Saturday, November 26, 2011

Driveshafts

A few months back i had sorted out my driveshafts.

They consisted of mini splines at the wheel hub end and Toyota splines at the other for the inner cv joints to the gearbox. This was done with the car on the hoist and all the suspension in place. I had to cut the existing driveshafts with a fairly large overlap to allow for adjustment in order to find the right length.

You ideally want to make the driveshafts the right length so that the shaft and cv joints are as close to the gearbox as possible without the shaft bottoming out as you hit a bump in the road. What i found is that the mini suspension worked in the complete opposite to what you would think. Instead of the shafts pulling away from the gearbox as the wheels were lowered (car raised), they actually pushed them inwards. It didn't take too long to get the jist of things until i marked the two shafts, cut them and tack welded them.

Originally i had planned to take these to a shop to reproduce and to make up into single billet heat treated driveshafts, but this didnt end up happening. I spoke to John at Rotomotion who previously did this for another Ausmini build, and he told me it would cost almost $1000 to make as the cost of heat treating had gone up since then. The other option he offered me was for their boilermakers to properly pin them, weld them then have them sort of heat treated by letting them cool slowly overnight. I forget what this method was called.

When speaking to John i did ask whether this was suitable and strong enough to withstand the force from the engine, and he said that because the rest of the driveshafts were already heat treated from factory and that it was just the weld that needed treatment, it would suffice. Also that the spline of the mini hub would break before the weld would, as long as it was welded properly. I took his word for it and it cost me $250.

Sadly i dont have a picture of them at the moment. But i will update with one in the future.

2 comments:

  1. Hey rj I'm looking for some specs on the drifshaft you made? Any chance you could post a photo or send me through the measurements

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    1. I know that in 2017, he broke one of these driveshafts on the dragstrip and later had a pair of one-piece shafts made - I don't know any specs though.

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