DIY Giubo replacement
 

A step by step DIY guide for giubo (propeller drive shaft flex disk) replacement for those that asked and are interested.

Step 1

Tools

Torque wrench
1x 18mm spanner
1x 12mm socket
1x 10mm socket
1x 8mm socket
2x wrenches
High Temp Grease
Loctite if re-using same bolts
6x 18mm lock nuts (optional)
2x Jack stands (rear)
2x ramps or another 2x jack stands (front)
1750kg trolley jack

Step 2

Place the vehicle on a solid level surface, use ramps or jack up the front of the car and use jack stands placed in the appropriate place on either side of the vehicle (when using jack stands make sure they are securely placed when lowering the vehicle)

Once the front of the vehicle is secured, use the trolley jack and lift the vehicle using the diff as your support. Jack the vehicle high enough to place jack stands in the appropriate spots on either side of the vehicle, gently lower the vehicle until it had bedded down onto the jacks, keep the trolley jack raised and in place underneath the diff.

Before getting under the car, give the car a shake and check for stability :thumbup:

Step 3

At the CAT ends, use some CRC or WD40 to lubricate the exhaust nuts and bolts, let it soak for a few minutes, then gently undo the nuts using the 12mm socket and wrench. Do Not Force the nuts as they may break off, instead use more lubricant spray and let it soak for longer, then repeat the undoing process.

After removing the nuts, go to the rear of the vehicle and undo a bracket that supports the exhaust just below the gas tank (petrol tank) using the 12mm socket and wrench.

while your under there, use the 10mm socket and wrench and undo the heat shield bolts.

Crawl back towards the front of the car and gently prise off the exhaust, a few gentle taps may be required, once it is dislodged, it will drop at the front so be prepared, although not heavy it may catch you out if you're not expecting it to drop, use a support or muscles and then gently lower it to the ground, there is no need to remove the whole exhaust so don't worry about the rear end of it all. Having done that, you will see the GIUBO (flex disk) in place, if it looks worn, tethered or damaged in any way, replace immediately, severe damage to gearbox, drive shaft etc will occur if it is left untouched.

Step 4

If you plan to use an 18mm spanner and a torque wrench then leave the transmission bracket in place, if you plan on using an 18mm socket wrench and a torque wrench at the same time then you will be required to remove the transmission bracket, before you do this, use a scissor jack or equivalent and a block of wood and place this towards the rear of the transmission in front of the bracket and raise the jack high enough so that it just touches the transmission pan - now remove the bracket - transmission will bed itself onto the scissor jack.

Place your vehicle in NEUTRAL so you can manually rotate the drive shaft to get to the remaining bolts. DO NOT spray lubricant on the guibo assembly area or the nuts and bolts, some force will be required to undo the bolts, hence your original shaking of the vehicle making sure it is secure! You can use a rubber mallet (hammer) to tap at the wrench to help dislodge the bolts, once you feel movement then just replace the torque wrench with a socket wrench for easier access. There are 3x bolts that secure the drive shaft onto the GUIBO (flex disk) once all 3 have been removed, go to the centre of the vehicle and undo the centre bearing bracket, hold the drive shaft in one hand for support as it WILL shift, the join in the middle of the drive shaft will collapse the shaft and this will suddenly release the front of the drive shaft away from the GUIBO (flex disk). Place the drive shaft gently on the ground betwen the lowered exhaust. DO NOT rotate the drive shaft while it has been removed and DO NOT bend or twist it.

Now you will have the GUIBO fully visible with a remaining 3x 18mm bolts to remove, again use the torque wrench and spanner to remove them, NO lubricants please.

Step 5

Take note of how the OLD Giubo (flex disk) was fitted (ie: lettering facing the rear of the vehicle) that way then the NEW one will go on in the same manner.

Fit the NEW Giubo (flex disk) inplace using the same bolts but the nuts are optional as a replacement if you're not going to use loctite. Put all 3 bolts in place with the NUT end facing the engine, use an 18mm spanner and an 18mm socket wrench to hand tighten the bolts and nuts, once done, check for fitment. If all is ok use the torque wrench and the spanner to fully tighten the bolts and nuts. (As a guide, i used the transmission support as leverage for the spanner enabling you to use the torque wrench with two hands)

Step 6

Coat a fair amount of HIGH TEMP grease on your finger and swab it over the end of the drive shaft making sure most of it goes inside the flange and a minimal amount on the outside of the flange. Lift the drive shaft from the front and the centre and aligning the front of it to the remaining bolt holes in the Giubo (flex disk). While supporting the drive shaft with 1 hand, take the 3 remaining bolts and push the through the GUIBO so that the NUT end is facing the rear of the vehicle, using your supported hand, you can push the drive shaft up and down to align and thread the bolts, now quickly thread the nuts on ( a few turns on each bolt) Now go back to the centre bearing and secure the nuts fully but only hand tight so the bracket is mounted right up against the chassis.

Now use the spanners or socket wrench and secure the 3 GIUBO (flex disk) bolts (the drive shaft will pull in towards the GIUBO, now use the torque wrench and spanner and tighten fully. once completed, return to the centre bearing bracket and fully tighten it to the chassis. Rotate the drive shaft by hand feeling for imperfections, rubbing or other possible problems, if all is ok then lightly clean the shaft using a cleaner and a rag to remove grease and dirt, then refit all the heat shields using the 10mm socket.

Step 7

Lift the front of the exhaust system and place the ends on the bolts that are attached to the CATs, use the existing 12mm nuts and gently tighten so that the exhaust slips neatly and evenly into the CATs, once fitted and adjusted you can now fully tighten the nuts.

replace the rear exhaust bracket using the 12mm socket.

By now you should have NO screws, No BOLTS and NO nuts left, If you have then go check and see what you have overlooked.

Clean the exhaust using a cleaner.

Remove all tools and pack them away, check under the vehicle making sure all is clear, go to the rear of the vehicle and jack up the trolley jack a little to help remove the jack stands, gently lower the vehicle fully. Do he same to the front if you used jack stands.

Step 8

If you used ramps, start the car, let it idle for a bit then reverse slowly off the ramps, clean remaining work area of ramps and debris, take the vehicle for a drive slowly, gently increasing speed, DO NOT EXCEED 50MPH.

You should feel smoothness, there should be no imbalance and gear changing is also smooth. If not you may have a damaged or twisted drive shaft as a result of a failed GIUBO (flex disk).

Voila....you definitely just saved yourself a few hundred if not more and you learned something new at the same time.

Cheers! :thumbup:

PS perhaps someone can reformat and insert the attached pictures under the step by step formation, since i'm not that computer literate, thank you!

Very nice writeup! Thanks. Weather looks wonderful!

How long did it take? You've made it sound dead easy. I can't imagine it is.

I'm computer literate and I haven't figured out how to do inline, attached images. :D

Thank you, and believe me, it is easy, i even impressed myself as well as the kids, i just used common sense, no books, no repair manuals etc, basically i got under the car and relied on memory as to how things were put back together, the hardest part was jacking up and stabilising the car lol. If i had the part at the time it would have taken a good 4 - 5hrs in total. This repair was done over a 3 day period.

To have inline images there must be a special feature then?

Couple things:

1. Did you preload the center bearing?

2. To insert image at step-by-step:
- Right click on the image you want and "Copy Image URL". For example you will see the 1st image as:

http://www.bimmerfest.com/forums/att...1&d=1294299314

- Then place the cursor where you want the image to be, hit the icon "Insert Image", then Paste the URL. You can leave the whole URL alone or shorten it to the picture id as below, the software of the forum only cares about attachmentid=261169, and not the strings of letters/numbers afterward:

http://www.bimmerfest.com/forums/att...hmentid=261169

Go back to your message and edit it and you will see, it is very easy to do this step-by-step picture thing. In fact much easier than replacing the Giubo!

Hello Cam. How do you do that? (For noobs like me...)


Thanks

You put it on wrong?
 

Just checking....

The arrows on the side of the flex disc are "supposed" to point toward the flanges. From your install pics it appears they're all pointing away. Tell me I'm wrong, or that it doesn't matter. Bentley and all the DIYs I've seen on these say to align the arrows to point to the flanges... got to be a reason but I don't know why.

Well..... another question. On my car the flex disc has all six nuts facing toward the engine/transmission. On yours the new install shows three loctited nuts on the driveshaft flange. Was this the way your previous flex disc was installed?

If you look carefully at the BMW Center Bearing anatomy, the ball bearing is surrounded by a rubber sleeve, itself suspended by a rubber boot (or ? polyurethane boot) that is attached to the metal holder.

This rubber boot allows some play in the bearing movement while preventing noise from entering the cabin.

When installing the new Center Bearing, one needs to preload the bearing toward the engine by 4-6 mm or so. This way when the car is lowered, the Rear Differential moves upward (in other words, the car body weight goes downward) and during that process, the Driveshaft moves forward a few mm. This is basically the fore-and-aft movement of the driveshaft when the car is lowered to the ground.

This preload procedure allows the Center Bearing to sit "perfectly" with little strain on it when the car is lowered to the ground.
Failure to do preload will kill the rubber boot very quickly.
On the other hands, if you never removed the wheels and raised the car via the tires (tires sitting on wood ramps for example) to do the repair, there is no need for preload.
The preload procedure was written for repair shop where the car is raised by the hoist for repair.
Here is a pic of premature rubber boot failure:


http://www.bimmerfest.com/forums/att...hmentid=261217

Your concern re bolt direction is addressed here:
http://forums.bimmerforums.com/forum...php?p=18811400

Awsome post Cam.
Thanks

I don't know why they say the Arrows have to face the Trans Flange.
From a pure Physics standpoint, this is just a chunk of rubber with steel reinforcement, pretty much like a tire anatomy, and 6 symmetrical holes.
My guess is the direction of the arrow is not crucial.

I just realized the the O.P. Ebonix is from Australia the Down-Under, so they tend to do things opposite of Northern Hermisphere people. They drive on the left side of the road and they install the Giubo backward haha... sorry Ebonix I am just joking around, "a laugh a day keeps the doctor away" kind of thingy....:)

Actually I don't see much consensus there.

I went and looked at the PelicanParts DIY (for a 3-series flex disc replacement). They state the arrows should be pointing toward the flanges on each side (three one way, three the opposite). Regarding the bolts/nuts, they suggest there's a rule of thumb that the arrows also indicate the direction that the bolts are supposed to be oriented. It makes sense of course to have nuts turning on top of those flanges I guess, but each disc hole has a big piece of steel tubing inside so I'm not convinced that protecting the rubber is really a consideration here as long as one is using washers as well. Don't these things have washers under each nut? Another thing I notice is that while the guy in the Pelican DIY states the arrows indicate bolt direction, the flex disc he removed was bolted up like I've seen on my car and in many other pics, that is... with the bolt heads toward the rear and the nuts all on the transmission/engine side of the flex disc.

G'day CN...

Centre bearing was ok so i didn't replace it, it went back into position when you tighten the bolts to the flex disk, no preload required unless you replace it with a new one.

Thanks for the tips, i'll try later and see if it works.

Cheers!

What you are seeing arrow wise is correct however as you hold the disk in your hands, there are numerous arrows on it, some face inwards and others face outwards, the original flex disk and bolt method was applied to the new one i installed...lettering on the flex disk facing the rear of the vehicle and 3 bolts in either direction, this is the first time a flex disk has been replaced on this car since i've had it from new so i would consider my setup to be as per factory set up. :thumbup:

Other than lettering on one side of the disk there is no difference, there are arrows on the side edges, 2 face inwards and 2 face outwards, i guess it doesn't matter how you fit the disk but in my case i just installed it the same way i removed the old one...lettering facing the rear of the vehicle.

Hahaha...we have what we call a "she'll be right mate" attitude...slap it together, start her up and if she moves, just keep moving. :rofl:

Just some clarification on arrows, see attached pics.

Cheers!

Ah ha,

Now I see a total of 6 arrows pointing in opposite directions.
So whenever one sees the arrow, just make sure that arrow faces the steel flange, whether it is the flange from the trans or driveshaft per Pelican DIY.
Ebonix, your arrows do not line up as Pelican says but I guess it does not matter that much.

http://www.pelicanparts.com/bmw/tech...uibo/pic20.jpg

Ebonix,

I do a bit more research and see that the Giubo has 3 pairs (Yellow Dots #1, #2, and #3) if you look closely.
For each pair, the rubber is thickened a bit.
There are also 6 "Cushion Holes" (Green Arrows) to take up sudden acceleration/deceleration (kind of a shock absorber).

Anyway, now it is obvious to me that the reason for Arrows is that in 99% of the time, the car moves forward, so the direction of rotation is Clockwise (when viewed from front of the car). See the Blue Arrow. So:

- When the Trans Flange 2a rotates, it transfers the torque to 2b which is mated with the driveshaft, thus the reason for the beefier rubber for this pair of 2a and 2b.

- Personally, I'd not worry about it because whether you line up the arrows or not makes very little difference to me because the whole unit works together as a unit.
Also, you would have to crawl underneath to go through this ordeal again.
Your Giubo may not last as long but what the heck, wait until the next time it fails then replace it. No big deal. Just enjoy the ride.
Also, you are from Down-Under, so you are allowed to do things backward LOL!!!

http://www.bimmerfest.com/forums/att...hmentid=261235

http://www.bimmerfest.com/forums/att...5&d=1294299588


THIS looks like wrong to me
THIS will give you DS vibration as central mount rubber boot is pushed to the right side

The bolts should be in the middle
The rubber inside central mount should be in the middle

happened to me after stupid shop installed my new DS and i still had slight vibration
readjust you central mount and feel the difference
you must to pre-load it on wheels/ramps ( this is how i did it )

GL

An instant classic!

I made this thread number one in the bestlinks reference:
- Worn drive shaft, center bearing, or "giunti Boschi", aka giubo - often misspelled as "guibo" (1) (2) (3) (4)

Do you mean, if we don't preload the center bearing manually while the car is up, we can lower the rear wheels down onto ramps before tightening the center bearing support bracket?

According to this thread This kind of makes sense, because during acceleration, the engine rotates a bit to the R side and therefore "twists" the whole engine/trans assembly, effectively "pulling" the driveshaft forward a tiny bit. Therefore by preloading, it creates a little room for picking up this slack.

http://tech.bentleypublishers.com/th...ssageID=353978


It is interesting that the E9 has a preloading of 2mm:
http://www.e9-driven.com/Public/Libr.../24000200.html

http://www.e9-driven.com/Public/Libr...4/00020007.jpg

why rear wheels ?
put whole car on ramps
check that your central rubber mount is in the middle
tighten it
if DS installed correctly bolts will be in the middle too

Some more info
E39 I6 DS design was changed in 03/2001
My car is 06/2001 525i and it has new DS design
I found this is the best position with 0 DS vibration
and i tested it up to 125 MPH
LOL

Guys I will be doing the CSB and Guibo soon on the Wagon as I am getting squeaks on take off (5 Speed). On preloading basically I have to have the back of the car up on either ramps or on the floor before I tighten the CSB bearing to the cars chassis correct?

I think that's what champaign777 was getting at. Haven't done this DIY myself yet ....