……
Corvair DiagramCorvair Photo
Corvair Center
home forum corvairs calendar links Corvair Podcast
California Corvairs
Clarks Corvair
Clarks Corvair
“CORSA"



Chevy Corvair License Plate
Chevy Corvair Chrome Wheel
Corvair Center Forum :  Corvair Center Phorum - presented by CORSA The fastest message board... ever.
Corvair Center 
EM rear toe-in question.
Posted by: lowandslow ()
Date: September 05, 2011 03:37PM

Using Matts sight-line method of checking alignment it appears that the right rear tire is lined up pretty well, but the left rear toes in a little. I had the front alligned several months ago and the mechanic said he "did the best he could" with the front but didn't check the rear because he didn't know how to adjust it anyway. The car does drift slightly to the left. My question is: would adding one shim to the left side at the transmission crossmember help correct the problem, Or is that not a good idea?

Patrick McGhee
1963 Spyder convertible
Weatherford, Texas

Options: ReplyQuote
Re: EM rear toe-in question.
Posted by: red64vair ()
Date: September 05, 2011 03:49PM

The way I see it adding a shim to the left at the transmission would increase toe-in. Then maybe I am looking at it wrong.

Options: ReplyQuote
Re: EM rear toe-in question.
Posted by: Bob Helt ()
Date: September 05, 2011 04:38PM

Hi,
The EM Corvairs have a tough-to-adjust rear alignment system. It is virtually impossible to adjust just one rear wheel for toe-in. The whole transaxle moves as a unit. In addition, it is necessary to loosen the two front mounts and the rear mount to get the transaxle to reposition properly when trying to do an adjustment. I suggest you find an alignment shop that knows how to work on the EM Corvairs. Camber is adjusted by altering the rear springs.

Regards,
Bob Helt

Options: ReplyQuote
Re: EM rear toe-in question.
Posted by: lowandslow ()
Date: September 05, 2011 08:44PM

Yeah, red64vair. Now that I think about it some more you're right. deleting shims would decrease toe in. Sigh......... It's not that bad. I guess I'll just leave it alone. Thanks for the input Bob.

Patrick McGhee
1963 Spyder convertible
Weatherford, Texas

Options: ReplyQuote
Re: EM rear toe-in question.
Posted by: corventure Dave ()
Date: September 07, 2011 08:45AM

How are your transmission rubber mounts? If they are not tight, the transaxil and engine will move front to back - side to side.... and there will be no true rear wheel alignment with the Early rear suspension. One rear wheel out of toe could be a "single" bad transmission mount.


Corventure Dave

Options: ReplyQuote
Re: EM rear toe-in question.
Posted by: Mel ()
Date: September 07, 2011 08:53AM

lowandslow Wrote:
-------------------------------------------------------
> Yeah, red64vair. Now that I think about it some
> more you're right. deleting shims would decrease
> toe in. Sigh......... It's not that bad. I guess
> I'll just leave it alone. Thanks for the input
> Bob.


Deleting shims increases toe out, adding shims causes toe in

Options: ReplyQuote
Re: EM rear toe-in question.
Posted by: MattNall ()
Date: September 07, 2011 08:56AM

Actually the bad front mount would cause camber change...


When Toe is different on each side...

The engine is not straight ...in relation to the centerline of the body...

Slotting the REAR engine mount for side to side adjustment is needed.

MODERATOR
Sea Mountain, between Charleston Harbor and Coos Bay! SW Oregon Coast
Click HERE for My Website...Click HERE for My TechPages!
...............110-PG.................................................Webered-Turbo

Options: ReplyQuote
Re: EM rear toe-in question.
Posted by: lowandslow ()
Date: September 07, 2011 01:46PM

Both the transmission mounts and the motor mount have been replaced within the last year and a half. The tires arn't old enough to show a wear pattern yet so I can't get a clue whether there is a real problem beyond the slight drift.

Matt: Is a difference in caster between the rear wheels a commonly seen problem?

Patrick McGhee
1963 Spyder convertible
Weatherford, Texas

Options: ReplyQuote
Re: EM rear toe-in question.
Posted by: MattNall ()
Date: September 07, 2011 03:27PM

Pat.. you mean CAMBER?

I cannot say..as I've only dealt with 3-4 earlies in my life...


My knowledge of the rear system comes from when I built the Speedskater...

I needed a high ride height for street....even higher for Off Road, and super low for autocrossing...

My engine mounts were fully adjustable in ALL directions

MODERATOR
Sea Mountain, between Charleston Harbor and Coos Bay! SW Oregon Coast
Click HERE for My Website...Click HERE for My TechPages!
...............110-PG.................................................Webered-Turbo

Options: ReplyQuote
Re: EM rear toe-in question.
Posted by: corventure Dave ()
Date: September 07, 2011 03:35PM

Tow will directly effect rear camber with the swing axil. More toe out = more negative camber. More toe in = less negative camber. Our Trucks like our Rampside and Greenbrier have a natural positive camber due to spring load rating and vehicle weight. The early cars can be set up with near zero rear camber when everything is new and rear alignment is set at 3/8 toe-in. then drive backwards and see the rear wheels camber out negative!
After around 50 years, there can also be a history of an accident sometime having occured. If the unibody was tweeked or the engine box bent... more drastic measures like modifying the engine mount as Matt said, may be in order. Your getting good advice here.

Corventure Dave

Options: ReplyQuote
Re: EM rear toe-in question.
Posted by: lowandslow ()
Date: September 07, 2011 09:45PM

But if you slot the rear mount to move the engine one way or the other doesn't that affect toe-in on both rear wheels at the same time? Also I've gotta replace the rear springs because the PO installed those adjustable boosters in the old sagging springs to raise the ride height. Camber appears to be OK but it sure makes for a stiff, jouncy ride. Will toe-in then be affected?

Patrick McGhee
1963 Spyder convertible
Weatherford, Texas

Options: ReplyQuote
Re: EM rear toe-in question.
Posted by: MattNall ()
Date: September 07, 2011 09:52PM

Pat. as you move the rear of the engine sideways.. the correct way... they will even out.


Then you add or remove the shims up front to adjust the toe.

MODERATOR
Sea Mountain, between Charleston Harbor and Coos Bay! SW Oregon Coast
Click HERE for My Website...Click HERE for My TechPages!
...............110-PG.................................................Webered-Turbo

Options: ReplyQuote
Re: EM rear toe-in question.
Posted by: Wagon Master ()
Date: July 10, 2013 09:18AM

When setting EM rear toe-in, and adding an equal amount of shims to both sides, do you add in the 1/4" thick spacer on the drivers side, or use the same amount of shims plus the spacer?

Options: ReplyQuote
Re: EM rear toe-in question.
Posted by: Mel ()
Date: July 10, 2013 09:22AM

Same amount of shims both sides, plus the spacer

Options: ReplyQuote
Re: EM rear toe-in question.
Posted by: Frank DuVal ()
Date: July 10, 2013 02:24PM

First, do the rear alignment first. Then make the front alignment track with the rear wheels.

Remember, the rear wheels steer the vehicle, the front just corrects for where you want to go.

Confused? The rear wheels set the track for the vehicle to go down the road. Get the rear wheels straight relative to the body of the vehicle. Then adjust the front so the car goes striaght down the road.

If you set the front alignment first, you may not have enough adjustment in the rear to get it to go straight down the road.

Just think of a standard straight axle car/pick up. The only adjustment is to mount the axle assembly to the frame, hopefully so the axle is perpendicular to the frame. If this is not perpendicular, the car will always dog-track. You can correct where the car goes down the road with the steering wheel, but the body will always be crooked compared to the road. Same with 4 wheel alignment vehicles, set the rear first!smileys with beer

Frank DuVal

Fredericksburg, VA

Options: ReplyQuote
Re: EM rear toe-in question.
Posted by: Wagon Master ()
Date: July 10, 2013 06:39PM

Thanks Mel. That's what I've always done, but that didn't make it right.

Friends Don't Let Friends Drive Stock
Been Aircooled Since 1973
Northwest Ohio 45840

Options: ReplyQuote


Sorry, only registered users may post in this forum.
This forum powered by Phorum.