Jeep project underway

[Mike K]

Hi Phil

The Hex bar I used to make the nuts , I am not sure what grade of steel it is - I think it's probably 1045 or similar which is medium carbon steel. It should be fine for this application. With buying parts , I have found RFJP to be hard to beat .Great communication and prices plus he goes out of his way to help you with the cheapest postage rates.

Mike

The Jeep is a basic generic MB but I will have to use some parts from the GPW I bought last year. The repro parts and the online information available now - if only we had this data earlier when we were not so fussy about bolt head markings .

[Mike Cecil]

Have to agree on both counts.

Many of the parts I've been buying have been from RFJP due to price, availability, level of service, and a proper, itemised and readable invoice. I also have the advantage in the USA of buying in lots of $200+ to receive free shipping. I still prefer Rockauto for bearings and seals, though, as I can get name brands. I still place some jobs locally, though, whenever I can, such as the generator and starter rebuilds I received back yesterday from Toby's Auto Elec, and the repro torque reaction springs done by Pohl Springs.

The internet/forums/FB have made answering queries easy and quick - a far cry from our earlier days of talking at club meetings and swap meets, eh Mike? In any event, I'm pretty sure an Army 'motor pool' rebuild or contractor were not too fussy about bolt head markings.

Looking forward to following your MB build.

Mike

[Mike K]

Made a start on the jeep spring pivot bolts. I can buy these from RFJP but the postage is high and I would prefer to learn some new skills.

This is a learning project for me, it involves turning, thread cutting, the use of a dividing head and thread tapping for the zerk grease fitting. I chose 4140 chrome moly alloy because it's a strong material, is easy to obtain and is relatively easy to machine in the tempered state .

First step is: turning the stock down to 9/16" ( .5625") and threading the ends to the correct N.F. thread pitch. I prefer the old HSS type single point tools that you grind to shape yourself on a bench grinder . The modern carbide insert tools, well, there are endless types and it is a never ending process finding the correct type to suit .

[Mike K]

I managed to do the threads on the pivot bolts. Single point thread cutting on a lathe is a somewhat meticulous job . If you lose concentration for half a second, the process usually ends in horrible mess.

Wrap the work piece in a piece of cut up Alu drink can and the chuck jaws will not mark the work piece !

[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

[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.

[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?