Can anyone tell me the bolt size that goes through the lower joint of the steering shaft where it attaches to the steering rack?  Is it supposed to be a shoulder bolt or just a standard bolt?  Also, what size and thread?

 

Car is a 76 280z if that matters.

 

Thanks

A picture tells a thousand words.. All i can say now is.. it will be a metric bolt..? Get yourself a service manual!!  It's in there somewere... i guess.

The Nissan parts book shows it as a M10x1.25 x 28mm long, metric fine pitch. To see if it is a shoulder bolt measure the ID of hole in the yoke, if it is10mm then it's not a shoulder bolt.

Perfect, thank you!

I thought my steering shaft was stored away but it was still under my car, here are a couple of pics. It is a M10x1.25 partially threaded, under head length is 28mm with 22mm thread length and has a number 9 marking on the JIS head, I believe that would cross over to metric DIN class 10.

Here is some info about the grade markings on the head of the JIS bolts of that era from the Datsun/Nissan torque spec booklet.

General-Datsun Torque Specifications.pdf

Edited May 17, 20231 yr by CanTechZ
Added torque spec info

Reading recommended torques for fasteners always makes me scratch my head.  It's my understanding that these values are usually* aimed at achieving sufficient 'thread bind' (my term) to prevent the fastener from loosening in service (* notable exceptions being locations like head gaskets, where the goal is to generate a required clamping force).  They'll also keep you under the point of snapping the fastener or stripping the threads.

It's also my understanding that these recommended torque values are predicated on clean, dry thread surfaces.  That's certainly the case during factory assembly, but rarely so after the vehicle has entered service.  For those of us who live and drive in the 'salt belt' areas, oiling the threads or applying Copaslip or some other type of anti-seize lube is normal practice (to ensure that an impact wrench won't be needed to take things apart a couple of years later).  I can only assume that 'thread binding' goes out the window because of this, leaving just the lock washer to keep things buttoned up. 

Except that I think I recall reading an article which said that split-ring lock washers don't really work very well...

And you can't use thread-locking compound on threads covered with lubricant.

Comments?

I've been using copper-antisieze on most of my suspension components, relying on the snap washer to hold it all in place. I'll replace the snap washers if i notice they have less spring to them.

Nothing has loosened up yet, drive the car pretty hard...

Always risky reusing 50 year old lock washers. Correct lock washers are still available from Nissan but they're  now plated clear. 

This can be a problem after replating too. I have seen it happen but not very often