328 diifferential disaster

heard a ticking sound from the rear end of my 87 328,looked underneath and found diff cover cracked,took cover off and found ring gear bolts loose and one bolt hitting cover,diff was rebuilt about 8k miles ago with new nuts on ring gear bolts,didn't think it would need locktite,this time I have decided to replace all nuts and bolts,checked on price of nuts and bolts,found list on each bolt is $88 and the nuts are $22 and it takes 8,since I really dont feel like spending a thousand dollars on nuts and bolts would it be ok to machine my own bolts?

 

Do you have the equiptment to "roll threads"?

 

why do you suspect the bolts as opposed to improper assembly. and to follow up with Mitch's comment do have the knowledge or equipment to make sure you got the right heat treating of those bolts? I'm sure you can source proper bolts for less. King Bolt, covina, ca. Hi Desert Fasteners hisperia , ca. are decent retail vendors for non-counterfeit bolts. Can you weld the cover?

 

The new bolts are cheap insurance that you don't have a problem. As Mitch said, unless you are an expert in manufacturing fasteners and can roll threads in the proper material and heat treat them, then you are asking for trouble if you machine your own bolts.

You can check with ARP to see if they have the fasteners in the same sizes. If not, bite the bullet and buy new Ferrari bolts. $1000 might seem like a lot now, but when the bolts break and destroy the transaxle it won't.

 

Dont know about these particular bolts but on many diffs the bolts are self-locking "pip" type. The underside of the bolt head has a raised ring on it around the outer edge. When the bolt is tightened the head flexes slightly giving some locking capacity. These should not be reused once removed although I have in the past used Loctite on this type of bolt successfully.
Sometimes (but not always) this type of bolt has radial grooves in the top of the head.

 

Also the price of the bolts from Ferrariparts.co.uk is 25 GBP which is a lot less than $88. Cant imagine shippng is that high.