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Horrible drivetrain vibration

ColdScrip

By ColdScrip,
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Frenchi934
Frenchi934

I believe you are experiencing engine harmonics. My car has a new/replace just about everything and had almost exactly what you are describing, then when I put my new exhaust on it got better, but is

Skullzaflare Newbie

Skullzaflare

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Guys, Killtoadie is right, with stock turbo i used to tractor my car and had ALOT of vibrations under 1500. with the 20g i cant anymore lol, anyway, trying to accel in any gear but first under 1500 resulted in the car feeling like theres no suspension riding on the rims
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The Rabbit1 Newbie

The Rabbit1

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Guys, Killtoadie is right, with stock turbo i used to tractor my car and had ALOT of vibrations under 1500. with the 20g i cant anymore lol, anyway, trying to accel in any gear but first under 1500 resulted in the car feeling like theres no suspension riding on the rims

I don't see why anyone would be putting that much load that low on the powerband. Like he's trying to wear it out.

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Skullzaflare Newbie

Skullzaflare

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It's the clutch if you ask me. I have a TEP street clutch in one of mine and it does what you describe, all except for the over 50 vibration. It chatters like mad due to the spring steel modifications they do to the Daikin PP. If I try to shift into a high gear too soon, it will shake like mad. My ACT and stock clutch cars do not do it. I know it is clutch related because I had a stock set-up before with no issues other than it wouldn't hold. It is partly due to the Fidanza too, but I ran the TEP on a lightened stock fly and it did the same thing.

I think your clutch has a cheaper spring steel combination that is causing the chatter from stop, and shake when going into 5th under 45MPH. You could have an actual clutch disc spring that is broken too. However, that shouldn't cause the vibration at speed.

You could measure one spot in the inspection cover area, as you rotate a little more and measure again to see if the flywheel is running true.

tim, your talking about noise when changing gears right? i have that too, OP is talking about noise while in gear, not changing

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ColdScrip Newbie

ColdScrip

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Quick update. I decided to buckle up after work and slapped 3 hours into it. Tranny and clutch are out. Tranny's drain plug had a decent amount of crud on the magnet. That magnet was spotless as well as the guts of the tranny (I cleaned the inside of it with kerosene during the restore). 4000 miles and what looks to be metal crud on the magnet. I will pull the pan for inspection tomorrow. Clutch is a Daikin made in USA clutch. A few searches brings up Exedy owns Daikin? Maybe. Instead of springs it actually has rubber bushings. Never seen that before, but I haven't seen many clutches to begin with. Tranny had 1 bolt to engine missing. The passenger side one that has the nut on the end.

 

Thats as far as I got so far which isnt bad for 3 hours :) Oh I had a drop of gear oil go directly in my eye o.O

 

I will be going through the suggestions in this thread for the most part. Saturday I will hopefully install another transmission with the same clutch to see the results. If it persists then I will buy a new clutch and slap that in to see the results. I will also be checking plenty of bolts, cleaning again underneath and fixing a coolant leak I found.

Edited by ColdScrip
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ColdScrip Newbie

ColdScrip

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Spent all day with it. Found my old transmission to have a slight rough spot when turning the gears with the cover off. I cleaned another spare tranny and its gears were very smooth. Slapped it in the car and still no change. I then noticed the tranny mount where the metal rod is welded to the top part of the mount, well they welded it crooked. So I slapped a new one on that my dad saved that was welded correctly. Still no change. Vibration issue remains.

 

Interestingly enough though, since I had the interior pieces for the shifter out during my test drive, I noticed that when I force the vibration to happen the tranny barely moves. In fact if I stick my hand on the tranny itself (where the shifter connects) i dont feel the vibration on the tranny at all. However the whole rest of the car shakes. By shakes I mean the car itself, not the steering or anything like that. I really feel the vibration near my butt lol. If the tranny isnt changing when making the vibration, would that imply a rear end issue? Just thought it was weird especially since the tranny is bolted right to the engine.

 

Im thinking clutch, exhaust, rear-end bushing mistake I made, diff + torque tube, or axles.

 

The torquetube is worn enough that when i move the flange left to right i here a rather loud clack noise.

 

Next order of business:

1. Take off half my exhaust so the portion that is hitting the rear subframe is no longer hitting it and test drive to see if the issue is gone.

2. Shelby I apologize I did not get to taking out the axles and making sure the joints are okay and that they are re-seated back properly. This is second on my list.

3. Drop the front part of the rear-subframe to remove the old stock bushing since I installed it with the new poly bushing. This I believe is forcing this part downward possibly changing the angle of the torque tube and driveshaft.

4. Replace clutch with a stock replacement one.

5. Install a better condition torque-tube and differential combo that I have.

6. Try a new set of axles.

 

Thats the 6 possibilities I see.

Edited by ColdScrip
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ColdScrip Newbie

ColdScrip

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sounds like maybe a control arm bushing, diff mount, or something related in the rear end.

 

Diff mounts are new OEM ones and those bolts were checked thoroughly and recently and lock-tited/torqued.

 

Mookeh bushing kit so control arm bushing should be fine. Will re-visit it though.

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The Rabbit1 Newbie

The Rabbit1

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Diff mounts are new OEM ones and those bolts were checked thoroughly and recently and lock-tited/torqued.

 

Mookeh bushing kit so control arm bushing should be fine. Will re-visit it though.

it's definitely something back there. wheel bearing, control arm bushing, pivot bushing, strut not installed tight onto hub, lug nuts, there are a lot of parts back there.

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ColdScrip Newbie

ColdScrip

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it's definitely something back there. wheel bearing, control arm bushing, pivot bushing, strut not installed tight onto hub, lug nuts, there are a lot of parts back there.

 

After work I'll be back at it. Exhaust test first then the rear bushings and bolts. Thats where i'll go over the rear as well as possible. Exhaust needs dropped anyways for me to fix my bushing mistake.

Edited by ColdScrip
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ColdScrip Newbie

ColdScrip

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Sounds like that is the problem right there. Replace those bushings.

 

?

 

What bushings? The torque tube having play left to right is the splines being worn on the torque tube and the pinion shaft coming out of the front of the differential.

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Chad Newbie

Chad

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?

 

What bushings? The torque tube having play left to right is the splines being worn on the torque tube and the pinion shaft coming out of the front of the differential.

 

Do you mean it has play clock wise and counter clockwise, or actually right to left (and up/down)?

 

If that companion flanges moves any direction but rotationaly, you have a bad torque tube bearing (it's been known to happen). If that is the case, you may have found your vibration, you certainly have a part that need replaced ASAP.

 

They are easy to replace and not too expensive either. I've had torque tubes where the splines were badly warn, but that bearing didn't let the shaft move right/left or up/down. They didn't vibrate either, just the usual "clunk" in the back.

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The Rabbit1 Newbie

The Rabbit1

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Do you mean it has play clock wise and counter clockwise, or actually right to left (and up/down)?

 

If that companion flanges moves any direction but rotationaly, you have a bad torque tube bearing (it's been known to happen). If that is the case, you may have found your vibration, you certainly have a part that need replaced ASAP.

 

They are easy to replace and not too expensive either. I've had torque tubes where the splines were badly warn, but that bearing didn't let the shaft move right/left or up/down. They didn't vibrate either, just the usual "clunk" in the back.

x2

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ColdScrip Newbie

ColdScrip

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If there is play like that, its the diff, needs a backlash adjust, it wont cause your vibrations. If the whole assembly moves, that's the bushings.

 

Okay look the torque tube attatches to the diff with splines. Those splines have the play which cause my clacking sound. That means when the clack hits the diff hasn't even turned yet.

 

Also I clarified above its clockwise and counterclockwise thus the whole assembly is not moving, and the bushings are fine. Btw bushings are new OEM TT bushings and I checked them all tonight in fact to make sure all the bolts were tight.

 

Update: Removed my additional bushing. I originally had the poly bushing with the original bushing installed at the top of the rear suspension (above the two big round bushings). I now left the original soft rubber one. I didn't have a chance to put the exhaust back on and test drive it yet. That will be for tomorrow. I also checked tons of bolts in the rear end. Sway bar, strut bolts where they mount to the hub, axle bolts, rear subframe nuts, and checked all my bushings to ensure they are all still intact just fine and their bolts are aligned properly in them.

Edited by ColdScrip
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Shelby Newbie

Shelby

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you said earlier that this only happens under heavy load,, you not going to find the problem by looking and feeling,,some thing is moveing under load,, so use a pry bar and move things or look for wear parks that indicate movement Edited by Shelby
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Starfighterpilot Newbie

Starfighterpilot

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I had similiar vibration scenario once - check your cv joints.

 

For What It's Worth.

 

KEN

 

Once again, have you checked the CV joints? When my Old Broad's drive train was vibrating VERY similar to what you are describing, it turned out to be the drivers side CV joint/axle assy. went bad. Replaced it and the vibs magically went away. :) Then I replaced the passengers side CV/axle assy.

 

The MAX LIMIT of the rear axle Total Backlash is 0.2" as measured at the torque tube forward edge and the drive shaft companion flange with the tranny in neutral and the parking brake on. See '88 FSM Page 3-16.

 

Have you checked the LSD dif for preload? See FSM page 3-17.

 

I know you know what you are doing, but have you checked the new u-joints to ensure that their clips are still all there and they are properly seated in their grooves. It may sound off the wall, but sometimes it's the obvious things that we miss.

 

For What It's Worth.

 

KEN

 

Edit - I'm sure that you know that the Starquest drive shaft assy comes pre-balanced form the factory. Perhaps, just perhaps, one of the PO's swapped in the sleeve or flange yokes off of another drive shaft assembly. And now the drive shaft is out of balance. Just a thought. :wacko:

Edited by Starfighterpilot
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ColdScrip Newbie

ColdScrip

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The preload was .001 or .002 off of spec. I remember going through that. Was the only diff I had at the time though. The backlash is probably much greater so I dont mind swapping the whole thing out. When your CV went bad, how did it go bad? Was it having trouble pivoting?

 

I'll double check the driveshaft clips but remember I did replace the entire driveshaft with another one with no change.

 

The bushing fix made it so my exhaust no longer hugs the subframe but the vibrations are still there. So I yanked the tt, diff, and axles out. Didn't really notice any big issues. I took pics of everything - even some spots like Shelby said where sometime may have been rubbing. I yanked, tugged, pryed, but nothing really shwoed itself.

 

With the axles out, how hard should it be to turn the hubs? They turn but its kinda hard to turn them but they do turn by hand with moderate effort. Parking break was off. The hubs have new wheel bearings. Calipers were rebuilt.

 

Anyways here some pictures. This has been so frustrating. I have been putting so much time and effort into this with no results.

 

My clutch - is it normal to have bushings instead of springs?

http://i719.photobucket.com/albums/ww192/ColdScrip/P5270111.jpg

 

http://i719.photobucket.com/albums/ww192/ColdScrip/P5270112.jpg

 

http://i719.photobucket.com/albums/ww192/ColdScrip/P5270113.jpg

 

http://i719.photobucket.com/albums/ww192/ColdScrip/P5270114.jpg

 

http://i719.photobucket.com/albums/ww192/ColdScrip/P5270115.jpg

 

Metal accumulation on the old tranny's magnet (Remember a diff tranny is in the car now and vibrations did not change):

http://i719.photobucket.com/albums/ww192/ColdScrip/P5270116.jpg

 

http://i719.photobucket.com/albums/ww192/ColdScrip/p5270117.jpg

 

http://i719.photobucket.com/albums/ww192/ColdScrip/p5270118.jpg

 

http://i719.photobucket.com/albums/ww192/ColdScrip/p5270121.jpg

 

http://i719.photobucket.com/albums/ww192/ColdScrip/P5270122.jpg

 

http://i719.photobucket.com/albums/ww192/ColdScrip/p5270123.jpg

 

http://i719.photobucket.com/albums/ww192/ColdScrip/P5270124.jpg

 

http://i719.photobucket.com/albums/ww192/ColdScrip/P5270125.jpg

 

http://i719.photobucket.com/albums/ww192/ColdScrip/P5270126.jpg

 

http://i719.photobucket.com/albums/ww192/ColdScrip/P5270127.jpg

Edited by ColdScrip
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ColdScrip Newbie

ColdScrip

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http://i719.photobucket.com/albums/ww192/ColdScrip/P5300136.jpg

 

http://i719.photobucket.com/albums/ww192/ColdScrip/P5300137.jpg

 

http://i719.photobucket.com/albums/ww192/ColdScrip/P5300139.jpg

 

http://i719.photobucket.com/albums/ww192/ColdScrip/P5300140.jpg

 

http://i719.photobucket.com/albums/ww192/ColdScrip/P5300141.jpg

 

http://i719.photobucket.com/albums/ww192/ColdScrip/P5300142.jpg

 

http://i719.photobucket.com/albums/ww192/ColdScrip/P5300143.jpg

 

http://i719.photobucket.com/albums/ww192/ColdScrip/P5300144.jpg

 

http://i719.photobucket.com/albums/ww192/ColdScrip/P5300146.jpg

 

http://i719.photobucket.com/albums/ww192/ColdScrip/P5300147.jpg

 

http://i719.photobucket.com/albums/ww192/ColdScrip/P5300148.jpg

 

http://i719.photobucket.com/albums/ww192/ColdScrip/P5300149.jpg

 

http://i719.photobucket.com/albums/ww192/ColdScrip/P5300150.jpg

 

POSSIBLE ISSUE: How far should a cv joint move in and out? My re-booted ones move in and out a lot more then the other axle but I think its jsut because my boot is very flexible and the older axle's boot is very stiff. These two pictures show how much I can move it in and out.

 

http://i719.photobucket.com/albums/ww192/ColdScrip/P5300152.jpg

 

http://i719.photobucket.com/albums/ww192/ColdScrip/P5300153.jpg

 

http://i719.photobucket.com/albums/ww192/ColdScrip/P5300154.jpg

Edited by ColdScrip
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