110 Salisbury Replacement

[=jon=]

Hi All

I've got a Salisbury drum braked rear axle on my 110 - it's getting a bit tired and clonky so I'm looking to replace it, and will probably take it as an opportunity to swap to disc brakes and also an ATB and strength upgrades from Nige for any future plans I may have.

With that in mind - what's the best option as a starting point for building one up - looking at ebay there's various TD5 / Puma rear axles listed - or if the diff is being replaced along with heavy duty shafts does it not really make a lot of difference?

Jon

[miketomcat]

Just remember if you use the rover axle you'll need a different rear prop to. Personally I went with Salisbury and upgraded to discs on the ibex but then I wanted the strongest stock axle without spending a fortune on diff, shafts etc.

Mike

[=jon=]

Thanks - figured I'd need a new prop as part of it

[Sigi_H]

Put the ATB to the front. The Salisbury is bulletproof anyway and if you put the ATB to the front it will be a better axle as well. The drums are not worse than the disks. The only disadvantage is that you have to do more maintenance. If you rebuild the Salisbury with an ATB your front is still weak with a two-pin diff

[Snagger]

I think the standard 110 shafts, for either axle type, are generally strong enough.  As far as I know, the weakness of the short nosed Rover diff is the pinion bearings, not the diff centre, so pegging is the only upgrade you’d likely need, but there are a lot of aftermarket diff upgrades to chose from if that takes your fancy.  With the Salisbury, you’ll have a stronger casing, stronger pinion and at least as strong shafts, and the diff can also be changed to some sort of locking unit if an overhaul doesn’t satiate you.

[=jon=]

Hmm - I was fairly sure I read somewhere (here potentially) that although the Salisbury was stronger than the rover diffs, there were weak points elsewhere that meant it could still cause issues. If that's not the case maybe overhauling that and converting to discs is the best starting point. I've dropped Nige a PM asking for his advice as he is certainly the man who can help..

Long term plan is to upgrade the front axle at some point as well..

[reb78]

Can you get Nige to post on here Jon? I have had the same thoughts and kinda wanted to keep the salisbury and was considering doing what Sigi suggests.  
 

My drum brakes can stay as they are. Quick twist on the adjusters at each service and they work just fine. 

[=jon=]

Sure - will do

[Sigi_H]

Thoughts on the brakes:

Since drum shoes have a much bigger active surface, they even should be better than discs in braking forces. Double active drums have even two self reinforcing brake shoes. The real disadvantages of drums are the maintenance on the adjusters and thermal behaviour, not the braking forces. They have a lot more fading than discs, because drums become wider with temperature.

If you can live with that, stick on the drums. I changed to discs, because i got sick of the adjusting (to have good performance, check twice a year)

[FridgeFreezer]

Discs are infinitely nicer than drums but bear in mind the rear brakes on any vehicle do very little - if you look at a lot of modern cars they have discs on the front and tiny p*ss pot drums on the back, even cars with discs all round have huge discs on the front and tiny ones on the back.

Personally I'd keep the Salisbury, they're much stronger than Rover diffs and you can get ATB's etc. for them if you want. Mate of mine had an early Puma 110 and the only thing he hated about it was the number of times the back axle sh*t itself, as soon as it was out of warranty he swapped a Salisbury under it. He did do a lot of towing though.

Half shafts would be the weak point - but I'd run it and see, if you break a shaft it's very easy to get to with a Salisbury (pop the cover off) and then you can treat it to an uprated pair of shafts if you want.

[Sigi_H]

look here too

 

[mickeyw]

On 3/18/2021 at 1:04 PM, Sigi_H said:

The drums are not worse than the disks. The only disadvantage is that you have to do more maintenance. 

This rather depends on how you use your vehicle. Frequent driving through the sloppy brown stuff not only means frequent adjustment of the drums is necessary, but the complete removal of the drums to clean out dried muck that causes varius components to rust a jam up. It takes quite a lot of time!
I found converting to a disk rear axle on my 90 a complete revelation from a maintenance POV. You still burn through pads in the mud, but generally a blast with the jet wash is all that is needed to keep everything in working order.

A disk conversion is on the cards for my 110 at some point.

[Tim2809]

If you swap axle from a td5 onward era you need it to be from a 110 as its a 4pin diff, the casing and diff length is different but a later prop will fit. 
 

[uninformed]

The Salisbury 8Ha has a much bigger and stronger differential. The hemisphere is a better design with 4 pinion gears rather than 2 in most P38 and Rover type diffs. The pinion is also offset (Hypoid) making the already larger pinion head, larger again by nature of gear design.
 

The cast centre housing is very strong but also very heavy. It is also harder to work on as the differential centre does not bolt in/out. (You need to forcibly spread the cast casing to remove the differential). It also has less ground clearance than a P38 or Rover type.

 

The Salisbury in the 110s had thinner wall tubes than the 130s . And there have been some failures on 110s where the axle tubes insert into the cast centre (abrupt change in stiffness) 
 

Drum brakes work but they are certainly not better than discs. On paper with a one off braking event they may be ( but you would not say a 110 rear drum has more braking force than the disc brakes on a Porsche Cayenne Turbo) . The point is drums fall away with repeated braking events and or water/mud. You can easily convert your Salisbury to disc with complete later Sals disc parts including hubs and stubs and shafts, or use early front hubs on your drum stubs and go from there but double check ALL ( and I do mean ALL measurements!)
 

There is a reason heavy industry has moved to disc brakes!

 

The P38 style diff (Td5 onwards) is often considered worse than a Rover style. Both can be had in 2 or 4 pinion ( I would never run anything less than a factory 4 pinion, but have always had lockers so 4 pinion is standard) Both will have a similar strength in the housing itself.

 

Shafts: well a 24 spline shaft is only as strong as a 24 spline shaft, front or rear! 

 

Fwiw I sold my locked Sals and custom built a Rover style rear for my 110. I really dislike Salisbury type housings.

[Sigi_H]

6 hours ago, uninformed said:

There is a reason heavy industry has moved to disc brakes!

Of course there is a reason. But it is not the bad braking power of drums, even though people believe that. There are other big advantages.

• Easily self adjusting, what means almost no maintenance.
• Cheaper
• Less thermal sensitivity
• Less mud sensitivity
• Easier to mount

On the other hand look at the brakes of truck trailers. They still have big drums. The reason is, that you can place a big braking surface in the drums. If the weight is big and there is an emergency, the trailer has to be stopped immediately but not often in a row. Here the drums are better.

 

[uninformed]

12 minutes ago, Sigi_H said:

Of course there is a reason. But it is not the bad braking power of drums, even though people believe that. There are other big advantages.

• Easily self adjusting, what means almost no maintenance.
• Cheaper
• Less thermal sensitivity
• Less mud sensitivity
• Easier to mount

On the other hand look at the brakes of truck trailers. They still have big drums. The reason is, that you can place a big braking surface in the drums. If the weight is big and there is an emergency, the trailer has to be stopped immediately but not often in a row. Here the drums are better.

 

I disagree 

 

first of all, if discs were cheaper every 4x4 Ute/dual cab would have them in the rear! That’s Ford,Mazda,Isuzu,Nissan,Toyota etc.

 

And you have even supported my argument where you write “less thermal sensitivity”. Re read what I wrote, drum brakes are good for one off braking event , or for that matter, holding power ( I prefer drum for the transfer brake) but they fall behind discs with repeated braking, mud, water etc. 

We don’t drive in a paper world, Real world data from heavy industry has discs stopping shorter than drums. 

 

“The main strong point for disc brakes is reduced stopping distance. With disc brakes, that distance can be anywhere from 17% to 33% shorter than drum brakes, depending on speed. ... Compared to disc brakes, drum brakes are generally more durable, requiring fewer lining replacements in a given period.”

 

 

[=jon=]

Do big trucks not have drums because they are air operated rather than hydraulic?

[western]

Lots of new hgv now have disc brakes as do new semi trailers, yes the are still air operated, well the air pressure keeps the brakes off, so reducing the air puts the brakes on, a air braked vehicle with no pressure in the system/tanks will not release brakes until sufficient pressure is built up. 

[hurbie]

43 minutes ago, western said:

Lots of new hgv now have disc brakes as do new semi trailers, yes the are still air operated, well the air pressure keeps the brakes off, so reducing the air puts the brakes on, a air braked vehicle with no pressure in the system/tanks will not release brakes until sufficient pressure is built up. 

not quit right , hgv and trailers use airbrakes (most use disc , but on some applications drums are still used) , the system is split in 2 sections , 1 is for parking and emergency braking (as in een air hose ruptered or a compressor failure) this system uses air to keep the brake off (normally around 8 bar , but newer trucks use higher pressure's) , in the emergency/parking brake cilinder is a huge spring, this put's the brake on if there is no airpressure.

second system is the normal brake , this uses a cilinder witch uses air pressure to put the brake's on , the 2 cilinders are put together in 1 unit for ease of fitting/space

not all axle's use the dual cilinder , only enough axle's to get a sufficient parking brake force (so the vehicle will stay on it's place when loaded with 40 ton on a incline with no airpressure.

[Sigi_H]

Back to Land Rover:  I just wanted to say, that only braking forces are not the reason to switch to discs. Good adjusted drums have easily the same power. But all the other reasons count.

[Snagger]

For well set up brakes on the same vehicle, there should be no significant difference in stopping distance between disc and drum brakes - the limit of braking effort is going to be determined by tyre grip, and that is not affected by brake type.  Discs are an awful lot easier to maintain, they cool more rapidly, they self clean better and they do seem easier for the driver to apply finer control with, so that last point may create an impression of improved braking distance, but that depends on the driver.

[Ed Poore]

Most of this info was summarised for me by Nige when I first popped down to see him quite a few years back but I did my own research as well and it was corroborated.

My 300Tdi 110 obviously came from the factory with a disc braked Salisbury axle. I was looking at putting a locker into the front and rear and for whatever reason I initially wanted to stick with the Salisbury unit on the rear. Following discussions with Nige I opted not to do that.

The primary strength from Land Rover's version of the Salisbury's diff (note I'm not talking about swapping in Dana components etc., but those that are actually found from factory in LR axles) comes from the cross-pin in the centre of the diff. The half-shafts, casings etc., for my purposes (hard but not abusive usage) were mainly 6 of 1 and half a dozen of another Salisbury vs. Rover casing. The only sensible option at the time for a locker for the Salisbury was from ARB and there were difficulties in sourcing parts and concerns over their reliability for infrequent usage. Note here I was absolutely not interested in a limited slip one - full locker for me so I can't really comment on their pros / cons. One of the things that happened when you swapped out the centre of the Salisbury is you lost that mahoosive cross-pin and thus one of the main strengths for the diff.

Compare this to the route of going down an Ashlocker which has been proven to be resilient in competition and parts are easily available in the UK and it seemed a bit of a no-brainer. I.e. Nige can build up a very strong Rover / Ashlocker setup that most people are unlikely to push the limits of.

The rear diff was fitted about 4 years ago and I think  I've changed the oil in it since (at least once)... Guestimate that it's done over 50k since then and it's been 100% fault free. The front diff got fitted about a year later and again has been absolutely fault free with pretty much zero maintenance.

@=jon= First I'd double check all the other bits of the rear axle are slop free - I thought my Salisbury was on the way out but once I actually removed the axle from the vehicle I found the diff itself had almost nothing and it was mostly drive-flange / half-shaft slop.

With regards to braking I'd concur with @Snagger a well maintained vehicle irrespective of type of braking (particularly with LR) will be limited by the tyre adhesion, discs are definitely lower / zero maintenance. Funny story but when I first took the 6x6 in for it's MOT I knew it was going to fail as a connection in the dash had worked loose but I was more concerned whether it was going to pass emissions because it was smoking quite a bit. Anyway it failed on the expected electrical issues but also on braking effort (flew through emissions). Damn forgot it was on drums and I hadn't adjusted them, anyway a week later on the re-test the tester took it off down the road for the Tapley test. Came back rubbing his forehead - "yeah, you sorted the brakes out alright - I hit the ****ing windscreen".