1973 Rebuild

[Patcon]

Those look like the same rotors I just installed. I am fairly confidant these are the original bolts and washers that I replated. They are slightly recessed when torqued. I had to go double check after you posted this

 

 

[Zed Head]

Be careful with those newly coated wheel flanges.  The coating can get squishy and compress, allowing the lug nuts to loosen.  There are stories.  Mating surfaces are best metal to metal.

[Matthew Abate]

Those look like the same rotors I just installed. I am fairly confidant these are the original bolts and washers that I replated. They are slightly recessed when torqued. I had to go double check after you posted this

 

What did you torque yours to? I couldn’t find the torque spec in the FSM so I went with what is in the Chilton, which is 43-54 pounds. I’m thinking that might be part of it.

 

As soon as I can I’ll pull a bolt and check the measurements to verify that.

[Patcon]

2 hours ago, Matthew Abate said:

 

What did you torque yours to? I couldn’t find the torque spec in the FSM so I went with what is in the Chilton, which is 43-54 pounds. I’m thinking that might be part of it.

 

As soon as I can I’ll pull a bolt and check the measurements to verify that.

I used the value out of Haynes. It was somewhere in that range, about 40 pounds. I don't think that is the problem. I think your bolts are 5mm too long

[Matthew Abate]

I used the value out of Haynes. It was somewhere in that range, about 40 pounds. I don't think that is the problem. I think your bolts are 5mm too long

 

Yep.

 

Z Car Depot said they get these from Nissan, so they are looking into it to see if they can figure out something better.

Note that the thread count is fine and it is the unthreaded shank that is way to long by at least 1.5 millimeters.

 

[Patcon]

1 hour ago, Matthew Abate said:

 

Yep.

 

Z Car Depot said they get these from Nissan, so they are looking into it to see if they can figure out something better.

Note that the thread count is fine and it is the unthreaded shank that is way to long by at least 1.5 millimeters.

 

And the OEM bolt head is thicker. Would be interesting to mic from the bottom of the bolt head to the end of the threads on each one for reference

[Matthew Abate]

I just got off the phone with them. They had only checked them on 260/280Zs so that’s part of the problem.

 

My options are find some OEM ones (just emailed Jim), find thicker lock washers, or grind these down.

 

I don’t like the grinding option because I would be reducing the thread contact area from the intended design.

 

 

For reference:

Bolt = 40209-22000 (NLA) m10x1.25, 27mm long, 10mm grip length

Lock washer = 08915-14010 m10x3mm thick

 

 

 

[Patcon]

The problem with grinding them down to me, would be, you remove all the zinc from the end of the bolt and they're going to rust badly there so close to the ground and potential water. I am not sure grinding them would affect clamping forces at all, but I am also not an ME...

[Zed Head]

I'd be more concerned about the shank bottoming out.  Easy to check though.  A flat washer under the lock washer might solve both problems.  With a dab of thread locker to be sure.  Would make it look like the original as far as the functional bits.

[Matthew Abate]

Yeah, that’s a problem too. I’ve read and been told not to use a regular washer with a split lock washer, so I’m trying to source some more correct bolts or a m10 split lock washer that is at least 4mm thick. Tall order.

 

These might work: http://www.dli-teknik.se/index.php?section=products&subsection=7&cat=83&s1cat=578&s2cat=1056&showprod=10154&lang=en

 

I called ARP and they said these were probably custom manufactured by them for this distributor. Looking into the details.

 

Sent from my iPhone using Classic Zcar Club mobile

 

[Zed Head]

2 minutes ago, Matthew Abate said:

Yeah, that’s a problem too. I’ve read and been told not to use a regular washer with a split lock washer, so I’m trying to source some more correct bolts or a m10 split lock washer that is at least 4mm thick. Tall order.

Thread locker.  You could leave out the split lock washer entirely.

[Matthew Abate]

Found some from a 210/310 on eBay. I have a feeling they aren’t the same, but they were $15 for 4 so I too the gamble. We shall see.


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