Gran Cushman suspension problems

[RGrove]

Hi, new to forums. I bought a '72 Gran Cushman last summer that I have spent quite a bit of time restoring. Put it on the golf course last fall and have been having a great time with it until recently. Started getting a pretty bumpy ride. Replaced shocks with shocks for a '52 VW Beetle (had the same compressed/extended lengths and same type of mounts as what was on her when I got her), no noticeable improvement. Maybe the leaf spring needs replacing, not sure how to tell, but am currently trying to find one anyway. But suddenly I have a worse problem. Yesterday I noticed a burning rubber smell. Turns out the bracket for the rear bumper is rubbing the tire on the driver's side. Looks like the rubber blocks right in front of the rear tires have given up the ghost, so I'm trying to find replacements for those also or figure out some way to rig up a suitable substitute system. Any advice would be appreciated.

[69makinitmine]

I have a Golfster with the same, hard, sagging rubber blocks. Rides like brick. Redesign ideas i've thought of are pulling the blocks and installing a pair of motorcycle shocks on the ends of the "wishbone" drive frame. There would still have to be a LATERAL control in the form of a panhard bar. The other option is installing a pair of small trailer leaf springs. They provide verticle suspension AND lateral control at the same time. Either way there will be fabrication work involved. OR you can buy NEW rubber blocks from

http://www.vintagegolfcartparts.com/...shman_steering

and be stuck with VERY limited travel and still relatively rough ride. My back is bad and that's why I will be building the rear with more flex and softer ride!

[RGrove]

69makinitmine,

Thanks for the reply. Vintage didn't have the blocks but Direct Parts does and I ordered a pair today.

Does your Golfster not have a rear shock? Mine did, but maybe it's not part of the original set-up. There is an L-shaped bracket welded to the rear of one of the "wishbone legs" for the bottom end of the shock to mount to, and the other leg looks like there was a bracket welded to it also that has broken off. I made a new one and installed new '52 VW Beetle shocks all around (two for rear, one for front). Unfortunately that hasn't help, but maybe it was because the shear mounts were failing.

If you don't mind sharing more detail about how you eventually go about softening up the ride on your cart, I'd greatly appreciate it. My wife has complained about ours and I'm afraid the new shear mounts are not going to make the ride sufficiently better.

[69makinitmine]

Mine has just one shock on one leg of wishbone too. But the rubber blocks have sagged and hardened up bad enough it's like a hard-tail chopper! If there's no movement a shock is non effective!!!! As you know the front solid axle articulates pretty well, design is weak in strength but soft in ride. The back SUX. I'd bet with the bad hard blocks AND new shocks are why still stiff. I couldn't tell you what will be like w/new blocks, don't know how pliable they are new. I can see it still being quite stiff just due to the fact of very limited movement cuz you're deforming rubber. BTW, Mine has just ONE shock on front in muddle of axle. Looks OEM to me. With this setup, all sway control is handled by the rear suspension. wow. There is a tiny sway bar up front, not much effect. One way I "poor man sofened" the back was to tube the tires and run them way low on pressure. Made tires the suspension for now. On top of just re-designing the rear susp. I am thinking up a good way to mod a lift in it too... I promise to post pics of mods and specs for ya when complete! I wish they had a Cushman section... Sorry so long!

[RGrove]

I'll let you know when I get the new shear mounts installed what the ride is like, but like you, I tend to think they are not going to allow enough vertical movement to provide much cushion, even with the extra shocks. I'm thinking about slotting the bolt holes and putting a piece of teflon sheet in between the shear mounts and the frame so that the inner frame can slip vertically and allow the rear shock(s) to work more effectively.

A lift kit would be cool, because if I ever decide to buy a newer cart for the course, this one will become a deer woods buggy.

[69makinitmine]

Remember your shocks don't actually hold up the back of your cart, the blocks do! The shocks just dampen the movement. If you slot them upwards, it will lower the back of cart hooptie style. You'll still have the same travel...

[RGrove]

Yeah, you're right, I'd have to add springs somehow. But I was able to get new shear mounts and the ride is much better, so I probably won't be making any suspension mods.

[69makinitmine]

After deciding to not go overkill on rear suspension design, It looks like to cheap lift the rear. Since the wishbone actually curves upward in stock position I came up with this:
Remove axle from wishbone.
Remove wishbone from cart.
Move/fab motor mount plate.
Turn wishbone over (flip over),
Bolt axle back to wishbone.
Install and align motor with motor plate attached.
Weld plate in proper position.
Cut off the block/shear mount extensions from sides of wishbone.
Fab lower shock mounts to aft ends of wishbone arms.
Fab a panhard bar mount to wishbone arm on drivers side arm.
Install whole assy back into cart.
Install a pair of regular coil over helper shocks from parts store.
Fab and weld/bolt panhard bar mount to passenger side on cart frame.
Install fab'd panhard bar and adjust to center axle with weight on wheels.
Done!
May have to install/fab an extension to front pivot of wishbone to move axle aft to align in wheel wells. Panhard bar can be purchased through a circletrack racing supply website already made to length and threaded with hiem rod ends(in rear link or tie rod section)! Sounds complicated but it's not, just listed step by step and strung it out for clarity... What do you think?

[RGrove]

Sounds pretty good to me, although I'm wondering if maybe you could make it even simpler. Maybe you could eliminate having to rig a panhard bar. Could you simply replace the plates at the end of the wishbone extension that normally bolt to the shear mounts with longer plates that would extend down the proper distance so that they would still align with the shear mounts even after turning over the wishbone? You wouldn't bolt them to the shear mounts (so that you'd still have vertical movement). Wouldn't that prevent any side to side movement of the rear axle?

[69makinitmine]

Good thinking but thought of that. That would work if rear suspension only moved up and down, without articulating like over a bump on one tire. the plates would bind up as axle twisted. When axle twists left and right, the plate ends will swing in an arc and either bind first, or be loose allowing axle to move side to side. The panhard bar will give total freedom of controlled movement. A "Watts" type axle locator is best but a little more complicated. Google "watts linkage" and check out design and advantages. I have a couple of mud bog trucks and helped build a couple rock crawlers too. All custom suspensions. Like doing to carts 'cause sooo much easier/smaller to work on!