Rear Disc Brakes.............the build...............

[Gremlin]

Righty ho, i finally started on my rear disc conversion. This is going to be a slow build as time is becoming difficult to manage.

So as a start, i will have to have a disclaimer, i am doing this on my vehicle, i am in no way responsable for some spanner monkey who wants to do the same, and or injur himself while making or testing the parts. these are brakes we are mentioning here! Remember.

To start off i did not want to stay without a landy so the first step was to find a doner axle, so i can take my time and do it right. The plan is to build and refurbish the axle complete with brakes and then swap it over to the landy.

I managed to lay my hands (free) on 1 semi stripped salisbury axle a few years ago from a good freind, for another project (home made difflock), it was a bare with missing shafts and brakes and just 1 hub. This was stripped down further to see if it was usable. It had fried pinion bearings so i put it all aside and looked for another.

About a year ago another axle was aquired (free again) complete. So i did the same a set to dismantle it, the first bad sign was creamy oil! Upon further inspection (cover off) the whole gear set is scrap (rusty), so are the main bearings and 1 pinion bearing. The axle was left with water contaminated oil for quite a long time. So again this one seems to be going to the scrap man.

So i will revert back to my first axle and change the pinion bearings, as the gear set is fine plus i have the modified cross shaft for the experimental homemade difflock to go with it. I will use the shafts from the scrap axle.

Now to the build, once again i will be using parts from the land rover parts bin. I will be using late stub axles (same bearings) so i can fit the front 90/110 hubs. I started mocking up the parts i have to see what need to be fitted and/or modified.

So i stuck the stub axle on, then the 110 rear caliper bracket, then the 90/110 fron hubs, then drive flange and shaft, it all seems to fit. I still need the caliper to confirm the exact spacing i need for the bracket or the hat hieght of the disc. Hopefully i will get the calipers some time soon.

Initial observations are that the bracket need slight grinding, and so does the axle tube. For the rest it looks like it will work. I have a lot of painting and cleaning to do to all the bits that will go on this axle. At this point its a pile of rusty parts.

A couple of weeks later i finally managed to get all the parts to have the assembly mocked up. Parts list as follows

90 rear calipers, 110 stub axles, 110/90 front hubs, front discs, 110 caliper brackets.

From various trial and errors in trying to assemble the the whole lot, i tried using 90/disco rear discs but that involved trimming the brackets down by 3mm. I did not like the idea so i went to front disks (or 110 rears). The problem with this is that again the brackets will not line up with the discs so i have to make a 5mm spacer between the bracket and axle tube.

Pictures will make this simpler to understand.

Calipers

Brackets

Stub axle and bracket

Washers being used as spacers for mock up.

Front hub on a 110 rear stub axle

Caliper in place

This the thickness i need and the spacer cut in cardboard as a template

Rendering in sketch up

Next steps are to have every thing cleaned up and refurbed, painted, and new seals and discs installed.

Here are couple of pics of the slight diff shave, thought it was worth attacking it with the grinder!

I guess thats it for now.

G

[minimaquinas]

it looks like a lot of work to me just to have rear disc brakes

[Soren Frimodt]

I like that crosspin, looks very similar to a locker I had planned myself a long time ago, where I would slide one of the halfshafts into the crosspin to lock, looks like you had a similar idea? I abandoned the idea because I couldn't find a clever way to slide the halfshaft, plus if the splines got twisted it wouldn't work..

[Gremlin]

Yes that is the idea behind it, a longer shaft with longer splines. My plan was to use some sort of system with a screw to move the shaft in and out with a spring. I am still contemplating on how to make it work. The idea came from a locker that used to be supplied by mc namara, look below.

G

[Soren Frimodt]

Cool! Heard of this but never seen it before! Though I will say that by todays standards it doesn't seem that great a setup. But sure, its way cheaper to build than an ARB type setup

[tiagoc]

it looks like a lot of work to me just to have rear disc brakes

For you (in Spain), it'll be easier to go the same path as I: get a complete front disc setup from a Santana, and change everything at the back.

Result:

[Snagger]

You are doing the same thing as I did to convert my early 110 drum braked Salisbury axle to discs. I found that I had to bevel the inside edge of the spacer washer inboard of the inner wheel bearing nuts as the disc braked front hubs seem to have very slightly narrower bearing spacing than the Salisbury rear hubs, causing the spacer washer to foul the bevelled end of the plain section of the stub axles about 1mm before they pressed up against the outboard wheel bearing. This might not affect Series axles in the same way as the Series stub axles may have slight dimensional differences over the 110 type - SIII axles don't have the same thick washer.

[Gremlin]

Hi Nick

Thanks for the tip, i will look out for that but on mine it seems to sit well.

Do you have some pics on your site?

G

[lexi]

Great work.

You even got sunshine in your garage to help you along.

[Snagger]

Try these:

http://www.nickslandrover.co.uk/archives/1412 and http://www.nickslandrover.co.uk/archives/1486

I used the Salisbury stub axles, flanges and shafts with 90/110 front hubs and disc. The calliper brackets are from a disc braked Salisbury axle and I used spacers just like you have drawn up to set the brackets further inboard from the stub axle flange to align the slot in the Discovery callipers with the discs. Using Discovery rear discs put the disc too far outboard, requiring the calliper brackets to be skimmed by about 3mm, and like you I was concerned that this would weaken the brackets too much. I thought I had pictures of the thick washer being modified, but apparently I don't.

[Gremlin]

Hi Nick

Thanks appriciated, same reciepe exactly then!

G

[Jon White]

Use range rover rear disks and hubs, and range rover rear calipers, and you simply need to thin the brackets down by about 1.5mm or so (cant remeber exactly i did it so long ago) - much easier than pissing about making spacers.

IIRC i use drum braked 90 rear stub axles. do a search on here, or possibly the other (old) forum for a post describing how i did mine many years ago.

Jon

[Snagger]

Use range rover rear disks and hubs, and range rover rear calipers, and you simply need to thin the brackets down by about 1.5mm or so (cant remeber exactly i did it so long ago) - much easier than pissing about making spacers. IIRC i use drum braked 90 rear stub axles. do a search on here, or possibly the other (old) forum for a post describing how i did mine many years ago. Jon

It would have been easier, but I believe Gremlin has the same concern about shaving the brackets as I did - that removing such an amount of material from around the calliper mounting bolt holes could weaken the bracket and lead to brake failure. Given what happened Gresh in his 110 accident, where braking, suspension and steering component issues were all contributory, I decided a spacer and front discs were a more prudent solution.

[jai_landrover]

How did you get on with the outtermost wheel bearing? When I mocked it up the outtermost wheel bearing was only 75% on the plain sub axle whereas 25% of the outtermost part of the bearing was out over the thread and not supported. We junked that Idea for the road because we plan on using stupid size tyres and we believed it wasn't as good as it could have been so its on hold until I can machine a couple of hubs out a few mm each side or come up with a better idea. Too many projects means it'll be done at some point tho.

[Jon White]

IIRC I skimmed the brackets on the side that bolts to the axle tube, so not affecting the bolt holes that the calipers bolt onto. The brackets are immense there, so there is plenty of scope to thin them down a little here. If you look at the construction of an disk braked axle with the welded on caliper mounts, and compare the two, the welded on mounts really are quite weedy when compared with these bracket.

I do take your point about what happened to Gresh etc, however i suspect that in a court of law, the simple fact that you have modified the braking system at all, would be enough to land in loads of trouble. I would also point out (although I accept that I'm not 100% certain of the facts) that part of the problem Gresh had was shockingly poor maintenance, such that he ended up with 2 brake calipers on an axle that were not even a matching pair!

Jon

[ejparrott]

Am I right in thinking your calliper brackets are FTC3306?

[jai_landrover]

Yea that sounds right x2. Paddocks didn't stock them and anywhere that did wanted £60 plus Vat each. Now Britpart have made them Paddocks are selling them for £30 plus Vat each!

[RobotMan]

Strength wise, on the brackets, I would not going below 3500Lbs.in applied at calliper bosses.

Get the monster torque wrench out if you are worried about thinned down brackets, it would put your mind at rest.

[ejparrott]

Brackets

What are the 2 small tapped holes in the bosses for? They obiously don't pick up on and stub axle holes, at least not on my Stage 1 salisbury axle...

Just been going through what I've got....I've got a complete set of 90 front swivels in the shed, so I've got hubs already, and some solid disks for a mock up. Planning on doing one side at the moment, and when I'm happy with everything, I'll order all the proper bits and do both sides.

[Snagger]

Those are the same brackets as I used. I think I got them from Dunsfold. The small, raised threaded holes near the bottom of the above photo are for securing the mud shield plate. I am currently debating whether to fit the mud shields when I fit the axles - they should keep a lot of rubbish off the discs when on wet roads or for light off roading, but will not make any difference in deep mud or water and I know someone who had a stone trapped behind a mud shield on a classic Jaguar which scored the disc badly enough that the rotor sheared off the hub. They'll also prolong disc cooling times. I have to decide whether the pros outweigh the cons.

[ejparrott]

ah ha! Cheers Nick!

[sussex-landy]

I have the same on my front and rear axles so have discs all round and I didnt fit the mud shields so I could power wash them off fully (and instepct them) and not get stuff hidden behind them. I also found on my P38 that when the discs rusted over time chunks of rust got stuck between the disc and the mudshield which also attracted mud and the discs rotted faster where this had happened.

[Gremlin]

Minor update

Got my spacers cut by waterjet!

Time to get cracking............

G

[ejparrott]

Nice Job Grem!

Here's a suggestion...a cheeky one...how about, an email of the CAD file for the cutting, in return for a donation to the forum??

Can you guess why I'm suggesting it...

[Gremlin]

Yeah no problem, i must get it back from the water jet guy as he amended my original file as i had some errors.

Tomorrow or friday.......................

G