rb5tfh

My STi7 is behaving very strangely - I suspect it may be something to do with diffs, but my dealer is clinging to the idea that it is clutch related - probably because the clutch is not under warranty or something. I originally thought that this problem was a slipping clutch - revs rising faster than speedo - but it seems that all along, it was something much worse. It doesn't seem to be the clutch at all - the wheels seize up - sometimes both front wheels seem to have completely different agendas. The ride is very jerky and jittery, the car will pull to either the left or right suddenly. If driving on a long bending road, the car will always drift to the outside of the bend. It almost feels like your going sideways! Tramlining has become awful. The car will actually follow the white line in the middle of the road! On acceleration the transmission whines excessively and seems to groan on deceleration. If I depress the clutch, when the car is jerking along the road, then the ride smoothes out. Also, considering how bad the jerky ride is, if I am reversing, the ride is very smooth even over quite a distance. Any ideas?

rb5tfh

nearly forgot to mention, there is also a burnt oil smell, which I can only smell on opening the door.

johnfelstead

Is this a UK or Japanese spec car?
Has the gearbox ever been replaced?

rb5tfh

uk car . . . and no, gearbox is original.

johnfelstead

it makes no sense that when you dip the clutch the jerking stops as the transmition system is independant of engine drive. You sure it doesnt stop jerking if you just hold it at a steady throttle cruise?

rb5tfh

I think you're right. sudden acceleration seems to give the worst effects, or tight corners.

johnfelstead

can you go drive it and then come back with what it actually does, it's hard to give you some pointers if you arnt being specific about what action causes what reaction.

rb5tfh

drove it in the dry last night and think that i have narrowed it down to the brakes. Drivers side front wheel is incredibly jerky - like bad wheel alignment or suspension problem. Harsh acceleration or deceleration provokes this even more. At about 4000rpm in any gear, the wheel seizes up as if the brakes are being applied on just this one wheel, and the transmission whines excessively. Decelerating from 4000rpm, the transmission groans and the wheel frees up a little. However, even driving with a steady throttle, this wheel can just seize up without warning. My guess is a sticking caliper or something. sorry to be a bit vague yesterday, but it really scared the s*** out of me!

johnfelstead

you could have a very badly damaged wheel bearing that has collapsed and allowing the disk to run against the brake caliper. I suggest you take this to a garage asap and get it inspected, if you continue to drive with a collaped wheel bearing you can lose the whole wheel assembly, if that happened and the wheel hit someone you could kill them.

It still sounds odd that its affected by engine rpm, i dont see why 4000rpm has any effect, unless thats a point where you are just deciding to back off. If it isnt the wheel bearing, i would suspect you have a broken front or centre diff.

Wheel bearing is the most likely, have a close look at the disk/brake caliper and compare the gaps to the other side. If you drive in a tight circle at low speed you can usually hear the bearing clicking or screeching when they are colapsed, so drive round both left and right in first gear in a circle and see what happens.

rb5tfh

thanks. its been off the road apart from a short spin the other night to see if i could pinpoint the problem. booked into garage for saturday. i have backed off at 4000rpm, as it becomes a bit scary, and i had already ascertained it was just one wheel affected. the affected wheel is 'dragging' or 'shuddering' so much by then, i am reluctant to go any further. will try your suggestions. have a good christmas!