PDA

View Full Version : Vibration & oil leak related?



merc123
09-04-2011, 10:52 PM
New race year with a new motor. I couldn't get the handling and smacked the wall. I had to replace the right axle tube, RF spindle, caliper, rotor, hub, LR hub and caliper. I let my buddy drive it to sort the handling out and he noticed a bad vibration that shook the whole car, it wasn't there before I hit the wall. He said it felt to be on the RF. We double checked everything driveline related and the hubs. We've raced it about 5 more times since and I tried to duplicate it. It seems to be more RPM related than speed or gear related. It has a Saginaw in it. I was in 2nd gear and got up some speed and felt it start vibrating to I shifted to high. When I shifted to high the vibration went away. I slowed down a little and when I picked up a little on the gas I could feel it but. It doesn't do it at all while racing that I can feel.

I did notice today that their is oil coming from behind the balancer snout where it goes into the cover. I'm wondering if possibly the balancer is wobbling causing the harmonics in the motor to be off and wearing out the seal? It's a rubber balancer, not liquid. Does this sound resonable and how can I check it?

rubbinsracin
09-05-2011, 03:40 PM
if you just put the car in neutral and rev it do you feel the vibration? that will tell you if it is in the motor or not. another thing is if you hit the wall hard enough that you had to change an axle tube you might have screwed up the rear bearing in the transmission by putting to big of an angle in the yolk. we did this with our falcon transmission early in the year when we smucked the wall. it had the same symptoms you are describing. if neither of those are the problem, i would then put it up on jackstands and put it in gear and rev it so you can see if the vibration is coming from somewhere else after that. just make sure its really secure when you start putting it in gear.

merc123
09-05-2011, 08:04 PM
Never thought about that as far as revving it up in neutral. No vibration. I may have to get it up in the air and try it in gear. When they were towing me into the pits the j-bar was broke so the rear end shifted far enough over to run the driveshaft into the rear corner of the c*ockpit. So maybe it's possible it's the drive shaft yoke. It did bend my top bar link when it did all that too.

BigBlueFord
09-06-2011, 06:34 AM
You might also want to check and make sure you didn't bend the driveshaft.

rubbinsracin
09-06-2011, 09:13 AM
i bet you destroyed the bearing in the tail shaft of your transmission when the rear end put such a big angle in the drive shaft when you hit the wall and broke the j-bar. we had the same symptom that your car had. when driving at slow speeds there was a horrible clunking/vibration. but once we got up to speed and the drive shaft got into a tight spin it went away. when we put it up on stands it was VERY VERY obvious. but i would suggest you just the car up, slide under and shake the drive shaft up close to the yolk and you will know if the rear tail shaft bearing is there. we had to pull the tranny, take the tail housing off and dump out all the bit of the bearing that were in there and pound a new one in.

merc123
09-08-2011, 03:00 PM
We're thinking the j-bar broke because I got hit in the LR hard. It was enough to break one of the sections of the bumper off. I "swerved" the car back and forth after that and didn't feel anything but when I went into one of the turns I the car felt funny. Same turn on the next go around the whole nose picked up and drove me into the wall. It broke the j-bar bung that gets screwed into it and the heim attaches to on the chassis side.

rubbinsracin
09-12-2011, 11:32 AM
ever figure out what was causing the vibration??

merc123
09-17-2011, 10:12 AM
Not yet, still looking.