Bad problem with (possibly) drivetrain

[dsm4bk]

I am getting a really loud metal on metal grinding noise from the drivetrain when I steer the car (but then rarely it can happen when I'm just driving straight too) My car always felt like something was wrong/different with the steering then my other 2 2G AWD's that I had. But all the mechanics I took the car to said it felt fine. Well it wasn't and it has gotten worse. It is not exactly the easiest thing to explain either, because it happens at all different times, and it isn't something you can really feel very well (when I go around turns I can feel that something is wrong with the way the car handles because of this problem, but cannot explain it, it might be that some of the wheels get locked up, while others are free, from front to back, or viceversa)Sometimes it feels like the car is going to lose control completely after a turn, but very rarely. 8 times out of ten, if I go full throttle into a left turn it will retard timing and make the clanking noise. I was also (at the same time) getting pulled timing (datalogger shows - 5, -6) which over time seems to be directly related to when this metal on metal clanking/grinding noise happens, so the vibration is so bad it is causing the knock sensor to pick it up. I replaced the knock sensor, did a leak down test and they are both fine. So basically I NEED someone who know these cars REALLY WELL to figure out what it could possibly be. I have spent TOO MUCH MONEY on other sh*t trying to fix this one problem, and it is becoming annoying as f*uck. (anyone knows how it feels to have timing pulled when you gun it)

Since this has been so ongoing, I will give a brief history of what has been tried.

-car was put on the hoist (after getting the car really hot) and put into gear while on the hoist and luckily enough we got it to make the noise while on the hoist (the noise was through the whole drivehsaft, and sounded like the center bearing of the driveshaft) so I swapped a used driveshaft, made no difference.

-next step was that since it was going through the shaft, maybe the transfercase was bad and distributing the noise/vibration through the shaft, swapped a different (older) transfercase, no difference, still there.

-could be related, but probably not. But the car pulls to either direction when it is cold and hot. The steering doesn't return to center, and the rack seems to have play in it. I replaced a few of the control arms, and got a polyurethane kit installed on most of the bushings. The car cannot be aligned no matter where I bring it. They set everything up, but it still pulls to either direction afterwards.

So now I need to know what could possibly distribute the vibration all the way to the driveshaft if it isn't the transfercase. Anybody had ANYTHING at all like this???????? or suggestions???????? Can a REALLY BAD rack and pinion cause the problems that have been happening with my car??

And the car had crankwalk on the previous engine and I felt all the symptoms, but the symptoms don't happen with the clutch pedal sinking to the floor aorund turns when these problems happen (in case you were going to say)

Thanks in advance!!

 

[92awddsm]

Could possibly be a broken center diff. Drain the fluid from the tranny and see if it has metal in it. Also, pull the side cover from the tranny and see if there are chunks of metal. If it is clean, then it could be transfer case, axle mount bearing on driver rear of block, wheel bearings, ball joints, or axles. Inspect and change rear diff oil while you are at it also.

 

[dsm4bk]

yeah good idea, I'm going to have the tranny fluid drained. But the first and third gear sometimes have trouble going into gear (but other times they feel fine) and just a few months ago the shop that installed my clucth opened up the tranny when I had really ####ed problems getting into gear and the 4 puck clutch disk seperated and lodged the realease bearing into the bell housing and took the metal sleeve off. So I had to swap off the bell housing. At that time the inside of the tranny appeared okay.

Another thing that happened a few months ago was a bad passnenger side front wheel bearing, but the drivehsaft was seized in the hub, so this guy was using a sledgehammer to free the driveshaft from the hub (while on the car) not sure if it was still in the tranny, but he couldn't have been that stupid. So he had to cut the drivehsaft and I had to get a whole new hub, and the rest of the wheel bearings are fine.

What is that axle mount bearing you are talking about. The noise I hear MIGHT be a bearing. Is it something that could make the noise when I steer pretty wide to the left and right?

 

[92awddsm]

yeah good idea, I'm going to have the tranny fluid drained. But the first and third gear sometimes have trouble going into gear (but other times they feel fine) and just a few months ago the shop that installed my clucth opened up the tranny when I had really ####ed problems getting into gear and the 4 puck clutch disk seperated and lodged the realease bearing into the bell housing and took the metal sleeve off. So I had to swap off the bell housing. At that time the inside of the tranny appeared okay.

Another thing that happened a few months ago was a bad passnenger side front wheel bearing, but the drivehsaft was seized in the hub, so this guy was using a sledgehammer to free the driveshaft from the hub (while on the car) not sure if it was still in the tranny, but he couldn't have been that stupid. So he had to cut the drivehsaft and I had to get a whole new hub, and the rest of the wheel bearings are fine.

What is that axle mount bearing you are talking about. The noise I hear MIGHT be a bearing. Is it something that could make the noise when I steer pretty wide to the left and right?

The driver side axle is 2 piece with a support bearing bolted to the back of the block. It is located right under the ac compressor. Check it and make sure the bolts are tight and no play in the bearing.

 

[dsm4bk]

I tried a lot of things, and finally a mechanic put a device that has aligator clips that clip on to the knock sensor, and he also put one on the rear heat sheild that goes over the exhaust (I put a 3" exhaust recently that was making contact with the heat sheild) and the wire runs all the way inside the car to a box where he can switch between the two clips and earphones. So we found out that the grinding noise that I thought I heard was the heat sheild and exhaust hitting eachother.

And it took a long time to get the car to retard timing (he thinks something to do with the different weight distribution with him in the car MIGHT be why it doesn't happen as often) but he listened at the knock sensor location and heard it pinging when it was retarding timing. So he said he thinks the ECU is making the car run lean when this happens and it causes pinging.

He cannot (and no one else can) figure what it can be. In my first post I showed all the things that I tried, and there is definately something wrong with the way the cars steering feels, but how can that have anything to do with the ECU retarding timing. Only thing he said might possibly be happening is something is wrong with a part of the wiring harness, and a bumpy road and/or turning around corners shifts the bad part of wiring and it gives the ECU wrong information. He said to diagnose that could take like a whole day, and I've already been spending mad doe doing other things.

On my logger, when the car pulls good, the timing usually is around 9 to 11 degrees advanced. When I go around a corner or a slightly bumpy road and go full throttle and it retards timing, the timing is at minus 5 or minus 6 degrees, but sometimes just at 5 degrees advanced (and feels very weak) The worst part is that there is no check engine light, and I did a boost leak test and it holds pressure very well.

PLEASE PLEASE PLEASE, if anybody can give me some suggestions of what I should do.

 

[1fast97gsx]

just see what steering component is loose or broken. A loose part can be enough to trigger the knock sensor when it senses the vibration of the part moving around and that's why timing gets pulled. Your best bet is to put the car on a lift and wiggle everything and check all bolts.

The first part to check out would be the 2 piece drivers side axle .... maybe the bracket is just loose as another member suggested.

 

[dsm4bk]

yeah I told both mechanics all the things that was recommended by you guys, and they checked the car on the hoist. Only thing about the rack and pinion is one mechanic said it has a little bit of play, but nothing that can cause vibrations or anything (so he thinks). They said everything seems fine on the hoist.

 

[4pistons]

Your drivetrain grinding is not being caused by your ECU or anything else electrical. But conversely the knock sensor may be picking up the grinding noises as knock and retarding your timing. The ECU pulls timing to prevent knock so I doubt your mechanic hears knock when the timing is retarded unless you are using really crappy gas.

Your problem was initially a drivetrain issue, let's try to stay there before we go running under the hood. Read through this entire thread and see if your problem is the same.

http://www.dsmtuners.com/forums/showthread.php?t=174508

Rick - '91 GSX

 

[dsm4bk]

The grinding noise I heard (that was consistent with cornering) was actually the rear heat sheild that goes on top of the exhaust (the 3" exhaust that was put in was sitting too close and the hangers were not stiff enough, so it hit when I cornered) It was always happening at the same time the other problem happened, so I assumed it was why it was retarding timing. My mechanic ripped the heat sheild off, so now the noise is gone.

When I go around corners now, there isn't really any noises now, but still the way the car feels around corners is not good, and always without fail, it retards timing. (also on slightly unlevel roads that are not smooth) There has also been a lot of memory steering (intermittently) sometimes once the car has been driving for a while and is hot, but other times can happen right when it is cold. The mechanic said he thinks it might be the top strut plate bearings.

Lastly, the driveshaft U-joint was binding when you rotated it one way, can this cause enough of a vibration?

4pistons: I read that thread and I don't think it is the same as my problem.