Confused about S60 axle bolts

Post by **paul1149** » 14 Apr 2022, 19:34

I've got a 2001 S60 that I'm doing some work on. I put in new front axles. Every video I watched showed the mechanic removing the soft plug from the axle end before fixing the axle bolt (the axle shaft end is drilled and tapped to accept the axle bolt). That plug apparently holds back grease, and yet the new axle bolts come with what looks like red locktite on them. That seems like a contradiction.

I had reason to pull one of the axle bolts after my installation, and when it came out half the threads to my dismay were loaded with grease. Also, when I unscrewed the bolt it seemed that it had lost torque from when I had installed it.

It seems to me that greasing an axle bolt would be asking for trouble. I guess the wheel wouldn't fall off, as it is bolted to the hub assembly, which is bolted to the knuckle. But none of this is adding up for me. Any insight would be much appreciated.

Also, it is true that the axle bolt washer should be greased before installation? Thanks.

Post by **vtl** » 14 Apr 2022, 23:26

The bolt is torque-to-yield, it stretches to clamp the best. Grease is for corrosion prevention. Even if the bolt greased, the clamped portion of the thread pushes the grease out and makes locking compound working.

Subframe bolts uses the same scheme: grease and threadlocker.

Post by **erikv11** » 14 Apr 2022, 23:34

I get the idea and vtl knows more than me but IMO there should be no grease. I've had trouble making them stay tight so if I find any grease at all, I clean it out and put the new bolt in dry.

Here is some related axle minutiae including the torque specs: viewtopic.php?p=583897

Post by **vtl** » 14 Apr 2022, 23:53

If I remember correctly, the CV joint is drilled all through, so you may see CV grease in the drilled channel.

Personally, I use improved Volvo bolts with rubber cones and never torque-to-yield them, so they last a very long time. I grease the area around the washer with marine grease when install, so they don't rust in, and spray their heads with cavity wax when they start to rust after NE salty winters.

In 10 years tenure with 4 Volvos never lost one bolt or found them slackened.

Grease is good. Better, than snapped bolt, which is a reality here.

Post by **erikv11** » 15 Apr 2022, 08:42

vtl wrote: ↑14 Apr 2022, 23:53 ...
Personally, I use improved Volvo bolts with rubber cones and never torque-to-yield them, so they last a very long time.
...

Could I get a part number for that? I have not seen a listing for one that says it fits the XC70 or S60. Are these the XC90 axle bolts?

Post by **paul1149** » 15 Apr 2022, 09:03

The rubber cones sound interesting. I will look into that. I saw them somewhere but I don't recall where. I have a hard time reconciling the grease to the threadlocker, and visualizing the threads adequately chasing the grease out upon insertion.

The other thing I wonder about concerning TTY in this application, is that the initial torque part of the loading might not be enough to seat the axle shaft fully in the hub, making the final angle torquing inadequate. Were that the case the bolt would loosen up quickly upon use as the shaft subsequently made its way home. I wonder if that's what happened to the axle nut I took off.

Thanks much for the replies. Any other thoughts would be most welcome.

Post by **vtl** » 15 Apr 2022, 09:50

erikv11 wrote: ↑15 Apr 2022, 08:42 Could I get a part number for that? I have not seen a listing for one that says it fits the XC70 or S60. Are these the XC90 axle bolts?

They are discontinued. You can buy short XC90 bolts and reuse the cones on your long bolts.

Or find any stiff rubber cones, drill them and use in you Volvo.