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Just for strength and to keep them from loosening up a lot of us drill and retap the M10 threads and replace them with a 7/16-20.
If one gives this a go be sure to get a screw length that has enough of an unthreaded shoulder to pilot into the hub for a good 5 mm, and of course create the pilot in the hub.
Thanks Keith I knew I had seen it done...I presume that 7/16-20 is a 7/16 bolt with 20 tpi.
Dave, the leak is from the edge of the maxidrive flange, right at the point where the bolt that has no holding pressure is located. I tried sealing it and just keeping the 4 remaining bolts tight but the 130 gets a bit of a load in it and flogged around and I think the 4 bolts struggle to keep pressure evenly between the flange and hub. I cant recall ever using a gasket on the drive flanges.
I have sourced some helicoils, but will check out the cost on Keiths' above imperial option. I guess I will need an inter and a bottoming tap to do the job well.
Steve
Do you really want two different threads and bolt sizes on one hub?
The logical thing is either helicoil one (keep them all the same) or retap the lot to a bigger size.
In between lie those people that future owners curse and complain bitterly about.
Dougal,
being the way I am, if I go down the re-tap new bolts route I will do all 10 holes on the rear. But that will annoy me front to rear, so the front hubs would get some drill press loving too!
I fear the helicoil... probably unfounded but those poor little M10s get a pounding. I guess putting a coil in is quick and easy and does not preclude over boring at a later stage?
Off to Allieds now to shoot the breeze.
Steve
Helicoils are fine, if you think about it the thread strength would be roughly equivalent to the next size up bolt diameter.Quote:
Originally Posted by roverrescue
I've used Helicoils a lot over the years, mainly in aluminium castings where over zealous spanner spinners pull threads.
In the finish I used to helicoil every aluminium thread on the race cars and then use 243 Loctite to hold blind bolts and never had one pull, and these things were coming apart every meeting or two.
Helicoils if done properly produce a stronger and harder thread than any landrover hub will.
Like Rick I've come across many aluminium cast pieces which are helicoiled from the factory. Kuka industrial robots being the main ones.
Well its good that I now have a "recoil" kit for M10 x 1.5 then cos it is obviously the option of choice! Will get onto that job this arvo me thinks...
S
Truely the main reason for the bigger bolts it to keep them from shearing off under load, the fine threads helps a bit keep them tight.
Another strength option is to put 10 10mm bolts in to hold the flange.
Guys do it both ways but I prefer five bigger bolts as hubs look less swiss cheese like.
Then again it's a lot of work if there hasn't been a problem in the past.
If the joint is loose enough to load the bolts in shear then you're already in the crap and even bigger bolts will fail.Quote:
Originally Posted by revor
You need to get the bolts tight enough that the flange doesn't move and the bolts just stay in tension.
From a wise sage forum member
"An 8.8 bolt has a shear strength of 375 N/mm2"
M10 in grade 8.8 would be 29000N or the shear of 5 of them 145,000N
I dont think even your 4BD1 could generate that Dougal :)
I agree though its the tension or lack of that would lead to failure, I was worried that a helicoil would be a weak point and continue to fail.
Thanks for all your help!
Steve