M38 Jeep Front Springs
 

Fully intending to pull the M38 out this year for it's long overdue restoration. A bit bothered by the front springs though. The left side spring shackle is angled quite a bit further forward than the passenger side one, by about 10 to 15 degrees. Is this normal? :confused

I checked the shackle orientation on Dad's recently completed GPW, and their position both correspond with the right side shackle on my M38. This makes me think that something is amiss with the left side spring. But there is no obvious 'lean' on the M38 to suggest one spring is more tired than the other. The springs are both 10-leaf, and appear to be original M38 spec (Mather Spring Co?).

I'm concerned that once the South Wind 978-M is eventually fitted onto the left side of the cowl, that shackle angle will be worse.

Any thoughts or opinions on this would be welcome.....

Thanks!
Owen.

I'm thinking a spring overhaul is in order as I see a broken clamp anyways. You could always switch them side to side after a re-arching and new bushings go in. I was informed that jeeps can have a left hand lean due to driver weight, fuel tank weight and a full jerry can on that side. Makes sense that the left side would wear a bit quicker.

Hi Peter,

Thanks for your reply. I agree with what you say about needing the springs overhauling. And also about the left hand lean; I suspect having the personnel heater on the left side isn't helping either.

What's the consensus among the MLU folks regarding re-arching 60-plus year old jeep leaf springs? A look on the web didn't really help. Has anyone here actually had it done? And if so, how did it work out?

Thanks!
Owen.

I have replaced individual leafs in springs of that era, as well as heated and tightened the eyes where the shackle bushings go into.

You kind of have two avenues. Take the pair of springs to a spring shop for re-arcing, or buy a replacement set of springs. New production springs will be a little more expensive than the re-arcing I suspect, but not by much.


A third option would be to open up both leaf packs, and mix the leafs. A couple of C clamps can help hold the packs together as you install the new center bolts.



How are the shackles themselves? The uneven position of the shackle could be a seized shackle bushing. You'll know when you go to remove them. Often though, a seized bushing results in a broken spring eye.



I had an M38A1 at work display some problems with the shackles. By the time it was all done, I had to replace one broken leaf, tighten two spring eyes, replace the threaded shackle sockets in two of the frame points, replaced all the shackles and bushings, and did the knuckle bearings and seals for good measure. The knuckle bearings really made a difference. Properly set up, the Jeep steers like it has power steering. If you can't remember the last time you did your knuckle bearings, then now is the time. Make sure to order the shim pack and use a fish scale to set the preloads.

Are the springs set differently on the front like an MB or GPW, to allow for the driver fuel tank etc. Quite different in the war time jeeps, from side to side, if memory serves me well.

Hi Rob,

Thanks for your reply. The shackles and bushings were new when I reassembled the chassis, about 7 years ago. I also applied some copper grease before reassembly, so I'm hoping they won't be seized. Both front shackle positions were fine until I dropped the engine in. :(

Replacement springs for the M38 are a problem over here in the UK; nobody sells them! So I can either settle for 8-leaf WW2 jeep springs, or pay out to have some shipped from North America. :eek:

Hi Lynn,

Your memory is correct. But no, left and right are the same part number on the M38. Wonder if the extra two leaves maybe negated that requirement? I know that moving the steering bell crank from the axle onto the crossmember did away with the torque reaction spring.

Owen.

I didn't catch that you are overseas, so I guess it does get a little pricey to just order a set. That kind of relegates you to the other options which are getting a spring shop to arc the pair to the same specs, or to mix and match the two spring pacs.



Once you have the springs off and sitting next to each other, you may be able to make a better call on which way to proceed.

I literally just had mine re-arched at a shop as I believe they've never been touched before; no actual leaves were broken but a few clamps were. I have read that due to the metals used during construction of the original springs they are a prime candidate for a re-arch and do well.

Hi Peter,

I'd heard the same, but can't remember where I read it. :coffee As Rob suggests, a thorough inspection is in order once I get the springs off. As for re-arching, I read of some folks doing it themselves. But I think I'd rather let a shop that knows what they're doing tackle it.

Thanks!
Owen.

springs
 

A crude and cheap but effective method of re-setting individual leaves is to use a hydraulic pipe bender, these benders are sold everywhere , made in Asia.

Years ago Tim Vibert wrote up a article describing how he reset his springs using a cheap pipe bender. Although the experts will say this is not a ideal thing to do, it does work. I have tried it and it was a good outcome. There is some risk of damage involved with cold bending spring leaves, don't be too heavy handed , be gentle.

You lay down the leaf on the floor and run a marker or chalk line along the outline, this gives you a reference point to gauge how far you have changed the shape as you go along/ You feed the leaf along the bender at small steps , being careful not to bend the centre where the hole is .

The other old fashioned method involves a anvil and a big hammer . You warm up the leaf , leave it out in the sun for a while . Lay the leaf over the horn of a anvil and basically bash it as you move it along the horn. Some people reckon the bashing has the effect of re-aligning the atomic structure of the spring steel back to the original state. Like the steel has a memory and the bashing wakes up the memory !

I believe I read it in Ryan Miller's M38 G-740 Reference guide

Good memory Peter! Page 139 of the M38 Reference Guide..... :salute:

Thanks!
Owen.