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Community => Auto Torque => Topic started by: rumb on 05 May 2020, 10:40 AM

Title: W108 Alignment
Post by: rumb on 05 May 2020, 10:40 AM
Aaron,

Do you any info on adjusting Camber on a W108 250S?
Is it even possible?

Title: Re: W108 Alignment
Post by: UTn_boy on 06 May 2020, 03:34 AM
I'm assuming you're asking about the camber on the front axle?  If so, then yes, it's very possible.  The pictures below show the procedure, specifications, and a picture of where the adjustment is to be done. 

If it's the rear axle in questions then yes, it's also possible.  You have to play around with the rubber pads atop the rear springs, and if the hydraulic compensator is bad that'll cause camber issues, as well.  Often times people will install a regular spring in place of the hydraulic compensator, but this requires the rear spring pads and bottom plates be adjusted to correct the height in the rear.  Most people don't know that and never make the corrections, so the car ends up sitting higher or lower in the rear affecting camber. 
Title: Re: W108 Alignment
Post by: rumb on 06 May 2020, 08:13 AM
Thanks for your help!

I have a good alignment guy, but of course his MB knowledge is non existent.   I will show him this and get it all squared away.
Title: Re: W108 Alignment
Post by: UTn_boy on 06 May 2020, 11:51 AM
Be sure to inform your alignment guy of the eccentricities of the Caster adjustment.  If you're not aware either then here's the beef on that:

The metal stiffening plate that the transmission mount sits on must be loosened (not removed) from the chassis, and the slip joint on the driveshaft must also be loosened.  The reason for this is that when you turn the eccentrics for the Caster adjustment the WHOLE subframe and engine will move.  If the rear mount plate and driveshaft slip joint aren't loose when it's moved it'll put the exhaust, engine mounts, sub frame mounts, flex disc, and driveshaft center support bushing in a bind causing premature failure of these components along with a weird vibration you'll never be able to get rid of. 
Title: Re: W108 Alignment
Post by: rumb on 06 May 2020, 01:11 PM
Aaron,
Double checking my notes, it is the Caster that needs adjustment.  I found the appropriate instruction on my old CD. IT wont autoplay anymore but all the pdf's are there.

Thanks for the info provided.
Title: Re: W108 Alignment
Post by: UTn_boy on 06 May 2020, 04:31 PM
No worries.  Glad I could help.  In the event you need the instructions I'll post them below anyway. 
Title: Re: W108 Alignment
Post by: rumb on 08 May 2020, 12:27 PM
As is often the case it requires reading the instruction several times to understand MercedeSpeak. I believe I have conquered this task aided by lying under the car examining the components.  I will visit Alignment shop again next week armed with new knowledge.

Beside what you mention about trans mount, the transverse centering rod has to be disconnected.

For those of you unaware of W108 design, there is a flat spring that locates the entire front subframe. The other point is the upper subframe rubber mounts.  The flat spring is at an angle that allow a small adjustment of the subframe forward/back, up/down to change the caster. One must be careful to not move too far as that will stress out the upper mount. There is an additional outside threaded shaft in the top kingpin mount that allows another 20' of adjustment to compensate for R/L differences.

On a separate note,

What MB Battery correctly fits a W108 1967 250S?

Tom Hanson only supplied a NLA part number 002-541-99-01-26 .

Local dealer was completely unhelpful .
Title: Re: W108 Alignment
Post by: UTn_boy on 09 May 2020, 07:57 AM
I don't recommend disconnecting the transverse lateral strut rod completely, but only loosening.  If it's disconnected completely and then reconnected after alignment the caster will be off after re-installation.  Possibly toe, as well, since re-installation afterward could move the sub frame in relations to the steering box location. 

The eccentric adjustments at the forward end of the flat springs are there to use in the entirety of their full range.  Even at the maximum forward most position the sub frame mounts and flat spring rushings will not be compromised.  The sub frame mounts are designed to mount/sit at a slight angle if necessary.  So it's not possible for one to move or adjust this adjustment too far. 

Regarding the battery......laugh at me if you want, but I've been using batteries from walmart and advance auto for many years.  I get 7-10 years out of those batteries.  I don't know/remember what group number the battery is, but both places have reference material to look up the correct battery.  If a proper battery is required for cosmetic appearances then I'd buy a replica Varta battery look-a-like from some place like AAB (Antique Auto Battery). 
Title: Re: W108 Alignment
Post by: rumb on 09 May 2020, 02:53 PM
Looks like AAB was bought a few years ago by https://jimsbatterymfg.com/

Yes, I am looking for cosmetic reasons.

I think I will try going to Interstate Battery and find the correct Group size and then go back to Dealer and see if he can match up that way.


Regarding the transverse lateral strut rod, but only loosening.

There is just a bolt on each end holding it on and one end is threaded like a tie rod end. Manual said to remove and then put back so there is no force on either end. I dont see how it can just be loosened.
Title: Re: W108 Alignment
Post by: mrkozzy on 09 May 2020, 05:39 PM
Hmm  Aaron,

I'll know where to come for knowledge when I get to my next merc project.
The 108 parked in the garage for the past 10 years.

you've made my day!

Kozzy
Title: Re: W108 Alignment
Post by: TJ 450 on 10 May 2020, 03:00 AM
I think may be a challenge to find someone who is able to carry out an alignment properly on these earlier cars. Relatively soon I'm going to have to tackle this.

Tim
Title: Re: W108 Alignment
Post by: UTn_boy on 10 May 2020, 03:49 PM
Rumb, the transverse support rod is only held in place buy two bolts and two nuts.  When loosened, the rod will be able to rotate on the axis of the bolts as the sub frame is move forward or backward.  When the bolts and nuts are tightened, the rod is only sandwiched tightly between the bracket off of the right frame rail and the bracket on the sub frame itself.  That's why when the bolts are loosened it'll pivot freely on it's connection points.  Obviously, the bushings shouldn't rotate in the rod itself, but they should rotate around the bolts.  If anything looks amiss on this rod, then take comfort in knowing that the bushings are available separately, and the whole rod is also available.

Kozzy, I love helping others out on their W108 cars.  Feel free to reach out any time!

Tim, I couldn't agree more.  That's why I ended up having to buy the manual style equipment to do it myself.  Getting it close with a plum bob and a measuring tape makes a world of difference before a more accurate check is performed.   
Title: Re: W108 Alignment
Post by: rumb on 13 May 2020, 01:04 PM
Just returned from alignment. Made small adjustment to castor with no effect, then he swapped front tires around and that fixed the pulling to the right perfectly.  Newer Uniroyals.
Title: Re: W108 Alignment
Post by: UTn_boy on 14 May 2020, 11:10 AM
OK.....something isn't right here.  Caster that's off doesn't cause the front of the car to pull one way or the other.  Only toe and/or the combination of toe and camber cause pulling.  It's very concerning that swapping the tires made a difference.....makes me wonder if one of them are getting ready to fly apart.   
Title: Re: W108 Alignment
Post by: rumb on 14 May 2020, 11:39 AM
The tires are about 2 years old. Alignment shop often enough has to correct pulling by swapping tires.  Guess they dont make tires like they used to.
Title: Re: W108 Alignment
Post by: Inshan on 14 May 2020, 01:21 PM
I admire the wealth of knowledge on this forum.  I have no experience with W108, but all of my steering and suspension training at Ford and GM reflected that steering will pull to the side of least positive caster.
Title: Re: W108 Alignment
Post by: UTn_boy on 15 May 2020, 05:07 AM
I admire the wealth of knowledge on this forum.  I have no experience with W108, but all of my steering and suspension training at Ford and GM reflected that steering will pull to the side of least positive caster.

It will on a GM or Ford because they don't have a common sub frame, and because any movement of the caster will affect the toe and camber independently on each side.  On a W108, W109 W110, W111, W112,and W113 the caster won't affect the toe UNLESS the caster is offset relative to each side.  Even then the mis-adjustment wouldn't cause any noticeable pulling due to the minuscule amount of travel provided in the caster adjustment. 

Rumb, I couldn't agree more regarding your previous commentary.