BFRieck

Looks like I've smoked this out. According to an FFR manual, the "black box" contains ballasted resistors that step the voltage down from 24v to 10v. These components also suppress interference with the radios which FFR vehicles normally carried. So, unless one is trying to maintain total FFR purity, there is no need for anything except the 24v to 10v converter. It is my understanding that a commonly available 24v to 12v converter should work - the primary side of the coil is somewhere between 3 and 4 ohms in resistance indicating a converter rating of less than 5 amps. There are commonly available 24v to 12v converters widely used in the golf cart industry which are durable, sealed, and waterproof units for less than $30 with a rating of either 5 amps or 10 amps (the 10 amp ones being a bit more costly). Either should work well. I had also wondered whether the distributor "cared" what voltage it received (the idea being that I could just use a 24v coil and dispense with the converter. The answer is definitely yes - 24 volts would quickly burn up the points.

Thanks, do you remember whether a replacement should be ballasted or not?

Anyone out there know the primary resistance for a 2.25 petrol Series III ignition coil? Bruce

I've found a manual tranny '95 Disco I for my Series hybrid project (I plan to put a Series IIa 88 body on the Disco I rolling chassis). The price of the Disco I is good for what it is, but it appears the motor is a goner as it probably needs a block to cure a water leak that replacing the head gasket didn't take care of. I may use the Disco for a while before I remove the body and start the hybrid build. Either way, I need a new motor. I'd like to improve the miserable gas mileage that apparently comes with the V-8 so am considering a diesel. Everything I've read indicates that the 200tdi is probably the way to go, simpler but just about as much power as a 300tdi. I've read, also, that the 200 is pretty much a bolt in on a Series chassis, especially if the turbo is re-plumbed so it won't foul the frame or the motor is de-turbo'ed. I understand the 300 is bigger and therefore not as easily fit. What are the forum's thoughts on this? Also, should I be considering any other diesels or gas motors, even non-LR? Please consider that I'm stateside which makes diesel motors less common (read pricier).

Further research indicates that further research, namely looking at my truck to see what I've actually got, is needed. Blanchard tells me that my truck was most likely factory fitted with Imperial thread u-bolts and nuts - all 4 u-bolts and all 16 nuts with the same threads, most likely 7/16" BSF - if memory serves, the threads are fine so maybe that's correct.

I was looking for the thread pitch (or threads per inch in the case of unc or unf botls - e.g., 1/4-20 meaning .25" in diameter and 20 threads per inch). I believe metrics are described as M10, M12, etc. which indicates both the diameter and the number of threads per inch (well, maybe not per inch). Based on the reference provided by FF the NY112041L is something other than a simple hex nut - perhaps a nyloc or some other sort of locking nut - I believe the 12 indicates an M12 size. According to the RoversNorth website, there are two different nuts used on the MoD Series III trucks - one is a 7/16" BSF (front leaf springs 109 - don't know if that includes the MoD trucks) and an M12 locknut (rear leaf springs 109 - same part number as provided by FF (NY112041L). If M12's come in either coarse or fine threads, I assume the u-bolts will be fine threads. It's starting to look like the only way to be sure is to take one off and see what it is.

FF, thanks so much. I was wondering if the part number held clues as to such things. You're an absolute storehouse for info and relative newcomers to Landrovers like me (and many others, I'm sure) appreciate it.

Thanks, I'll try that this weekend when I'm once again LR'ing. Mine are the twin ExMoD under-the-seat tanks so getting at the fuel sender devices is a reach-in affair.

Can someone provide me with the diameter and thread count for the Leaf Spring U-Bolts on my 1974 Series III ExMod 109? I'm not near the truck for a few days and can't check for myself. I looked at the parts manual and green bible and couldn't find it in either of those. Is there a source for bolt and nut sizes on Series III's?

I assume Blanchard does stocks the proper cork gasket (don't know for sure as mine has not yet arrived). However, for us yanks they are pretty expensive what with the exchange rate and shipping - a single gasket came to nearly $20 fob Texas. By contrast the one I made cost $0 for the material - I needed so little the hardware store gave me a scrap of 1/8" cork sheet and about an hour of work including removal and disassembly of the valve, using a cad program to draw the gasket, transferring the drawing to the cork, cutting out the gasket with a Stanley 99 utility knife and a leather punch, installing the gasket, and reassembling and re-fitting the valve. Installing the gasket from Blanchard would have saved about half that time. Of course, as my wife reminds me - at my billing rate doing it myself cost a lot more than buying the gasket - to which I reply that what I do for money is not nearly as much fun as fiddling with the LR so I rightfully regard any labor devoted to the LR as money well spent. I did not put any lubricant on the gasket which I might have had I thought of it, but the way the gasket is captured and the fact that the brass surfaces which slide on the gasket are pretty smooth pretty much rules out any tearing of the gasket. I tend to agree with the theory that the left hand tank gauge wiring is shorting because it reads the same (pegged to full) whether attached to the sender or not. Cleaning up the contacts on the right hand tank (both the contacts on the selector switch and the contacts on the tank sender unit itself) did not change the "nearly half full" reading reagardless of tank volume. Is there any way to tell if the tank mounted sender unit is functioning short of having a known functioning gauge and getting a proper reading?

I need a new front leaf spring u bolt plate for my Series III (the plate beneath the leaf springs with four bolt holes and a hole in the middle). I can't figure out why they are so expensive here stateside as they appear to be nothing more than a piece of flat plate steel +/- .25" thick with slight downward bends fore and aft and five holes drilled. What am I missing? If they are no more special than I think, does anyone have a drawing or know of a drawing so I can fabricate one myself?

Well, I wished I had never ordered the replacement gasket from Blanchard as I was able to make one in about an hour without too much trouble. Turns out the one I had was bad but good enough to make a pattern. I made a new one out of 1/8" cork sheet from a hardware store. It appears to be the same material as the original; works fine, no leaks, etc. Couldn't get the gauges sorted, though. It may be the senders. Apparently, the gauge is pegged "full" when there's no connection.

Probably good advice. Blanchard has a replacement gasket that they think may fix the problem as I've described it. I ordered one so we'll see. I've learned that Phil Hancock's earlier post accurately described the gasket as cork about 1/8" thick. At my request, Nick at Blanchard was gracious enough to look at the gasket they sell and said it was cork 3-4 mm thick so that tallies. I'm going to attempt to homemake one. It's a bit of a surprise that the factory taps are so problematic - how complicated can that be - particularly when there are no electrics involved (save the gauge stuff which doesn't have anything to do with the tap - it's just a matter of the switch handle contacting the selected side and disconnecting the unselected side). As for the later electric taps that you've found to be more reliable, can you give me a part number or more specific id? I'd like to check out that option.

Perfect. Just what I needed to know.

I'm not sure, but I think the gasket in question is different - it appears to have holes in it which may be opened/blocked as the valve handle moves from left tank to right tank and vice-versa. Not sure how to go about getting an image in this message, but here's a link to a picture of the valve and the gasket on Blanchard's website. https://secure.pablanchard.co.uk/photos/Web%20Fuel%20Tap%20Etc.jpg Any ideas what that gasket might be made of? I am hoping I can recover the existing gasket sufficiently intact so as to copy it.

Cool. Sounds like I might be able to go with a later model Disco (and its likely lesser mileage, etc.) while avoiding the increasing complexity as the cars get newer. As a general rule, I prefer EFI over carbs - do you know when each of the models (RR vs Disco) got EFI? Although I fear showing my ignorance, I need to ask what you mean by "Flapper" and "hotwire" - the rest I think I understand.

Being able to use either an RR Classic or a Disco complete rolling chassis makes the pool of available body damage only wrecks a good deal bigger. That's a plus here stateside where the selection is probably nowhere near what it is in the UK. I'm only finding about a half dozen '86-'96 salvage title RR's offered and only a couple of those are suitable on account of the type of damage, mileage, or other reasons for their not being deemed repairable. If I throw in the Discos, I probably increase availability by a factor of 1.5 or 2.

Thanks for the info. It turns out that the part is the same regardless of the (a) or (b) suffix. Also, I have learned that there is a gasket, available from at least one supplier (PA Blanchard - their part number NRC5364), which may repair my leak - at least the people at Blanchard think so. Obviously, the gasket is far less expensive than the entire valve at about $12 but still pretty pricey to my mind. I plan to remove the valve this weekend to see if I can replace the gasket with a homemade one (assuming the gasket material, shape, and my skills are all compatible). I don't see that part shown on the drawing supplied, however.

Blanchard says all the part numbers refer to the same part. Problem solved, I guess.

Well, I've solved part of my own problem. PA Blanchard's website lists the changeover valve as an in-stock item (part numbers: 526783, 526783a, and 526783b - don't know what the difference is, if any). I still don't know if it can be rebuilt. FWIW, it's not in any of the parts manuals being an MoD vehicle item, I guess. Still don't know what what's going on with the fuel gauge, but I assume it's electrical in nature as the fuel changeover valve simply switches from one tank's sender to the other mechanically.

Well, more research has produced the following part numbers: Auxiliary Fuel Tank Changeover Tap 526783, 526783a, and 526783b - not sure what the difference is, if any. Part numbers are not in any of the forum parts books but were supplied by the P A Blanchard website. They have them in stock at +/- $135 (89.95 in pounds, couldn't find the symbol for UK currency, sorry).

One more question: For my purposes, is there any significant difference between a RR Classic and a Discovery of the same my? If so, is the RR Classic necessarily preferable?

Looking for the part number for either a rebuild kit or (if no kit is available) the fuel tank switch. It is located beneath the drivers (RHD) seat on the seat box. My 1974 Ex MoD Series III 109 FFR 2.25 petrol has two identical fuel tanks, one beneath each front seat. There is a manual switch or valve and mine is leaking when the left hand tank is selected. The valve also is set up with contacts to select the proper fuel tank gauge sender so the fuel gauge on the dash represents the selected tank. Any ideas as to part number (kit or valve) and a source?

Spent the weekend messing with the Series III and have a new item to repair. My Series III is an ex MoD (109 FFR) and therefore has dual fuel tanks - two identical tanks, one under each front seat. Two problems have cropped up - I get a leak at the valve when I switch from the driver's side tank (rhd) to the other side and the fuel gauge shows full (left hand side) even if the tank is only about 60% (the least amount in it during my time to observe it), and it shows slightly less than half full all the time (regardless of how full the tank is - from completely empty to completely full and everywhere in between) when the right hand tank is selected. First question: Is the valve rebuildable? If so, is there a rebuild kit available and, if not, where shall I try to get a replacement valve - I've had no luck from my usual suppliers here in the USA. Second question: Can any of the pros out there diagnose the fuel gauge deal? I didn't have a chance to try to clean all the contacts, etc. My guess is that gauge is fine - the senders are likely to be the culprits - am I on the right track? Thanks.

Well, I have a bit of egg on my face since Googling produced a lot of results including more than one reference to this forum! Should have done that first. It was kind of y'all not to point that out in a nasty manner. It appears to me that most of the ready-made stuff is aimed at Defenders. Nevertheless, there are a number of DIY solutions as well. I'll do some more research and see what I can invent. Toward that end, what are the long term ramifications of removing whatever support the intact bulkhead provides and what portions or characteristics of the bulkhead would need to be kept to retain such support?