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Discussion Starter · #1 ·
I have an 04 with a drive line vibration that gets worse above 70. First, the car has a one piece DS, and it had the typical one piece complaint, vibration at above 125. So, I was Ok with that.

But, in the last year or so the vib is getting worse. I recently changed the differential because the spider gears were shot. No more noise and hop while turning, and I was hoping it would stop vib too. No such luck.

So yesterday I checked all the bolts in the drive line. Found all tight, but also found the transmission mount was broken. I thought great this is it. Well, it was part of it. So back on the stands after the test drive, and what did I notice a slight amount of AT fluid on the tunnel.

I noticed the fluid before, but stopped and fixed the mount first. I pushed up on the DS and noticed play, but figured it was due to the broken mount. After changing the mount, there was less play but still some and a little oil residue on the tunnel. The vib is less but still there.

I pulled the DS and the yoke is yellowed a little from what appears as tailshaft bushing material (brass). The leak is not a drip and no spots are on the floor. When I push up on the yoke, there is some play.

So, how much play is allowed? Second should there be any yellowing, sometimes this is common on yokes. This is a one piece with no guidos and with 1350 spicer u joints at the front and rear. I was thinking of having the shaft checked for balance, but this shaft never had a problem before

So. what sort of play is acceptable for the DS yoke. BTW, the shaft has been in the car for over 10 yrs and the current vibs started in the last few months. It had the usual one piece vibs at over a buck and a quarter, but at 70-80 this is getting out of hand. Any help provided is appreciated.
 

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Well the driveline angles tend to be the major cause. Old engine and trans bushings, old diff and subframe bushings. Over time that effects things like how the yoke is gonna ride on the output shaft. Should have wear marks on it, cant compare without a pic. All of mine have play, even on new parts as they wouldnt fit other wise. Again, cant measure the play over the internet so cant compare.
 

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Discussion Starter · #3 ·
I
Well the driveline angles tend to be the major cause. Old engine and trans bushings, old diff and subframe bushings. Over time that effects things like how the yoke is gonna ride on the output shaft. Should have wear marks on it, cant compare without a pic. All of mine have play, even on new parts as they wouldnt fit other wise. Again, cant measure the play over the internet so cant compare.
I got stopped by rain today and had to call it quits. Your points are taken. I have new, 1 yr old, motor mounts and now a new trans mount. I have a Harrop cover and Energy Suspension poly sub frame bushing, although they are over 10 yrs old.

I started to try an old SBC Muncie trans trick today until it started raining. You take a couple of large hose clamps and crisscross then over the tailshaft and tighten around the crossmember. This holds the tranny tightly down. Then, drive the car. The trick is if the vibs stop or are reduced the problem is in the tailshaft. If it gets worse its also in the tailshaft. If it stays the same, its somewhere else.

We'll see tomorrow. I'll also try to get some pics of the yoke when its out. Also its vibrating in neutral at seventy. It vibrates when I push the clutch in. I also shut the motor of at 70 and it vibrated in neutral and with the clutch in and motor off.

I'll see what the test shows tomorrow, and I'll listen with a stethescope.
 

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I

I got stopped by rain today and had to call it quits. Your points are taken. I have new, 1 yr old, motor mounts and now a new trans mount. I have a Harrop cover and Energy Suspension poly sub frame bushing, although they are over 10 yrs old.

I started to try an old SBC Muncie trans trick today until it started raining. You take a couple of large hose clamps and crisscross then over the tailshaft and tighten around the crossmember. This holds the tranny tightly down. Then, drive the car. The trick is if the vibs stop or are reduced the problem is in the tailshaft. If it gets worse its also in the tailshaft. If it stays the same, its somewhere else.

We'll see tomorrow. I'll also try to get some pics of the yoke when its out. Also its vibrating in neutral at seventy. It vibrates when I push the clutch in. I also shut the motor of at 70 and it vibrated in neutral and with the clutch in and motor off.

I'll see what the test shows tomorrow, and I'll listen with a stethescope.
I ended up spacing my crossmember down about 3/16-1/4". Got it with one degree of the diff flange and dont have any vibration anymore with my current 1pc but it was custom made locally. Good up to 150 so far. My dss 1pc shook at 80, checked the angles and shook at 120 which was still a concern if its under 1/4 mile trap speed.
 

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Discussion Starter · #5 ·
So. did you use washers?? I too had a DSS one piece and returned it to get my money back. It also shook at 80. My DS was made by Inland Empire 10 yrs ago. It was good until the last year or so. But it shook at 125. I'll try spacers too. I liked the DS, it is really stiff and delivered the HP to the pavement. But now this. Also what bothers me, is that the tunnel has a slight bit of AT on it, which it never had before. Hmmm, could be the seal but with the vib too, it makes me wonder. I'll let you know.
 

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Have pretty much the same issue as you OP. I did what naughty did and even a rebalance to no avail. I really don’t think I’m checking driveline angles right and haven’t messed with it since I have it parked now. Since I have a silly knack of having to upgrade everything I think I’m going to get the aftermarket two piece to have the best of both, no vibes and direct guibo-less feel.
 

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Discussion Starter · #10 ·
Have pretty much the same issue as you OP. I did what naughty did and even a rebalance to no avail. I really don’t think I’m checking driveline angles right and haven’t messed with it since I have it parked now. Since I have a silly knack of having to upgrade everything I think I’m going to get the aftermarket two piece to have the best of both, no vibes and direct guibo-less feel.
Thats sad. My problem is that the DS used to be good until 125, but now shakes at 70. I do not know what caused it?
 

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Did you lose the balancing weight? Maybe it came off making the driveshaft unbalanced and you feeling it a lot sooner than before.

Also, spin the driveshaft in the tail shaft 90 degrees to see if that helps. May have to do it a couple of times. I have fixed a vibration by doing that in another car.
 

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I'm here too and I'm thinking of going back to an aftermarket 2 piece again to stop the vibration. GTOG8 has one. I thought that the 1 piece was the way to go but all I read from folks with a 1piece especially the DSS is driveline vibration. So since the car is up on stilts that will probably be the last thing before getting her back on the road.

There is one idea I'm playing with and that's the aluminum couplers for the C5 that they use for their driveline instead of the solid rubber ones. But there's also lies the issue. That what the rubber coupler helps with is dampening the driveline vibration that's we experience with a 1piece. I mean changing out a coupler isnt that bad, is just the money and time to prove it will be a fail. I guess once I get there I'll figure it out.
 

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Discussion Starter · #13 · (Edited)
Did you lose the balancing weight? Maybe it came off making the driveshaft unbalanced and you feeling it a lot sooner than before.

Also, spin the driveshaft in the tail shaft 90 degrees to see if that helps. May have to do it a couple of times. I have fixed a vibration by doing that in another car.
Good thought. There are no weights to lose since they are welded on. I did not spin it at 90* but did add some spacers which helped a lot
 

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Discussion Starter · #14 · (Edited)
I'm here too and I'm thinking of going back to an aftermarket 2 piece again to stop the vibration. GTOG8 has one. I thought that the 1 piece was the way to go but all I read from folks with a 1piece especially the DSS is driveline vibration. So since the car is up on stilts that will probably be the last thing before getting her back on the road.

There is one idea I'm playing with and that's the aluminum couplers for the C5 that they use for their driveline instead of the solid rubber ones. But there's also lies the issue. That what the rubber coupler helps with is dampening the driveline vibration that's we experience with a 1piece. I mean changing out a coupler isnt that bad, is just the money and time to prove it will be a fail. I guess once I get there I'll figure it out.
I'd like to see the results of this. You maybe on to something. I was thinking of going to a cardan joint, that is a double u-joint coupler, like used on Lincolns particularly the older town cars. Those cars have long DSs and need the coupler to cut the vibs,
 

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Discussion Starter · #16 ·
Two things happened today. One, I followed Mick Naughty's advise and spaced the trans lower about a 1/4 of an inch. This helped a lot. The high speed vibs were way less. When I say high speed, I mean 100, and didn't have the chance to go faster. Two, vibs are still present from about 45 to 75, but not as bad as before. In otherwords, things are getting better so I'm on the right track.

I posted some pics of the yoke. They show yellow marks and you can see also the shinny rubbing marks. The yellow marks are of course from tailshaft bushing wear, but what's causing the shinny marks. Does anyone have any thoughts about these marks? Blow up the pics and you will see the resolution.
 

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Two things happened today. One, I followed Mick Naughty's advise and spaced the trans lower about a 1/4 of an inch. This helped a lot. The high speed vibs were way less. When I say high speed, I mean 100, and didn't have the chance to go faster. Two, vibs are still present from about 45 to 75, but not as bad as before. In otherwords, things are getting better so I'm on the right track.

I posted some pics of the yoke. They show yellow marks and you can see also the shinny rubbing marks. The yellow marks are of course from tailshaft bushing wear, but what's causing the shinny marks. Does anyone have any thoughts about these marks? Blow up the pics and you will see the resolution.
shiny marks are from wear. against seals, or contact against anything else.

the only thing that should be noticeable normally is the groove/shiny area from the seal. everything else? bruh, somn wrong.
 

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Discussion Starter · #20 ·
shiny marks are from wear. against seals, or contact against anything else.

the only thing that should be noticeable normally is the groove/shiny area from the seal. everything else? bruh, somn wrong.
Thanks. I think the silvery gray marks are from aluminum. The yellow from the bushing. So, I think the yoke wobbled in the tailshaft and scuffed the case. Obviously, the wobbling would cause vibration. I'm going to pull the tailshaft and replace the bushing.

It looks like the vibs are from two areas. Spacing the xmember 1/4" helped, but I am almost certain the tailshaft bushing is shot. There may be more too, although the trans shifts well and there is no bearing noise.
 
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