Jump to content

Disco 1 axles on SII SWB


backball
 Share

Recommended Posts

I'm considering Disco 1 axles for my 1962 SIIa 88' petrol for mainly two reasons:

1. give it that extra few inches of track

2. disc brakes; I love that feeling on drum brakes after a decent river crossing :(

I know you probably could achieve both through other means (e.g. wheel spacers, disc brake conversion kit) and some might argue cheaper means but this shall not be the topic here as it really depends on how cheap I can get second hand axles.

My key concern/question is the change in overall gear ratio (if any). I want to keep my current gearbox and transfer case (if it ain't broken don't change it). Would disco 1 axles change the ratio assuming I'm on an original gearbox and transfer case? btw, on a side note how can I tell whether I still got the original gear box/transfer case? First and second gears are not synchronised

thanks

Link to comment
Share on other sites

best to look at another one thats done 1st

unless u do a spring over you'll find a few problems with the steering bar on the back of the axle

hitting the springs

would be easier to fit discs and diffs to your existing axles

Link to comment
Share on other sites

Swings and roundabouts - fitting discs to a series is a fair bit of work, but then bolting coiler axles on to leaf springs is just as much of a PITFA, and you can't just use Will's pigeon to weld the brackets on either. Converting to coils is the most obvious way, but these days you may as well sell the series and buy a defender rather than bugger up the series.

Sorry, that's not a lot of help is it? :unsure:

Link to comment
Share on other sites

To get the clearance for the trackrod you will need to use the 2" longer military shackles.

PDR_0421.jpg

The lower shock mount needs to be moved up and forward as well.

PDR_0422.jpg

Another problem is a U bolt can't be used on the inside of the rhs due to the shape of the axle case.

PDR_0419.jpg

Doable but not straight forward!

Link to comment
Share on other sites

To get the clearance for the trackrod you will need to use the 2" longer military shackles.

PDR_0421.jpg

The lower shock mount needs to be moved up and forward as well.

PDR_0422.jpg

Another problem is a U bolt can't be used on the inside of the rhs due to the shape of the axle case.

PDR_0419.jpg

Doable but not straight forward!

So the loss of ground clearance by having thicker spring mounting saddles is compensated for by the thinner parabolic springs ?

I have an obsession with front axle tramp as I strongly believe it to be the main contributing factor to the premature death of transmission and suspension components on leaf sprung Landeys that are used off road.

Clearance between trackrod and spring appears marginal, and I would suspect severe fouling would occur with axle tramp when the front wheels are scrabbling or traction. Never underestimate how far things can move with axle tramp. Standard series front shocks get bashed up badly against the swivel housing flanges due to axle tramp,and yet there is over one inch of clearance in this area, just to give you some idea of the clearances you should allow.

Swinging the lower shock mount up and foward aims the shock more towards direction of travel, but the reduced distance to the axle centre gives the shock less effective leverage to assist in controlling tramp. The bolts threaded into the mounting saddle in place of ''U'' bolts worries me a little. The early Nissan Patrols had this arrangrment and used to suffer regular bolt breakages due to corrosion and fatigue. Better to weld a piece of hollow bar to axle housing instead and use a plain nut and bolt.

Bill.

Link to comment
Share on other sites

disco axles are 3.54:1 ratio, whereas your axles at present are 4.7:1, if you do put disco axles on then your diffs will bolt straight into the disco axles and the halfshafts are 10 spline so will mate up to your diffs too.

Thanks for the clarification. So does this mean I could reuse my current diff? If I stay with the disco diff then my offroad-ability would be compromised given the lower ratio, right? Onroad driving might also be a problem as the engine revs lower at the same speeds. Is my understanding correct?

Link to comment
Share on other sites

Swings and roundabouts - fitting discs to a series is a fair bit of work, but then bolting coiler axles on to leaf springs is just as much of a PITFA, and you can't just use Will's pigeon to weld the brackets on either. Converting to coils is the most obvious way, but these days you may as well sell the series and buy a defender rather than bugger up the series.

Sorry, that's not a lot of help is it? :unsure:

Well, I see myself as a Land Rover owner who likes to go off the beaten track (like many of us I'd like to believe). It's a hobby and part of it is looking for alternatives to improve my rig and have fun along the way - and exchanging my trusted Series for a Defender is not part of that script - :rolleyes: However, I appreciate every bit of info from the community as this will certainly enhance the final outcome...

Link to comment
Share on other sites

Thanks for the clarification. So does this mean I could reuse my current diff? If I stay with the disco diff then my offroad-ability would be compromised given the lower ratio, right? Onroad driving might also be a problem as the engine revs lower at the same speeds. Is my understanding correct?

your current diffs would fit into the disco axles, your diffs are lower ratio than the disco units, low gearing offroad is generally better.

Link to comment
Share on other sites

^^^ Wot Tonk said, I had high ratio (3.54) diffs in the 109 because of the V8 but they were a bit high for controlled hill descent off-road. Wasn't bad but not quite as slow as you'd want, if you see what I mean! :blink:

Glad to hear you're keeping it Series ;) any axles can be made to fit, it's just a question of effort, have you considered axles from anything non-LR? G-wagen ones seem V strong and I think they come with lockers to boot. Then again, portals come with lockers and would be even more fun :D

Link to comment
Share on other sites

Did mine differently using rangie axles

DSCF0113.jpg

DSCF0104.jpg

DSCF0106.jpg

DSCF0114.jpg

DSCF0128.jpg

P1010100.jpg

Picture007.jpg

CopyofDSCF0029.jpg

CopyofDSCF0026.jpg

P1010102.jpg

And before you say it, i know my shocks are the wrong way around

very nice job... especially the steering damper. Also the issues discussed earlier with track rod clearance can be controlled by the height of spring mounting saddles althrough there's a trade-off to ground clearance as outlined by Bill.

Could you reuse the original U-bolts or are they custom? I figure these are classic RR axles, right?

Link to comment
Share on other sites

very nice job... especially the steering damper. Also the issues discussed earlier with track rod clearance can be controlled by the height of spring mounting saddles althrough there's a trade-off to ground clearance as outlined by Bill.

Could you reuse the original U-bolts or are they custom? I figure these are classic RR axles, right?

mine uses saddles that are extended by 20mm to give the clearance, yeah they are classic rangie axles.

i used the longer shackle that would be nearest the diff on a standard series model for 3 of the ubolts, but the one nerest the diff on the rangie axle was custom made by a company... properly heat treated etc. but cost about £40.

my conversion is a little bit different. i set mine up to the original manufacturers spec of castor angle with standard shackles. instead of setting it once the military shackles are installed. this means if i wanted, i can go back to standard shackles at any time.. but negatively gives you increased castor with extended ones.

thsi set up is to change some time in the future. with a custom track rod to allow the saddle blocks to be reduced, essentially giving a stadard set up, although that will require the revision on the shock mounting plates ( most likely) with out the necessity for extended shackles, although it will still have them :D

but that will be looked up once ive finished with the 4wd/5speed conversion

the shock lower plates on my conversion are actually just a swb rear set mounted on the front, pulling the shock closer to the axle casing, and giving enough clearance for the track rod.

Link to comment
Share on other sites

So the loss of ground clearance by having thicker spring mounting saddles is compensated for by the thinner parabolic springs ?

I have an obsession with front axle tramp as I strongly believe it to be the main contributing factor to the premature death of transmission and suspension components on leaf sprung Landeys that are used off road.

Clearance between trackrod and spring appears marginal, and I would suspect severe fouling would occur with axle tramp when the front wheels are scrabbling or traction. Never underestimate how far things can move with axle tramp. Standard series front shocks get bashed up badly against the swivel housing flanges due to axle tramp,and yet there is over one inch of clearance in this area, just to give you some idea of the clearances you should allow.

Swinging the lower shock mount up and foward aims the shock more towards direction of travel, but the reduced distance to the axle centre gives the shock less effective leverage to assist in controlling tramp. The bolts threaded into the mounting saddle in place of ''U'' bolts worries me a little. The early Nissan Patrols had this arrangrment and used to suffer regular bolt breakages due to corrosion and fatigue. Better to weld a piece of hollow bar to axle housing instead and use a plain nut and bolt.

Bill.

The spring mounting saddles aren't any thicker so no ground clearance is lost. Infact it is increased as there is no shock absorber hanging below the spring plate.

Yes I agree that axle tramp can be a problem with leaf springs. It is no better or worse than with the standard setup. The photo showing the track rod clearance is taken with the suspension on full droop and the steering on full lock, this is when the clearance is at it's minimum. There is 3/8" clearance with the suspension loaded and the steering at the straight ahead position. The track rod is 30mm dia which does reduce it slightly. As the track rod is quite close to the axle centre there is minimal variation in the clearance as the suspension moves or when the axle tramps. (I've tried it)There has never been any contact between the two. To make the shocks hit the swivel flanges must take some very brutal treatment, I'm not surprised that the transmission breaks!

Moving the shock mounting up allows the shock to work at 90 degrees to the axle centre, the ideal angle to reduce tramp as any twist on the axle is converted directly to vertical movement of the shock absorber. With the standard mounting below the axle the twist is converted to fore/aft movement as well as up/down. In both cases I would think the effect on tramp will be minimal due to the closeness to the axle centre line.

The inner mountings are studs not bolts. They are threaded into steel blocks welded to the axle case and the mounting saddle. The stud material and nuts are the same as the U bolt so are no more likely to fail than the U bolt.

There's always more than one way to get round a problem though isn't there!

Link to comment
Share on other sites

Paul,did you rotate the axle forwards to help with trackrod clearance? - your diff pinion looks to be pointing up at a higher angle than standard.

If so,did you notice any effect from reduced castor?And did you change the prop to a double cardan?

Looks like a good job.

Link to comment
Share on other sites

A nice tidy job there Meccano, awesome set of brakes :D

cheers, i quite like your shock mount idea. keeps them out of harms way. Got any more close up pictures of top and bottom, as i just about see you have extended the top mount to compernsate. i think it would compliment the modified track rod idea.

What leaves are you running, mine are CP springs, and i think a bit to soft on the rear end to handle the axle wrap caused by rear discs.

Link to comment
Share on other sites

Jericho, from memory the axle is rotated 12 degrees from vertical, this gives 3 degrees of caster which I believe is the standard figure for the RR. I don't know how much caster the Series has originally? It drives just fine, no wandering. The prop is a standard Series front from Paddocks. The original prop was only just long enough but the new one has a different sort of slider so it won't bottom out.

Meccano, your axle doesn't seem to be rotated as far as mine, hard to tell from photo's I know? What castor angle is yours set at?

Yes I moved my top mount as well mainly because my shocks were nearly new and I didn't want to replace them!

My springs are Ti Console which I bought from Chris Perfect. I'm using a dual circuit master cylinder with servo off of a 109. I haven't had any problems with this set up.

PDR_0426.jpg

PDR_0425.jpg

PDR_0424.jpg

Link to comment
Share on other sites

Meccano, your axle doesn't seem to be rotated as far as mine, hard to tell from photo's I know? What castor angle is yours set at?

Yes I moved my top mount as well mainly because my shocks were nearly new and I didn't want to replace them!

My springs are Ti Console which I bought from Chris Perfect. I'm using a dual circuit master cylinder with servo off of a 109. I haven't had any problems with this set up.

a series is also at 3 degrees. mines set up to be 3 degrees castor with standard shackles. so when i fitted the military shackles it approx 3 more degrees. it does make the steering a bit heavier than id like ( but i do have a small sttering wheel). but it makes it really nice at higher speeds.

im also using a servo, dual circuit. no problem with the braking power. but as i reach lower end speeds i get a juddering corse noise. its only since i fitted the 2 leave parras all around , the old less marshmellow 3 leaf on the didnt suffer at all. planning on fitting a third link/ damper on the rear axle using the rangie mount that is still on the casing to stop the shuddering.

have you noticed any prop vibration, i use to get it at about 70mph

Link to comment
Share on other sites

To get around the track rod fouling with the springs, there is another solution. Find an Left hand corner from a left hand drive axle (a lot of military LRs were LHD) and bolt that on to the axle. Have a new track rod made that also has the mount for for the drag link in it, and you then have a system that keeps the track rod up out of the way, and it clears the springs. Okay, you loose the Ackerman effect on the steering, but that is not the end of the world. (I did have one, but I think it's been butchered/thrown away, I'll try and remember to check).

Don't forget, you will also have to use a steering box from a vehicle that pushes across the vehicle rather than front to back, so when you break your Disco, get that too, and you then have the benefit of power steering.

Any more questions, PM me.

Toby

Link to comment
Share on other sites

The spring mounting saddles aren't any thicker so no ground clearance is lost. Infact it is increased as there is no shock absorber hanging below the spring plate.

Yes I agree that axle tramp can be a problem with leaf springs. It is no better or worse than with the standard setup. The photo showing the track rod clearance is taken with the suspension on full droop and the steering on full lock, this is when the clearance is at it's minimum. There is 3/8" clearance with the suspension loaded and the steering at the straight ahead position. The track rod is 30mm dia which does reduce it slightly. As the track rod is quite close to the axle centre there is minimal variation in the clearance as the suspension moves or when the axle tramps. (I've tried it)There has never been any contact between the two. To make the shocks hit the swivel flanges must take some very brutal treatment, I'm not surprised that the transmission breaks!

Moving the shock mounting up allows the shock to work at 90 degrees to the axle centre, the ideal angle to reduce tramp as any twist on the axle is converted directly to vertical movement of the shock absorber. With the standard mounting below the axle the twist is converted to fore/aft movement as well as up/down. In both cases I would think the effect on tramp will be minimal due to the closeness to the axle centre line.

The inner mountings are studs not bolts. They are threaded into steel blocks welded to the axle case and the mounting saddle. The stud material and nuts are the same as the U bolt so are no more likely to fail than the U bolt.

There's always more than one way to get round a problem though isn't there!

The spring mounting saddles certainly appear thicker(deeper) and would have to be anyway to provide the necessary

trackrod clearance to the spring, otherwise coil model axle conversions to leaf sprung Landies would be commonplace.

I personally don't see how fitting longer shackles provides more clearance between trackrod and spring? The trackrod is part of the axle assembly, as is the spring. How do longer shackles increase the distance between the trackrod and spring?

It doesn't take that much effort to bash the shocks on the swivel flanges when the front wheels are scrabbling for traction on loose ,rocky firetrails,thanks to short springs and rearward shackle placement.

Bill.

Link to comment
Share on other sites

Meccano,

Tighten your U bolts, the rust showing between the axle/spring and spring /plate is a sure sign that the axle is moving and rubbing the paint off. If you leave it like this, you'll snap a U bolt.

Toby

nope your wrong

bill van....

they mean by keep the axle set at 3 degrees castor when the leaf is pushed down by the extended shackles you have this effect:

the leaf essential rotates around the axle casing

extendingshackles.jpg

red dot = track rod

grey lump = sectioned axle casing profile

curved line = leaf profile

Link to comment
Share on other sites

OK thanks Meccano. I have more than just a passing interest in all your efforts, because last week a friend asked me if I would be interested in performing a similar conversion to his series 3 109, mainly to improve turning for when manouvering his boat at congested launching ramps, so I'd guess a slight loss of ground clearance would not be a major concern to him.

Bill.

Link to comment
Share on other sites

  • 3 weeks later...

[i have been looking into this for some time. How have people measured accurately the angles for the front axle, so the vehicles steers [properly and it doesn't scrub tyres. I expect the rear one is less critical.

Which axles are the easiest to fit. I would perfer to use the salibury rear on mine though.

Pat

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

 Share

×
×
  • Create New...

Important Information

We use cookies to ensure you get the best experience. By using our website you agree to our Cookie Policy