Jeep project underway

[Mike K]

Originally Posted by Philliphastings

Hi Mike K,

Just curious how do you go about broaching the interference fit neck of the pivot bolts.

I have a good grasp of the more basic machining but broaching in such an inaccessable spot must be very tricky ?

Cheers

Phill

Hi Phil

The short splined section of the bolt that is located right up against the bolt head . I believe they designed the bolt like that in order to prevent the bolt from turning in the chassis hanger, in others words, to lock the bolt in place . The splines bite into the chassis hanger hole as you tighten up the nut and draw the head up against the hanger.

I don't like the method myself, it is actually a bit of a bodge . Problem is: The splines really make a mess of the reamed hole. If you have to remove the bolt a few times , the hole ends up being torn and messed up. The hangers are only made from 1/4" plate which is a design flaw.

Not easy to replicate that splined section in a hobby workshop, you could knurl the area which will create a raised pattern. I am not off roading this jeep , it will be OK to leave the bolt head as a plain finish.

If I did buy new bolts from RFJP, I would have machined off the splines before fitting his pivot bolts.

[Mike K]

I managed to almost finish the pivot bolts. I don't have a U.S. standard NPT 1/8 tap for the zerk grease fittings so I used a 1/8 BSP tap - I will lose points at the concourse but I will say its a field fix 1/8 BSP zerk fittings are available at most auto shops here.

The dividing head I made myself to Harold Hall's design. Harold has had many books published and he is the doyen of the hobby engineering scene , he must be getting close to 90 these days .

I have a 48 tooth gear on the dividing head. To machine the bolt head flats you divide 48 by 6 = 8 notches for each flat.

[Lynn Eades]

Mike, without the pin locking in the hanger, the pin movement will occur between the hangers and the pins. This will happen rapidly because the surface area is relatively small. Not only that, but the fix is difficult because your hangers are riveted to the chassis.
The whole idea is for the movement and wear to occur between the shackle pin and the spring bush which is set up for greasing at that point. Also the bushes are an easy replacement along with the pins.

Note that the nuts for the shacle pins are castleated so as to be located by a split pin. This leaves some free movement at the ends of the bushes relative to the hangers. This helps to prevent spring breakage.
Maybe you could try an interfearance taper and step at the pin head? Just a thought.......

[Mike K]

Hi Lynn

The original design is flawed. With the original setup in good condition , the bolts will rotate after a very short period of use. The rotating happens because the bolt splines damage/enlarge the reamed holes , this hole damage begins the process of the elongation of the holes, and it becomes worse as time goes on. A much better method of preventing the bolt from turning is what the Dodge WC vehicles have, that is, a protruding flat section on the outside face of the hanger, the protruding face locks one of the bolt head hex faces in place.

As for floating bushes, the problem with that is, if there is any amount of wear in the bushes or bolts , a yawing or sideways movement of the whole front axle will occur. The yawing action will actually add to the elongation of the holes in the spring hangers. At the other end of the springs, the threaded U shaped shackles don't have enough rigidity to hold the axles in the correct aligned position , those shackles have some wobble , even when new. I am not a automotive engineer , these are my theories .. my theories might be wrong but on the practical side of things, I've seen more than one WW2 Jeep chassis in otherwise excellent condition, with badly elongated spring hanger holes

[Mike K]

This is a good instructional video on how NOT to install your jeep pivot bolts The bushing is loose in the spring eye for a start . And those spring washers

You can see the hanger hole is too large for the bolt anyway

https://www.youtube.com/watch?v=A70wHVerz2k

[Mike Cecil]

Yep, pretty dodgy method in that video, Mike. I suppose, given the limited service life span that the GPW and MB were designed for, the method of preventing the pivot bolts from rotating was cheap, easily installed and sufficiently robust, so 'good enough' in the circumstances. I doubt the designers envisaged that MB and GPWs would be still employed by armies well into the 1960s, or that civilians would be trying to rebuild them nearly 80 years later.

There are possibly plenty of improvements that could be made to various parts of a jeep to make it more robust and longer-lasting. The chassis came in for some officially-promulgated strengthening while in service by the addition of 'T' pieces at the rear, and the steering bell-crank received an added web, for example.

Nice job on the bolts: very skillful.

Mike

[Lynn Eades]

Unfortunately Mike and Mike, there are lots of "how to" You tube clips that demonstrate less than "best practice" info. I guess if the bush was longer and was locked in the hanger and you didn't mind wearing the spring eye that would do? (except that no grease gets to the right place)
I note that my replacement bolts have an 1/8th gas thread in them (and it appears) like the one in the You tube clip. He has used an NPT zerk. (very loose)
His use of the spring washer, is to fill the gap, other wise the nut floats around under the split pin. I used a flat washer.
All in all, that clip fails at all points. As you say, "How not to".

[charlie fitton]

"I don't like the method myself, it is actually a bit of a bodge . Problem is: The splines really make a mess of the reamed hole. If you have to remove the bolt a few times , the hole ends up being torn and messed up. The hangers are only made from 1/4" plate which is a design flaw."

Might I suggest that you could weld a tab on to the Hanger plate to stop the Bolt from "working" and therefore restrict the wear to the bushings?

[Mike K]

Long term saga with the front springs .

My jeep came with the 1950s Aust. post-war made springs.

I later on found a couple of WW2 era front springs , in very bad shape.

Purchased 2 new front springs from a vendor here.

Ok the story:

Repro front springs look very little like the WW2 era springs: leaves are thicker, no bevel on the edge of the leaves, the clips look all wrong, the centre bolt is a joke , how people can sell junk like this !

Pulled apart the WW2 era springs. Hmmm some deep pitting is evident , sagging too and one main leaf end is bent badly. Wear is evident where the leaf ends move and dig into the next leaf.

So I made up a spring pack using the new repro main and 2nd leaves and the rest are the old original WW2 leaves . I had to re-arch the old leaves in my pipe bender. Had to bevel the edges of the repro main and 2nd leaves .

Now make new Willys style spring clips..... the originals are .110" gauge . All I can find here is 3mm flat bar, but it is the correct width .
Lots of filing cutting . Had to make a die to press the dot into the clips and heat up up the metal cherry red .

Very hard to get a tight radius on the 3mm bar ,so my old trick, you cut half way through and bend, then weld and file the radius ...do this 24 times for 2 springs

Also had to machine up new centre bolts , out of good steel, not the plastic stuff the repro bolts are made from. The bolt head needs to be a good fit in the spring saddle .... which is usually worn to a oval shape.

Been working on these springs for over 2 years ..... not finished yet.

I have become rather fed up with the poorly made and expensive repro parts ..I now make my own parts when it is feasible to do so.

[Mike K]

Is there anybody out there who is considering buying a new Chinese cast L134 engine block ?

https://www.youtube.com/watch?v=d9yfaRZ0nSw

Metalshaper is the guy who knows his vintage jeeps.

I read a report on these Chinese blocks , the valve guide bores are out of alignment, the bores are not perpendicular to the camshaft, that would explain why the valve stems and guides are very worn after only 3k miles of use. .

[Mike K]

I am making new spring/shock plates, the originals are often bent/warped, the factory used 1/4" plate which is prone to bending as the axle U bolts are tightened up with 4 long nuts.

I found an old bumper bar and cut it up , it is a slightly heavier gauge that 1/4" so should hold up OK .

Looks like the jeep designers had weight in mind and they tried to manage weight versus the projected life span of the vehicle. The bumper bar is one example of the weight compromise, made from light gauge sheet steel with a wooden insert for added rigidity.

[Mike K]

Spent some hours over the past days removing the 50 year old tyres from the combat divided rims. Some swearing ensued ! Hydraulic jack and levers , lubrication and much physical persuasion - all needed.

Jeep owners: please install the rust bands for future problems will arise. The divided combat rims do rust to the stage of being U/S. The original rims are now around 80 years old.

Repro rims are now available , but they are not cheap ( $1500 for a set here ) and there have been reports of a particular brand actually failing

In my case , I have four useable rims and one only good for a spare. The four best have rust to varying degrees but IMHO are safe enough. But I have to check them for runout and balance.

Looking at this G503 video shows how the rims rust but are still serviceable. https://www.youtube.com/watch?v=eHmnqpCk22E

The other very common problem : people overtighten the lug nuts, doing this damages the tapered holes in the rims, the hole is splayed out into a distorted oversized shape and this results in the situation where the lug nuts do not have enough grab effect, the rim can be slightly loose on the hub......have seen this problem myself.

[Mike K]

My GPW block is back from the machinist...Hmmm 4 years wait.

The block had some corrosion evident and it was a 50/50 call if I should find another block. The machining turned out sort of OK , but even at +40 the bores have some tiny pit marks visible. The opinion of the G503 experts is: the Willys blocks are better , with thicker castings and less prone to cracks.

The engine machine shops are mosty gone in this part of the world, retired and closed. You have to travel a long distance to find one. The remaining engine machinist guys know this and they charge like a wounded bull and don't care how long it takes. The VMVC guys use a business in the S.E. suburbs of Melbourne, that's where I will be going next time.