No More Spreader Bar?
 

I just called AutoScope (respected Indy) and Ewing (dealer) as I plan an alignment on my W210 after I replace the driver side inner tie rod end. Imagine my horror when AutoScope didn't even know what the spreader bar was. Ewing too said they didn't use one. Is this normal? Are they phasing it out?

AutoScope wanted $139 and the dealer wanted $85 *if you don't need new cam bolts.* If you needed new cam bolts, they said it could be as high as $250. Can someone explain the need for cam bolts? My car is totally rust free, so I don't imagine they would need to break any bolts during the process.

Is the spreader bar overrated? Also, is the dealer pricing fair?

FWIW, a well respected indy alignment shop..........been in business for 30 years.........and knows the M/B well..........doesn't use a spreader bar.

Don't know whether he's successful without it, but he did know the caster specs and the fact that the two sides are slightly different on caster...........off the top of his head.

So, I've got to decide whether to trust him with the SD.........or not.

The $85 dealer price is tempting, but the caveat *if you don't need new cam bolts* scares me a bit. I'm thinking every car they align will somehow need the new cam bolts.

I'm seriously wondering if I shouldn't just mark the inner tie rod with white out and then duplicate the position with the new one, maybe even measuring with my calipers to ensure the distance is identical. My last set of tires wore perfectly evenly and served me well for about 45K miles. I put 4 new Michelins on a few days ago and just want to protect them...

Rust isn't the issue with the bolts. The factory bolts for the lower control arms aren't adjustable. They simply mount the lower arms in the "neutral" position from the factory. If it's determined that the caster and/or caster needs to be adjusted, replacement bolts are available which allow the adjustment to be made. To adjust the camber, the coil springs need to be compressed to allow the bolts to be installed, hence the higher cost. Adjusting the caster is just a matter of installing the new bolts in the proper position.

The most your car will need would be four bolt kits if both caster and camber, on both sides, needs to be adjusted.

Thanks for this awesome explanation.

Is it likely that I would need all four bolt kits if my previous set of tires went 45K with even wear and the car still handles properly? I am simply replacing an inner tie rod end.

I have used the caliper method and it works fine. If your alignment is good and all you are doing is replacing a part then this is the best way to go IMHO.

Put the car up on the jack stands and lock steering wheel so nothing moves. Now get one of those laser levels and clamp it to the brake rotor flat surface. Turn laser pointer on and mark it's position on the garage wall. Do your replacement, and then adjust it to the same marked position. Car needs to be stable and installation of the laser level should be repeatable. Worked for me very good on ML430. And you have nothing to lose to try this method.
Mike

I don't believe a proper alignment on our cars is possible without the use of the spreader bar.

Because our suspension uses so many bushings, the suspension needs to be pre-loaded to simulate the weight of the car and the position of the alignment under load.

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When setting front end alignment, a spreader bar must be used when adjusting the toe. This is a spring loaded bar that forces the front wheels apart with 90-110 NM(66-81 ft-lb) of force. The use of a spreader bar allows the alignment to duplicate driving conditions by preloading the rubber bushings in the suspension. The use of a spreader bar is the only way to get an accurate front end alignment.

Stu Ritter, Mercedes-Benz E-Class Owner’s Bible 1986-1995, p.212.
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In my experience, not many MB's require all four bolt kits to get the alignment within specification, but there's no way to know until the car is on the rack. Either way, why not let an MB dealer do the job? They should provide a before and after print-out. This will clearly show whether or not any bolt kits are needed.

P.S. Some of the home-spun ideas posted in this thread are pretty clever. I'm always impressed by the ingenuity of DIYer's. It proves that necessity is the mother of invention. :)

If it's a threaded part, just count (carefully) the number of turns required to remove the part, then install the new part the same number of turns. Should at least be really close. I put an outer tie rod end on a couple of years ago, then took it to the alignment shop and it did not require further adjustment.
Hope this helps you.

"I don't believe a proper alignment on our cars is possible with the use of the spreader bar"

You meant "without"?

In Dallas, take your car to Rodney Herson (http://www.rodneyhersonautomotive.com/).

He does only MB's, very knowledgable and alignment is his specialty. Fun guy to talk to also.

I've got a spreader bar. I bought it to write an article about MB alignments for a trade magazine. Thirty years of first dealer then indy alignments were done successfully without it and continue the same.

In the experiments I ran using the bar I got toe differences of between .5mm and 1.2mm over five cars. Of course if you are aligning that 210 car with the bad tie rod still in place the reading would be vastly different. Any tech worth a hoot can judge the level of flex in the toe through various techniques. The acceptable range of toe variation is considerably larger than the spreader bar change in solid front ends.

Thanks for this post! I recalled reading something to that effect but did a search and couldn't find it again. Anyway, I plan on using my calipers and just replacing the inner tie rod end WITHOUT realigning. I'm sure this too would be well within the acceptable range of toe variation.