Driveline vibration

[parshal]

I put a steel PST driveshaft in today, my 70-75mph passenger seat shaking vibration is still there.

I get this in most all my cars (one truck, two cars) on certain roads. It annoys me to no end.

 

[KJGT]

I mean lots of slop...

I'd say 3/16-1/4" movement at the end of the flange on mine, I didnt measure it. It had more play than I was expwcting..

I get this in most all my cars (one truck, two cars) on certain roads. It annoys me to no end.

Yea, recently my old dmax pickup had it at 45mph (something to do with the frame beaming at that speed) and you would think the pass seat was going to snap off, my old G8 had the steering wheel shimmy that was never fixed right, the 2010 GT500 I had vibrated pretty bad at 80mph, my 2010 RAM pickup has some kind of driveline shudder at 65mph. All of them are common complaints if you read the forums.

I may be a little too picky about it though, I ask my wife if she can feel it and she looks at me like I'm nuts most of the time lol. But yea, some roads bring it out more than others.

 

[Trav4011]

I put a steel PST driveshaft in today, my 70-75mph passenger seat shaking vibration is still there. But I did make a few 70-130mph pulls and no vibration I could feel, I dont plan on going faster than that often so I'm happy with 130.

FWIW the steel PST was 21.7 lbs, the stock DS was 36.9 on my scale. 15lbs is 15lbs It looks like something else other than the driveshaft is causing my 75mph vibration though..

Nice.. I think the tires are the culprit for the seat shake. I used to get that too, and now that the tires have some wear on them, it has gone away.

 

[KJGT]

Nice.. I think the tires are the culprit for the seat shake. I used to get that too, and now that the tires have some wear on them, it has gone away.

I have had 3 sets of completely different wheels and tires on this car, the stock 18s, 18" DRs on the rear with different OE wheels and the GT500 wheels that are on it and they all shake the seat right at 72-73mph.

It sure feels like tires, I have had these GT500 wheels/tires road force balanced twice, second time I did them myself, and it still does it. When I put the aftermarket PHB on the car it made it worse so I'm guessing its coming from the rear. May be a brake rotor or axle thats out, its not terrible, but the speed limit is 65 around here and naturally right at the usual 72-73mph flow of traffic speed is where it does it worse.

I'm just happy the driveshaft didnt make it worse

 

[parshal]

I have had 3 sets of completely different wheels and tires on this car, the stock 18s, 18" DRs on the rear with different OE wheels and the GT500 wheels that are on it and they all shake the seat right at 72-73mph.

I would not have believed this if I didn't experience it myself. When I lowered the GT500 and replaced the panhard bar with the watts link I had a vibration around 70 mph. About 400 miles later I had it aligned and the vibration is completely gone. The only thing that was out on the alignment was left wheel camber. Total toe was reduced from -.19 to .13.

 

[KJGT]

I would not have believed this if I didn't experience it myself. When I lowered the GT500 and replaced the panhard bar with the watts link I had a vibration around 70 mph. About 400 miles later I had it aligned and the vibration is completely gone. The only thing that was out on the alignment was left wheel camber. Total toe was reduced from -.19 to .13.

Anything is possible, never checked the alignment. Like I said its not that bad, when someone is sitting in the seat they dont even feel it. It just looks bad when you look over at it, not the first car or truck I ever had that did it for sure.

If thats the worse problem the car has while I own it I'll be happy

 

[parshal]

Like I said its not that bad, when someone is sitting in the seat they dont even feel it. It just looks bad when you look over at it, not the first car or truck I ever had that did it for sure.

That's EXACTLY what mine was doing.

 

[KJGT]

That's EXACTLY what mine was doing.

The seat shaking is pretty common with any vibration, its a big heavy unsupported part sticking straight up.

I'll look at the alignment next tome I have my alignment tools out but I hate to mess with it since the car drives perfect as it is, like I said I live with it. 90% of my driving is between 40-65 anyhow. My luck I'll fix it at 73mph and then it will start at 55mph lol.

 

[GeorgeInNePa]

I have had 3 sets of completely different wheels and tires on this car, the stock 18s, 18" DRs on the rear with different OE wheels and the GT500 wheels that are on it and they all shake the seat right at 72-73mph.

It sure feels like tires, I have had these GT500 wheels/tires road force balanced twice, second time I did them myself, and it still does it. When I put the aftermarket PHB on the car it made it worse so I'm guessing its coming from the rear. May be a brake rotor or axle thats out, its not terrible, but the speed limit is 65 around here and naturally right at the usual 72-73mph flow of traffic speed is where it does it worse.

I'm just happy the driveshaft didnt make it worse

I have the passenger seat shake with the OEM wheels and tires and I have it with my 16" wheels and drag radials.

It's not the tires and wheels.