S60 vibration at speed?
Thread Starter
Joined: Nov 2010
Posts: 808
Likes: 62
From: Toronto Ontario Canada
S60 vibration at speed? Recently I replaced my 10 bolt with a new S60 complete fully opted for the chromoly yoke,caps, driveshaft and lpw cover. Ive done the slow process to break in the diff and now have roughly 400 miles on it. Gradually taking it up to higher speeds on the highway Im getting a driveline vibration that I didn't have on the stock 10 bolt with upgraded driveshaft a month ago. The vibration feels like its just off center of the car towards the rear seat area. Around 75mph while cruising at a steady speed I can start to feel the vibration. The faster I go the more evident it becomes where it feels like an unbalanced driveshaft or as if I popped a tire off when Im hit nearly 120. I also noticed that if I were to drop gears and accelerate midly enough and hit higher speeds..the vibration isn't as strong until I let off but still very uneasy feeling of something is going to break free from the car.
Ive put the car up and checked every nut/bolt and retorqued them. Cant find anything that would suggest something was either loose or miss-aligned. Sort of having my tires checked again for balance, Im stuck trying to figure out whats the cause and don't want to find out the hard way at the track trying to run times and something severely goes wrong.
Any suggestions of things to test or look out for would be greatly appreciated.
Ive put the car up and checked every nut/bolt and retorqued them. Cant find anything that would suggest something was either loose or miss-aligned. Sort of having my tires checked again for balance, Im stuck trying to figure out whats the cause and don't want to find out the hard way at the track trying to run times and something severely goes wrong.
Any suggestions of things to test or look out for would be greatly appreciated.
Thread Starter
Joined: Nov 2010
Posts: 808
Likes: 62
From: Toronto Ontario Canada
To the best of my ability I put everything to factory spec. But I haven't measured an exact pinion angle. I can arrange to get an alignment but not sure if that would correct the pinion angle
An alignment wont typically cover setting pinion angle unless you specifically ask for it. And even then most of the help that do the toe & go alignments wont know how or just make it worse. If you can do minor work on your car you can set it. BMR or UMI have a good video on how to check and set it in the sticky's I think.
On The Tree
Joined: Apr 2017
Posts: 105
Likes: 0
From: Florida
Could be, and it could also be the driveshaft and yoke being out of phase, if so you can correct it, or improve the problem by adjusting the driveshaft to yoke orientation. This happens a lot when people dont mark the orientation of the drive shaft and put it in a different way when reinstalling it. Ask me how ik, same vibration at 70-80 and I didn't want to push my luck past that.
I have an S60 in my car and while the rear is designed to fit under the Camaro/Firebird, you cannot get the transmission u-joint working angle under 3*. Mine is at 4.6* and there simply is not enough adjustment in the torque arm nor enough shimming to get it such that the u-joint at the transmission will not wobble. There is a lengthy thread in which another forum member had the same setup and had the same ridiculous working angle and had to have a custom driveshaft made with a cv joint at the transmission. I am starting the process to do the same. Sure, the Strange S60 rear end bolts up, but the location of the pinion puts the working angle of the transmission u-joint out of range and gifts you intolerable driveline vibration. You can spend a whole lot of time trying to chase down all of the things that will be suggested by people that do not have the same equipment, or you can take a few minutes and simply confirm what I already know. You have a working angle on the transmission u-joint that is causing the problem and the solution is not readily at hand with a simple adjustment.
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Thread Starter
Joined: Nov 2010
Posts: 808
Likes: 62
From: Toronto Ontario Canada
These are both very sound advice. I didn't think about the yoke being out of phase as a very easy mistake to make. But I had no idea about the thread of someone needing a cv joint to correct the working angle of the driveshaft.But I don't have a u-joint at the trans,its slip yoke.The only u joint is at the diff. Not sure how much of that would apply to my car being a 3rdgen,though Im sure a 4thgen is the same.
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11 Second Club
Joined: Jan 2003
Posts: 1,000
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Spooled S60 here and no vibration whatsoever at any speed all the way up to 135mph. But I have a long tail th400 so my driveshaft is only 37" long (3" chrome moly) so maybe that has something to do with it.
These are both very sound advice. I didn't think about the yoke being out of phase as a very easy mistake to make. But I had no idea about the thread of someone needing a cv joint to correct the working angle of the driveshaft.But I don't have a u-joint at the trans,its slip yoke.The only u joint is at the diff. Not sure how much of that would apply to my car being a 3rdgen,though Im sure a 4thgen is the same.
TECH Enthusiast
Joined: Jul 2018
Posts: 635
Likes: 329
From: Missouri
Damn this thread, my next big purchase was/might still be, S-60 S-trac and 3:73s now I'm second guessing my future expenditures........ Looking forward just to see negative/positive post on this.
11 Second Club
Joined: Jan 2003
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Dude don't listen to the guy above. His transmission yoke is probably too loose on the splines and/or not deep enough into the transmission or his driveshaft is out of balance. The angles he's talking about won't induce vibration. I know because i've had mine at different angles and get no vibe whatsoever. I have a sonnax chrome moly billet transmission yoke and PST chrome moly driveshaft from bob at brute speed.
11 Second Club
Joined: Jan 2003
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And it gets driven hard.. a vid of my cam only ls1 car in sig. 2nd gear pull while it had faulty coil packs and wouldn't rpm over 6800. It's much quicker now 
https://www.bitchute.com/video/TCrxy3AUVzdn/
https://www.bitchute.com/video/TCrxy3AUVzdn/
My s60 short tail th350 combo actually has the factory lt1/4l60 steel drive shaft in for the moment. Just with a conversion joint for the rear end and has no vibrations up to the 115mph+ I've been at the track. Also cruise at 60 on the street and upwards of 80 on the highway and Its nice and smooth.
Dude don't listen to the guy above. His transmission yoke is probably too loose on the splines and/or not deep enough into the transmission or his driveshaft is out of balance. The angles he's talking about won't induce vibration. I know because i've had mine at different angles and get no vibe whatsoever. I have a sonnax chrome moly billet transmission yoke and PST chrome moly driveshaft from bob at brute speed.
2nd, the notion that the working angle of the u-joint has no impact on drive train vibration is misinformed and incomprehensible.
3rd, I have a Sonnax yoke and my driveshaft was properly manufactured to the appropriate length for my T56 Magnum.
4th, I can thrash my car down the 1/4 mile and there is no driveline issue to speak of. It is driving at speed around town that the vibration comes and goes. You can actually see the u-joint behind the yoke wobbling in 6th gear.
Is my driveshaft out of phase? NO. Is it bent? NO. Is it balanced? YES. Is it possible for the harmonics of the u-joint with an operating angle of over 4* in the front to balance or cancel the harmonics of the rear u-joint with a 1* operating angle? NOPE. Is there room to shim the transmission enough to make it right? NO. Does the adjustable torque arm have enough adjustment to make it right? NO.
I my car unique? NO. If I knew then what I know now, would I still buy an S60? NO. Have other forum members had issues with nearly every other aftermarket rear end? Yep.
Will a S60 alter the driveshaft angle and u-joint working angles in any f-body in which it is installed? Without a doubt.
Should the people you are advising take that advice? That's their call.
My only advice was to check the working angle of the u-joints. Should the OP take that advice? That's his call. It's neither here nor there to me.
11 Second Club
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Two replies from two auto owners.. no vibration. And lots of others never had an issue. Like I said, I've changed my driveshaft and pinion angle several times to see if it makes any difference to traction and ive never had any vibration at any speed. And trust me I know what a driveline vibration feels like because I've had it in other cars and it's annoying as hell. But my Camaro is smoooth.
I'd be looking at your M6 gearbox as the culprit.
I'd be looking at your M6 gearbox as the culprit.
I have a T56 car and the S60 is every bit as smooth as the 10 bolt was. It did vibrate right after install, but I didn't have the pinion angle set correct. Once I correctly set the pinion angle, there was no vibration at any speed.
Thread Starter
Joined: Nov 2010
Posts: 808
Likes: 62
From: Toronto Ontario Canada
Jeff99 do you have the stock torque arm or an adjustable one? Im using the stock torque arm. Im using stock length tubular lower control arms, which my only adjustment is switching holes on the lca brackets to correct angles and I have an adjustable panhard bar to center the rear. Im thinking either the driveshaft is out of balance or maybe the ujoint isn't happy when I bolted it up. I don't want to bring the car upto those speeds and wreak havoc on the pinion etc.
I had no troubles cruising 120mph+ and roll racing with the stock 10bolt prior to install. Im sure id be on a tow truck home if I try that now.
I had no troubles cruising 120mph+ and roll racing with the stock 10bolt prior to install. Im sure id be on a tow truck home if I try that now.
Thread Starter
Joined: Nov 2010
Posts: 808
Likes: 62
From: Toronto Ontario Canada
Two replies from two auto owners.. no vibration. And lots of others never had an issue. Like I said, I've changed my driveshaft and pinion angle several times to see if it makes any difference to traction and ive never had any vibration at any speed. And trust me I know what a driveline vibration feels like because I've had it in other cars and it's annoying as hell. But my Camaro is smoooth.
I'd be looking at your M6 gearbox as the culprit.
I'd be looking at your M6 gearbox as the culprit.
Why would my t56 now be a problem after install when it wasn't an issue a week before swapping the diff? Its not like the trans was removed or loosend up to be out of line during the swap. From what Ive been told from numerous people and vendors that pinion angle does not change traction but does affect driveline harmonics and when its not correct,I would get the vibration im experiencing now which feels like its coming more towards the rear seat area.