion-county-what-master-cyl-booster.html
http://www.aulro.com/afvb/projects-tutorials/83616-county-drum-rear-disc-rear-booster-upgrade.html
http://www.aulro.com/afvb/technical-chatter/50181-salisbury-disc-brake-conversion.html
http://www.aulro.com/afvb/good-oil/...scs-drums-handbrakes-conversion-calipers.html

 

[Snagger]

My case is a bit different because it's part of fitting later axles to a 109 - I have a Discovery front axle and an early 110 Salisbury rear axle. I am using the Discovery braking system throughout to make sure I have suitably balanced brakes - the maximum gross weight for a 109 is only 50 kg heavier than that for a Discovery, and given that the 109 will be slower than a Discovery and isn't used for towing boats, big caravans or horses, should be more than up to the job. The only snag was that using Discovery rear discs would have required a lot of skimming of the calliper brackets to get the calliper to line up with the disc, but using front discs (I think they're also used as standard 110 rear discs) allows the calliper to fit with a shim between the bracket and axle flange.

Master cylinder pressure is, as you noted, critical to good brake operation. Disc brakes use less fluid transfer but higher pressure than drums. You might need to replace your master cylinder, though you already have front discs, so I suspect the mc will be fine and that you would only need to replace the pressure reducer in the rear lines for a more modern one. Have a look at the axles section on my blog to see what I have done (I know some other people have done the same thing too); www.nickslandrover.co.uk

If in doubt, then refurbishing your existing system with good quality standard parts is the safest option, like you have already suggested. The drum brakes should work well - they just need more cleaning and adjustment, while discs are largely self-cleaning and are self-adjusting.