Rear axle Drum to Disc Upgrade

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MichiganMadness

New Member
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4
Location
Michigan
Hi all, I am a new member (living in USA) with 87 RHD Defender 90 I am currently refurbishing and updating with a number of changes.
I am looking to upgrade rear axle to an Ashcroft limited slip diff and convert to disc brakes at same time as doing a 2 inch lift kit and fitting new HD axles etc
As I am in the USA I have almost no access to good used Defender parts but can get Discovery ones.
My current rear axle is Serial # 22S22655B.
I have found 2 Discovery bare rear axle housings for sale here.
1st.- Is listed as LR Part# FTC3437 and suitable for 99 Discovery I model VIN numbers beginning with SALJY + Discovery II models beginning with SALTY
2nd - Is listed as LR Part# TVI100150 and suitable for 99 Discovery II model VIN numbers beginning with SALTY.

Will either of these work as relatively easy replacements for what I have today and get me caliper mounts and disc brakes ?
I have some fabrication capabilities but to save time and hassle would like to go the replacement way if I can vs modify existing as I have seen on the forum.

Your thoughts and input appreciated
 
I don't think they will fit, you'll need axles from an original (1989-1997) Discovery or a Range Rover Classic. Other members with more Discovery experience will know the answer for definite.
 
You also need the correct compensator valve , other wise front and rear won't be balanced properly, your rears will lock up before the fronts, that's not a good thing.
 
nobber said:
You also need the correct compensator valve , other wise front and rear won't be balanced properly, your rears will lock up before the fronts, that's not a good thing.
Click to expand...
Nice to see someone thinks about what's what. That's the main reason I haven't bothered to do the same, to be honest if the brakes are as they should be my 90 stops as quick as the tyres let it anyway.
 
Rear drum brake's on a 90 are just as good as rear disc's provided they are kept in good order. To "upgrade" Brakes on an 87 90 the simplest way is to fit larger 110 front calipers which became standard on all models when the Defender 200tdi was produced. It's a bolt on job. My 1990 90 [ with 110 calipers ] is still on rear drums and I have no plans to change.
Most of the braking on any vehicle is done by the front wheel/s Its the job of the rear's to stabilize the vehicle.
When towing it is the brakes on the trailor that should be doing the extra work. Upgrading rear brakes to improve towing capability is not the way to go.
 
tottot said:
Rear drum brake's on a 90 are just as good as rear disc's provided they are kept in good order. To "upgrade" Brakes on an 87 90 the simplest way is to fit larger 110 front calipers which became standard on all models when the Defender 200tdi was produced. It's a bolt on job. My 1990 90 [ with 110 calipers ] is still on rear drums and I have no plans to change.
Most of the braking on any vehicle is done by the front wheel/s Its the job of the rear's to stabilize the vehicle.
When towing it is the brakes on the trailor that should be doing the extra work. Upgrading rear brakes to improve towing capability is not the way to go.
Click to expand...

And by doing so you unbalance the vehicles braking capacity between rear and front, simply put, dont do it, its not a racing car, the brakes should work just fine, the purpose of a balanced braking system is not just to stabilise the rear when moving in a straight line, most drivers will brake into a corner and most vehicles will handle Ok while doing so, try and do an emergency stop going around a corner, or braking hard on a corner descending a steep hill, a lot of time and effort went into brake design on a vehicle, granted an old Defender is very very basic but the brakes it came with should be good to do the job, Fitting discs to the rear is fine if done properly but it wont make it stop quicker, not that you would want to anyway, its just easier to maintain, easier to spot worn pads and possibly cheaper to keep in decent condition, if you need to "upgrade" for more braking efficiency then you either put your truck through hard trials, have a worn braking system or drive like a loon.

How many people here have ever changed their brake fluid?

Its a bit like light bulbs, ''oh, my lights are sh1t, I best upgrade them to something stupidly bright and potentially dangerous" instead of "Oh , my lights are sh1t, I best service the electrical system feeding them and put in some new standard bulbs which will be a damn sight better at lighting the road, cheaper and safer for other road users"
 
Ok - thanks all for your responses and input.
I had not thought about fitting the 110 calipers on front to get a useful improvement in braking power for relatively small outlay and effort and will do that.
As for the rear I still plan on replacing with new axle (as diff, shafts etc are all worn) and moving to discs at same time as well. They are just easier to maintain, easier to keep in decent condition and more efficient in all conditions. the bias I will take care of at same time.
 
I was doing unintentional 360 spins going around corners until I figured out the valve issue, in this weather you dont want the rear locking up.
 
30mph or less, not even a sharp bend, tapped the brakes, rear locked up, 180 spin, hit the ditch backwards and was catapulted into a 360 and eventually came to a stop, that scared the pants clean off me, I was lucky.
WP_20180227_07_55_19_Pro.jpg
 
tottot said:
Rear drum brake's on a 90 are just as good as rear disc's provided they are kept in good order. To "upgrade" Brakes on an 87 90 the simplest way is to fit larger 110 front calipers which became standard on all models when the Defender 200tdi was produced. It's a bolt on job. My 1990 90 [ with 110 calipers ] is still on rear drums and I have no plans to change.
Most of the braking on any vehicle is done by the front wheel/s Its the job of the rear's to stabilize the vehicle.
When towing it is the brakes on the trailor that should be doing the extra work. Upgrading rear brakes to improve towing capability is not the way to go.
Click to expand...
What you guys reckon if the 86 90 is going to get an engine upgrade (planning td5) from the 12j… still ok to stick with drum brakes? (Always felt like it she stops bloody well)
both my drums are leaking fluid so either I get a disk conversion kit (seems complex and $$$) …a d1 rear axle (with 4 bolt diff flange) or just get drum repair kit…
what you reckon?
 
Alistair Davidson said:
What you guys reckon if the 86 90 is going to get an engine upgrade (planning td5) from the 12j… still ok to stick with drum brakes? (Always felt like it she stops bloody well)
both my drums are leaking fluid so either I get a disk conversion kit (seems complex and $$$) …a d1 rear axle (with 4 bolt diff flange) or just get drum repair kit…
what you reckon?
Click to expand...

Do as we all do with Nineties. Stick with rear drums, rebuild what you've got fitting new brake cylinders and brake shoes - suggest you use Mintex 1144 shoes, they very good on the rear - and above all just properly maintain your brakes and the braking system. It's not difficult.

If you really need improved braking upgrade to 110 discs, callipers and pads at the front. Job done.

For ref' I've a correctly breathed on 200Tdi in my Ninety. It pulls like an Ox and many a TD5 struggles to keep up. My brakes are as above...110 stopping power at the front, std new drums, springs and cylinders at the rear with Mintex 1144 material all round.
 
As above. My 200tdi Ninety is much the same, 110 calipers on the front [ bolt on job ] drums rear.
With any four wheeled vehicle it is the front brakes that do most of the [work] braking force, around 75/80%. It is the rear brakes that provide stability.
 
Also, too much rear brake bias (e.g. by fitting uprated disc brakes) will actually increase stopping distance- the rear wheels lock up before you can apply full braking with the fronts. It's one of those things that initially looks like a good idea and is relatively simple to do (just bolt on a Disco 1 rear axle) but isn't necessarily that straightforward.
 
Early Ninety's had 600x16 cross ply and then went to 205x16radial. As most today run on larger boots a good mod is to fit 110 calipers to cope. It is what Land Rover did with the introduction of the Defender 200tdi model.
 
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