EM - Axle rubbing on A-Arm opening

[Wittsend]

After 4-1/2 years of in depth work on my Lakewood..., the past 4 months waiting for the California DMV cycle to register (they charge you for a whole year even if it is one day from the new Reg. cycle) I FINNALY drove the car on the road for the first time today. When accelerating I don't hear any strange sounds (that said the exhaust is rather "Boomy"). However when coasting I hear a lot of rubbing, at times almost clanking sounds similar to stones tumbling in a drum.

During the rehab of the car I cleaned and re-lubricated the rear wheel bearings. At the time nothing seemed worn or dislodged (from the one side they can actually be seen). And from "feel" after complete they seemed to turn smoothly. The U-Joints showed no sign of wear or looseness (I removed each cap) and they were re-lubricated. I also tightened up the diff, one notch on the pinion and three notches on the side bearing that is the one typically recommended to tighten. Sorry I can't remember which one it was but the end result was the proper back lash and torque wrench readings. When I was breaking in the cam I had the rear suspension in full droop and curious if the PG trans rebuild went well (it did, all gears working) I put the car in gear and heard no strange sounds. I put the toe shims back where they came from when I installed the power pack. Lastly while the A-Arm bushings are old they seem intact and show no signs of wobbliness.

Anyway, I say ALL that (above) because I believe it rules out any of them being the cause of the axle rubbing on the opening of the rear A-Arm. So, I'm kind of baffled. I can see where Toe can cause the axle to move fore and aft but the problem seems to be the axle is too low in the opening. I know the power pack has been out of the car by a previous owner so the rear Toe might not be correct.

The pictures are the respective left and right. They were taken with the car jacked at the A-Arm as close to the wheel as I could get, but there was still some droop. Any guidance would be appreciated.

[SpyderMan]

I don't have a specific answer to your question but recently I discovered that the springs on my wagon are all sagging quite a bit. Myself and three other club members piled into my wagon to go to an event about a month ago. During the drive I noticed that we were almost riding on the bump stops. When I got home I looked up the ride hight in the shop or assembly manual I don't remember witch and discovered that I am a 1.5"-1.75" low in in the back unloaded and an 1" low in the front.

Now this being said I have no axle rubbing like you do but it might be a factor?

[Wagon Master]

Severely worn/failed front engine mount(s).

Sam, Overloading or sagging springs would rub on the other side of the a-arms.

[toms73novass]

I agree the mounts on the crossmember by the differential, there are two. Getting to the nut on top of the mounts are a pain with it in the car. Some bend a wrench to get it to fit. I have always done mine when I am doing the engine/trans.

Clarks sells them (cant link at the moment their site is down)
Or Cal Corvair https://californiacorvairparts.com/tran ... 0-63-.html

[RexJohnson]

A 9/16" Chevy dist wrench has worked good for me to hold the top bolt.

[Wittsend]

Thank you for your replies. I had a lot on my "plate" the past few days and it made my "plate" theoretically too heavy and I hurt my back.

Hopefully I can get the car jacked up and I'll look at the transmission mounts soon. I did observe them before everything went back in and though they looked "dry," there was nothing that looked beyond usable. That said all the weight was hanging rather than holding the car up. I'll see if I can get pictures with the weight of the car on them in a few days. BTW, I do have the distributor wrench, thanks for the tip.

[66vairguy]

Thank you for your replies. I had a lot on my "plate" the past few days and it made my "plate" theoretically too heavy and I hurt my back.

Hopefully I can get the car jacked up and I'll look at the transmission mounts soon. I did observe them before everything went back in and though they looked "dry," there was nothing that looked beyond usable. That said all the weight was hanging rather than holding the car up. I'll see if I can get pictures with the weight of the car on them in a few days. BTW, I do have the distributor wrench, thanks for the tip.

Worn out EM transmission mounts have been found to cause odd problems. At one time folks complained that their EM clutch would chatter horrible ONLY IN REVERSE to the point of shaking the car! Going forward the clutch worked smooth, no issues. Someone discovered it was the EM transmission mounts. When this issue would come up with others, they got the word and new mounts fixed it. Why only a reverse problem? I'm not sure if anyone figured it out.

[RexJohnson]

In reverse the drive train would be "rocking" the opposite direction causing different reactions than going forward.

[Wittsend]

"Upon further review...," my recollection of the trans mounts was with the car on stands and the powerpack weight pulling them downward they somehow looked better. As is obvious in the pictures they are rather worn. It was only the other day this car (sitting for 29 years that I owned it, 51 years total since parked in 1973) that it rolled its first (and only) mile - so far. Yikes $170 with tax and shipping for those two small mounts. Anyone know the Shore A Hardness of the rubber? A DIY Polyurethane rehab of those mounts is likely. Typical they are in the 50-60 Shore A range.

[Wittsend]

OK the transmission mounts have been remedied. The problem scraping/rubbing sounds still persists. The transmission mounts made absolutely no difference in the close proximity of the axle to the lower A-Arm opening. In frustration I even cut out a portion of the lower A-Arm to gain axle clearance to no avail. With rudimentary measurements the car is exhibiting an excessive 4 to 5 degrees of negative camber at the rear. As far as my logic sees the only thing that will affect the camber on the swing axle is the springs. There seems no other adjustment.

These are at rest, axle clearances before new trans mounts and A-Arm notching (left), then after (right). There is essentially no difference.

I have tried jacking the rear of the car (at the A-Arm) and powered the wheels to isolate the noise problem. However, in doing so the car can't be jacked and not have the camber go near zero or positive camber before the wheel comes off the ground. I have the jack as close as it can come to the tire without rubbing it. So, there is no testing as the car actually sits. Anyway, when I do this near zero camber test the results are a smooth movement with barely a faint brake drag which is common. I hear no U-Joint or bearing noise.

So, my questions are:

1. How can others cut their early rear springs and have as much..., if not more negative camber than I do and not have the issues I'm having (and my springs aren't even cut)? I'll add that the weight of the battery has been moved to the front and the weight of the heater is not present in the car, both of which are favorable.

2. Assuming I have spring sag would that be common for a car that was only on the road for 12 years (1961-1973) and the past 29 years in my possession it sat on jack stands with the wheels drooped? I've owned 40+ cars in my life and I can't say I ever noticed spring sag as a problem. Is this a "Corvair Thing?"

3. Even after notching the lower A-Arm I still barely have marginal static clearance with the axle. But at this point I can't see any additional axle scraping. So, where is the noise coming from..., the brakes??? Is the negative camber causing the drums to rub on the backing plates??? For the record the backing plate pads were welded and ground smooth. So, it wouldn't be brake shoe hung up in a wear notch on the backing plate.

I HATE Swing Axles. They seem the most ridiculous design. The immense camber change, the weight jacking, the "weird" stuff that do to the brakes..., it seems crazy to me. I'm so DONE with this car. I've spent about 15-20 hours a week for four years trying to bring this car back to life. And every time I think I'm "their" to take it the infinitesimal 8 miles round trip to Cars & Coffee, 20 or times a year it say, "NO!"

[joelsplace]

Springs do sag and mounts go bad but I've never had an axle rub the control arm like yours. Something is bent or wrong parts installed. Corvairs are designed to handle full up and down wheel travel without the axle rubbing.
You need to have a good Corvair guy look at it.
What is your rear toe? I'm thinking possibly severe toe out could cause your issue but that is just thinking and not actually looking at it.
Don't worry about the camber for now.
Looking at the pictures it appears you are jacking up under the control arm between the pivot and shock mount. Is it possible you bent the control arms?

[vairmech]

Do you have any shims between the trans and the mount bar? Most cars have a 1/8" to 3/8" stack of shims for rear wheel toe alignment. This actually moves the engine rearward to set the toe in/out of the rear wheels but also gives clearance on the axles.
Have you checked any of that? Also did you have any of the rear suspension apart? Even if you didn't loosen the arm bolts and try to push the bushing shaft forward taking up any slop in the bolt holes and then tighten again.

On a worse case scenario you can trim where the axle is rubbing but this is a last resort, not the first go to thing. There has to be something you are not seeing. In the aviation industry we always had 2 pair of eyes look at all work done!

[Dennis66]

I agree with Joel and Ken. The contact point on your axle in the picture seems to indicate that your powertrain is too far forward as it's rubbing on the inside. I just went through replacing the rear suspension mounts on mine (between body and rear suspension cradle). It changed ride height by maybe 1/4'' even though the original 61 year old mounts were squished by age. I added rubber spring spacers between the coils and that gave me around another 1/2''. The car has newer springs, but the whole car had been sitting for 15+ years when I bought it. I don't have any contact issues, but didn't like the "saggy butt" look. Maybe a picture of where your transmission bolts to the crossmember? Dennis

[jimbrandberg]

I don't know what's going on with your axle location.
Generally speaking negative camber shows up when people lower the car by using shorter springs. Raising the powertrain in the chassis is one approach to helping cure that but quite difficult to accomplish. More a thing for someone bound and determined to have a lowered car.
I would think a Wagon roof is a little heavier than a sedan so the springs would be a little different.
I might expect a Wagon to have some positive camber when empty and some negative camber with a load.
These are just general statements and I'm interested in how this all pans out.
It's hard to get Corvair folks to talk in terms of spring weight and measurements.
I'm curious about your ride height measured at the wheel well opening compared to the Specifications in the '61 Service Manual.
Even if curing the negative camber doesn't help your axle problem it's still a good thing to straighten out. I'm interested to see how the toe-in thing Ken mentioned affects your malady.
Good EM wheel alignment front and rear is not so easy to accomplish with the shims and all especially with time constraints on an alignment rack. You almost have to get a reading, go makes some adjustments at home with shims and such and go back for another reading. Maybe showing up well equipped at a place that will let you "help" but that's hard to find these days.
Jim Brandberg
Isanti, MN
CorvairRepair.com

[kmart356]

The shim is shown as 4.085 on this diagram. The 4spd has a thick washer on the other side but I don’t know about the PG.

[joelsplace]

He has a normal looking stack of shims at least on one side. You can see them in the first bad mount picture.
Spring sag will not cause the axle to rub. If it did all axles would rub every time the vehicle was loaded and or every time you hit a bump.
Lots of us drive our cars hard and never have axles rub.