For want of a nail, the war was lost (Lynx story).

rob love · #1 04-05-12, 19:38

For want of a nail, the shoe was lost, for want of a shoe, the horse was lost etc....

So anyway, poetry aside, a month and a bit ago I started working on a Lynx scout car at the Shilo museum. It had a severe shifting problem, getting caught in gear or unable to shift into a gear. The main volunteer mechanic felt it was in the front remote shifter mechanism, and after removing it from the vehicle, sure enough, there was some wear on the bottom plate that made it look like the shifters were interfering with each other. I built up the bottom plate, cleaned out the rust and crap, new O-rings, and reassembled it, making sure everything was free pin fit with the linkages running to the transmission. Steering was also jamming up, so the nose to the vehicle was removed, and the coupling to the pitman arm was found to be loose and coming apart. That was fixed. After that, the vehicle got a complete brake job (new double flared steel lines to replace the copper lines someone had installed with single flares), all new cyls including master, new flex lines, and wheel seals of course. Then on to the electrical. Lots of bare wires and splices, so all the wiring was gutted, and new braided wire installed, all numbered by the book. All new toggle switches, all lights repaired and made functional. Then on to the fuel system. All new lines, 3 way valve fixed up, large cannister filter on the frame with an electric pump installed to function as a primer (like the original autopulse). Carb had already been done but a choke setup was arranged, and the fuel pump was already new. Gas tanks have been sent downtown for cleaning and repair. Oh yeah, and I made a new front fender to replace a badly bent up one.

So after all that, yesterday I go to finally drive it out of the shop. I had some fuel problems, which were the result of running on a POW can of gas as the fuel tanks were still downtown. But then the unthinkable: the lynx got stuck in 3rd gear again....hopelessly stuck. I managed to get it back into the shop, and today managed to get it onto the hoist. After all this work I was very discouraged, and sure I was pulling the engine to fix up the transmission. I'd had to disconnect the linkage to the 3rd and 4th gear shift and pry the shifter back into neutral against great resistance.

So anyway, I get it onto the hoist, and had the drain pan all ready to pull the oil, when I decided to look at things again. That's when I noticed a bit of shine on one of the greasy clevis pins at the transmission rails. No cotter pin. And another pin only had a small piece of thin copper wire through it. This was allowing the clevis pin to vibrate down and jam up with the reverse shifter shaft.

So with 2 X 3¢ cotter pins installed, I held my breath, started up the lynx, and headed outside for a nice mile long road test. It performed flawlessly. What a hoot to drive.

Sometimes it's the little things that really count, and make all the difference.

Bruce Parker (RIP) · #2 04-05-12, 20:11

Rob, sometimes it goes the other way. I got the Fox back from an outing last summer and put in the garage to remove the 50 cal. Browning (you may know the one). There, in the middle of the floor was a 1/2" diameter polished metal rod, about 3" long with a machined recess in the middle. Rust free, it recently fell out of somewhere. I think I know where every pin/hinge/clevis goes having put each one in personally. But where this one came from (or should go back to) I have no idea. So far everything is running OK and nothing has fallen off.

charlie fitton · #3 04-05-12, 21:21

(Ah - the fun you can ahve taking spare parts to a show...)

Lynn Eades · #4 04-05-12, 22:07

Good one Charlie, now...who don't I like?

Bruce Parker (RIP) · #5 04-05-12, 22:12

Quote:

Originally Posted by charlie fitton

(Ah - the fun you can ahve taking spare parts to a show...)

Hmmmmm....come to think of it you WERE there....

Do you want you PIN, SECURING (CONFUSION) Mk.II back?

rob love · #6 05-05-12, 01:50

Didn't somebody do that at a sailing race one time? They tossed a loose pin into the other teams boat and they were so concerned trying to find where it came from they blew the race.

Next challenge on the lynx will be to stop the last of the leaks from the brake system. I thought I would give DOT5 silicone brake fluid a try, and am starting to regret it. I'll be replacing two or three lines on Monday, as I have overtightened them trying to stop them from leaking and likely split the flares. To top it off, I think one of my brand new cylinders is also leaking. Lucky that they pay me by the hour and not by production.

Mike Cecil · #7 05-05-12, 17:21

This thread reminds me of a visit I made to the Australian Army's Maintenance Engineering Agency in the early 1990s, when the new ASLAV was being introduced into service. I arranged for a photo shoot to illustrate the article I was writing, and my contact said to come back later in the week after he'd had a chance to put some bogus 'bumps' and aerials on the vehicle.

His comment was that modelling magazines were a low grade source of intelligence, so he was going to drive some foreign int officer mad trying to work out what the Australian Army were installing in their ASLAVs!!

Must take an assortment of nuts, bolts and clevis pins to the next MVPA convention ....

Mike C

chris vickery · #8 05-05-12, 18:06

At my local club we have one individual who is rather, how can I say, uptight. He relishes his car so much, carefully putting it into storage each winter, up on blocks, all polished, cleaned and triple tarped.
The fun one can have with one ounce of clean brake fluid applied inconspicously on the floor is amazing....

rob love · #9 05-05-12, 18:48

Reminds me of a story about the old duece and a halfs. They could leak anything and everything. On a convoy, one of the Mcpls driving a 5/4 ton relieved himself in the area of the fluid coupling on the old M135. A minute later the driver came back to his duece, and the MCpl tell him" Your truck is leaking something; you had better check it out. The MCpl then heads back to his 5/4 ton. The Cpl checked the mystery fluid for feel, then smell, but figured it out when he tried the taste test. All he could see of the 5/4 ton was a smiling face in the side mirror as it left the scene.

Don't ask me how he knew the taste!!

Yeo.NT · #10 05-05-12, 18:56

If DOT5 fluid is used in a braking system designed for DOT3 and DOT4 the seals will breakdown and degrade.

rob love · #11 06-05-12, 03:01

The entire brake system is new. Wheel cylinders, lines, flex lines, master cylinder. The companies making wheel cylinders are not using two kinds of rubber for their cylinders these days. The cylinders should be compatible with both. To add to that, there is actually an additive in the silicone fluid that is there to cause a slight swelling of the rubber.

I had the back wheels off on Friday afternoon (the new brake return springs came in) and I also have to pull the fronts on Monday. I'll see whats going on in that front left cylinder. With the tires off I should be able to get some good visual of whats going on at the fittings.

From what I can glean on the internet though, the copper washers at the banjo fittings are the big culprit on these systems. And of course, the lynx has copper washers at every wheel station, at the master cylinder, and at both frame to axle flexlines.

I am going to give it the old college try this week and see what happens. I have an unconventional plan that is crazy enough it might just work.

rob love · #12 06-05-12, 03:24

Also, on another related lynx topic, how many of these vehicles were actually made? I see the number "at least" 3255 made in a few sources. This lynx, though, has a hull serial number of 4542, with a build date of 1-1945. What other serial numbers are out there?

chris vickery · #13 06-05-12, 05:24

I just used silicone on my M38A1 CDN3 rebuild as all my brake system is new- no issues. The only leak I had was from forgetting one crush washer....

Lynn Eades · #14 06-05-12, 10:09

What is it about the copper washers?

45jim · #15 06-05-12, 23:26

Just a point, did you anneal the copper washers? Often the washers we find these days from normal suppliers are work hardened during manufacture and not stress relieved post manufacture. I have often found a simple annealing solves the sealing problem.

rob love · #16 06-05-12, 23:31

I used all new copper washers. Since they are specifically for brake systems, one would think they are of the correct hardness. I'll be doing a bit of experimenting this week; annealing may well be one of them.

Barry Churcher · #17 07-05-12, 03:36

Rob, at work we never use the new copper washers. They seem to be prone to leaks. We carefully re use the old ones and never have any problems, whether on wheel cylinders or calipers. We can't afford a customer comeback be it the time or our reputation.
Cheers,
Barry

rob love · #18 07-05-12, 04:30

Quote:

Originally Posted by Barry Churcher

Rob, at work we never use the new copper washers. They seem to be prone to leaks. We carefully re use the old ones and never have any problems, whether on wheel cylinders or calipers. We can't afford a customer comeback be it the time or our reputation.
Cheers,
Barry

Aaaargh.

There are two sizes of washer on the lynx. I used some mil spec ones from base maintenance that were the same size as the MLVW. Then I used some commercial ones we got from NAPA for the other size. Want to guess which ones are leaking?