deep

Lots of good points made here. I'll just add, from experience, that having larger tyres on bigger off-set rims exacerbates any problems by quite some margin and a decent steering damper hides the problem by the same amount! That said, I'd rather not have the problem at all. My last bout was brought on by a slightly loose wheel bearing. Quite amazing really.

True. I drove a IIb forward control once which had a 3 litre motor fitted and it was screaming at 45m.p.h.! Those ratios are rare though.

A Trutrac is not exactly a locking diff. It's more an automatic torque balancing unit (how do you explain that in six words or less? There are videos on youtube showing how it works). I believe that they are quite sturdy. A friend has one in his alleged 90 (shortened 110) and it has taken many years of off road abuse.

Interesting links, Garry. I'm pretty sure the high ratio I put in my Stage One was 1.113. I think 0.996:1 would have been way too high with my tallish tyres! Raggylad: RR transfer gears were designed for tyres with a considerably smaller diameter and, perhaps, not so much for towing a heavy trailer across a desert, so they needed a higher ratio. It's not super-easy to work out what your gearing is but you could take off your driveshaft and count how many engine revolutions (turned with a spanner at the crank pulley, diff lock off, engine very much off...) it takes for one revolution of the handbrake drum, with the gearbox in top, high ratio, then go to those charts and check the maths.

Sounds like the transfer gears are Range Rover, not 110. They could have been swapped any time in the gearbox's life. Low ratio remains unchanged but there are a few options for high gear. I actually did this deliberately on my Stage One V8 and was glad I did but I guess it depends on driving style etc. When I put a 3.9 in, it was fabulous. Swapping ratios was an afternoon's work for two people, not that hard and you can do it with the box in place. You do need a tool to act as a dummy shaft to hold all the bits in place as you thread the shaft through. We made one out of slightly larger diameter PVC pipe, which we cut a slot in - it expands and holds the gears etc. perfectly.

I don't know what a pulse ambulance is, sorry, but odds are you have a Rover axle in the front and a Salisbury in the back, unless it's relatively modern. Either way, the TruTrack would only fit the front. Hopefully someone more up to date will chime in as I believe there are some compatibility issues beyond that.

Some more agricultural diesels hit the wall at under 3,000 r.p.m.. They'd be finished by 45m.p.h.! I wasn't that clear, sorry.

Good decision!

I've just realised 255/85 BFGs are on the Stage One V8 in my signature pic. I sold the car last year but kept the tyres. That says a lot!

If only you lived in New Zealand! 2nd hand just isn't happening here and they're $500 each new. Sigh...

My old Series III diesel was governed to around 60 m.p.h in top (it wouldn't even go faster downhill) but it got there within a minute or so with standard gearing. The big question is: is it revving its heart out at 45m.p.h (suggesting it's not actually a Land Rover diesel, or that you have tiny little tyres on it) or is it just no power (suggesting one of the things mentioned above or, very likely, a clogged filter or line?

I've got to wade in! Having had similar thoughts myself, I tried fitting one of my 255/85 BFG Mud Terrains onto a standard 110 rim and it worked just fine (I do have wider rims but don't like the extra offset they come with, hence my experiment). The only downside is a little bit less steering lock. I know they recommend 7 inch rims but it's not mandatory. After all these years, I still think 255/85 is the perfect size for a Land Rover. It near enough equates to 33x10.5x16 in the other system. I've also seen 33x9.5x16 for a Silverstone, which might be even better for some but that wasn't an ideal road tyre.

Just to close this topic off - The second hand engine I eventually bought turned out to be a 2.5TD (19J) with an alleged cracked head. The vacuum pump and drive were a direct fit in my 12J motor, though not quite as easy to do as I'd have liked, with quite a bit in the way. It made it hard to line up the drive bush locating screw but I got there. Anyhow, the brakes are absolutely perfect now and I'm already planning to swap one or two other bits over, so the $NZ400 wasn't a bad deal in the end. The design of the standard pump looks like it would be far longer lasting and less maintenance-intensive than the belt-driven pump I removed, so that's a bonus too. One thing that surprises me is that the "proper" vacuum pump vents to the crankcase, hardly desirable in a motor which is already known to be a heavy breather. Still, it's not really happening when the motor is under load so maybe it's never an issue.

I've had an extinguisher not work when needed. Turns out the cheap and popular dry powder type can pack down with the shaking of a vehicle and so becomes more useful as a paper weight! So good you had a spare. Makes me think it must be time to replace mine...

Interesting! In terms of the breather, I have done some experimenting. The motor does put some pressure out of the breather, more than I would expect for a reconditioned unit, though there is little oil in the vapour ... so far. But I notice that the fitting on the manifold which the pipe connects to, far from having some vacuum at idle, actually pumps a little air out, which is bizarre. Totally unintuitive. However, it does explain why the engine pressurised after a long idle. Just yesterday, I bought a TD engine (just for the vacuum pump, what a long story that has been) and it has a far more complex breathing system. I think I'll just make something. I'll be keen to see how the motor plays out off road. I have already noticed it is more able to hold on to low revs than either my old 2 ¼ or any turbo diesel I've driven but I was so spoiled by my previous V8s and current Holden six, which all seem to be totally un-stallable, that I don't have super high expectations. My experiences of a TDi off-road don't seem to match the general Land Rover world. Such a tiny rev range that you can use them in!

Wasn't the last North America model a V8? It's thought journalists from that land can forget what happens elsewhere...

I have a 2.5 na diesel 110 (ex Singapore Air Force) that I am slowly putting together, so I read this thread with interest. Many years ago, I ran a 2.25 109. That was remarkably gutless but economy was excellent (a very constant 30 m.p.g. on any sort of run, even better before I fitted an overdrive...). I was hoping the economy on the 2.5 would be similar. Is it? I note the 110 feels far "crisper" (the motor was newly rebuilt by the military) that the 109. It should be fine on the road (55 mph cruising is fine for me) but I suspect it will struggle off road in soft conditions, as I am used to a 3.9 V8 and 3.3 in-line 6! I do have a question about the breathing, as mentioned above. Is the breather on the rocker cover the only one or is there another one? I can't actually see anything obvious and a quick look at the Haynes manual wasn't helpful. I ask because I left it idling for too long one day, to charge the battery, and oil started working its way past the dipstick. Obviously the crankcase is pressurising. It's quite a worry as there is a lot of evidence the rebuild was comprehensive. However, I know how easy it is to put a gasket on back to front or otherwise block a breather.

Well, the solution I have arrived at has to be the most overkill of my career. I'm getting a whole engine block, complete with standard vacuum pump! It's got to have everything I need and is in the same ballpark, price-wise, as the kit quoted above. Having just had to replace my laptop yesterday, I can't say I'm a happy chappy but it seems my options are very limited - and there is much to be said for having standard parts next time I need something. Time to stick one of my cameras on Trade Me, I think... Meanwhile, in other news, a friend and I have committed to another Aussie trip in a few years. Gonna have to sell more than a camera to pay for that but it is real incentive to keep this build focussed. (One day I will take all the photos I have taken of the build and make a proper thread about it.)

I looked into that. It would be one step harder than going electric and not as ideal a solution. I actually had a similar problem with the fuel pump on my Holden powered Series 2a. I couldn't get new diaphragms for love nor money so ended up going electric. Times are changing!

Thanks Eric. I've got to confess that translating those pages isn't straightforward but I get the picture. Why the Singapore military chose a Spanish pump may be something which has to remain a mystery but knowing there are diaphragms I can adapt gives me hope. It must be worth trying to get a pair because the electric option is far from easy and isn't cheap either. The electric pumps I've managed to find to date are pricey, plus you really need a tank and switching system so it doesn't run flat out all the time. I would like to do that and probably will, in time (and an electric fan for that matter), simply because it bothers me to run anything full time which is only needed some of the time!

Hmm. A bit of Googling and it seems several outfits stock this item - all at the same price - and in some lists it is called "Membrane, vacuum pump". Obviously the right thing. Ouch! Thanks for the help, everyone.

All I had to do was take off the drive belt. That part was easy! I do like the electric idea but there is quite a bit of cost and complexity involved and I have a ton of other things to sort out on my minuscule budget, sigh. Western: that price was almost exactly the same as a local supplier quoted from a source in England (I believe it was Craddock's?). Unbelievably, it would really be my cheapest option from what I have seen so far. Surely, though, it includes more than just the diaphragms? I will enquire, thank you very much for the link.

I'll have to do some investigation tomorrow. Looks from the picture like that corresponds to the old injection pump location on a 2¼. That's blanked off on my motor but is part of the bracketry for the throttle cable/linkage. There must be a reason that system wasn't used. Thanks for the information. If it comes to it, I may have to get radical like that but you'd think it sure would be easier just to find two diaphragms!

Definitely two diaphragms in this one! However, I am now thinking - the cheapest new pump on my radar is a 300 TDi one (http://www.trademe.co.nz/Browse/Listing.aspx?id=923754049). Would this fit in the "normal" position on my motor?

That was quick! Yup, the standard one you show is the one in my catalogue. I saw that Santana one on EBay but it's not the same type as mine. I guess I could get another type, as long as I can get the right pulley to line up. I think they fitted the belt drive one because the massive 24volt generator meant things got swapped around. It has actually been a giant pain all round as I had to sort out a mount for a 12volt alternator on the "wrong" side of the engine too. Having a power steering pump and vacuum pump on the left side of the engine meant I couldn't just buy and use a standard alternator mount.