A different way to do a bus swing lever

[94touring]

Running out of things to do so wanted to try something I got from Brazil to test out. It's a swing lever replacement kit that uses a taper bearing on one end and a radial style ball bearing on the other. The idea being it eliminates the stock swing lever kit, gives lighter steering, and can be infinitely adjusted. Well it sorta worked.

The problem was the radial bearing end allows the pin to move around a bit more than you'd expect, so I ended up with more steering play, not less. The steering was a little lighter.

What I decided to do was modify the kit to remove the steering play created but maintain what lighter steering it created. If you've ever had the tie rods, drag link, and steering damper disconnected from the swing lever arm, you'll note it has a considerable amount of drag created by the compressed wavey washer. With the Brazilian kit there is virtually no drag. So I eliminated the radial bearing end, added a sleeve to accept a stock bushing, and replaced the wavey washer with thrust needle bearings. The thrust needle bearings can be sealed using a standard link/king pin rubber seal. The taper bearing end still pulls it all down nice and snug and there's no drag when moving the arm by hand.

But wait there's more... The arm has flex. Not a lot but it's there. When I was rebuilding the entire steering system I had mounted a camera under the bus looking for anything that would create steering slop. Low and behold with a back drop setup, I could watch the arm flex up or down depending which way you turn the wheel. What this does is pause steering until it stops flexing, at which time the tie rods move the wheels. Adding a 3/4 inch wrench eliminates most of the flex. It was a noticeable improvement at the wheel as silly as it looks.

Another thing to consider when having the arm in a vice clamped to a pin at the factory 55ft lbs, you can still get slippage if enough elbow force is applied. Both the arm and pins used were brand new, so there wasn't a wallowed out arm situation going on. Before clamping together if you clean thoroughly and add loctite joint compound, it won't budge. It will unclamp without issue. You can also find longer bolts in grade 10.9 from bolt depot so you aren't riding on threads in the slot.

So all back together driving and steering is excellent. Testing on a straight road, 70mph, no winds for best accuracy, I have steering response somewhere between a 1/4 and 1/2 inch. What "steering play" is noted at the wheel still has steering response in what you'd think is a dead zone. The steering play dead zone "bounce back" is I think created from the steering damper. Steering is lighter from a stop, minimally but it is better. Oh, and other pertinent information... everything in my system is brand new. That includes the steering box. This is a Brazilian so uses a different box and column and I was able to find NOS. I had it on the bench to find dead center and set the high spot per the manual to 20.8 inch pounds (ok rounded to 21).

[Brian_e]

Good research and execution.

On my hybrid bus beams I build, I shorten the center pin for the lowered guys. On those beams, I ditch the center pin wavy washer, and replace it with shims similar to shimming rocker arms. I have thin shims from mcmaster, and I shim it till there is very little up and down movement, but it still swings perfectly free. They swing very nice with fresh reamed bushings, and shimmed up.

Brian
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www.type-emotorsports.com

[94touring]

Yeah this wouldn't be ideal on a lowered bus. Since mine is factory height I'd have a difficult time clipping something with the bottom end.

I have some spindle king pins I'm currently testing which also eliminate the phenolic spacers with thrust needle bearings. A few months in and doing great. No reason they shouldn't hold up per the load ratings. I only did one side for now but wow does it turn easier VS a fresh spindle build when everything is still tight. I'll post something on them eventually.

[chrisflstf]

Alot of good info there. I never liked the wavy washer setup. Kinda lke the wavy washer setups on the rockers. That was one of first vw mods i ever did, solid shims. The stock center pin setup isnt ideal, but works if all in spec

[94touring]

Brians idea of the shims is a great way to do it too. I'd venture to say better than stock actually. I have the same shims in my shop that I've used to setup a worn set of king pins. Eventually all this metal on metal wears parts and a bag of shims can get you back where you need to be.

Sneak peak of the spindle testing. I ditched the caged needle bearings and went back to standard bushings. The interference and drag is created at the spacers and not the bushings. Shims were used to create a perfect tolerance, though I used a lathe to turn down the stock spacer to fit the thrust needle bearings, then shimmed as required. Only adds half a MM of ride height. Stock rubber seals are still used. With the tie rods disconnected and the wheels off the ground, you can turn the wheel just about by blowing on it. The other spindle is freshly rebuilt and has to be about 10x harder to turn by hand. NOS spindles were used so tolerances are tight with the spacers. I have to think when it's sitting on the ground the load on the spacers really creates a lot of drag. May convert the stock side next weekend time permitting to see what overall lightened steering ends up to be. We'll call all this poor mans power steering.

[chrisflstf]

Is there a reason why the stock center pin setup can not be solid shimmed , instead of the wavy washer?

I like the brace for the swing lever idea. Looks like there is plenty of room to add some support to reduce flex.

[Brian_e]

[chrisflstf]

Looking for 24 mm Ring shims, but only can find 22 or 25 mm.

The wavy washer measures .170" uncompressed, so an extra stock thrust shim takes up most of the difference as its about .070". Was thinking to try that first, so its loose, then put an indicator on it, push up and see how much play there is.

What do you think would be an acceptable end play? 003" to .005"?

Gonna try to buy a pre 68 swing lever to experiment with also

[94touring]

I believe the shims I have are 25mm. Just left the shop but can verify with some calipers when I'm back out there.

[chrisflstf]

Gonna take a stab at this. At first I didn’t think the swing arm could flex, but I remember the first time I put a dial indicator on a flywheel for end play and watched it flex with my fingers.

Bought a used swing arm and a $5 piece of 3/16” steel for a gusset. I made 3 templates, but I think #2 is what I will use.

The wavy washer will disappear and I bought some Ring Shims from Mcmaster-carr. Very nice German spring steel. Only few dollars for a pack of 10. I bought .004, .008, .012 and some .040” shims. Also wont need to fight the wavy washer and use a 8” clamp to compress it for install.

BTW, these shims ( smaller size) I used to shim side play on my rockers, thanks to a tip from Brian E. Nice stuff they are

Also will use loctite on the clamp bolt at 55 ft lbs.

I will report back later after install. Thanks for the idea! Always looking for ways to make improvements

[94touring]

Nice! Look forward to seeing how it turns out for you!

[nsracing]

I will not be screwing around w/ steering components - that is an accident waiting to happen. Steering parts are special items in metallurgy. Cannot just stick cold rolled steels for them.

Bushings are easy - you can make them all day long w/ any materials you like. But bronze bearing stocks are available so easy to make them on the lathe.

I would hate to find any of you on the obituary - coz you experimented on them controls in your bus or car.

Have at it - if it makes your day fuller.

[94touring]

One thing on your gusset Chrisflstf, will you have a vertical strip too? Meaning, a piece that replicates the wrench on mine. You'd get additional support in both axis that way. The flex I saw in my investigative video was more up and down, rather than left and right. Although it's surely a combination.

[chrisflstf]