Steering Darting ack and forth??? Any Help?

[kenehresman]

Ok, Fixed the trans program... So no I have to work through other issue...

I installed 06 750IL wheel and tires on my 90 750IL and the tires are wider but fit. Max size in case anyone is wondering is 245/40/r18 in front and 245/50/r18 in back.

Now that I have larger front tires the steering is darting back and forth.... Sometimes it will steer normal then all the sudden pull to the left and I can correct then it is like that a while then might go back center or dart the other direction...

Any one have any Ideas?

[markus]

sounds like tramlining.

how are your tierods and center linkage? if they are old id replace them. also check tire pressures.

[Phatty5BMW]

Thats what my car is doing. I got new tie rods and an alignment with new tires and walaa, i can barely drive my car..... Looks like I just drank a case of beer when I drive.....

Pat

[kenehresman]

Ok, I assume the tire pressure is fine since they tires were brand new today... I have no idea if the tierods or linkage is good or bad. I will be inspecting it soon, since this isn't drivable like it is. Just way too dangerous for anyone to drive I feel....

It only became apparent when I installed the 18" tires and wheels. the Stock 15" tires and wheels seemed to drive fine other than a horrible shimmy sometimes around 45+ mph. It would be so bad I would have to slow down and try to accelerate again. Any of these symptoms sound familiar or can they influence this "tramlining"?

[Barney Paull-Edwards]

Ok, I assume the tire pressure is fine since they tires were brand new today... I have no idea if the tierods or linkage is good or bad. I will be inspecting it soon, since this isn't drivable like it is. Just way too dangerous for anyone to drive I feel....

It only became apparent when I installed the 18" tires and wheels. the Stock 15" tires and wheels seemed to drive fine other than a horrible shimmy sometimes around 45+ mph. It would be so bad I would have to slow down and try to accelerate again. Any of these symptoms sound familiar or can they influence this "tramlining"?
The answer to your problem lies in forum`s excellent pages. OFFSET! Somewhere in bruno`s site is all the offsets and sizes, not clever enough to pass on details but they are there.If you don`t have wobble caused by centre hole of wheel being wrong then it must be offset.

[kenehresman]

Not sure I followed that Post, who is Bruno, and where is his site? And are we talking wheel offset??? These wheels are off an 06 750IL and are on a 90 750IL, the offset is like only 2mm difference from the stock wheel and tire combination... More information please....

[winfred]

make sure that the tires are not rubbing on the struts, another thing to look at set the steering wheel straight and then look at the tires, to they point straight ahead and line up with the rear tires when you look at them from the front, if not the alignment is off, i have been doing this **** long enough i can tell at a glance what the alignment is like, towed out and it wants to dart back and forth as the road changes, towed in and it's hard to steer till you get to a certain point and it takes off

[kenehresman]

The Tires indeed are close, like probably 1/4 inch from the strut but not rubbing.... COuld be alignment, this car has 230K miles, and has been neglected for the last 1-2 years, so who knows....

FWIW, what are the most common failures to look for in the front end of a 230K mile car?

[Barney Paull-Edwards]

Winfred dead right.1/4 inch liveable,so check alignment by length of string front to back across diameter of wheel.Still worth checking I.D. of wheel and O.D. of hub centre.Bruno is at Racing Kings I think.Bow down and pray to Winfred!Failure factor,hubs,steering joints,inner wishbone bushes,nut behind wheel.

[Johntee540]

Larger tires and wheels exacerbate any front end issues that you may not have known you had. I would also look at Control Arm / Thrust Arm Bushings as if they are worn they wont be able to hold the new wheels and tires in place. You are putting non-factory standard stresses on old bushings and they are just letting you know - JT

[winfred]

common dead parts can be most of the front end, as for what's worn out on your car it's impossible to say without getting under the car, jack up the front end get it on jack stands and you can play around with it, grab the wheel at 3 and 9 o clock and rock back and forth, this checks the steering linkage, if you get movement get under there and see what's shaking, grab the wheel at 6 and pull in and out, this checks the lower control arm, grab the wheel and pull it toward the back of the car (direction of travel) this checks the thrust arm and bushing, just about any movement here signals at least a worn out thrust arm bushing which is common, while under there grab the steering center link and try to twist it and see if you can move the side opposite of the steering box up and down, twisting is a bad link and up and down is a bad idler arm bushing

[kenehresman]

Ok, I will just order and change the control arm bushings.... and the thrust arm?? I don't see a listing for that, is there a more formal name? and which control arms upper / lower?

[winfred]

thrust arm = upper control arm, get either e32 750il bushings or my recommendation e34 m5 bushings for the thrust arms, they last longer then the stock bushings

[kenehresman]

Ok, THanks will order right now :-))
Another thought, in the trunk were a few parts ??? Looked through a catalog but were unsure what some of them were.

There are 2 metal dog bones with bushings in each end.... Baout 4 inches ling..... Guessing someone think they needed changed but were too lazy, or only did one side or set.... These sound familiar? What are they??

(O---O) kind looking thing you know like a dog biscuit / bone...

[kenehresman]

Ok,I think they are rear trailing arm or sway bar parts..

Anyway, how many sets of bushings do I need? There are probaby 2 upper and 2 lower arms per side? and this is a 750IL so do I have steel lowers or alumimum? without looking, its like 3 feet of snow, 11:00 pm, and -5 degrees out :o)

[kenehresman]

Ok, it's only getting up to 19 degrees today so the likelyhood of me crawling under my car in 2 feet of snow is slim to none....

So can anyone make me a shopping list of front end parts to reduce/eliminate tramlining?

I have a 1990 750IL
I need qty, and descriptions... and anyone have any preference on where I order them? It is nice to get help from these forums and if anyone is making a living from these cars, I would like to spend my money with them instead of a total stranger....

thanks,
Ken

p.s. the driveshaft needs rebuilt so I am thinking for 387 bucks paid plus the return of my old core, this place in San Antonio looks like they know all about these and offer a 1 year warranty... Any input on using them?

http://www.thrashdriveshaft.com/import2.htm#BMW%20DRIVESHAFTS

[632 Regal]

Call BMA parts.com they can press the M5 bushings into the thrust arms, get Lemforder parts, they are up with the best parts. Stay away from cheap replacements unless you like doing the same job over and over.

Some people have had the U-joints machined and replaced at driveline specialists for less money.

ever go to realoem.com ? you can get your own part numbers and stuff there.

[George M]

Front wheel alignment or toe...also camber which is less adjustable....an out of adjustment steering box, and lastly worn suspension components...pitman arm...control arms/bushings, outer tie rods etc. Tires also have a fractional effect.
Bottom line for these cars with their recirc ball steering and relatively heavy weight, they have to be set up on the money to track just right.
HTH,
George