Can I cut Guibo Flex Joint?

[nfinsness]

Just got driveshaft back from cutting for my 5-speed conversion. It is too damn long!!! I have pushed the diff back as far as it will go, and I am still too tight...it fits but is tight and binding...I figure a quarter inch will do it.

Can I cut 0.25" off the guibo to compensate for this??? New shorter bolts of course...

For the guy who was wondering about the driveshaft cut, it was done by RI Driveshaft in Warwick RI for $80..took 3 days to get it back. They could not install u-joint or get nut off to replace center bearing though.

Nat Finsness

[Mike87]

You should be able to loosen the differential and slide it back the 1/4". If not, have the DS cut and rewelded.

I would not cut down a guibo. It has to do enough as it is and taking away strength will lessen its life.

[skipsfcr]

Sure, I suppose theoretically you could make a 6 bolt guibo thinner but you'd probably want to remove 1/8" from either side to retain symmetry / balance. It would need to be done VERY precisely...Almost impossible to achieve imo. When you say it fits tight...how tight? Is there just a bit of "spring" to flex the driveshaft up into place? Some preload is necessary to prevent driveshaft hop. If you install the driveshaft and rotate it how much does the guibo flex? If the shaft was actually 1/4" long you'd have a REALLY hard time getting it into place if you could at all. Do you seem to have to force the engine forward noticeably on its mounts to push it into place?

[nfinsness]

It is probable less than .25 inches too long...the guibo is noticably stressed and it takes force to push center of driveshaft up to bolt at center bearing. I figure I would take a little extra and make it up by adjusting diff forward.

[jimk]

No, you cant cut the guio. It will shred quickly.

I'd bet you told the shop to shorten the shaft a given amount and now what was cut off is on the floor in bits. Instructions to a shop should always be to give them the new dimension you want it to be, then you can put a tape to the finished product!

[dubois]

You should be able to loosen the differential and slide it back the 1/4". If not, have the DS cut and rewelded.

I would not cut down a guibo. It has to do enough as it is and taking away strength will lessen its life.

I second that, cutting the guibo would bring you bad Karma 10-20 years from now, when the next owner will have spent an entire week sending back the "defective" guibos and trying new ones, or different ones. What he is going to say about you when he finds out is not going to be really nice...

[Guest]

Just got driveshaft back from cutting for my 5-speed conversion. It is too damn long!!! I have pushed the diff back as far as it will go, and I am still too tight...it fits but is tight and binding...I figure a quarter inch will do it.

Can I cut 0.25" off the guibo to compensate for this??? New shorter bolts of course...

For the guy who was wondering about the driveshaft cut, it was done by RI Driveshaft in Warwick RI for $80..took 3 days to get it back. They could not install u-joint or get nut off to replace center bearing though.

Nat Finsness

HOLD YOUR HORSES! What type of Giubo are you using? 6 bolt maybe? If you are using the round donut style, that typically comes with a compression ring, there is another approach. Other giubos are available and in particular, I am referring to the flat stronger style (laminated with layers of fabric) that is perhaps as much as .5" thinner than the fat donut style. There are many different Giubos to choose from, including those used by other makers Mercedes, Merkur, etc. Just as example of shape differences look here: http://www.realoem.com/bmw/showparts.do?model=1743&mospid=47175&btnr=26_0000&hg=26&fg=05

I'd wager you could plane the round style on a fat belt sander. The rubber is the easy part, the metal, not so easy. But this would be the last resort and least desirable modification!

[nfinsness]

OK...bad karma. I will return to the driveshaft shop tomorrow and humbly ask him to cut another .25"...that is the correct difference. I just pulled it and measured. The engine must have been pushed forward when I measured the first time...damn!

Mine is an 8-hole guibo...same as on the 320i the new trans came from.

No shortcuts on this one...

[TobyB]

Actually, you could machine .125" off each side of an 8- holer with no

problems. There's about that much extra metal there.

Whether there's clearance in the nose of the driveshaft for the extra length of the

trans shaft, that's a different question, but easy to answer on the shop floor.

But yes, the RIGHT way is to have it done right!

They could not install u-joint or get nut off to replace center bearing

That worries me- the u- joints are sealed, but getting the shaft apart's easy-

heck, even I can do it... and I'd replace the carrier bearing, if'n it were me.

t