Salisbury axles
- Thread starter Ned
- Start date
This site contains affiliate links for which LandyZone may be compensated if you make a purchase.
Teflon
New Member
- Posts
- 683
Yes.
No.
DIY - think you need a kind of back to front puller to spread the case and get the diff out though
No.
DIY - think you need a kind of back to front puller to spread the case and get the diff out though
Thanks Teflon, dig your website by the way. DIY means different things to different people but I think that with my knowledge and my tools I need to keep looking for a supplier to recon this diff for me. If you hear of anyone, let me know. It's not urgent, but I would really like to get it done. I understand that Salisbury diffs are not made anymore and am starting to turn my mind to alternatives for a load carrying 109 diesel that will need a tough diff set up. I haven't really started investigating this yet. Do you have any thoughts? Ideally, I would get a tough back diff and higher "gearing".
Teflon
New Member
- Posts
- 683
The Salisbury axle has been around and used on so much for so long, i wouldn't worry about it not being in production any more. I mean, neither are Series 3's, and it is a strong bit of kit. The competition lads go for them to fit to SWB's becouse they are harder to break, even under V8 strain, so I wouldn't have too many quarms about them.
But, does stick you with the stock 4.7:1 crown wheel ratio.
But, that's no great handicap. There are better ways of upping the gearing, if needs be.
Personally, a 2.25 struggles to pull the stock gearing, so there's not much to be gained from going higher ratio.
Now I know that you are planning on going Prima Td, but think about this. Prima motor, while it makes 30% more power, lacks the low down grunt of the 2.25, especially at or near tick-over where theres not enough gas to get the turbine windmilling.
So, if you upped the gearing, you would suffer badly at crawling pace where you just cant get the motor to make motive force that slowly.
Ie not so good off road or towing, or loaded.
Keep the gearing low, and let the thing spin, and you have less of a problem, as the motive force will be 25-30higher for the same engine speed, and as at the same road speed, the motor will be spinning faster, you'll have 25-30% plus at the wheels.
And, on the road, remember the stock motor will rev out at 4000rpm. I think that the stock transfer box ratio is 1.2:1 reduction from the crank, multiply that by 4.7:1 reduction at the diff, and a 30" wheel, and theoretically, a series three Landy is geared to pull 100mph at the rev limiter.
Yeah, in your dreams!
But that means that the stock motor is toping out at about 2500rpm, which actually doesn't sound that unreasonabe given the power it makes and the shape of its torque curve.
Prima motor makes more power and more of it higher up, and it will rev 25% higher to 5000rpm. On stock gearing thats a theoretical 125mph!
Realistically, the extra grunt is probably enough to get it up to about 85-90ish, which on stock gearing would be around about 3-3500rpm.
And you'd still only be pulling about 2500rpm cruising at 70.
If you were to bump up the gearing by 30% going to 3.5:1 crown wheels on Rover diffs in a SWB axle, then you would be geared for a theoretical 165mph at the rev limiter.
40-70 in top would equate to 1000-2000rpm - you just wouldn't have enough power that low down the rev range to pull those speeds, you'd be driving every where in third!
But, does stick you with the stock 4.7:1 crown wheel ratio.
But, that's no great handicap. There are better ways of upping the gearing, if needs be.
Personally, a 2.25 struggles to pull the stock gearing, so there's not much to be gained from going higher ratio.
Now I know that you are planning on going Prima Td, but think about this. Prima motor, while it makes 30% more power, lacks the low down grunt of the 2.25, especially at or near tick-over where theres not enough gas to get the turbine windmilling.
So, if you upped the gearing, you would suffer badly at crawling pace where you just cant get the motor to make motive force that slowly.
Ie not so good off road or towing, or loaded.
Keep the gearing low, and let the thing spin, and you have less of a problem, as the motive force will be 25-30higher for the same engine speed, and as at the same road speed, the motor will be spinning faster, you'll have 25-30% plus at the wheels.
And, on the road, remember the stock motor will rev out at 4000rpm. I think that the stock transfer box ratio is 1.2:1 reduction from the crank, multiply that by 4.7:1 reduction at the diff, and a 30" wheel, and theoretically, a series three Landy is geared to pull 100mph at the rev limiter.
Yeah, in your dreams!
But that means that the stock motor is toping out at about 2500rpm, which actually doesn't sound that unreasonabe given the power it makes and the shape of its torque curve.
Prima motor makes more power and more of it higher up, and it will rev 25% higher to 5000rpm. On stock gearing thats a theoretical 125mph!
Realistically, the extra grunt is probably enough to get it up to about 85-90ish, which on stock gearing would be around about 3-3500rpm.
And you'd still only be pulling about 2500rpm cruising at 70.
If you were to bump up the gearing by 30% going to 3.5:1 crown wheels on Rover diffs in a SWB axle, then you would be geared for a theoretical 165mph at the rev limiter.
40-70 in top would equate to 1000-2000rpm - you just wouldn't have enough power that low down the rev range to pull those speeds, you'd be driving every where in third!
I've been thinking a lot recently about the Prima transplant and whilst I have not given up on the idea, I have decided to shelve it until I have the long list of other bits of work done. I have had this 2a for 15 years and from the start I said that I would put a diesel engine in but never actually have followed through. This is the closet yet, because I want to do a 3,600 mile trip to Senegal Christmas after this one, but even then, with the additional tanks I have on my work list, I will have the range I need even for the rough bits. In terms of fuel I would save money for sure but in terms of dealing with any engine problems I would be throwing away 15 years of petrol engine experience in a place where I really need to get it going again! Also, for relatively little money I get really get some more horsepower out of the petrol and still run on low octane fuel.
The 4.7:1 diffs feel OK to me given that I will have the Ashcroft transfer box giving the extra gearing and I have an as-new Fairey overdrive in the garage which I could add on if suitable (don't want too much strain on things). I must get a driver operated diff lock, partly to push a 109 through heavy going, and partly because the compressor is an essential re-inflating tyres after softening them out for going through sand, good for tyre repairs, too. I had a look at the diffs on the Ashcroft website. Have you got any comments?
Also, do you know if I am right in thinking that the army ran 109's on large tyres, 900's? Any comments on the pros and cons of that? Obviously, higher centre of gravity is a bad thing, rubbish turning circle makes Sainsbury's car park interesting, extra strain on halfshafts trying to turn a bigger resistance than designed for (maybe this can be overcome with performance half shafts? Guess that's why the army also fitted Salisbury back axles.
The 4.7:1 diffs feel OK to me given that I will have the Ashcroft transfer box giving the extra gearing and I have an as-new Fairey overdrive in the garage which I could add on if suitable (don't want too much strain on things). I must get a driver operated diff lock, partly to push a 109 through heavy going, and partly because the compressor is an essential re-inflating tyres after softening them out for going through sand, good for tyre repairs, too. I had a look at the diffs on the Ashcroft website. Have you got any comments?
Also, do you know if I am right in thinking that the army ran 109's on large tyres, 900's? Any comments on the pros and cons of that? Obviously, higher centre of gravity is a bad thing, rubbish turning circle makes Sainsbury's car park interesting, extra strain on halfshafts trying to turn a bigger resistance than designed for (maybe this can be overcome with performance half shafts? Guess that's why the army also fitted Salisbury back axles.
