Caster alignment - LotusTalk

plastique999 · 05-29-2009, 05:49 PM

Just did a a laser alignment and my caster is about 1 degree different....how is this fixed?

jordantii · 05-29-2009, 06:55 PM

Moving shims fore and aft on the upper control arm.

LastToy · 05-30-2009, 03:09 PM

My Elise came from the factory with the shim/washer fore on one side and aft on the other side. My mechanic noticed the caster being off and figured it out. Now its balanced. I guess this kind of things happen w/ hand built cars. I also found a socket stuck to my speaker magnate... a little gift from Lotus.

kertong · 07-10-2009, 10:10 AM

Quote:

Originally Posted by LastToy

My Elise came from the factory with the shim/washer fore on one side and aft on the other side. My mechanic noticed the caster being off and figured it out. Now its balanced. I guess this kind of things happen w/ hand built cars. I also found a socket stuck to my speaker magnate... a little gift from Lotus.

I thought these removable shims adjusted camber, not caster?

fpitas · 07-10-2009, 12:12 PM

Quote:

Originally Posted by kertong

I thought these removable shims adjusted camber, not caster?

There are removable shims near the upper ball joint that set camber (at 7 in this picture). The ones for caster are at each of the upper arm mounting bolts, fore and aft (24 and 29). Shim(s) are removed from one end (say, the front) and placed at the other end to move the upper ball joint fore and aft.

kertong · 07-10-2009, 01:53 PM

Quote:

Originally Posted by fpitas

There are removable shims near the upper ball joint that set camber (at 7 in this picture). The ones for caster are at each of the upper arm mounting bolts, fore and aft (24 and 29). Shim(s) are removed from one end (say, the front) and placed at the other end to move the upper ball joint fore and aft.

Ahhh, I wasn't aware of those shims. Thanks! The diagaram helps a bunch.

How hard is it to get to these shims by hand? I've been contemplating increasing caster, I've been seeking a firmer/more weighted steering feel..

fpitas · 07-10-2009, 01:57 PM

Quote:

Originally Posted by kertong

Ahhh, I wasn't aware of those shims. Thanks! The diagaram helps a bunch.

How hard is it to get to these shims by hand? I've been contemplating increasing caster, I've been seeking a firmer/more weighted steering feel..

Moving the big shims is relatively easy, but there are some tiny washer spacers that are a complete pain in the *ss to get back in there and lined up with the bolts.

apk919 · 07-10-2009, 02:06 PM

Quote:

Originally Posted by fpitas

Moving the big shims is relatively easy, but there are some tiny washer spacers that are a complete pain in the *ss to get back in there and lined up with the bolts.

How tough is it to remove bolt #29 (red arrow below)? It looks like the rack boot/steering tie rod would interfere with backing it out enough to move the washers around...

fpitas · 07-10-2009, 03:25 PM

Quote:

Originally Posted by apk919

How tough is it to remove bolt #29 (red arrow below)? It looks like the rack boot/steering tie rod would interfere with backing it out enough to move the washers around...

I popped the outer tie rod and swung the steering link back and out of the way. Once I did that it was easy to get the bolt out. I forget, but I may have turned the steering a bit too.

apk919 · 07-10-2009, 04:24 PM

Quote:

Originally Posted by fpitas

I popped the outer tie rod and swung the steering link back and out of the way. Once I did that it was easy to get the bolt out. I forget, but I may have turned the steering a bit too.

Yup, I kind of figured you'd have to do that... thanks!

apk919 · 08-23-2009, 12:04 AM

Quote:

Originally Posted by fpitas

Moving the big shims is relatively easy, but there are some tiny washer spacers that are a complete pain in the *ss to get back in there and lined up with the bolts.

I did the caster adjustment tonight... maxed out the caster by moving all but one washer in front of each of the bushings. I actually used a little rubber cement to hold the smaller washers together while refitting them... and a complete set of drift pins to help line everything up. Not as bad as I thought, but still no picnic.

Pic 1: Measuring the caster...
Pic 2: Washers in position for maximum caster

fpitas · 08-23-2009, 04:36 AM

Out of curiosity, how much caster did you get?

If I have to do it again I'll try the rubber cement trick. I forgot to mention I made a pointed bolt to center the washers once they were nearly in place.

apk919 · 08-23-2009, 05:44 AM

Quote:

Originally Posted by fpitas

Out of curiosity, how much caster did you get?

If I have to do it again I'll try the rubber cement trick. I forgot to mention I made a pointed bolt to center the washers once they were nearly in place.

Well, it's interesting that the two sides were not set symmetrically from the factory... the left side was 0/4 (0 washers ahead of bushing/4 washers behind) and the right side was 1/3. I measured the starting caster as 3.4º left and 3.2º right. After setting the caster both sides' washers are 3/1, and the caster I measured was 4.6º left and 4.0º right. The manual says 0.4º of caster change per washer... which seems to be accurate.

fpitas · 08-23-2009, 05:52 AM

Quote:

Originally Posted by apk919

Well, it's interesting that the two sides were not set symmetrically from the factory... the left side was 0/4 (0 washers ahead of bushing/4 washers behind) and the right side was 1/3. I measured the starting caster as 3.4º left and 3.2º right. After setting the caster both sides' washers are 3/1, and the caster I measured was 4.6º left and 4.0º right. The manual says 0.4º of caster change per washer... which seems to be accurate.

Driven it yet? You may get some pulling with that much more caster on the driver's side.

apk919 · 08-23-2009, 05:59 AM

Quote:

Originally Posted by fpitas

Driven it yet? You may get some pulling with that much more caster on the driver's side.

Yes... I was wondering whether I'd notice the asymmetry; it feels fine so far. Haven't taken it on the freeway yet though. I'm going to do another measurement of caster after put a few more miles on the car. The factory spec is 0.35º difference side/side...

fpitas · 08-23-2009, 06:03 AM

Quote:

Originally Posted by apk919

Yes... I was wondering whether I'd notice the asymmetry; it feels fine so far. Haven't taken it on the freeway yet though. I'm going to do another measurement of caster after put a few more miles on the car. The factory spec is 0.35º difference side/side...

If it drives OK, if it were me I'd leave it alone. A little more caster won't hurt anything.

apk919 · 08-23-2009, 06:09 AM

Quote:

Originally Posted by fpitas

If it drives OK, if it were me I'd leave it alone. A little more caster won't hurt anything.

Agreed

Elise 323 · 08-23-2009, 05:20 PM

You probably already did this but don't forget to reset the toe. Changing the castor changes the toe.

apk919 · 08-23-2009, 07:59 PM

Quote:

Originally Posted by fpitas

Driven it yet? You may get some pulling with that much more caster on the driver's side.

After a much longer test drive, it does seem like 0.6º of difference is too much... there seemed to be a perceptible pull to the weaker side. I moved around one set of washers on the left side and now I'm back to a 0.2º difference, and the steering feels much more neutral. Of course, with more caster, the car is more sensitive to crowning and irregular surfaces anyway...

Quote:

Originally Posted by Elise 323

You probably already did this but don't forget to reset the toe. Changing the castor changes the toe.

You're right, and I will... I wanted to finalize the caster setting first.

569dean · 08-24-2009, 12:46 AM

what is the factory spec on the elise

camber
caster
corner balance
and all that

05-29-2009, 05:49 PM	#1 (permalink)
plastique999 Form and Function Join Date: May 2008 Location: Alta Loma, CA Posts: 3,046	Caster alignment Just did a a laser alignment and my caster is about 1 degree different....how is this fixed? __________________ www.FaceNBody.com 2005 Lotus Elise: 2bular decat\GT3 exhaust,HID's,turn signal&rear fins delete, CFside scoops, CFbinnacle,CFcenter console,Zoom CF mirror,APR Aero kit,CF 5-elem. diffuser,Exige mesh,Ohlins DA,RTD brace,RAC 'lites,Toyo R888's,HawkHT10's,CO painted calipers,SS lines,Reverie XC CF seat,Reverie CF steering wheel,Schroth Profi II 6 pt harness,shifter re-Enforcer,Manly mounts, Accusump,Moroso pan,BWR key to BWR S/C! Spec Racer Ford #237

05-29-2009, 06:55 PM	#2 (permalink)
jordantii KMG365 Join Date: May 2006 Location: Tampa Bay Posts: 737	Moving shims fore and aft on the upper control arm. __________________ Never Lift....

05-30-2009, 03:09 PM	#3 (permalink)
LastToy Registered User Join Date: Nov 2004 Location: Boston Posts: 250	Yes, check those shims/washers... My Elise came from the factory with the shim/washer fore on one side and aft on the other side. My mechanic noticed the caster being off and figured it out. Now its balanced. I guess this kind of things happen w/ hand built cars. I also found a socket stuck to my speaker magnate... a little gift from Lotus.

08-23-2009, 04:36 AM	#12 (permalink)
fpitas User, Registered Join Date: Sep 2005 Location: Leesburg, VA Posts: 1,833	Out of curiosity, how much caster did you get? If I have to do it again I'll try the rubber cement trick. I forgot to mention I made a pointed bolt to center the washers once they were nearly in place. __________________ Francis 2006 Chrome Orange Elise: LSD/TC, Nitron SAs with 425/650 springs, BWR 7/8" Front Bar, Eliseparts bumpsteer kit, VF Stage 2, 2bular Header + Sport Cat + 8x24 GT3 Muffler, ECU Tune by Jermaine, Smaay's fuel rail, ACT XT clutch, Saikou Michi dual catch can, Moroso pan, Manly's mount inserts & FF Engine Damper 2000 Black Integra Type R: - 213,000 miles...running again!

08-23-2009, 05:20 PM	#18 (permalink)
Elise 323 Registered User Join Date: Feb 2006 Location: IN Posts: 86	Castor Effects You probably already did this but don't forget to reset the toe. Changing the castor changes the toe. __________________ Ardent Red, Biscut, Sport, Touring, Starshield, DA Ohlins, Adjustable front bar, 888's, stainless brake lines, Pagids, Sport ECU, Stage 1 exhaust, Cup Car Airbox, HIDs, Lotus driving lights, mini-mirror, LETSLA shifter, locking gas cap, painted engine covers, inprogress

08-24-2009, 12:46 AM	#20 (permalink)
569dean Registered User Join Date: Jul 2008 Posts: 66	what is the factory spec on the elise camber caster corner balance and all that

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