Reverse-thread breeds insecurity

Using a car to secure the wishbone
Using a car to secure the wishbone

Who invented reverse-thread, and why? I bet there are a bunch of good reasons actually, but when the #$@! hub-nut is stuck fast, you really start to question whether you’ve got the thread right.

Today has been a good day. In the morning I managed to find two front uprights, and they look in good condition. Even better was that the pair cost the same as what I was originally quoted for just one.

Then I decided to put some more effort into stripping the diff. Armed with my sparkly new 41mm socket, and chunky 450mm 3/4″ power-bar, no hub nut could stand in my way. I followed the advice of the Guru, and dropped a car on the wishbone. I figured this was overkill, but why not. Important note – those wishbones have some nasty screws spiking out of them, make sure you don’t give your car (or more importantly, the missus’ car) a puncture.

Side shaft (normal thread) and bent steel bar
Side shaft (normal thread) and bent steel bar

I had prepared a steel bar to attach to the wheel bolts, to prevent the hub from rotating. I also had an old piece of steel tubing to extend the power-bar. “Normal Thread Hub Nut” came off very easily, and I thought that too much fuss had been made of this whole business. However, the force did manage to put a curve in the flat bar I was using to prevent the hub from rotating.

Finally the reverse-thread hub-nut shifts
Finally the reverse-thread hub-nut shifts

“Reverse Thread Hub Nut” was to teach me a lesson. Eventually I had to add two pieces of wood on top of the wishbone to try to distribute the car’s weight better to keep the whole shaft on the ground. I also had to reinforce my steel anti-rotation bar to prevent it bending. Finally the nut shifted, although about three times I checked that the thread truly was reverse. Useful note – the reverse-thread nut has a white nylon strip, whereas the normal thread (in my case) was green.

Note the reinforced steel bar to prevent rotation
Note the reinforced steel bar to prevent rotation

To finish a good evening’s work I popped one of the front uprights in the vice. This also has a 41mm nut, and once again the white one was reverse threaded. It came loose relatively easily. I’m holding thumbs the other is as easy.

Next the whole lot gets a good cleaning, to see what condition all the joints and bearings are in.

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