Corvair Forum

StukintheMud wrote: ↑Sat Jun 17, 2023 7:16 am My car is a long way away from being on the road, but at least I'm starting..

Good man, take it slow & easy! My car hasn't driven in 22 years, I pulled her out of storage in 2020 as a Covid project. Just started the engine a few weeks ago, probably another week before she drives. https://www.youtube.com/shorts/C-PadSAJvhg

Little by little FTW!

One other question I had regarding solid crossmember mounts. The front suspension is solid mounted. Is the rear mounted with the rubber bushing to help with engine vibration? It can't be road noise as that would transfer through the front suspension. I'm looking into making my own out of nylon.

The front CROSSMEMBER is solid mounted. That's just a subframe, removable to access the front suspension parts. Every part in the front suspension attached to it has rubber bushings. You have to have some rubber in the system to absorb shock.

Recently I read a post about replacing the rubber bushing for the front lower control arm strut rods (sometimes called brake reaction rods). They are also used to adjust the caster.

The strut rod goes through a bracket welded to the crossmember. The rod is held in position by rubber bushing on each side of the bracket. At one time you could use the more substantial rubber Chevy II bushing, but they are no longer made. Folks are experimenting with stiffer materials like nylon and this resulted in the brackets BREAKING OFF THE CROSS-MEMBER, something that never happened with the rubber bushings. Needless to say this sends the vehicle out of control if it is moving at speed.

I'm always surprised by the desire to "firm things up" when I find the rubber parts work fine, and changing them to solid parts can sometimes result in awkward suspension movements that actually degrade handling. No suspension is ideal, at least in practical vehicles that must contend with all kinds of road conditions and loads. Rubber parts not only isolate harness, they flex to prevent overloading the solid mounting points.

I still have all solid nylon rear strut rod bushings on my '67, which was Clark's performance recommendation way back when I bought my car in 1980. Bushings are still in good shape and still make it extremely difficult to assemble the rear suspension (just did it last week) since the only "give" is the torsional spring of the long 1"-dia rod itself. A bit like like a Chrysler torsion rod front suspension.

The current recommendation is one nylon and one rubber per rod, to allow some flex.

erco wrote: ↑Wed Jul 05, 2023 10:47 am I still have all solid nylon rear strut rod bushings on my '67, which was Clark's performance recommendation way back when I bought my car in 1980. Bushings are still in good shape and still make it extremely difficult to assemble the rear suspension (just did it last week) since the only "give" is the torsional spring of the long 1"-dia rod itself. A bit like like a Chrysler torsion rod front suspension.

The current recommendation is one nylon and one rubber per rod, to allow some flex.

Yes at least one end should be rubber. The lower strut rod is CAST it will not flex like a torsion rod, but it will break, or more likely it will bend the trailing arm bracket (yes they will bend --- a fellow move his car not axle shafts or lower strut rods in place and it bent he trailing arms to the point they rubbed on the axle half shafts!! I would not have thought it possible, but I've read two accounts of bent trailing arms.

Clark's makes a few recommendations that are based on "seems like a good idea" with no actual engineering to back it up. Of course this is a common occurrence in the old car hobby.

erco wrote: ↑Wed Jul 05, 2023 10:47 am I still have all solid nylon rear strut rod bushings on my '67, which was Clark's performance recommendation way back when I bought my car in 1980. Bushings are still in good shape and still make it extremely difficult to assemble the rear suspension (just did it last week) since the only "give" is the torsional spring of the long 1"-dia rod itself. A bit like like a Chrysler torsion rod front suspension.

The current recommendation is one nylon and one rubber per rod, to allow some flex.

Yes at least one end should be rubber. The lower strut rod is CAST it will not flex like a torsion rod, but it will break, or more likely it will bend the trailing arm bracket (yes they will bend --- a fellow moved without the axle shafts or lower strut rods in place and it bent the trailing arms to the point they rubbed on the axle half shafts when he assembled his car later! I would not have thought it possible, but I've read two accounts of bent trailing arms.

Clark's makes a few recommendations that are based on "seems like a good idea" with no actual engineering to back it up. Of course this is a common occurrence in the old car hobby.

I was looking at my rear cross member of my Spyder again this morning, thinking. Dangerous, I know. But when I look at the mounting bolts, they have a steel sleeve between the heavy washer of the lower bushing. The sleeve goes through the cross member mount hole, and through the upper bushing. And, I'm guessing, when its all tightened together the sleeve sits tightly against the body mount. Does that make sense, as to how I explained it? Not to how GM engineered it. So, will that allow some rocking of the cross member?