Giubo Bolts ... done to death I know, but ...

[zambo]

I've read all the threads that related to the topic and related where possible to my situation but hope the brains trust would indulge with a couple of follow up for my particular case.

 

Finalising all the fasteners for a Getrag 245 upgrade to my Euro '72 auto (RHD). All hydraulic components, the GB itself, pedal box, tail shaft, clutch kit, flywheel, etc. have been either resealed, overhauled, balanced or renewed. So all ducks seem to be in a row on that front. Giubo is from FCP - 26111225624

 

My couple of questions are as follows;

 

a) I've found the M10 10.9 hex at 50mm (1.50 pitch) which seems to be correct from the various threads (these are engineering supplier standard, not the ones that I can source from our Oz version of Home Depot) - but the AF on the head is 16mm. I have read (here) that 17mm gets raised as the OEM size to spread the load on the metal sleeve in the giubo. How critical is that 17mm (versus 16mm) in the scheme of things? High tensile locking cone nuts are what I'm going to use at the other end.

 

b) I also have access to a low head 10.9 socket or caphead screw - all other specs the same I'm wondering if that is an appropriate alternative? Logic tells me it would secure things though it too has a diameter of 16mm. I only looked at this because I seem to recall somewhere in the many old threads, Toby mentioned that an E46 (?) had used an ETorx fastener ...

 

That's it - thanks for looking and hopefully responding.

 

Rich 

[AceAndrew]

From a pure engineering perspective, as long as the entirety of the metal sleeve is covered... then have at it.  Avoid fully threaded fasteners for this, but conversely as long as the thread length is within a reasonable margin of factory then your MS is still well in the clear.

 

From a practical perspective, that area is frequently the most gunked up on the car.  Grime-clogged Allen-heads are a pet peeve.

[calw]

With really tight bolts and low head allen socket screws, you have fewer chances to loosen due to the reduced depth of the hex socket.  Gunk in the socket head and holding the tool at the wrong angle will eat either the end of the tool or the screw if you're not careful. 

 

Be careful out there....

[zambo]

I’ll stay with the hex head bolts and keep it simple 👍  

[gwb72tii]

On 10/5/2023 at 6:50 AM, calw said:

With really tight bolts and low head allen socket screws, you have fewer chances to loosen due to the reduced depth of the hex socket.  Gunk in the socket head and holding the tool at the wrong angle will eat either the end of the tool or the screw if you're not careful. 

 

Be careful out there....

this

plus once you strip the hex, imagine how much fun it would be center drilling the bolt so you can use an easy out, all lying on your back under the car

[TobyB]

If I remember, and I might just be delusional,

the eTorx has a chubby bit to spread the

load out across the entire sleeve in the guibo.

So it has quite a bit more surface under the head than 

the inhex 'Allen' bolt.

 

In aviation, when they use the inhex, they usually spec a warsher to go

under it for just that reason, too.

 

Me, I just reuse whatever BMW put in there stock.  Or if that's gotten chewed

up, then a spare or 2 off parts cars. 

I've had rear hub inhexes come loose, but never the driveshaft.

 

totally FWIW.

 

t

 

[ray_]

On 10/5/2023 at 9:50 AM, calw said:

With really tight bolts and low head allen socket screws, you have fewer chances to loosen due to the reduced depth of the hex socket.  Gunk in the socket head and holding the tool at the wrong angle will eat either the end of the tool or the screw if you're not careful. 

 

Be careful out there....

Then you just grab it with your trusty Vise -Grips. 

 

😋