Zigzagging guibo

[Touring2002]

 Hey fellow 2002 owners, 

 

I just finished replacing some driveshaft parts (center bearing and guibo). 

With everything tightened down I removed the metal bracket that compresses the guibo. But then I noticed this: (image) 

 

The guibo is basically zigzagging the whole way around. 

 

According to my limited knowledge, there are 2 possibilities:

 

- For some reason the guibo is being pulled apart by the differential and gearbox. (unlikely) 

- The guibo was compressed using the metal bracket, so the thing is willing to expand, which is only possible there where it isn't attached to a shaft. 

 

Has anyone here experienced something similar? I'm just hoping this isn't dangerous or at least reducing the life expectancy of the guibo. 

 

Thank you in advance! 

[halboyles]

It may be the perspective of the pic but it looks like the driveshaft flange face is not parallel with the transmission output flange face.

Edited February 12, 2019 by halboyles

[M3M3]

looks like it could be poor driveshaft alignment, and yes, that is bad.  guibo life will be very short.

[Simeon]

Try loosening the differential mounting bolts and the centre support bearing nuts.  You can then push and pull the drivetrain back and forth a bit while rotating the driveshaft by hand to see if you can get that wave out of the guibo. Then tighten the diff before pushing forward on the centre support bearing a few mm to preload and then tighten. 

[CoastalCrush]

 

[jgerock]

Since you have only replaced the giubo and CSB, and presume not the transmission and entire driveshaft, I have to question the quality of the parts you purchased.  The alignment is critical, but the quality of the parts is up there as well.  BTDT.   

 

The quality issue has been around for a while.   

[andyleonard]

4 hours ago, Simeon said:

Try loosening the differential mounting bolts and the centre support bearing nuts.  You can then push and pull the drivetrain back and forth a bit while rotating the driveshaft by hand to see if you can get that wave out of the guibo. Then tighten the diff before pushing forward on the centre support bearing a few mm to preload and then tighten. 

 

This. You have 1/4" of freeplay in the slots at the diff which should solve your problem. If I've had everything apart, before I put it back on the ground I loosen it all, motor, trans, CSB, diff...and start and run the car gently in gear to settle everything. Then as above.

[71bmr02]

My comment wouldnt allow flexing, just what the guibo was intended to do.  Hmmmm...

 

 

Edited February 13, 2019 by 71bmr02

[02Les]

1 hour ago, 71bmr02 said:

My comment wouldnt allow flexing, just what the guibo was intended to do.  Hmmmm…

 

 

 

Yep

Edited February 13, 2019 by 02Les

[Son of Marty]

The guibo is meant to absorb torsional loads not lateral (alignment) loads if the output and driveshaft faces are not parallel your guibo life will be short. 

[Jimmy]

8 hours ago, Touring2002 said:

 Hey fellow 2002 owners, 

 

I just finished replacing some driveshaft parts (center bearing and guibo). 

With everything tightened down I removed the metal bracket that compresses the guibo. But then I noticed this: (image) 

 

The guibo is basically zigzagging the whole way around. 

 

According to my limited knowledge, there are 2 possibilities:

 

- For some reason the guibo is being pulled apart by the differential and gearbox. (unlikely) 

- The guibo was compressed using the metal bracket, so the thing is willing to expand, which is only possible there where it isn't attached to a shaft. 

 

Has anyone here experienced something similar? I'm just hoping this isn't dangerous or at least reducing the life expectancy of the guibo. 

 

Thank you in advance! 

 

As others have mentioned, alignment is critical. From the picture above, it appears to me that the output flange of the transmission is meeting the driveshaft flange like this / \ with the giubo caught in the middle. This is causing the rubber to flex toward the transmission at the bottom of the rotation.

Now, it's possible that it's doing the same thing on top at the same time. If it is, that would indicate the diff needs to move forward. I suspect that it's worse at the bottom, which isn't resolved solely by moving the diff forward.

 

The flanges should be parallel both vertically and horizontally. The giubo should not be taking up any changes in alignment or angle. On my car I had to shim the transmission mount up quite a bit to get the vertical alignment right, I also had to shim the driveshaft support bearing down a bit. I also had to adjust the transmission bracket to the right as far it would go. Once I had the flanges aligned with the driveshaft moved forward so that the upper and lower flanges were touching, the difference between the left and right flanges was a gap the thickness of a business card.

 

Things to keep in mind:

 

Loosen the shift platform adjustment before raising the transmission.

 

When you raise the transmission, your fan and alternator get closer to your radiator and shroud. Watch out, especially if you have an aftermarket radiator or your nose has had work or needs work.

 

What kind of shape are your motor mounts in? If you plan on doing them any time soon, understand your driveshaft alignment will change and you'll need to perform this exercise again.

 

Tighten the CSB last. Once you have the transmission and driveshaft alignment worked out, loosen the CSB before you move the diff forward. If the giubo bends the other direction (toward the rear at the bottom) the diff is too far forward.

 

Once the diff is in place and the giubo is neither squished nor stretched, tighten the diff down, then re-align and tighten up CSB. The CSB should be preloaded toward the front of the car slightly before the fasteners are tightened. It can be a bit of a trick to get everything right the first time.

 

I think torquing the giubo with the band in place compresses the rubber and gives the giubo strength, so I don't recommend loosening the bolts. Others may be able to chime in on that subject. It may be ok to loosen one at a time, but that won't really get you visibility as to the unloaded alignment of the giubo.

[Touring2002]

Holy moly, this is all so helpful!! 

 

After reading all these replies this morning, I crawled under the car and spend an hour trying to better identify the issue with the help of all your replies. 

 

I'm pretty sure now that I was wrong about the guibo zigzagging the whole way around, and that the transmission might need to be raised (by a decent amount) like you all said. 

 

What is the best procedure to raise the transmission? 

Replace the transmission mount that sits next to the guibo or just add some washers? 

 

Here are some pictures of how low the CSB has to sit in order for the guibo to be straight (+useless bonus )  

 

 

[jgerock]

Something isn't right with your car.  Inspect the engine mounts for wear and the left side subframe for cracks.

 

It appears the transmission mount was upgraded to the larger diameter e21 unit which is always a good thing.

[Jimmy]

EDIT: Due to the distance from the mount, the CSB has to go down more than the transmission has to go up to achieve the same effect.

 

You may be able to make it happen with a few spacer between the transmission mount and the transmission. The longer stud on the E21 tranny mount should point up so you still have a safe amount of thread with your spacers.

 

That is a lot of misalignment. 

 

Does anyone know if its possible to screw up the motor position in these by "upgrading" the motor mounts to E21 or E30 or something as well? That is, are there mounts with the same bolt patterns but are much thicker that mess up the angle? 

 

The other thing I wonder is if the front subframe or mounts are bad or incorrectly installed somehow causing the motor to sit higher than it should relative to the transmission crossmember.

 

 

Edited February 13, 2019 by Jimmy
Additional thoughts

[02Les]

4 hours ago, Touring2002 said:

 

 

 

I see new hatch struts in your future. The original set on my Touring lasted 25 years, I recently put in the 3rd replacement...…...not made like they used to be!