Snagger

A 12J block is sunstantially different from a 300Tdi block - the right side protrusion for the oil pump skew gear and circular brake vacuum pump was deleted and changed to a flat faced mounting for the fuel lift pump whiule the left side water jacket was all but deleted, having a shape which follows the contours of the cylinders. The 12J block also lacks the oil galleries and ports for a turbo charger. You simply would not be able to fit the 300Tdi ancilliaries to a 12J block. Are you sure the engine number isn't 21J, as I seem to recall that being a Tdi number? Photos would resolve the issue.

I have an article about it on my blog. It's not hard, but you do need a decent work bench, a vice and a few special tools like feeler gauges and big internal and external circlip pliers, hide or copper mallet and a torque wrench. The Haynes manual is spot on in its detailing of how to do the job, but make sure you check the supplemental revisions in the back of the book too. It is a DIY proposition if you have the space and tools. In fact, I always recommend people rebuilt their own rather than buy second hand or recon - those latter two options always result in trouble, and there is more con than re in the recon industry. Use genuine or OEM parts only - no pattern parts. I'd use Dunsfold LR for that. Make sure you replace the detent springs, all bearings, seals and gaskets, the 2nd/3rd gear bush (needs trimming to correct length) and look closely at the condition of the reverse gear bush and idler shaft (especially in your case). Make sure you seat the rear bearing carier into the main casing with seating compound such as Locktite Lock n' Seal (it's a little like thread lock) as this not only prevents the carrier spinning in the casing (wearing the casing hole, loosening the fit and generating aluminium swarf), but also is the key element in preventing the normal oil migration from gear box to transfer box - this is a step missed by every reconditioner, including on my LR factory recon unit.

The XtraGrip tyre is terrible for noise, as is the later XCL. Range Masters aren't too bad for noise, but are bad on wet roads and next to useless in mud or on wet grass. I'd recommend getting a set of 7.50 XZLs from Vass - they have thousands of old new-stock ex-MoD tyres at very low prices.

Yep, definitely a 200Tdi. A bit harsher than a 300, but more robust. A great engine.

The wheel bearings are packed with LM grease and plenty of oil from the diff and swivels gets into the hubs too, so the seals have to be oil tolerant. I have always seated the seals all the way in, but the depth of the seal land allows a pretty wide range of seating positions for the seal. I can't see any problem with having the seal face flush with the hub's lip unless the stub axle's seal land is scored or pitted, in which case seating the seal as deep as possible in the hub will move the lip out away from the pitted area on the seal land. That means that you can fit the seal by getting its edge inside the hub and then turning the assembly over so that the seal is sitting on a clean work bench top and tapping the hub itself down with a mallet, thus avoiding any impacts or point loads on the fragile seal...

My 300 Tdi has a seized turbo response system - the diaphragm can't increase the fueling in response to boost from the turbo charger. It's an assembly fault (the timing was also way off, needingt he sprocket to be reset on the main shaft), but as it was second hand from a cast Wolf engine (and I'm guessing they cast the engine because this brand new pump failed to cure a running issue), I have no come-back on it. It needs rebuilding by a specialist like DieselBob.

My wife's Lightweight has a stoved in diff pan, though it doesn't appear to have contacted the corwn wheel (must be close, though). For the cost, I think they're worthwhile on vehicles used off road.Personally, I'm wary of the circular clamp-on types. They're easy to fit, but they trap mud and water so will accelerate corrosion of the diff pan. I have QT gaurads on my 109 and like them a lot - very tough and self draining.

I had similar problems with my RRC and it was due to a faulty volumentric sensor (the one that I think you removed - a plastic wedge with a black circular pressure sensore at each end). With that removed, I had no more trouble. Close inspection showed some mould on the internal circuit board of the sensor block, so I fitted a good second hand one and haven't had any trouble in the years since. Old LR alarm remotes don't have good range. Replacing the batteries in the fobs may help, but often doeasn't; they seem to wear out with age. Remotekey.co.uk sell a modified two-button alarm system to retrofit to older RRCs and Discoverys which have the single button fob system. They have better sensitivity and Remotekey can activate a range of four or five options that LR didn't include such as auto re-lock (locks the car again if a door isn't opened withing a set interval from unlocking), auto unlock (unlocks all doors after an impact), auto-imobilise (re-sets the immobiliser if the engine isn't started within a set time from unlocking, even if the doors have been opened) and so on. It didn't cost much to buy the whole system, and took me about five minutes to fit with no special tools and no computer system at all. I have been very pleased with it.

Standard springs and dampers should give a comfortable ride and still deal with heavy loads, but you could add helper air springs (Matt Savage) that sit inside the rear springs and can be inflated to help with heavy loads and deflated for normal use. Of course, that is an additional cost over a set of coil springs, but if you think that standard springs aren't enough for the heavy load occasions, it's about the most flexible and reliable system to have.

WD40 cuts through all the grease and grime without harming the plastics and doesn't leave a residue like white spirit does. Rub with a cloth on the vinyl parts and, if necessary, a nail brush on the hard plastic parts and it should all come up very clean. It works well on unpainted wheel arches, rad grilles and head light surrounds, too. Scratches on smooth plastic (like the gauge lenses or watch glass) can be polished out with a cloth and tooth paste (a very fine abrasive) or a product like Mer or T-Cut.

Two other considerations when galvanising bulkheads: 1) The bonnet hinge clasps can unfurl due to the heat,so need re-curling with a tool made of steel angle with a slot cut across one face to grip the hinge tab; 2) The vent flap hinges fill with zinc and will need clearing out with a drill or reamer, but this is difficult due to the proximity of the hinge line to the bulkhead. I have heard that holes like this and captive nut threads can be protected with silicone sealant, to be easily removed later, though I haven't heard it from any experts. I wish I had known about these before I bought my galvanised bulkhead, or even before I had painted and fitted it!

I use an old bearing race as a drift for tapping in new bearings and seals. The face of the seal sits slightly lower than the rim in which it fits - keep gently tapping it home until the bottom edge seats against the lip and the seal moves no more (generally leaving the face about 1-1.5mm below the rim). I use grease to seat seals and gaskets as it enables them to be easily and cleanly replaced in the future. Hylomar is horrible and unreliable. RTV sealant is silicone based, which lubricates a seal's insertion but then acts as a good sealing and bonding agent when set; I use that on assemblies where the seal seat is scored or corroded or where the fit is not very tight. I use LM grease on the seal lips and a light smear of the same on the seal land before refitting the hub.

I think rear seat belts only became mandatory in 1983, or around abour then. They certainly weren't a requirement in the 70s. However, there is no way that carrying passengers without a seat is legal. Bench seats are fine for adults, and there is a loop hole for kids (under 12 yrs or 135cm, whichever is reached earliest) that allows them to be used on occasional circumstances (just not frequent or regular). You must inform your insurers, though, as icorrect seat details would invalidate your policy, even if the seats were unoccupied.

Try your local commercial truck auto-electrical suppliers - most heavy commercial vehicles are 24V and they may be able to source a solenoid if you take the existing one in. Alternatively, using a voltage dropper (I have a Durite one in my 24V Lightweight to allow a standard ignition to be used) will not only power the solenoid, but will also allow you to drop the voltage for the dash power sockets or an aftermarket socket for phone chargers, as stereo or whatever else you need that only draws a few amps. They cost about £30.

Have you tried cleaning the old switch up first? It might just have a bit of dirt trapping its plunger...

The mounts to use are Bearmach's higher quality 19J/200Tdi units (apparently they do three grades). Glencoyne Engineering sell them on e-bay at a good price - I think I paid less than £20 including postrage and VAT. They cured the problem completely.

I think it depends on how the vehicle is used - I fitted them to my RRC because they protect the swivel casings from stone chips on the motorways and I don't use it off road, so they can't fill up with mud or water. The 109 does fairly little off roading too, so it also has gaiters (rubber, not leather) for the same reasons. If it was going off road frequently, I wouldn't fit them...

Check your speedo calibration with another vehicle - 3.54 diffs are roughly 35% taller than 4.71, so an unmodified speedo will be under-reading by about 26%

Leaking head gaskets don't always cause oil emulsification, coolant or oil loss - it depends on where the leak is. If there is a leak from an oil way to the bore, you'll burn oil. If you have a leak from the coolant way to the bore, you'll lose coolant (either through sucking it into the bore on the induction stroke and then vaporising it, or by pressurising the coolant system and blowing it out of the header tank cap). You'll only get emulsification if the coolant and oil mix. The OP's symptoms suggest a fairly knackered head gasket or warped head (300 heads are much more delicate than their predecessors) as prime suspects, though.

What oil are you using? Some garages mistakenly think LT77s and R380s use EP90, which causes selection problems

Close - one of the switches is for the AC auxilliary fans if the viscous fan isn't managing by itself, and the second is an AC cut-out trigger to kill the AC and ease the engine load if the combined cooling of the viscous and electric auxilliary fans still can't cope.

It sounds like a head gasket or rings/bore issue to me - valve stemn seals would produce a little blue smoke after starting while any oil that dropped onto the pistons while the engine was off is burnt away, but would stop well before the engine was fully warmed up. A turbo problem would probably worsen with warmth as the oil thins down, not disappear. Something is expanding to prevent oil ingress into the bores when warm, and that suggests rings or head gasket to me, or less likely a slightly warped head (which can be skimmed if it's small enough). Changing the rings and head gasket are not difficult, just a little time consuming and messy - someone familiar with the job with the tools and dry space to do it could manage in a day without busting a gut, so don't look for a new engine just yet - that's a much bigger job!

Removing the thermostat can actually cause overheating too, as the flow through the rad is too fast for the coolant to shed its heat properly. It looks like it'll be a fun vehicle after a bit of tidying up and sorting out - hope it serves to well, Zim.

So, it really just depends on whether you need the flexibility of being able to select and deselect the gearing increase for towing and steep hills.

If you do a lot of towing or drive around very hilly areas, then go for an overdrive. If you drive more typical roads and only rarely tow, then the gear swap is cheaper, quieter and more reliable. One thing overlooked in assessing the benefits of overdrives is that by their nature, they will sap some power from the engine - more gears, shafts and bearings to turn, more fiction to overcome and more oil to splash around ... the energy has to come from somewhere. So, while an overdrive's 28% gearing increase looks good on paper, its benefits aren't as big in reality as the 15% gearing difference between fitting 1.22 ratio transfer gears in place of the 1.4 you currently have. The final gearing in 5th with overdrive might be a bit too tall for use other than motorway cruising, too, while 5th with 1.22 gears will be more widely appropriate. So, it really just depends on whether you need the flexibility of being able to select and deselect the gearing increase for towing and steep hills.