All, I am interested in feedback from the group about steering experience with my well-maintained 2001 330i with the sport package and 95K miles. Especially on asphalt roads with uneven surfaces, I am constantly fighting the steering to stay pointed straight ahead. However even on smooth concrete, any road imperfections affect straight line travel. I believe this behavior is called tramlining. It seems I am having to constantly and excessively correct and apply pressure on the steering wheel to keep a straight line. It does not make for a pleasant, relaxing driving experience. Be aware both control arms were replaced with BMW parts due to wear within the past year. A shop compentent in wheel alignment has serviced (and re-checked) the alignment specs. Checks for play in tie rod ends and steering rack were normal. The dealer checked the alignment and indicated this is normal with the larger tire sizes with the sport package wheels and suspension of the 330i. They said the sport package "transfers road feel to the driver". Hmm, I'm not feeling the "Ultimate Driving Machine" experience. I've driven a friends car, which also a 2001 330i with sport package. It felt more directionally stable than mine. I am running Khumo Ecsta SPT tires with the stock sizes. The tires are about a year old with about 8K miles. When the tires were new, the car tramlined about the same as now. I had a Porsche 968 with a similar steering experience, and the shop recommanding having the caster setting increased, which improved the steering on uneven roads. I understand non-M3 cars don't have adjustable caster. I know the difference between the handling of a BMW and a Honda. I'm going to get more road feel with the BMW, but I just don't think my car is right. Ideas? Roger Sass
Wider wheels and tires exacerbate this, and directional rubber or run-flats seem to add to the problem. Different tires have differing resistance to tramlining. A little extra toe-in seems to help.
As low-profile tires wear, tramlining usually goes up substantially. I know on my E46 I recently replaced the BFG KDW2 tires that were about 3/32" tread left, and it was tramlining like crazy (56k miles, new thrust bushings and RTAB less than 8k ago). However, I have a set of autox wheels/tires (BFG R1) that showed essentially zero tramlining when I drove them on the street to check the car out, so I suspected new street tires would cure the horrendous tramlining. After replacing the tires with new Dunlop Star Specs, the tramlining is gone. I would bet the tires are the culprit. I've never had a set of low profile tires that didn't substantially increase tramlining as they worn in...at least on my current cars. If the thrust bushings are fresh, the tire rods have no play, and the alignment (toe in up front) is set in the middle of the factory range, you shouldn't be having a tramlining problem...unless your rear trailing arm bushings are shot. Have you had those replaced? At your mileage, if not, they are likely very worn.
I haven't had an e46 for almost 9 years (had a 1999 E46 328i) but I did manage to put almost 100K miles on that car in 1 years time. During that time I dealt with quite a bit of suspension wear and parts. I too had noticed that tires did make a big a difference in how sensitive the car was handling wise. I went through six sets of front control arm bushings due to wear, replaced the RTABs atleast twice, and eventually replaced shocks, springs, shock mounts, etc. For the most part all of these parts replacements/upgrades made a difference but the biggest culprit was tires.
I noticed a huge difference in with just the tires on my E46 323I sport package. Pirelli P Zero Nero tramlined horribly. I had the suspension and alignment checked and all were good. As soon as those wore down, I switched to Bridestone RE960AS and tramlining was immediately gone.
My 2001 325i Sport package has had similar tramlining issues in the past. Tires are probably the #1 contributor, but not the only one. The famous rear trailing arms bushings allow riduculous rear toe variations over road crowns and bumps which is a contributor (also to rear tire wear). I installed the Turner RTAB limiter kit (essentially big aluminum washers that limit lateral bushing deflection) and that helped plus felt better. Running rear toe and camber at the minimum of the BMW recommended range has also helped. I tend to run Pirellis and my current set has very low tramline tendencies so the problem is not noticeable. I've had issues with other Pirellis and Bridestones in the past.
