nileseh

I have a 1987 110 ex-MOD with a 2.5 NA diesel. I have both the MOD parts catalog and the 1986 110 full line parts catalog. From these, it appears that the part numbers of the appropriate bits are: pulley - ERC6860; damper - ETC4105; flinger - ETC4390. I think I can also derive that the pulley/damper assembly in this military truck is the same as that used in the civilian truck fitted with AC, so I can use the civilian assembly part number 554971 (from the John Craddock catalog). I think that's all straight forward. The uncertainty is the flinger. Is it best practice to fit a new one on the damper hub, or try to use the one in place now. It seems pressed on, and I'm afraid that removal will expand the bore and render it unusable. While I type this it occurs to me that it is quite a silly question. The flinger is available and not expensive so the prudent course of action is to get a new one. But just for my enlightenment, is this really designed for a one-time use? Also any comments on my part number conclusions will be appreciated. Thanks. Niles (also posted to the Defender forum)

I have a 1987 110 ex-MOD with a 2.5 NA diesel. I have both the MOD parts catalog and the 1986 110 full line parts catalog. From these, it appears that the part numbers of the appropriate bits are: pulley - ERC6860; damper - ETC4105; flinger - ETC4390. I think I can also derive that the pulley/damper assembly in this military truck is the same as that used in the civilian truck fitted with AC, so I can use the civilian assembly part number 554971 (from the John Craddock catalog). I think that's all straight forward. The uncertainty is the flinger. Is it best practice to fit a new one on the damper hub, or try to use the one in place now. It seems pressed on, and I'm afraid that removal will expand the bore and render it unusable. While I type this it occurs to me that it is quite a silly question. The flinger is available and not expensive so the prudent course of action is to get a new one. But just for my enlightenment, is this really designed for a one-time use? Also any comments on my part number conclusions will be appreciated. Thanks. NIles

Right. The tow hitch shown here is the type used in the UK, a ball on a curved arm. In the US the standard tow hitch is a ball on a 2" square tube hat is inserted in a 2" socket receiver on the car. The LR4 adapter has the taper insertion tab and pin lock, but instead of a arm and ball, it has a 2" square socket. That leaves the adapter somewhat bulkier than the UK item and it won't fit in the Styrofoam seat of the storage bracket. It's a little odd, because the first image in the graphic install instructions clearly shows a square receiver opening in place in the side storage compartment. I suppose I can cobble the foam to make it fit, but if there is an appropriate device already available I'd prefer that solution.

The car is a 2012 LR4, It came without the tow package. I bought the Land Rover original parts to add it, the wiring harness, and the LR040248 receiver, a clever bit that. So now storage, I came to understand that the left rear load space outboard side cavity was available and there is a Land Rover original part to facilitate, LR020002. I bought that, not yet installed, but I can't see how the storage fixture will accommodate the receiver. It does not seem to fit in any possible orientation. Am I missing something here?

A final closeout on this..... I received the mini-refrigerator thermostat, inserted the probe into the core and connected the compressor control wiring. By golly, it works nearly the same as the OEM Land Rover part (that is nla) when set to the lowest temperature. So I have a replacement if the original item goes out. I spent a bit more time adjusting the original engage-disengage core temperatures. System is working brilliantly. We have had a week of unusually high temperatures here in Eugene, 100F plus a bit, and I'm seeing full air flow at a 25-30 degree drop from ambient. Once the initial cooling takes place in fresh air mode, I change to recirc. It makes for a quite comfortable cabin in this big old truck. Successful conclusion.

Rather good indeed. It's brilliant. Thanks.

What version of dashboard is in a Defender County 95? I'm not familiar. If it is the same as the 93 110 NAS, I just spent some time troubleshooting mine and may be able to assist. Can you send a picture of the dash?

The story goes on.... I removed the original compressor thermostat control, RTC7434, in anticipation of replacement with the refrigerator thermostat. Also to see if it was serviceable. As it happens it is not a fixed device, it is fully adjustable, with separate adjustment screws for setting the core temperature at which the contacts open and close. Go figure. The adjusting screws are on the back of the device, facing the Evaporator housing and not visible without removing it. Also not documented in the workshop manual. It probably was repurposed from a refrigerator or freezer application after all. I carefully drilled a second hole in the top of the evaporator housing so I can place a thermometer parallel with the thermostat probe, ran the AC and set the open point to about 32F and the close point at about 50F. I think perhaps after 30 years the expansion gas in the system has slightly decreased shifting the mechanical set point down a bit, but it is still within the adjustable range. I'm going to leave the thermostat hanging for a while to fine tune the set points before I remount it. Another observation: I think the operation and set point on this component is pretty important to correct operation of the system. I bypassed the thermostatic switch while removed, ran the engine at idle, 70F ambient and low blower speed. Under those conditions the core rapidly went to below 20F, sufficient to freeze any moisture pretty quickly. That is of course ideal conditions to freeze, increased air flow, higher ambient will mitigate low core temperature, but after it freezes the system won't operate until it defrosts. It seems it would be worth while to check operation occasionally to be sure it is cycling the compressor.

Thanks. But I'm in the US and the AC system in the NAS trucks is quite different. Of course it mounted on the right, and the configuration of the evaporator, heater core, blower, plenum is not simply opposite hand, it is completely different. The documentation for these systems is lacking so I'm going to draw up the airflow path so I don't forget. However I think the control is about the same RHD to LHD. Nor sure though. I hope to rebulid the system at some point, but that project sounds like one for a clean, warm garage on a cold winter day.

Also, with reference to simonr above, once i get the original switch out I'll try to repair it. However my hopes are not high. The contacts could be welded, or the diaphragm operated trip mechanism could be jammed. I can probably fix both of those conditions. But if the gas in the tube has leaked out it's over. The refrigerator switch is a safety as required.

A bit more to update..... Evaporator temperature ranges are published in the workshop manual. I checked this by inserting a meat thermometer in the hole intended for the thermostat switch and found that the evaporator core is well within specification for the conditions, 95F outside temp and I measured 52F at the core. However the air outlets in the car were at 75F. That didn't seem right. I little bit more investigation led me to the air mix door controlled by the temperature slider on the facia. As it happens, the full cold position did not fully close the door on the heater core side. The core does not contain hot water by virtue of the vacuum water switch, but a bypass for ambient air is provided to mix with the cold air from the 52F evaporator core. 95F ambient will warm air up quite nicely. I adjusted the cable to firmly close the door on the heater core (the notion is that the foam that originally sealed the door was gone leaving a gap). Instantly I have 65Fto 68F air from the vents. So a 25-30F drop from ambient which I am told is normal. The other issue of reduced air is probably what I suspected a bit ago: freeze over of the evaporator. The temperature switch that seems to be intended to prevent this remains closed (compressor engaged) at 28F, I couldn't get any lower, but at that temperature the core will freeze and humidity in the air. I'm calling the switch defective after 30 years in service. The switch is, as noted above, nla, but I found a adjustable capillary operated switch, with 6mm male spade terminals, intended as a refrigerator control for $9.00. I'll set that for 36F or so insofar as the workshop manual shows the minimum temperature expected of the evaporator core under ideal conditions is 40F. That should drop the compressor out well before freezing. I think that does it. I'm going to call the effort successful. I love it when that happens. Niles

Well, I appreciate all the comments, and have learned a bit about the system. I also spent some time moving levers with and without vacuum to see what moves under what conditions. I've ruled out vacuum being the problem. My experience is that on a long drive the volume of air decreases and the temperature of that air increases from the facia vents. I thought perhaps I was losing vacuum that operator a door that directed blower air (post evaporator) to the facial plenum. Not the case, I think now the total air volume to the interior is decreasing. Pretty much a clear case of frost buildup on the evaporator restricting air flow and insulating what does get thru from the evaporator heat exchange. Of course the evaporator is totally enclosed so it is not possible to observe the condition. There is a note in the Owners Manual that the evaporator can freeze over in maximum cold control position, and the remedy is to bump the control up a bit. I'm not sure what that is intended to accomplish. In any case it doesn't work. The lever operates push-pull to a door in the evaporator box that I think mixes air with the heater core. It also operates a vacuum valve that opens the coolant line the the core. But it does not, as is common in AC systems, change the setting on the thermostat that senses the air temperature at the evaporator. The control thermostat is apparently fixed so it does not open the circuit to the compressor when the temperature goes below an operator selected point. So if this thermostat is faulty, the compressor could be on continuous rather cycling as is the case with most AC systems. And of course the part, RTC7434 is nla. That said, the thermostat is on the outside of the evaporator enclosure and the temperature probe tube goes thru the top adjacent to the evaporator. Should be an easy conversion to an adjustable mechanical replacement, or even conversion to a thermocouple solid state temperature control (I did this on another car sometime ago and it works well). If the replacement is adjustable I should be able to empirically determine an appropriate control temperature. But I don't suppose anyone knows something about this system, for instance what temperature does the thermostat want to see to drop the compressor out? Then of course I appreciate comments on this diagnosis: am I dreaming or does this make sense? Niles

I'd take XZL in a heartbeat, but I don't think I can get them in the US. I think you're right on the size: 235/85R16 is a better size, but I needed to replace them on the 110 NAS quickly, wanted to use Michelin and that size had been discontinued in the XPS. Only the 215/85R16 was immediately available. Speedometer reads a bit high, otherwise they seem okay for sound on the highway, fine for general off-road and passable in snow. I'm fine with tall and skinny tires. I have spent quite a bit of time thru all sorts of terrain in Washington and Nevada on XCL 750R16 mounted on a 1989 Range Rover classic, lifted with the anti-roll bars removed. Always came thru with finesse. I have time for a leisurely search on the ex-MOD 110. I'll spend more time looking for the XZL.

Quite interesting where this thread has gone. From military tires (not necessarily ever intended to travel on pavement so an obvious lack of concern in the acoustics) to the acoustic similarity with classic aircraft. Happily, I am also a pilot and very much taken with all of the aircraft mentioned. Thank you all for contributing. I recently put Michelin XPS LT215/85R16 on my 1993 110 NAS, but still in search of a suitable replacement for the XCL 750R16 on the Military 110. I'll probably try to find the Goodyear G20 (i think that was it) unless something else comes along.

Making headway and learning lots. The British car industry seems to be plagued by uncertainty in naming. I've encountered the same thing with Jaguar XJ6 series cars and XJ40 cars labeled XJ6. It's difficult to keep straight. The parts manuals are great, but the workshop manual is still problematic. I found a electrical schematic, not as simple as I imagined, but the vacuum remains elusive. From the parts descriptions there are numerous vacuum valves associated with the controls and vacuum "motors" (I assume to be diaphragm servo operators) but it's not clear what air doors are operated by these things and with what logic. The hot water valve for the heater is also tied in with a vacuum operated valve. I found a Haynes manual (not a fan) that purports to be for 83 all the way to 07 so I'll see if that sheds any light. Any other suggestions will be appreciated. Thanks all.