Megajolt Ignition Upgrade
Valve Guide Seal

Disclaimer and Warning: the following information on suspension spring/shock replacement is meant as an explanation of how we replaced 45 year old parts, not as instructions on how to do any suspension work. USE AT YOUR OWN RISK. Suspension work is potentially dangerous and can cause loss of vehicle control, injury or death. This work must only be conducted by trained and experienced technicians. ALWAYS TAKE TIME TO CHECK TIGHTNESS OF ALL FASTENERS AGAIN, AFTER A SHORT TIME OF DRIVING.

The New Willys Springs Journey begins...

Here is the complete set of suspension parts Carl Walck sent. The springs are US made as are the Munroe shocks. U-bolts are from Taiwan as probably are the shackles and bolts.

Note the front (shorter) springs have the correct military double wrapped 'eyes'.

Surely, this will be an easy job!

Rear axle spring replacement.

After carefully installing car jacks and supporting the rear axle with a floor jack, I begin to undo all the bolts. The rear shackle wouldn't budge until I drilled into the rubber multiple times and squirted in WD40 - I then levered out the bolts with a small crowbar.

Note: Remove the shocks before you work on the springs. I discovered the old rear shocks were incorrect and were so short (at full extension) that the springs could not fully flex!

New correct length Monroe gas shocks were installed: Monroe 31094 rear and 32207 for the front.

It is obvious that the ancient U-bolt nuts will not unscrew and so the obvious answer is to use a cutting wheel.

I did not cut all the way through the U-bolts... just 3/4 the way. Then a few twists with the socket bar and the tensioned bolts break with a loud crack.

Support the old spring so it doesn't fall on your person!

Next, from the inside, pound out the pivot bolt located at the front end of the spring - this will require a good soak in DeepCreep or PB Blaster overnight.

The old rear spring pivot bolt shows wear after almost 1/2 a century of use. The design is odd as it is difficult to tighten the securing nut without the bolt turning. I was tempted to weld a bolt head on to give a purchase point, but instead drilled two holes in the head so that a "homemade tool" could be used to hold on - see below.

45 years of use can be seen in the old rear spring vs a new one. Although the springs are rusty and suffering from metal fatigue, they could be "re-arched" if necessary for another vehicle. Everyone says to throw them away...

But, you can see that the OEM springs had an interesting cross-section (a lengthwise 'valley' in the underside middle of each leaf). Restoration "Purists" might want to see that profile preserved...

Before you can attach the first side new spring to he axle, you will have to release the old shackle on the other side (arrow) - this allows the axle to move around and makes lining up the new spring with its spring perch practicable.

Note, the axle will still maintain its approximate position and caster because the old spring is still attached at the perch and held by the far side pivot bolt. This is important as you don't want the axle to strain the brake flex hose or tug on the drive shaft.

There is a specific order to assemble the pivot (front) end of the rear leaf spring. If you push in both rubber grommets into the spring eye and then try to line up the spring eye with the hanger, it won't work. The fit is far too tight. Instead, insert one of the rubber grommets, the inboard one, then push the spring eye into correct hanger alignment and then insert the second rubber grommet through the big outer hanger hole. Grease everything and slide the round-headed pivot bolt into place. Use a large C-clamp to press the pivot bolt home into the hanger and then thread on the inside nut. At first, you can hold the round head with vise grips as you tighten, but as it is pulled into the hanger hole you will eventually lose grip.

A simple way to hold the round head of the pivot bolt while tightening the nut can be seen at left. My special "homemade tool" fits into two drilled holes you make in the round head.

A quick measurement of the axle to pivot point shows 1/8" difference between sides. This may be good enough for a simple Willys vehicle but would be unacceptable for something fast.

The rear of the vehicle stands 3 1/2" higher with the new springs and seems to flex much better when the rear bumper is 'bounced'. Will the ride be improved enough to please a certain Lady?

Front Spring Replacement

The US made front springs have the correct double wrap

Here you can see the difference between the OEM greasable pivot (top) and the replacement. The zerk fiting is on the outer end.

The most important improvement can be seen in the way the grease is distributed in the bronze rear spring bushing. The OEM bolt has a large machined "pocket" for the grease to spread while the new design has a smaller milled slot. The new design keeps more steel in contact with the bronze bushing.

Here I persuade the new pivot bolt into position until the 35 splines are fully seated.

The shackle end of the new springs require bushings which , after greasing, are simply pushed in with a C-clamp.

The U-bolts on the passenger side front are interesting because the inner one rides on the Dana 25 differential housing (it's curve is larger in diameter) and not on the axle tube. Note also that the block which will anchor the bottom of the shock absorber has an offset hole to reflect the difference in U-bolts.

All the 7/16 inch (20 tpi) U-bolts are torqued to 44 ft/lbs. They should be re-torqued several times (perhaps at a week and a month)

Before tightening the U-bolts, a measurement of the distance from axle tube to the rear spring pivots yielded a 1/4" difference. By pushing the axle forward on one side and backward on the other, this difference was reduced to 3/16". Is this acceptable? It may be time to check the chassis for straightness...

All ready to go once the top shock absorber eye is engaged at the chassis. One detail that was unexpected can be seen here... the fully extended shock is shorter than flex of the spring dictates. Once in place the shock will limit the downward axle flex by about 1 inch. This was the case with the old shock absorber also. Strange, but the manual calls for 17 - 7/8" maximum extension which is what was measured.. the shocks must be the correct ones.