Last updated on the 25/07/2010 11:28
Common markings found on a Ferret and where to look
What do you do now that you have found the Army Registration markings on you're Ferret?
Contact the Tank Museum at Bovington and for a small fee of about £15 they will send any information that they hold on you're vehicle. www.tankmuseum.co.uk
Nuts and Bolt Threads
The thread types as used in the Ferret UNF, UNC and BSP. The only metric thread possibly being a nut that holds the windscreen wiper arm on.
UNF is used in / on the hull, engine, gearbox and the wheel stations
UNC is used in / on the gearbox, steering components and the oil tank (commonly used in conjunction with aluminium).
BSP is used with any brass component with a thread - hub plugs, fluid flywheel plugs, grease nipples, sump plug & banjo bolts to name a few off.
Nuts and Bolts Common sizes
Grease Nipples
All Grease Nipples on the Ferret bar the grease nipples on the prop shafts are 1/8th BSP, this applies to the early hook on type of grease nipple and the later push on types. The hook on variety can be bought quite readily on eBay UK as can the push on types.
Hook on grease nipple commonly found in early Ferrets.
Later style push on grease nipple (its common to find both the hook on type being used with the later push on varities).
90o Push on type
45o Push on type
A quick way of buying the correct type of bolts (grease nipple in this case) is to take along an original bolt as removed from the vehicle and place it next to the new bolt, the threads should intermesh along the full length of the threads.
Ferret Basket
Nice and simple and easy to alter for extra length or height
Petrol Cookers Mk2, Mk2 Modified and Mk3 double burner.
All these cookers potentially have an asbestos heat shield it might not kill you today but it will eventually kill you if you do not take the right precautions. You have been warned! See here for more information
The Mk2 cooker was standard issue CES for the Ferret and many other Petrol powered British Military vehicles. I have collection of these cookers, they all seem to follow a standard design but with different manufactures fabricating them over the years they have some subtle differences. They can operate with paraffin and I believe diesel also but its not something that I have tried yet.
Early Petrol fuelled cooker below date 19** and asbestos heat shield. Ignore the rust it works!
Picture required here
Modified earlier Petrol fuelled cooker with a new flame control and asbestos heat shield.
Picture required here
Later MK2 modified Petrol fuelled cooker without asbestos heat shield and purpose built box.
Having played around with these cookers the main problems tend to be blocked priming pumps, dried out leather cup in the priming pump, perished filler washer, jet blocked and sediment in the tank. Wonder why it was replaced?!
Watch out for soldered joints leaking as well just for good measure!
Poor flame control can be attributed to over priming of the tank, six pumps should be more than enough to pressurise the tank. Any more than that consider adding a drop of oil to the priming pump and then depressurise the tank and try again. If that doesn't correct the problem replace the leather cup in the priming pump . When priming the tank each full pump should be accompanied by a raspberry sound which indicates that the tank is being pressurised.
No sound and the pump isn't pressurising itself properly and probably will require the priming pump to be removed from the tank to free off the valve at the end of the pump.
What would I do now if I bought a Petrol Cooker with an unknown provenience?
Buy a new filler washer and a new leather cup for the priming pump. The Primus / Optimis range of petrol cookers seems to have compatible items to those required for the Mk 2 cooker. I have bought new filler washers and cups and have fitted them without any great problems.
If a cooker has been left with petrol in the tank of the cooker or you have just bought it and the condition is unknown now's the time to strip it down. More often than not the valve on the priming pump has stuck which results in the priming pump being pressurised rather than the cookers fuel tank. Downright annoying having to empty of the fuel before you can strip it down to correct the problem. The small rubber washer usually sticks to the end of the priming pump removing it frees it off.
Picture required here or a drawing of the valve on the end of the priming pump
As petrol is a mix of different chemicals it tends to leave a sediment in any type of petrol container if left for long periods. This can be enough to block the outlet hole on the fuel tank and block the pipe to the jet.
Picture required here of the fuel removed from cookers with sediment at the bottom of the bottle
I'll deal with the early type of cooker first as it has more parts to be stripped down.
I would remove the priming pump, this can be interesting as it's usually tightened on by a gorilla leaving gentle brute force as the only option!
Picture required here
Strip the tank down removing all parts that can be removed or harbour sediment. Once that is done add a handful of small nuts and bolts (count them in and out) and then block the holes with you're fingers and add water and shake. Shake and replace water repeat this till the water runs clear. I have also tried adding cellulous thinners as well to remove sediment and any remaining water.
Be very careful with the heat shield as nearly all the early stoves have an asbestos backing to the shield.
Wear a mask and try not agitate the fibres!
Stripping all versions is quite easy in that two screws retain the tank assembly to the case. Which when removed allow the tank and burner to be slid out of the case.
Two further screw hold the shield and the tank in place.
A common problem on early stoves is that the adjusting wheel is soldered onto a ferule and it sometimes comes loose. This ferule is screwed onto the needle which controls petrol flow. The adjusting wheel is made out of brass and the securing nut can be made of brass or steel depending on the manufacturer of the stove (I have seen both). The Steel nut has brass braised onto it to enable it to be soldered.
The rear of the nut has been soldered onto the adjusting screw which is then screwed onto the needle (both have separated here).
The best way that I have found to repair the offending items is to clean the all the parts back to bare metal with sand paper or a wire brush (scouring pads work quite well also). Dry assemble all the parts back together and then disassemble ready for soldering. Lightly smear flux onto all components that are to be soldered which includes the knurled adjusting screw, the nut and the thread. Reassemble in order and solder back up.
Now that you have reassembled the cooker refuel it and test it. Have a brew you deserve it!
Mentholated spirits has been found to be a very quick way of heating the burner up.
Mk 2 Modified
The modified cooker has less parts to be serviced by the user and I am presuming it was meant to be more user friendly. The Mk 2 M lacks the front flame control of the earlier cookers and has the flame control moved to the side and is fitted with a different burner assembly.
Some early cookers were modified into Mk2 M's so they still have the front adjustment position but the control is moved to the side.
Picture required here of the two types side by side
Mk 3 Double burner
Picture required here
No 12 Diesel cooker
The MK 2 and MK3 petrol cookers were replaced by the No 12 Diesel cooker which in many ways is superior to the early petrol cookers in that its easy to clean and strip apart. Not part of Ferret CES but its a great portable cooker.
I use paraffin as the fuel in my cooker but kerosene can also be used (not suitable for petrol).
Timothy Rendall's five cylinder Ferret
The Ferret had been running on five cylinders when I bought it and I have now found out why. The oil feed to the head was blocked I had to take out the centre bush shown in photo but to do it I had to make a jig to extract it.
I’ve put in new valve guides and second hand rockers as you can see they were 'us'.
Replacement Switchboard Letters
I needed to rebuild an early switchboard stripping and painting the switchboard was the easy part reapplying the original letters and having it look reasonably o.k. was the difficult bit. I am not going to claim that this was my idea as it would be nothing new to a model kit maker.
Click the picture and a word document will pop up in a new window with instructions on how to do it.
Electrical Problems
It's what happens if the main ignition feed from the main switch panel to the engine junction box isn't properly clipped up, or the clips corrode through.
The cable drops and rubs on the drive shaft/bevel box flange which eventually wears through the casing. This usually starts with the engine cutting out intermittently, gradually getting worse until the electrics are dead. You can hear the distribution box relay trip and re-set.
As the contact isn't direct, a standard Multi meter doesn't show the short, but 24v easily jumps, creating the short. A new cable is £90 and a pain to replace. The clips also hold the main alternator / generator cable which is a bit more substantial (£££) and will probably destroy the rectifier if it shorts.
I noticed the same problem on my Ferret when I was putting my Ferret back together my solution was to use tie wraps (cable ties) its an inexpensive solution that only the owner will know about and if it saves ££££ / $$$$ well worth doing.
Many thanks to Dave Rose for passing the above information on.
B60 Distributor
Petrol Tank
Diagram of the Petrol Tank and Change over Tap
Change over Tap
When I was first setting up the petrol tank on 00CC09 I found that I had a problem with the change over tap in that it would not let any petrol flow through the tap handle. To add insult to injury their was a leak in the Filter bowl itself. I had no other choice but to strip the tap down, when I stripped it down I found that the handle itself was clogged as was the body of the unit. Cleaning the tap and the body resulted in a damaged cork gasket which I then had to replace, which isn't a difficult as it sounds. The cork gasket is quite easy to make as the hole pattern is just the same as five on a dice. The cork gasket has locating lugs to stop it rotating when the handle is turned.
Vokes Filter bowl
Clean the bowl out when a new filter is required and clean away any sediment and check for holes in the filter body. If any holes are found in the bowl it might be repairable if the rust inside is sandblasted away and it then has the hole brazed up with brass. The bowl would have to be cleaned throughly before blasting (no smell of petrol)!
I enlarged the hole in the filter bowl for the camera.
After my own experiences I would suggest cleaning out the bowl and replacing the filter element if the vehicle has been standing for an unknown length of time. It would also be good idea to clean the tap out as well and fit a new cork gasket. Don't forget to clean the little filter on the carburettor in feed pipe if your doing the above.
Banjo Bolt modification
I can not claim this modification as my own it was found on a petrol tank that I helped remove in South Wales, a past REME modification when and where who knows.
Banjo Bolt with a one inch brass extension tube / Purpose to stop sediment from the bottom off the Petrol tank being sucked into the system blocking the petrol filter / banjo bolt filter. Occasionally sediment bypasses the main Petrol filter and is only stopped by the smaller filter at the banjo bolt on the Carburettor which eventually blocks stopping the engine. This modification lifts the Banjo bolt in-feed off the bottom of the tank. It only needs to be recessed into the Banjo bolt by 1/8th of an inch and it is then soldered into place.
Picture off a duff bolt which has a crack across one side with a copper tube to illustrate the drawing.
Extremely rough job on my part to illustrate!
Priming the fuel system on the Ferret
Vokes Filter set up in the Ferret and a Vokes Filter body
This is what I do when I prime the fuel system on a Ferret it is worked every time for me.
When writing about left and right I'm looking directly at the Fuel tank with the Vokes filter on my right.
For this to succeed safely you MUST remove the batteries from the vehicle, sparks and petrol don't mix! Unless you like the idea of being fried alive or having a super rapid tan! I would also suggest that this is a two man job. The 2nd person is there to hand you tools, cloths, help and laugh at you while you're doing the majority of the work.
The 'work'
Label up the battery cables + / - and then remove cables from the battery's left hand side first.
Disconnect and remove both batteries and the battery box under the inter-vehicle starting box. Remove the middle gearbox support on the side that the battery box was removed from. You can now gain access to the priming handle on the fuel pump. Reach your hand in under the fuel tank and feel for the pump, the priming handle is on the thumb side when the pump is cupped with your right hand. With the thumb press on the handle and feel if there is any resistance (not easy to quantify), if fuel is already in the system you might hear it attempting to suck / draw fuel to the pump.
Place a cloth under the fuel tank under the filter, loosen off but don't completely remove the T shaped handle on top of the filter body. The blue filter body (in these pictures it is blue) should now drop down by about a centimetre / 1/4 inch. The unfiltered petrol pipe coming from the top of the tap in the picture above stops the filter body from dropping to far.
Fill the filter bowl with petrol no.3 in the picture (it might run over the top) the cloth underneath is there to catch any petrol drips, retighten the T shaped handle which should bring the filter bowl up to the sealing ring.
Undo and remove the air vent no.1 in the picture to a safe place (assistants hand no chance of dropping it) and fill the pipe with petrol all the way to the top. Re place and tighten the vent up.
Undo and remove the air vent no.2 in the picture to a safe place (assistants hand no chance of dropping it) and fill the top of the filter up with petrol, once it is full replace and tighten the vent up.
Reach your hand in under the fuel tank and feel for the pump, the priming handle is on the thumb side when the pump is cupped with your right hand. With the thumb press on the handle and start priming the pump, it could take up to ten strokes to prime the pump. It should be possible to feel the priming handle stiffing up when fuel has reached the pump / carburettor. A quick way of testing to see if fuel has reached the float chambers in carburettor is to remove the carburettor air horn and operate the accelerator rod. Two jets of petrol should shoot into the carburettor indicating that the float chambers in the carburettor are full.
Replace batteries and operate the starter Ferret should now start.
Generator
(Dynamo or Alternator)
If it is a Dynamo it will say Generator No.2. The picture below shows the No.2 Dynamo at the top of the picture.
Identifying features for the Generator No.2. (Dynamo). Grill on the top off unit next to the plug and oil pipes running to the Dynamo from the engine block. The rear end of the Dynamo is fluted with a grill and the unit has no cooling fins. The pulley has the capacity for three belts (same as the Alternator) but only two belts are fitted.
If it is an Alternator the plate on it will say Generator No.10. The picture below shows the No.10 Alternator at the bottom of the picture.
Identifying features for the Generator No.10. (Alternator). A large plug connection is fitted at the opposite end to the pulleys and has cast in cooling fins at either end of the Alternator. The pulley is designed for a narrow car type V-belt (three belts fitted).
Alternator and Dynamo engine crankshaft pulleys. Dynamo crankshaft pulley and Alternator crankshaft pulley (first picture) reversed in the next.
Generator (Dynamo) belt tensioning
Wheel Station
A damn good reason to replace twenty plus year old tyres.
Tyre Pressures
| Normal Road Use | Marks 1 to 2 | Marks 3 to 4 | Mark 5 |
| Front | 30 lbf | 18 lbf | 18 lbf |
| Rear | 36 lbf | 20 lbf | 22 lbf |
| Cross Country | |||
| Front | 18 lbf | 18 lbf | 18 lbf |
| Rear | 25 lbf | 20 lbf | 22 lbf |
Brakes
Steel or Copper Brake pipe lengths inside the Ferret hull
From the Left hand side rear elbow approx 94 inches long
From the Right hand side rear elbow approx 98 inches long
Connection pipe from left side to master cylinder inches ** long
Brake Booster (Servo)
Wheel Hub
I was given a wheel station (hub / bevel box) that was still mounted to a small piece of armour plate. The wheel station below had seen better days so I stripped it down to help me understand the workings of the hub and the planetary gears. Before I started stripping the wheel station down I'd always been wary about stripping down a hub, having done it I now cannot see why I was so bothered! The worse bit was removing the eight allan headed bolts on the hub face all but one was seized in place!
The the brake linings are / could be made of asbestos you have been warned!
I'll list the basics and I mean basics off stripping it down
Tools needed:
Mask consider the brake linings to be made off asbestos and treat accordingly!!!
Hammer normal and plastic faced, flat bladed screwdriver large and small, cir-clip pliers,1/2 spanner, 9/16 spanner, 7/32 allen key, Impact driver, two 1/2 inch by 1 and a half inch bolts, 2 x 19mm spanners or imperial spanners, 19mm socket or imperial equivalent, 1/2 inch & 9/16 sockets,
| Capacities | Key | Imperial | Metric (litres) | Oil Specs Military | Oil Specs Civilian |
| Steering bevel box (upper) | 1 | 1½ pints | 0.85 | OEP-220 | 90EP Gear oil * |
| Steering cross-shaft bevel box (lower) | 1 | 1½ pints | 0.85 | OEP-220 | 90EP Gear oil * |
| Inner tracta joint housings, including bevel boxes | 2 + 10 | 3 pints | 1.7 | OEP-220 | 90EP Gear oil * |
| Outer tracta joint housings, including road wheel hubs | 3 + 11 | 1½ pints | 0.85 | OEP-220 | 90EP Gear oil * |
| Front and Rear Prop shafts | 4 | Three grease nipples per shaft | Multi purpose grease | ||
| Transfer box | 5 | 6 pints | 3.41 | OEP-220 | 90EP Gear oil * |
| Gearbox | 6 | 1¼ gal | 5.7 | OMD-110 | SAE 30 straight |
| Air cleaner | 7 | 4 pints | 2.28 | OMD-110 | SAE 30 straight |
| Fluid coupling | 8 | 9¾ pints | 5.52 | 0M13 | ISO10 or ISO15 |
| Engine lubrication system (dry sump) | 9 + 12 | 3 gal | 13.64 | OMD-110 | SAE 30 straight |
| Engine cooling system | 13 | 4½ gal | 20.46 | Not spec. | Antifreeze |
| Fuel Tank - total including 3 gal reserve | not in pic blw | 21 gal | 95.5 | N/A | N/A |
| Brake fluid supply tank | not in pic blw | 1¼ pints | 0.71 | OF-20 or OF-24 | Dot 3 / 4 (mineral based fluid) |
* Straight mineral oil not a Multigrade Oil as the additives can erode / degrade Phosphor Bronze bushes *
Last updated on the 25/07/2010 11:28 Copyright © 2007, 2008, 2009, 2010
