510 Half-shaft bolts - spitballing replacements

[Dguy210]

Currently putting my 510 back together and I've realized I'm going to need to source the outer half-shaft bolts. After looking these up and finding out they are specialty and extremely damn expensive, and I need 8 of them, I've been brain storming some alternatives. 

 

Now onto the sizing, these have a hex head and overall length of 22-25mm, a 10 mm bolt section that is threaded about 1/3 that section and the specialty bit is a wider than stock shank which is a very tight fit for the hole in the half-shaft to the wheel flange (looking something like below, not my pic). 

 

So after some measurements of my half-shafts we can see the hole it passes through is a bit over 10mm (~10.25 when measured) meaning a shanked 10mm bolt would be a bit too small and a full threaded bolt would be quite a bit too small (about 9.5 mm or so from crest to crest). 

 

I couldn't find a spec on the grade of the bolts but suspect a grade 10.9. 

 

However, this size of 10.25 mm is very close if just slightly under that of the crest-crest of a 7/16 SAE bolt. 

 

So this gives me 2 ideas;

Bad Idea 1. Mount the half shafts to the wheel flange tightly (through a bolt through one of the holes) and tap in place through the half-shaft and flange together with a 7/16-20 tap so the threads are continuous. Make an alignment mark so I can get them aligned again next time to the specific holes and use a grade 8 or higher fine thread 1in long 7/16-20 bolt with a lock-nut and some red loctite. Bit of a pain to tap (as the metal is anything but mild steel) but highly unlikely to back out as the hole will be completely threaded and there is a no room for the bolt to "Wiggle" in place.  This is a permanent change but then makes the bolt a very easy thing to find and replace in the future for more up front work 

 

Bad Idea 2. The second idea was a bit easier, was to get a grade 12.9 10 mm bolt with a short shank and put a metal "shim" collar around the shank to make a near-interference fit with the hole. By going up a grade the strength should still be there and by making the fit very tight it should not be able to "wiggle" itself loose or get any motion to it. I would then use a lock nut and some red loctite so it stayed put. I did test this version with a bolt I had and got a very nice tight fit so it seems reasonable. This method also requires no permanent modifications and is what I'm leaning to right now.

 

Of course the other option is to just get some grade 8 7/16 stock and a carbide insert and I cut and thread some custom bolts up on the lathe, but I'd really rather not do that.

 

 

So, please feel free to tell me how stupid this idea is. 

 

Edited December 29, 2024 by Dguy210

[fiveoneO]

When I get into situations like this, I tell myself, time is money. The right bolts might cost more, but they will drop right in, everything will work, and you'll move onto the next thing that needs to get done. Messing around with alternatives will cost you time and might not work right the first time, so then more time will be waisted. Its nice to save money, but sometimes its just easier to buy the right part and move on.

[Dguy210]

55 minutes ago, fiveoneO said:

When I get into situations like this, I tell myself, time is money. The right bolts might cost more, but they will drop right in, everything will work, and you'll move onto the next thing that needs to get done. Messing around with alternatives will cost you time and might not work right the first time, so then more time will be waisted. Its nice to save money, but sometimes its just easier to buy the right part and move on.

That doesn't really answer the question, and for this build I'm fine with dumping time into it. 

 

I want a different solution to this common problem that doesn't require an expensive specialty part.

 

The bolts are $18 a piece and I need 8. Now generally I'd agree about time vs money in certain situations but they're just shoulder bolts and that seems like a bit of a ripoff at that point.

 

Especially, as per my description the time to shim some higher grade bolts is almost nothing. Hell, I know where a rusty 610 is where I could just pull them for basically nothing.

[chukar]

Have you checked out Z car depot? 

https://zcardepot.com/products/axle-driveshaft-half-shaft-boot-kit-oem-240z-260z-280z-510?_pos=1&_sid=5d6b54411&_ss=r#

 

Might be what you are looking for?

[iceman510]

Or these aftermarket alternatives form Z car depot:  https://zcardepot.com/collections/rear-axle-and-differential/products/axle-driveshaft-half-shaft-bolt-special-240z-260z-280z?variant=20319893880945

 

I ordered a bunch of these from Amayama last year as spares for my race car so the shoulder/hole fit would be perfect.  About $8 through them.

[DARIN 510]

https://www.nissanpartsdeal.com/parts/nissan-bolt-driveshaft~39628-e4100.html
looks like the dealer still carries them. 39628-E4100 Part number

[Dguy210]

Thanks. Worked it out and went with option 2. Will update with details when I have some miles on the car. 

[bananahamuck]

I got some from keeper a few years ago. 

[yenpit]

If your spitballing does not work, I have good USED...............