[s-cars] Musing on Tramlining

[forgied at direct.ca]

As you know, tramlining is when your car follows the ruts in the pavement
or concrete with no input from you. As a result, the car seems to dart
from side to side a bit and the steering wheel moves in your hand.
Tramlining can be caused by poor alignment (e.g too much too out (or in)),
incorrect tire pressure(s), tire design (some tires tramline more than
others), tire width (wider seems to be worse), bad tie rod ends,  etc.

My car (93 S4 with 191,000 km) has been pretty good for not tramlining for
the 8 years I have had it. A while ago, I did get tramlining with some
Toyo Proxes T1's but I never had any with either my winter tires (Pirelli
Wintersport 210s) or in the past two years with my Falken Avenus (sp)
summer tires.

However, in the last month or so, I was noticing a looseness in the
steering and quite a bit of tramling. This became more evident on a recent
trip from Vancouver BC to Walla Walla WA for a wine tasting long weekend
via I-5, I-90 and I-82. These roads get a lot of semi-truck and trailer
traffic and the right hand lane(s) are quite rutted from the weight of the
trucks.

I was kicking myself in the middle of a sleepless night in Walla Walla for
not checking my steering rack or ball joints etc before I set out on this
1400 km round trip. Monday morning, while the car was still cool, I
checked the steering rack for tightness and lack of cracks on the mounts
(everything seemed fine). Then I checked the steering damper.

WTF?!! The bolt holding the passenger side down was loose and the end of
the damper could be moved up and down about 3/16". Hmm... I whacked the
end of the damper down with my hand and tightened up the bolt.

The drive home was much better. Almost no tramlining. When I did get some,
the road was very rutted pavement (as opposed to concrete).

On the basis of this experience, you might want to check the tightness of
your steering damper - just on general principles but especially if you
have a tramlining problem. Personally, I am finally going to replace my
steering damper with the one I bought 2 years ago (the expensive one, not
the MUCH cheaper Fox damper - which works just as well). I don't expect
any (or much) more improvement. Just a peace of mind that I have the
stupid bolts tight (again). D'oh!!!

HTH.

Dave F.