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Diff Crossmember Bolt Sizes?

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I’m trying to install the crossmember that supports the front of the diff and front of the rear suspension arms and having a problem with the bolts. There are two bolts on each side. The inner bolts are M10x1.25 but the outer ones are a different sizes. They are larger The outer bolts were not insattled when I got the car. I can't work out what size they are.


I thought perhaps M12, but both 1.25 and 1.5 pitch but neither fit. I did find a bolt that fits and it’s 11mm OD and has a pitch of 1.25mm. I used a thread pitch gauge to match the thread. That’s a really odd metric bolt size.


I’m thinking someone may have stripped the outer holes and retapped them.


Should all the bolts be M12x1.25mm? or are the outers an odd M11?


M11 is very unusual so I’m thinking perhaps the outer bolt holes have been tapped 7/16” UNF.


Any thoughts?



Edited by GregTas

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Thanks. I did a bit of a search on the web, but wasn't too sure. As the M12x1.25 went in a couple of turns so thought perhaps mixed bolts. I bought some special M12x1.5 thinking the pitch was the issue but they didn't either. Cost me $5 per bolt :(


You are correct they have been re tapped. I just found a couple of 7/16 UNF bolts and that fitted. Not great, but thread looked of so I'll assume they be ok.


So all sorted. :)

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