Stripped stub axle

[Dr J]

I was tightening my cv joint bolts to the axle stub and felt one yielding at less than 24 ft-lbf. I have the M8 bolts that torque to about 33 ft-lbf. Can the stub axle be repaired with a helicoil or best to just get a used or new stub axle?

The bolt had about 6mm engagement. I was using slightly longer 50mm bolts vs the 45mm bolts that were there.

[kevingross]

Given the bolt grade and application, my own bias would be toward replacing the stub axle.

[PeteKz]

A new stub axle would be best, but Helicoils provide a very strong repair, and Timeserts even better. If you can't wait for a new stub axle, or can't bear the price, I would install a Timesert and if it torques to 33 lb-ft, then I'd run it and check it frequently until you are confident it is holding.

[stownsen914]

I'd be comfortable timeserting it. It would be a better fix than a helicoil.

For what it's worth, I had a 4 bolt, 2 pin output flange timeserted in the two pin holes to make it a 6 bolt flange. I haven't had any issues with the timeserts holding torque.

[yelcab1]

Timesert, or helicoil, retorqued, and then safety wired in place. That sucker will not come back out.

[safe]

Helicoil works, I've had that in my track car for a few years until the stub axle broke and the helicoil had nothing to do with that!

[Dr J]

Thanks all for the advice. I put up a wtb ad and have multiple responses. I guess they are pretty available in the used market and not very expensive. That’s where I’m going. Getting the whole timesert kit was as expensive as the used stubs. Interesting data on the helicoil Magnus.

The whole reason I was tightening bolts was because one axle came off. Fortunately for me, it was a very benign incident as I was a few blocks from home, was going through a school speed zone at crawling speed, and was coming off a stop sign.

Here is an interesting datapoint on all the discussions on how to keep the axle on. Three of the bolts were intact and three sheared off. The intact ones had backed off and had no washers on them. The sheared ones, that held to the bitter end, had nordlock washers. I guess I only had a few some years ago when I put them on some of the bolts only. Shame on me. From now on, they all get a nordlock washer.

[safe]

The Nordlock is great. I had those on my broken stub axle and the amount of torque I had to apply to get the bolt (M10) of was insane. To stretch a fully torqued 12.9 M10 the ramp height of the Nordlock, that takes some force!