GreenBes

Hey All,

Thanks for the tips and tricks along the way with my new 97Sc3. I have replaced the front LCAs with supra tt arms, put on some new tires, flushed out the power steering system and replaced the serpentine belt (old one was all cracked) and also through in some daizen steering rack bushings. All of this has helped the steering feel immensely.

EDIT: I have also had a 4 wheel alignment done and everything is to spec. Car drives straight and does not lurch. Just getting nasty feedback through the steering wheel over pot holes.

However, I still seem to get some pretty good bump steer over pot holes. Is this normal for the SC3 or should I be looking into other repairs?

Tie rod ends? Shocks?

-Sam

5sp_jzz30

iTrader: (2)

is your car lowered at all. bump steer becomes an issue if/when you lower the car a lot. the tie rods are not parallel to the ground any more and dont travel in the same arc as the control arms. this causes the wheels to assume toe out on suspension compression and toe in on suspension rebound. the way to fix is JIC or Megan tie rods made for the supra. they work on our cars just fine. they have a spacer between the mounting point of the outer joint and where it mounts on to the spindle. this creates a drop in the rod and makes it more level with the ground.

if you are on stock suspension then i would look into an alignment first or at least check if its to spec.

keep us updated on what you do and what comes out of it.

GreenBes

Stock suspension and had an alignment done.

-Sam

vwynn

iTrader: (4)

least u only have bump steering...

My car goes right.. Bump steers like crazy and tramlines like crazy sigh...

rykwebb

I just started undertaking this problem, just put on the Daizen steering rack bushings, now its two new Kumhos on the way for my front tires, then an alignment when that is done...after that if I still have problems Ill look into LCAs, etc.

Keep me updated if you find anything specific, my car is also on stock (almost broken, lol) suspension.

5sp_jzz30

iTrader: (2)

tires can definitely lead to the car wondering and some minor tramlining. i had this before. when i replaced the front tires the problem virtually went away.

TheMole

iTrader: (13)

I have the same issues and setup as the OP: Proper alignment, Supra LCAs, Daizen rack bushings, and oem suspension w/ new tokico shocks. I have narrowed it down to the outer tie rod ends. They come in this week and I'll be replacing them this week along with another alignment after. I'll keep you guys updated.

Also, it might be a good idea to post your alignment figures so we can check the specs.

GreenBes

Will post up my alignment specs when I get home. Lemme know how those outer tie rod ends work out for you. I am thinking that would be the most likely culprit. If that doesn't do it, then the final step would be to look into replacing the entire rack.

-Sam

Jeembo

I have minor bumpsteering and moderate tramlining issues with my stock '99 SC and I had major bumpsteering and tramlining with my '98 ES. I just assumed it was a Lexus thing...

GreenBes

Not getting any tramlining, just bumpsteer. Maybe I am just used to years of BMW ownership.

GreenBes

And maybe I will seafoam this weekend - seafoam is supposed to cure all that ails these things right?

TheMole

iTrader: (13)

Theres a thread on seafoaming here: https://www.clublexus.com/forums/per...hlight=seafoam

Generally be prepared to change the spark plugs/oil after you seafoam.

BattleVer

If your wheel shakes going over bumps, it has nothing to do with bumpsteer. Bumpsteer is just the name of the toe change you get when your car goes into bump, meaning into compression or rebound instead of static height.

I dont know how many of you have driven an old truck or something with bad bumpsteer, you basicly feel the wheel move different then what your doing to it whenever your turning and the suspension compresses.
Guess the easiest way to kinda feel bumpsteer is turning into a steep driveway. While your wheel is turned, when you start driving up the thing, do you feel the wheel move or change angle to keep the car going in the same turning radius. The amount of steering correction you need to keep the car in the same arch would be the toe change or bumpsteer your getting. In an old truck, sometimes it would be like a half turn, now that is bad bumpsteer.

I dont suggest getting those outter tie rod kits. For one they use cheep rod ends and they create alot of play in the steering. Then have you ever seen data on how much bumpsteer the car has stock compaired to having the kit? If they ever did test it, on any car, other then putting it on and saying "yeah, it fits, people will buy it" then why is there no data. Just cause someone makes something, doesnt mean it works, they are just trying to get you to give them your money.

5sp_jzz30

iTrader: (2)

doesnt necessarily have to be a cheap bearing in the kit. if you really want to get technical on it and how much bumpsteer correction you need then it will depend on ride height of the car. the more you lower the car the more the control arms move in the CCW direction, up, and the less the tie rod is parallel with the ground.

i dont know what you mean that they create play in the steering. "play" is created when you have clearance issues in components such as work bushing/mounts of rack-to-frame, inner and/or outer tie rods, or internal issues with the rack gears. if the bearings you use are so sloppy that they have play then yes you will have undesirable results.

the best solution to this is to buy hex shaped extruded bar stock. you put it in the lathe and machine to appropriate size. one end you tread the same size as the tie rod and the other the same as the spherical bearing you are going to use. best bet would bee Peer or Aurora Bearings. go through the catalog and fit the one with the bearing ID that matches the bolt hole size on the spindle and has the biggest offset. after that you make a bunch of spacers and you stat going to town with it.

the best way is to have the car level at ride height and remove the shock on that corner. then you can put up the measuring tool and see how much bump steer you are getting. then you put the spacers between the spindle and the spherical bearing. the lower you are the more spacers you would need.

there is no data on it because this is a very vague topic as far as setup. it will vary totally from car to car. most people wont do this themselves.

i think i will be doing this on my car come summer. i dont feel like working in 30* weather outside. this similar concept im also going to apply to my friends sti. he has aftermarket lower ball joints that are made to accommodate spacers. this can help with the roll center of the car if done properly

TheMole

iTrader: (13)

-BattleVer

The "bumpsteer" I experience is that when going over potholes and rough/uneven roads I have to hold the steering wheel tightly so that the car does not wander all over the place. If I were to let go of the steering wheel, my car would be going in all sorts of different directions lol.

I am replacing the tie rod ends with oem and not rebuilding them with a kit. I don't remember my car wandering when it was stock. When I was lowered on coilovers I had some bumpsteer, but that was to be expected. Now that I have stock suspension components again, I would assume that it would go back to how it drove before, but that is not the case. It just puzzles me that when I drive a civic and camry over the same roads, I don't get that kind of steering play/feedback.

Thanks for everyones insights on this.