Thread Size on Steering Wheel Nut, 1968 Volvo Penta?

[Stamey]

I have a 1968 Fibra with some kind of Volvo Penta sterndrive. I still have not been able to find an actual model number, so I'm flying blind here. It was repowerd with a Ford 302, so there are no engine model numbers to be had, and I have not seen any model tags on the sterndrive.
The steering wheel on this boat was falling apart and I have a spare, so I went to replace it. Even though I used a copper hammer to smack the end of the shaft, it took a long time for it to pop off, and even though I had left the nut on, flush with the end of the shaft to protect the shaft threads, they still got screwed up, as did the nut threads.
As near as I can tell, the shaft size is 13mm (.501" is the actual measurement with dial calipers), and the thread pitch is 1.25, as measured by thread gauges, both American and metric.
I am looking for confirmation on this, if anyone can tell me, before I begin looking for this odd tap/die size.

Thanks,
Chris

 

[Silvertip]

Re: Thread Size on Steering Wheel Nut, 1968 Volvo Penta?

Your outdrive has nothing to do with the steering system, nor does the boat make and model. Get under the helm and look for the steering system manufacturer stamped or cast into the steering mechanism. Then and only then can you get help. The other method is to buy a handful of metric nuts from any hardware store and try each one. We don't know where you are, but if this boat was made in 1968 in the U.S. it is very likely not a metric fastener. If you are outside the U.S. then it probably is.

 

[Bondo]

Re: Thread Size on Steering Wheel Nut, 1968 Volvo Penta?

I am looking for confirmation on this, if anyone can tell me, before I begin looking for this odd tap/die size.

Ayuh,... It's an old Antique, 'n ya trashed it...

A New helm, 'n cable are reasonably Cheap...
Replace it...

 

[Stamey]

Re: Thread Size on Steering Wheel Nut, 1968 Volvo Penta?

Oops, I didn't realize I had not filled in my location. I'm in Virginia. But anyway, I was under the impression that it would be American, since it is 1968, and the socket for the nut is 3/4", which suggests a 1/2" bolt. But when I took the American thread gauge to it, it wasn't a 20, or 24, and those were the only ones even close, so I got out the metric and found that it is 1.25. This means the nut could actually be 19mm. 14mm is .551 and 13mm is .511. considering putting threads on a rod takes a few thousandths off of the outside diameter, measuring the thread diameter at .501 suggests 13mm to me.
Since it is a Volvo sterndrive, I thought that the steering may be from Europe too, which practically guarantees that it is metric.
I have not looked too deeply behind the dash, but I suppose I could take the steering from the junk boat I pulled the new steering wheel from. Hopefully they use a standard mounting pattern, and the end of the cable will mount correctly, except that the junk boat has power steering and the one I am trying to fix does not have PS.

Thanks,
Chris

 

[Stamey]

Re: Thread Size on Steering Wheel Nut, 1968 Volvo Penta?

Further research as revealed that it IS in fact a Volvo steering system. http://www.marinepartseurope.com/en/volvo-penta-explodedview-7740890-64-13138.aspx
I was able to remove the shaft from the unit fairly easily and now I can remove the bunged up threads and re-thread with a die to 7/16-24. Not the optimum way, but without a lathe you gotta do what you gotta do.

Chris