Hey there folks, I hope you can help me! My '59 Oldsmobile Ninety Eight Holiday Sport Sedan has some really nasty vibrations which start at 40mph. They are at their worst point at 45mph and the faster I drive, the "better" they get, but they are still very present even about 100mph. The vibrations are so bad that the Olds creates a bass sound and some screws in the interior losen themself after a while. Sometimes there is also a sound that sounds like the row of a giant marine engine. Also, sometimes the Olds hops up and down at 15mph like the Olds really wants to show me how happy he is. I've checked a lot of things... I checked the driveshaft and center bearing of the shaft. The U-joints and bearing are solid, the center bearing has very little play. The front suspention is perfectly OK, everything's tight and greased and rock solid, steering has very little play and it handles like a dream. I've replaced the motor mounts and the transmission mounts look good to me. The differential doesn't make any sounds and has barely any play. The rear suspention is alright, the leafs are OK, a bit worn out. All shocks are new. Wheel bearings are also in good shape and have no significant play. There are only 2 things that worry me a bit... the flex plate and torque converter whobble a bit and the holes of the rims for the bolts are worn out. I could imagine that the worn out holes of the rims cause all the trouble, but perhaps someone here has simular problems or knows how to fix that major problem that ruins the entire ride. 3 different shops belanced the wheels and I also bought new tires, but no improvement. I wish I could buy new or good used rims, but I can't find any. I've got 14x6 rims.

Someone around here has a '59 Oldsmobile Super 88 for sale and the exact same issue like me, but he has also no clue. ;-;

Here's a link of a video I made of the whobbling flex plate and torque converter: Down below are 3 picture of the wheels.

I really hope someone can help me here.

Best regards from Germany,
Maximilian

 

Max, also check your motor mounts. If they're broken you will get a vibration.

 

Having owned both a 59 olds and 60 Pontiac in my youth (50 years ago), the problem is in the center drive shaft bearing. The rubber support is very likely bad.

Both olds and Pontiac have simular drive shafts in those years of 59 and 60.

Same problem in most two-piece drive shaft cars and trucks.


Ron

 

Thanks, I'll search for some rubber support for the driveshaft! Please let me know where I can get some, I'd really appreciate it. :-)

I also hope that more people will participate in this thread and bring up other ideas and possible causes!

Max

 

The rubber is bonded to the bearing and it's support. It is located in the frame cross member. I am sure the rubber is in bad shape after all these years. I would think the bearing itself is in need of lubrication and it is a sealed bearing. Parts manual might provide a basic view of the drive line.

 

#1 Do the lug nuts protrude through to the back side of the rim or contact the hub ? Since you have a 55 Olds, you can borrow the wheels and tires from the 55 and run them on the 59 Olds to check for vibration. Measure the lug nut holes in the wheels (1959 and 1955) with a dial calipher.
#2 You don't have either a "flex plate" or "torque convertor". You have a flywheel/starter teeth and a "dual coupling" Torus. You can check tightness of the Torus bolts but it looks fine to me..
#3 As someone suggested, most likely your vibration is due to the center driveshaft bearing, check that first.

 

With sad shape of the wheels, are the tires balanced?

Swap the tires between the two cars.

Or put you and the car in a lift and have someone carefully observe as you speed up the car.

Just a process of elimination.

 

Are tires out of round?

 

In addition to the driveshaft, I would look at the tires. Are they radials or bias ply? Radials can split a steel/polyester belt under the treads. I've had that happen and caused similar symptoms you described, worse at a particular speed.

 

Sorry for the late reply... the tires are balanced and a shop put balancing pearls into the tires that are supposed to eliminate any inbelance. Unfortunetly, it doesn't help. The tires are round, they are new, got them last year. They were laying in a shelf for 6 years, got a discount. I swapted the tires and I also swapted the tires from the '55 Olds to the '59 Olds and didn't help either. I couldn't tell anything by lifting the car and speeding up. The entire car was vibrating again, just like usual. I took a look at the center support bushing for the driveshaft... it's old but looked fine to me. I moved the driveshaft up and down and left and right, so the rubber still seems to be quite soft and the movement is minimal, it takes a lot of force to move it a bit. I decided to replace it anyway and maybe give the driveshaft to a shop that checks everything. Maybe it's not balanced anymore or someone put it back together wrong or it's bent. I also want to check the pinion angles.

Maybe it's the rear bushing in the transmission? Guys told me that can also cause that kind of vibration.

I think they are radial but I will look again. The tires are the same like the once before. The old once were 11 years old when they got replaced with new once, but still no improvement.

Thank you all and best regards.

 

first off,
I CANT BELIEVE YOU TOOKTHIS CAR UP TO 100 mph after describing the problem. You are lucky to be here telling the story.


anyways, I would suspect the driveshaft. I’m not familiar with the design of yours but if the rubber support is fine then it could be like you said, the shaft is either bent or out of balance. Take the drive shaft to a shop to get balanced.
that should solve your problem

 

It wasn't as scary and risky as you think. It was a warm, sunny day with no wind and not much traffic. Ideal conditions for driving fast. My speedometer is completely messed up and it was maxed out but the GPS showed above 160 km/h / 100 mph. Also, it's legal to drive as fast as you like on 70% of the Autobahn and so in theory, I could go as fast as the speed of light without breaking any laws. I was going that fast for testing, only 2-3 minutes and usually I drive with the semi-trucks, they are electronically limited to 90 km/h / 56 mph here. Maximum for me is 65 mph because I want a relaxing and beautiful ride, but these vibrations destroy my joy!

Anyways, that's what I would like to do next autumn when the season is over and I need to find someone who has the knowledge and time for it. Usually, the experts for stuff like that here have more than enough to do and they're becoming extinct.

 

Weather or not it’s legal to drive that fast isn’t the point. You mentioned that along with the vibration, it will hope at lower speeds. If your drive shaft fails at 100 mph you could potentially catapult yourself into oblivion.

do you not have driveline shops out there? Shops that can make a driveline will have a balancing machine

 

It only hops around 15 mph. When I drive slower or faster, it doesn't hop at all. Nah, the driveshaft is solid.

There are a couple shops for driveshafts in Berlin but getting an appointment can take sometime. There were more shops in the past but the demand is higher than never before, so they have plenty of work to do.