Flex-Disc (Guibo) DIY

[2kredz3]

I know someone on here replaced theres with an aluminum peice anyone know who did that?

[willscam]

The guibo dampens drivetrain vibration, I would think an aluminum guibo would shake the fillings out of your teeth.

[2kredz3]

To some extent you are right. however, corvettes and other high preformance cars do not put that in the driveline because it gives a mushy feel to the clutch

You for sure will feel more driveline vibs but there really should not be that much from a devorced drive shaft (two drive shafts) I remember talking to the guy that had an aluminum one made and he said that he didnt think it was worth it for the difference it made. however, you could have an aluminum one made with delrin / poly bushings around the bolts best of both worlds.

[bblars]

I replaced my Flex Disc on Sunday, but did not grease the inside. Think I'm ok?

FYI - I also did not remove my exhaust. The entire process was pretty easy.

[DaneKane]

..that's gonna help a lot of DIY guys..thanks...Z3 Cheers! dk

[mz3onturn7]

Make sure you have a good torque wrench when you tighten the nuts down...they strip easily if over tightened... ask me how I know.

[bblars]

My torque specs were only for [wrong]47[/wrong] 75 ft-lb on a 1999 M coupe. That was the specification in the Bentley manual for a [wrong]M10 (10.9 grade) [/wrong] M12 bolt.

[Finn]

just did my replacement yesterday. thanks to the DIY i did it myself in about 45 min not counting the smoke break and bs at my buddies shop. thanks for the great writeup it was perfect. oh i didnt have to drop my exhaust either. 99 m coupe here.

[willscam]

just did my replacement yesterday. thanks to the DIY i did it myself in about 45 min not counting the smoke break and bs at my buddies shop. thanks for the great writeup it was perfect. oh i didnt have to drop my exhaust either. 99 m coupe here.

[Coupe Monkey]

Great writeup...

Wish mine was this easy (did mine a month ago)... two of my bolts were seized into the sleves and one of the nuts stripped out... Real pain in the butt working under their with these problems and with the car only 12" off the ground... Ended up doing the tanny mounts since I had to remove it to get the stripped nut off anyways... but its done now and I'm happy ...

[enigmalss]

So I'm ready to pull/replace the cracked guibo on the M Coupe. Aside from the fact that I somehow have no 18mm combo wrench, I have one main question.

When I go to torque, I understand that I'm supposed to torque only from the side of the flange, not that nut/bolt head directly bedded to the Guibo.

But here's my question: Since you can't get the torque wrench socket head on the tranny side of the guibo, how will I torque the nuts that secure the guibo to the tranny output flange?

Do I just put the torque wrench and socket against the rear of the guibo, hold it steady, and try to apply 75ft/lbs to the combination wrench that is slipped between the tranny support brace, up to the nut/bolt heads? Otherwise I can see no way to torque those tranny flange bolts

[Ron Stygar]

My torque specs were only for 47 ft-lb on a 1999 M coupe. That was the specification in the Bentley manual for a M10 (10.9 grade) bolt.

Bolts are M12 - 10.9.

[enigmalss]

Hey Ron,

First off, can you address the "real" question...I have no doubt you can How am I supposed to torque the tranny flange nuts if I can't even get a torque wrench up to the tranny side. I can slip a combo wrench up there and apply torque to it while I'm holding a torque wrench/socket to the rear bolt head on the guibo. That will keep the head that's touching the Guibo from spinning and twisting the insert, but will it read accurate torque since it's not the actual torque wrench that's doing the turning?

Next: I have factory bolts..99m Coupe...Can you confirm my torque specs? Bently is confusing, people here say 75lbs, you say 47lbs

[lokijibber]

So I'm ready to pull/replace the cracked guibo on the M Coupe. Aside from the fact that I somehow have no 18mm combo wrench, I have one main question.

When I go to torque, I understand that I'm supposed to torque only from the side of the flange, not that nut/bolt head directly bedded to the Guibo.

But here's my question: Since you can't get the torque wrench socket head on the tranny side of the guibo, how will I torque the nuts that secure the guibo to the tranny output flange?

Do I just put the torque wrench and socket against the rear of the guibo, hold it steady, and try to apply 75ft/lbs to the combination wrench that is slipped between the tranny support brace, up to the nut/bolt heads? Otherwise I can see no way to torque those tranny flange bolts

Never personally done the job, but I had the same thought when first looking at the pictures.

I'm sure a crow's foot would work if you have that.

[Ron Stygar]

Hey Ron,


Next: I have factory bolts..99m Coupe...Can you confirm my torque specs? Bently is confusing, people here say 75lbs, you say 47lbs

I didn't say it was 47.

[Randy Forbes]

Never personally done the job, but I had the same thought when first looking at the pictures.

I'm sure a crow's foot would work if you have that.

Most (open-end)crow-foot wrenches spread enough to slip at that torque value. Rather than rounding off the nuts, I torque the bolts in this application.

[enigmalss]

Ron,

Sorry, I must have misunderstood you. Can anyone clarify the correct torque specs for a stock 99 M coupe? Bently chart confuses me

Randy,

Are you saying that you torque the bolt heads directly touching the guibo while holding the nuts directly touching the tranny flange? Sounds like the easiest option to me, but I heard here that it twists the metal guibo inserts and causes premature failure? Any thoughts?

I'd really like to spend this rainy day knocking out this project.

Loren

Has anyone thought of just adding a simple washer under the bolt/nut that directly contacts the guibo insert? It would eliminate the stress from twisting the guibo inserts no matter what side of the disc you are torquing!!! And if you added one on each of the 6 locations you wouldn't screw up balance or anything.

[Ron Stygar]

Hey Ron,

First off, can you address the "real" question...I have no doubt you can How am I supposed to torque the tranny flange nuts if I can't even get a torque wrench up to the tranny side. I can slip a combo wrench up there and apply torque to it while I'm holding a torque wrench/socket to the rear bolt head on the guibo. That will keep the head that's touching the Guibo from spinning and twisting the insert, but will it read accurate torque since it's not the actual torque wrench that's doing the turning?

Next: I have factory bolts..99m Coupe...Can you confirm my torque specs? Bently is confusing, people here say 75lbs, you say 47lbs

http://bimmerfest.com/forums/showpos...8&postcount=46

http://bimmerfest.com/forums/showthr...ighlight=quibo

[enigmalss]

Ron,

Thanks for the links. I had seen them but still have the same question:

Is my 99 M Coupe an M10 or M12 trans? I'm going to go with the M12 and 100nM on the torque unless I hear different, but I have no idea where to find the answer?

Thanks again

[Ron Stygar]

Ron,

Thanks for the links. I had seen them but still have the same question:

Is my 99 M Coupe an M10 or M12 trans? I'm going to go with the M12 and 100nM on the torque unless I hear different, but I have no idea where to find the answer?

Thanks again

I posted here and Bimmerfest M12.

[SunzOut]

Ron,

Thanks for the links. I had seen them but still have the same question:

Is my 99 M Coupe an M10 or M12 trans? I'm going to go with the M12 and 100nM on the torque unless I hear different, but I have no idea where to find the answer?

Thanks again

M10 and M12 refer to the size of the bolt...

10mm or 12mm diameter.

the 8.8 or 10.9 refer to the grade of bolt. This should be marked on the bolt head.

[willscam]

According to realoem, the bolts on a 99 M coupe are M12, part# 26112283795 or 26112227195 (ended).

[enigmalss]

So it's not the first time I have felt like a clown...and I'm sure it won't be the last.

Thanks Ron (didn't see the earlier post...see clown comment above). Thanks Willscam. Thanks mom, dad, Jenny, .....

I'll make it M12, 100NM, and pray the skin on my knuckles holds up!

[willscam]

You can probably get by with just buying six self-locking nuts (part# 07129900047) for 50 cents each. The hex bolts are only about $3 each, so they're not going to break the bank if you decide to use all new hardware. You can tighten down the nut on the transmission flange with the open wrench while the torque socket wrench is wedged stationary against something solid. When you get to 75lbs the torque wrench will click. That's the way I did it anyway, so that I wouldn't be torqueing directly on the rubber disc. I used the torque wrench directly on the bolts through the driveshaft flange, while counter bracing on the nut on the transmission side. There may be a better way... , but it seemed to work OK. Looking at Ron's information, BMW states to always tighten the nut rather than the bolt. My understanding though, is that it's a no-no to torque down directly on the rubber guibo. Bottom line, use your best judgement if you want to do it yourself...alternatively, a mechanic can do it for you, just going cost you more.

[enigmalss]

Willscam,

That's pretty much what I was planning on doing. Couldn't see getting it done any other way. Thanks for the reinforcement though...FYI...your DIY sequence is GREAT