Lynx I MkIII purchase

[Alastair Thomas]

My Lynx is now ready for the road except for the fact that the instruments do not work.
I see from the wiring diagram that there is a resistor to drop the 12v supply voltage down to 6v for the instruments. I do not know where this resistor is.
Browsing in the spare parts manual to identify a unit mounted on the front bulkhead of the engine compartment, I see it is called "C19SR 12250 Circuit breaker - ignition coil and resistor assembly". This looks a likely candidate.
Can anyone confirm this is the beast I am looking for and where to test its output please.
Regards,
Alastair
F60S
Lynx I MkIII*

[Mike Cecil]

If the circuit is anything like the Ford CMP and MC 6 Volt circuitry, the resistor is to drop the voltage to 4.5 volts for the ignition coil.

Doubtless other Lynx owners can help with more detail.

Mike

[Andrew Rowe]

You can by-pass that and depending on whether you are using a resistor at the coil end, which gives you the same effect. Cheers Andrew.

[Colin Alford]

Alastair

For a detailed discussion on "C19SR 12250 Circuit breaker - ignition coil and resistor assembly" have a good read on this thread:

http://www.mapleleafup.net/forums/sh...ad.php?t=25315

Colin

[Peter Duggan]

Alastair,

PM sent.

Peter

[Tony Smith]

https://www.ebay.com/itm/Ford-C19SR1...IAAOSw4q9XTz2A

While it appears to use the same resistor and circuit breaker components used in the 01A-12250 and 11A-12250 units, it has two ignition resistors and that large cylindrical item in the middle. So while there is some commonality with the 6v parts, there is obviously different needs for the 12v system.

[lynx42]

Hi Alastair, I purchased a new old stock unit from Dirk and Stephan Leegwater. I am not sure if they still have them or not but it might be worth contacting them to see.

Regards Rick.

https://www.lwdparts.com/

[lynx42]

Tony Smiths post No. 36 is cheaper than what I paid to LWDParts. So a good buy. I reckon.
Cheers Rick.

[Alastair Thomas]

Thanks everyone for the flurry of replies and suggestions.
I now know enough to fault find the unit fitted to my vehicle and, hopefully, I can sort the problem out.
Alastair
F60S
Lynx I MkIII*

[Alastair Thomas]

Well, on Sunday we spent some time shunting vehicles around and got the Lynx out of the barn at last. Remarkably all the vehicles started and moved without any trouble.
We then celebrated by taking it to the Half Moon pub 3.5 miles down the road.
First impressions were good: very cold on the eyes and hands without goggles and gloves and no flies eaten.
The steering is good and the brakes adequate when I can find them. I am still to get used to the offset seating position. The time lag, caused by the hydraulic throttle and clutch controls, that I had been warned about, was not present on this vehicle - my gear changes were just as bad as when I am in the F60S.
The vehicle pitches a bit but not as bad as when we picked it up and towed it on a solid bar.
The armoured roof, folded back, makes a terrible racket. Even the Stukas would have heard it. Presumably there are some discrete rubber pads to be added.
It seems to understeer but I was not going fast enough to induce slippage in the front tyres so I think it is just a matter of getting used to the fact that there is very little vehicle in front of the driver giving a different perspective on the road.
I felt that I was going like the wind but my brother Gordon, who was following in the tow car just in case, tells me I was doing only 30mph.
I did not measure the fuel consumption but it is sobering to think that if I have the reported fuel consumption of 4mpg I should have used nearly 2 gallons for the round trip.
Anyway, here is a picture of it in the open. You will see that I have added easily removeable head lights and indicators for public road driving.
Alastair

[Alastair Thomas]

In the process of refurbishing a pair of military Butler lights, I left them on the kitchen table before going out for the evening.
When I got back I saw that my wife had restored their modesty.
Alastair

[Alastair Thomas]

We have had some trouble getting the Lynx to run reliably. Annoyingly for my brother, it fails to start for him when he wants to show it off to visitors but starts promptly for me (usually). We have been trying to find the problem especially when it broke down twice away from home. In each case it re-started after a delay of 20 minutes or so. It broke down again 20 miles from its home yesterday. An ignition tester showed us that there was little or no spark. We had suspected the ignition side since fitting a petrol pump with a glass bowl top enabled us to be sure that petrol is getting through. So we checked the points (OK), changed the condenser and coil but no better. Eventually we took the distributor cap off and found the rotor arm a little past its best.
Are these readily available in the UK?
Alastair
F60S
Lynx III MkI*

[Harry Moon]

"The armoured roof, folded back, makes a terrible racket."
I don't have any rubber on mine but I don't have any racket either. The roof is held down tight with the locking mechanism, I couldn't see what you had.

[Alastair Thomas]

Thanks, Harry.
I have the same locking mechanism. It is very positive and I need the help of a tyre lever to release it. When we get the vehicle going reliably I will ask the passenger to tell me what is rattling against what and we can take it from there.
Alastair

[Harry Moon]

Originally Posted by Alastair Thomas

Thanks, Harry.
I have the same locking mechanism. It is very positive and I need the help of a tyre lever to release it. When we get the vehicle going reliably I will ask the passenger to tell me what is rattling against what and we can take it from there.
Alastair

There is the locking mechanism for the bottom or rear roof panel and the separate mechanism for the top or forward roof panel..... I can't see if you have the latter in your pictures.


I find that the viewport lids bang when ever i hit a bump hard enough. the locks just rest in place and don't apply any camming to hold them in place and often i find they bounce out of the locked position when i get to my destination.
Can't help on the ignition as the motor I'm using is a later top mount distributor, 12 volts, petronix.

[Mike Cecil]

Alistair,

This might sound crazy, but have you felt the temp of the coil when it stops running? The symptoms you describe are exactly what was happening when I first drove my first F15 in the 1980s, and we soon discovered that the 4.5 volt coil was getting 6 Volts - and gradually overheating. After 20 minutes, it had cooled, and the engine started again without a problem, then would run until the coil overheated. No/little spark, so no ignition.

Of course, your Lynx system is 12 Volt - is the coil also 12 V or a standard 4.5 V Ford coil working via a resistor?

Mike

[lynx42]

Originally Posted by Mike Cecil

Alistair,

Of course, your Lynx system is 12 Volt - is the coil also 12 V or a standard 4.5 V Ford coil working via a resistor?

Mike

Mike, The Lynx electrical system runs 12V and 6V and 4.5V. It is a real pain as all wires are in woven shields and are black in colour and not labeled. To make it more confusing the power comes off the battery through a main switch then after it has done a circuit through the 12V generator it comes back through the same switch with different contacts in the other direction. There is nothing on the wiring diagram to show which way the current runs.

The coil runs 4.5V the instruments run 6V and the lights etc 12V.

I am still having trouble sorting mine out.

Cheers Rick.

[Alastair Thomas]

Thanks for the suggestions chaps but some of you did not notice that the rotor arm is missing the contact to the central carbon bush. Clearly that is a show stopper! I am going to try to replace it but I will not be happy until I have a reliable replacement.

[Alastair Thomas]

Not being willing to await the arrival of the rotor arm I had ordered from Mack Auto, I decided to fix the broken one.
I removed the head of the rivet holding the brass "contact" and revealed the broken end of the spring strip contact.
I commenced drilling the rivet out but the drill wondered off the hard rivet into the soft plastic as I feared so I drilled from the other side until I hit the rivet and then punched it out upwards.
I took the spring strip from a set of points, ground it to the correct width and drilled a hole through it (using a tungsten carbide spear point tile drill). I reassembled the whole using a self tapping screw but, fearing that the plastic would burst under the pressure of screwing the screw in I chose a small screw and Araldited it in.
I feared that the "contact" may have shifted in the process so I removed the distributor, assembled the rotor arm and cap onto it and turned it by hand. The "contact" did indeed foul the contacts inside the cap by about 1/32". Having filed this off the end of the "contact" everything is sweet and the Lynx now runs reliably again.
Alastair

[Alastair Thomas]

I see that some vehicles have a marking "W/T" on them. Somewhere I believe I have read that all vehicles fitted with a radio transmitter were so marked. My Lynx has a Mk19 set but is not marked in this way. It is true that it has been completely restored in the past so the markings may just have been missed. However, I would like to confirm that my vehicle should have them as the restorer, Mike Ebeling, was most meticulous in all other respects.

Secondly, I have seen in one photograph, a sign "SLING HERE" alongside a lifting eye on the vehicle. This was a picture of a prototype Lynx in the factory. Did this continue into production and would it have been stencilled alongside each of the four eyes?

Alastair
F60S LAAT
Lynx I MkIII*

[Bruce Parker (RIP)]

Unless there's some really odd explanation it's almost certain your Lynx had the W/T. It was factory applied and visible on every wartime 'repaint' I've ever seen.

Originally Posted by Alastair Thomas

I see that some vehicles have a marking "W/T" on them. Somewhere I believe I have read that all vehicles fitted with a radio transmitter were so marked. My Lynx has a Mk19 set but is not marked in this way. It is true that it has been completely restored in the past so the markings may just have been missed. However, I would like to confirm that my vehicle should have them as the restorer, Mike Ebeling, was most meticulous in all other respects.

Secondly, I have seen in one photograph, a sign "SLING HERE" alongside a lifting eye on the vehicle. This was a picture of a prototype Lynx in the factory. Did this continue into production and would it have been stencilled alongside each of the four eyes?

Alastair
F60S LAAT
Lynx I MkIII*

[lynx42]

Alistair, before stripping down my Lynx for restoration, I took photos of everything I saw.

The hull number was painted on the leading edge of the petrol tank armour. It was protected by the mud flap.



W/T was on both doors as you can see here.



Sling here was painted close to the lifting rings.



The weight etc was on the side of the left petrol tank armour.



The 5 ton bridge sign was on the front left.



I hope these help.

Regards Rick.

[Alastair Thomas]

Thanks everyone. I must say that I was particularly doubtful about the "SLING HERE" sign but we now know it is correct.
Alastair
F60S LAAT
Lynx I MkIII*

[Davdberg]

Hey guys,

I was wondering if you could help me out. Are the axles and gear box on the Lynx Scout similar to any CMP Ford trucks? A friend of mine is looking at a project but its lacking axles; gearbox and engine. Chassis is unknown.

Best regards

[Harry Moon]

my understanding is the Lynx1 has F8A axles and the Lynx2 has F15A axles but 63 inchs centre to centre.

[Andrew Rowe]

The Mk 1 is 12 spline and the Mk 2 Lynx axle is 16 splines. Lynx 1 is of a smaller diameter than Mk2. The axles from a C8A (maybe F8 as well ?)are the right length but are 10 spline. They have the correct flange thickness and 8 hole bolt up pattern. The short one is about 678mm to the inside of the flange. My theory is that you can get a C8A axle and vee the spline a little deeper and weld up and then re-cut the new spline to 12, if making a Mk1 axle. The other idea is to take the longer axle from the other side and cut it down to a short side length and then re-cut the spline. The axles I believe are just case hardened so with modern carbide cutters, can do the job. Using a C8A axle is about 38mm thick, this will get turned down to about 34.8mm where the spline needs cutting, this is for Lynx 1 only. The Lynx 2 starts with an axle that is about 43.8mm dia. , so quite possible other axles in the CMP range would work, the spline is 16 , so would have to check that against a larger CMP axle.
The Lynx gearbox uses standard Ford 4-speed truck gearbox components, but the housing is different. They have turned the main part of the gearbox 90 degree to the bellhousing part of the casting that bolts to the engine, so to give you a flat floor. The shifter housing that bolts to the side is all enclosed and uses double shifter rods to make the gearchanges remotely, if that makes sense.I Have cast up new gearboxes for the Lynx, but have still to machine them up at this stage.
Just to add some technical info:
Lynx 1 axle: 12 spline, 34.8mm at the spline dia. approx., length of spline 65mm, inner axle diff seal runs about 130mm from end
of the axle, ( spline end ) Short side axle is 678mm from the end to the inner of the flange, Long axle is 1048mm to
the inner of the flange. The flange is about 1/2" thick and about 134mm dia. with 8 holes @ 114mm dia., NO
counter sunk drilled for these holes like other CMP axles.

Lynx 2 Axle: 16 spline, 43.8mm at the spline dia. approx., length of spline 80mm, inner axle seal runs about 90mm from the end
of the axle ( spline end ). Short axle is 678mm to the inner of the flange and long is 1048mm to the inner of the
flange. Flange and holes are the same as Lynx 1.

If anyone is passing by a bunch of CMP F8 or F15 axles, it would be interesting to see what these measure at? I do know C8AX axles , could be converted to Lynx 1 as I have mentioned above as they are the right length and start life at about 38mm, so there is enough meat to work with when re-machining......if my theory works out?

Cheers Andrew.

[lynx42]

Originally Posted by Andrew Rowe

The Mk 1 is 12 spline and the Mk 2 Lynx axle is 16 splines. Lynx 1 is of a smaller diameter than Mk2. The axles from a C8A (maybe F8 as well ?)are the right length but are 10 spline. They have the correct flange thickness and 8 hole bolt up pattern.

Andrew, Lynx 1 Mk's 1,11,111, and 111* all have 6 stud bolt set up not 8. The wheels are like those on the Chev HUP's. The tyre size is also unusual at 9.25" x 16. I am running 9.00X16 tyres as the others are not available.



A bit of a difference in rolling circumference, but that shouldn't cause me too many problems.






I was luck to get my original gearbox. You will have a few blokes looking out for your new cast housings as I have had many enquiries re the gearbox availability.

Cheers Rick.

[Andrew Rowe]

Hi Rick, with regards to the axles, I was talking about the axle flange that bolts to the inner hub is 8 bolts on ALL models.
You are talking about the wheel rims, that use 6 stud Wheel nuts on Lynx 1 and
8 stud Wheel nuts on Lynx 2. The 6 stud wheel rims are of lighter construction than the 8 stud wheel rims, which use the standard heavier CMP 9.00 x 16 rim on the Lynx 2. With regards to my gearboxes, I have to find a friendly guy ( meaning cheap !) with a CNC centre mill/lathe? to program the line- boring of the holes and the facing off of the surfaces. All hole and face dimensions are that of the standard Ford 4 speed "crash" gearbox. They are excellent quality castings ready for machining, Calling anybody out there with the skill and equipment! , Cheers Andrew

[Andrew Rowe]

I probably went off on a tangent talking about axles....too much covid lockdown! , I guess if you were talking differentials, there were 3 types for the Lynx, serial 0 to 201 was a 5.83 ratio with 14 &7/8" across the width of the flange housing , serial 201 to 3000 is 5.83ratio and is 12&1/4" across the width of the flange housing, from serial number 3000 the ratio is 6.66 and is 14 &7/8" across the flange housing. This last diff is basically looks like the same
dimensions as the standard Ford 3 ton axle, similar to Bren Carriers, except they use C8A backing plates and the axles are different lengths., Cheers A.

[Alastair Thomas]

Well this COVID business is a bind. I cannot get to my Lynx nor can I collect the chore horse I bought recently, because of the lock down.
However, I am puzzled.
It is my understanding that the Lynx I carried a chore horse because the dynamo was not up to keeping the battery topped up when the Mk19 set was being used. This explains the uprated dynamo fitted to the Lynx II (and the two speed dynamo fitted to the Dingo).
My question is: where should the chore horse be stowed? The stowage diagram does not mention it and I have not found any Footman loops or otherwise to give me a clue.
Thanks
Alastair
F60S
Lynx I MkIII*