I found out today from my Z mechanic that both u-joints on my driveshaft need to be replaced. He said that they are 'crimpted' in, that only the '75's did this, and that it would cost about $325 to replace them.

I asked if it would be better to swap the entire driveshaft with a different year model that I could replace just the u-joints in after they wear out. He said that, again, in '75 only, Datsun increased the rear flange bolt size from 8mm to 10mm and there again we're looking at machine shop work to match the '75 flange.

I could swap out the differential and driveshaft for any other year, but there goes more money into it.

My question now is, can a different year driveshaft flange, say a '77 or '78 with the 8mm bolt holes and a replaceable u-joint be drilled out to 10mm so that it can be bolted to my '75 differential?

Any help, advice, and thoughts are very welcome.

Thanks,

Rob:cry:

I'm fairly sure all the 280Z's from 75-78 had the non-replaceable u-joints. MSA has a replacement driveshaft for the 75 that has replaceable u-joints in their old catalog for 234 bucks (wish I knew why they haven't sent me my new catalog:angry: ) so that would probably be cheaper than doing what he wants to. I'm not 100% sure, but I don't think there is any difference in the 75-78 flanges, however I haven't tried swapping them, and don't have one to check. I see no reason the holes couldn't be drilled out to a larger bolt if that is the only difference in the flanges.

I have an extra 75 drive shaft in my garage,

Happy days are here again!

I went ahead and bought a replacement driveshaft from MSA for my '75 at a cost of $225. It fit perfectly and is well balanced. No more driveline slap (or clunk)! I'm very happy with how well it turned out. I was a little worried about getting the right part because a few years ago I was sent a left side brake caliper when I ordered a right side unit.

I installed the driveshaft myself and it went pretty smoothly except for the differential/driveshaft bolts. It turns out that the bolt heads are on the forward side with the nuts and washers on the rear and there is not enough clearance around the bolt head to accept a socket. After panicking a bit, I called a friend/Z shop mechanic who sold me my 5 speed for help. He told me the trick is to put a wrench on the nut (in back) and turn the driveshaft with a large screwdriver to break loose the nut. It worked flawlessly! Thank God for knowledgable people like yourselves.

Now for the leaking differential front seal!?!?

I hope this info might benefit someone out there in ZLand

Thanks for all your help,

Rob :classic:

I have a 12/74 280Z and i just ordered from rockauto.com the four rear u-joints. ACdelco part # 45U0174 for $18 ea.

I have a 12/74 280Z and i just ordered from rockauto.com the four rear u-joints. ACdelco part # 45U0174 for $18 ea.

What's your point? Read the thread again.