My Disc Brake Conversion

Evening all,

I have been working on a disc brake conversion for my series 3 front axle and have looked at a few options that would bolt to the swivel housing. I tried with various defender parts then I had a vag 312mm disc machined to fit the defender hub but the bracket was just too complicated and being tight for space I was planning to use off the shelf performance calipers that were adding up to a scary amount of pennies.

Then I came across a conversion previously done with Range Rover Classic 6 bolt swivels and associated hubs and disc brakes, this involves making a spacer to bolt the Range Rover swivel to the series axle casing and the halfshaft needs modifying. Looking like the cheapest option I located an early RRC axle with good swivels and picked it up.

I split the axle down and started getting bits ready for the conversion including a full CAD model of the required spacer to give the correct castor angle.
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One of the swivels was in a bad way, but the axle I got came with an almost perfect condition one to replace this. I havent got any pictures of the measuring up but I have a few of the conversion so far.

The flange on the RRC swivel it a perfect fit into the series axle tube flange where the halfshaft oil seal would have been. This was ideal to help line everything up.

Checking the spacer dimension

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As for the steering the problem of the RRC steering arm hitting the shock and the track arm hitting the springs, the series steering arms can be used if the swivel pin is ground off and extra holes are drilled and tapped into the RRC swivel housing.

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I cant get a decent picture of the caliper brake hose inlet but it is close to the shock as its dual line input and the series only has single line I will be using a brass brake union plug to blank off the extra hole and use the single line series brake system. This gives around 10mm clearance between the back on the caliper and the shock.

Well more will follow all being well, and the postman being on time tomorrow. Hoping to have the spacers machined within the next week to 10 days so i can get the series back on the road.

Interesting thread from an engineering point of view. Look forward to seeing more on this.

Update time,

After the mock up i was happy with the results so cracked on with the spacer design and sent the drawing off for machining.

2 weeks later and..

Spacer arrived and fits perfectly.

I specified M10 x 1.25 thread pitch to get some good torque into the bolts.



The drivers side bolted on nicely and then allowed me to bolt the hub assembly to it.





All bolted up nicely and allowed me to knock up the new brake lines.

Noting at this point that my Halfshafts aren't fitted, i have started machine them down to the correct length and one is finished but awaiting the other one.



Part machined, i am fairly confident that with a good weld over a 25-30mm fillet the halfshafts should be up to driving the wheels, we will have to hope.



Clearance between the disc and the steering joint is limited but is clear enough so I'm happy with that.

Brakes now feel solid and work right from the top of the pedal travel, they do take some effort to push but I'm ok with that, at least i can now stop easily.

Very tidy job, would a more modern servo help with the pressure needed on the pedal? Also will you make spacers for the rear wheels to keep both axle widths the same?

Chief ancient post excavator here.

I want to do this! love it in fact. Though I did have a brain wave, rather than modify the series half shaft, why not just fit a RRC differential, then the RRC CV half shafts would fit right in#!

If nobody else does I want to start making these, or pay this man for a set of adapters or a copy of the drawings...

Series3 man are you staill active here??

Beers!
HH

I think the Zeus or Heystee conversions take some beating as they do not require any machining. For a DIY conversion I think the one on Expedition Land Rover is very good.
http://www.expeditionlandrover.info/discBrake.htm

Yeah I want to go the Heystee way was hoping to go whole hog and have disc brakes all round but noticed their website doesn't show the rears anymore

used H eystee on my series one cost mount with calipers disc etc may have to modify linkage arm as the rubber garter sit close to the disc edge ,still in pro having problems with rear brake cylinders original and new .
they seem to leak over time yet when examined piston are fine original aluminium new cast iron ,only happening on driver side ?

Interesting that its a vented disc which is wider. I know vented is better, but for space an unvented disc may be better and the speeds are low on a series. I would think an unvented would be OK for this use. I've had some pretty fast heavy cars with unvented discs, not ideal but still much better then drums.

the disc and calipers were ordered after request via e-mail to Paul Heystee " the parts required are highlighted on info sheet" hence vented

Intersting, I'm thinking of getting either the Heystee of Zues kits. The Heystee seem to always be in stock whereas the Zues are made in batches. I know from talking to Zues that they will not fit with std series wheels, they must be Wolf style to clear the caliper. Is the Heystee the same?

the series one wheels fitted but found one of the five fitted the counter balance weights fouled the caliper I have since fitted the modern tubeless wheels from Chris Turner https://4x4tyres.co.uk/if anyone want's my old wheel they are free to collect

That does sound like the Heystee leaves a little bit more clearance to the wheel, I think the Zues is min 6" rim..

I had a quick look at the Zeus kit, why on earth do you need a wider rim for clearance. I can understand a larger diameter or different offset but I would have thought a wider rim can only compound clearance issues.

This is the quote from the Zeus website,

"PLEASE NOTE: The vehicle needs to be running on 16inch 6j profile wheels or larger. These have the extra space to accommodate the calliper and most importantly an enlarged "footprint" through which the increased braking power can be applied."

What I think they meant to say was,

"We have had a good go at getting the kit to fit standard Series rims but it isn't going to happen so what we will do is spin it and make the need for different wheels a safety issue"

The standard series rim wheel well is in the same space as the caliper on the Zeus kit.



The width is irrelevant.

Wolf or modular for Zeus.

the balance weights in question

Ohhhh! Never saw them before!

Thanks for those pics, very informative. It does look like (as you say) both riims clear the Zeus calipers.

The series 3 LWB rim doesn't clear. The white rim in my photo couldn't seat on the hub as it hit the caliper.

This is a hard contact interface.


The rim wasn't on the hub.