Giubo (flex disc)

Has anyone changed out just their flex disc to an aluminum one using the OEM driveshaft.

Also has anyone ever snapped one of the bolts that mounts the flex disc to the trans output shaft.

Is that guibo damaged? It looks like it has tears in the surface area (looking at pic, face of guibo).

I see what you are talking about in the pic, at first glance from underneath it didn’t appear it was so I went and looked again and it isn’t torn. What you are seeing are the dimples on either side of the bolt hole.

Out of curiosity, what torque did you use on them? Apparently, even the factory service manual doesn't list a torque value.


Edit: sorry, it was the other set of bolts that thread into bolts that don't have torque values in the service manual. I believe the one that broke takes 80/81 lbs.

Prior to it breaking I have no idea what it was torqued at. I haven’t replaced it yet as I’m waiting for FORD to open to see if they have any in stock. I too am curious what the torque spec is for those bolts

How did the bolt break, where you putting the stock DS back in or removing it to install an aftermarket?

As for a metal guibo replacement, I don’t think anyone makes one for the S550. I think the reason it is rubber is to absorb NVH and also if in a bad collision it’s design may allow it to break away.

Having been the prior owner of a 95 BMW M3 and BMW 318is, those guibos are known to wear out over time, so it’s definitely a serviceable maintenance part. I wonder if it could be replaced with an aftermarket urethane piece?

Cobra Jet said:

How did the bolt break, where you putting the stock DS back in or removing it to install an aftermarket?

As for a metal guibo replacement, I don’t think anyone makes one for the S550. I think the reason it is rubber is to absorb NVH and also if in a bad collision it’s design may allow it to break away.

Having been the prior owner of a 95 BMW M3 and BMW 318is, those guibos are known to wear out over time, so it’s definitely a serviceable maintenance part. I wonder if it could be replaced with an aftermarket urethane piece?

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I did a hard pull from a slow roll in 2nd gear, felt like the shifter moved more than normal and I heard a noise, right after that I started getting a vibration under any load and deceleration.

I know the aftermarket shafts have a billet aluminum one, I’m fine with the rubber one and was also curious about a poly one but haven’t seem to find anything. The Giubo isn’t or doesn’t appear to be damaged so I think I’m good there. I just hung up with ford and ordered all new bolts.

JOKER GT said:

I did a hard pull from a slow roll in 2nd gear, felt like the shifter moved more than normal and I heard a noise, right after that I started getting a vibration under any load and deceleration.

I know the aftermarket shafts have a billet aluminum one, I’m fine with the rubber one and was also curious about a poly one but haven’t seem to find anything. The Giubo isn’t or doesn’t appear to be damaged so I think I’m good there. I just hung up with ford and ordered all new bolts.

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If that stock bolt didn’t hold up to such a load, then I’m wondering if they should be upgraded? Did you try to remove any of the other remaining bolts to see if they have any fatigue or may be bent or twisted?

Cobra Jet said:

If that stock bolt didn’t hold up to such a load, then I’m wondering if they should be upgraded? Did you try to remove any of the other remaining bolts to see if they have any fatigue or may be bent or twisted?

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No, not yet but I plan on doing that tonight and I’ll post pics of everything. I am assuming the bolts that connect the driveshaft to the Giubo are of a higher strength due to them costing $20 each, the bolt I broke is an $8 bolt which connects the output shaft to the Giubo. I am replacing all 6 bolts and the 3 nuts to help eliminate any further issues.

JOKER GT said:

No, not yet but I plan on doing that tonight and I’ll post pics of everything. I am assuming the bolts that connect the driveshaft to the Giubo are of a higher strength due to them costing $20 each, the bolt I broke is an $8 bolt which connects the output shaft to the Giubo. I am replacing all 6 bolts and the 3 nuts to help eliminate any further issues.

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Since there aren't torque specs for the broken bolt, you might want to set a torque wrench to a low setting when removing one of the remaining two and bump the setting up bit by bit to see what torque it breaks free at. Won't be what Ford used to install but should be safe to use to install them.

I made the mistakes of removing all 3 assuming the manual would tell me what torque to use to reinstall them. No. The specs for the other three that go into nuts are in the manual.


Edit: I was describing the other set of bolts than the one you broke. Sorry for the confusion.

HoosierDaddy said:

Since there aren't torque specs for the broken bolt, you might want to set a torque wrench to a low setting when removing one of the remaining two and bump the setting up bit by bit to see what torque it breaks free at. Won't be what Ford used to install but should be safe to use to install them.


I made the mistakes of removing all 3 assuming the manual would tell me what torque to use to reinstall them. No. The specs for the other three that go into nuts are in the manual.

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Good idea, I’ll do that. Do you mind sharing what the torque spec is on the other ones. Also do you think it’s possible the torque is the same on both.

Removal torque can be as low as 50% of the initial torque spec. not good guidance imo.

Jay-rod427 said:

Removal torque can be as low as 50% of the initial torque spec. not good guidance imo.

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I already said that won't get the factory install torque.

Then what do you suggest in an absence of published specs?

Tables for those thread sizes would assume solid metal for both threads but the female threads are some kind of insert in rubber.

Would it be better to go the other way and see what value will tighten an existing bolt some more and assume that small amount won't break it? Then back off on that number a little to install the new bolts he's buying?

Whoa. Just realized, its the smaller bolts with the nuts on the other end that I removed and don't have torque specs for. The one the OP broke has a 80/81 lb spec:

https://drive.google.com/file/d/0B0YMWzYwztZkUFJVNWlCeUNPNzg/view

Its the other ones that don't have a spec. I know you want to replace all 6 and if you do, you still need to figure out a torque for those.

As to both sets of bolts using the same specs, I doubt it since they are significantly different sizes and one goes into inserts in a rubber part. I wish I remembered what I finally used.

Just to be clear, all the bolts go through spacers in the Giubo, none of them are threaded into the Giubo. The grade 8 yellow zinc bolts (one that broke) thread into the trans output shaft. The grade 9.8/10 bolts go through the drive shaft flange, through the spacers in the Giubo and have nuts that tighten against the other end of the Giubo.

So the other 2 grade 8 yellow zinc bolts were fairly loose and one of the last 2 were bent as seen in the photo. The 3 grade 9.8/10 bolt and nuts were tight AF.