Should I replace wheel bearings?

[rwest]

Hi,

I had some bad tire wear on the rear driver side and I'm pretty sure my front pass. side torsion bar has broken. I have owned it for 17 years and have not done anything with the suspension, and the receipts that came with the car don't show any susp work either. So I have parked it for the winter, and will re-do the entire susp. and give it some new tires in the spring. The question I have is: Should the wheel bearings be replaced or are they a "lifetime" part?

Rutager

[BK911]

If you are replacing the entire front end, why not spend the extra $20 and do the wheel bearings too?

[island911]

If it ain't broke...

Bearings will let you know (noisy) when they need attention.

[IROC]

Wheel bearings are not a "lifetime" part, but if when you remove them and inspect them and find no excessive wear, etc., there is no reason to replace them. My car still has the original wheel bearings in it (except for the driver's side rear)...

[KTL]

Agreed about "NO" on the replacement. 911's are indeed great with respect to front wheel bearing ease of service and replacement. Inspect them first and don't just do them while you're in there. If you don't see any scoring of the races or blueing of the rollers, they're fine to simply repack with a quality EP grease.

The rears are a bit of a bear to replace. If they aren't making noises, leave them be. They'll let you know when they need replacing. Not to mention the new bearings these days aren't necessarily as good as the old bearings. Some of the bearings from FAG and SKF are not as good as the old Timken and FAG bearings from years ago.

[rwest]

Thanks for the great info, guys!

I was sort of on the fence with them, on one hand they're not expensive, but on the other, I have been reading a lot of susp posts and bearings rarely came up. In fact one poster made the comment to replace every 500,000 miles! I wasn't sure if it was a joke or not, it might be spot on! Another thought I had was that they might be pressed on and with my luck I would end up with a cracked trailing arm!

Any other thoughts would be greatly appreciated.

Rutager

[KTL]

Well they're both pressed on. Front less so than the rear.

Fronts have the races pressed into the hub and are easy to service if you heat the hubs in an oven or the BBQ grill to use the different thermal expansion of the metals which allows you to get the races out without damaging the hubs. The bearings just lie in the races and fall right out when you remove the hub from the spindle. They are GREAT for ease of maintenance- regreasing is messy but that's the price you pay for it being so easy.

The rears are pressed into the trailing arm and you have to destroy the bearings to remove the stub axle hub and then slightly heat the trailing arm to draw the bearing out with a press tool arrangement. Installation is equally slightly touchy in that you have to press the bearing back in without damaging it. It's not all that hard, just need to know what you're doing so you don't damage either the trailing arm or your new bearings.

[BK911]

Wow, I guess I am in the minority here. I def agree with the aint broke don't fix it rule. But if I am spending north of 1k to replace the entire front end, I just couldn't sleep knowing I reused 17 year old $20 bearings. In fact, if I replaced the front bushings I would do the rears too. And while I had the banannas off, I would put new rear bearings too. Maybe that's why I am broke?

[Mitch Leland]

I think we still can agree that there is a service cycle to the bearing so you might as well replace them "while you're there" if for no other reason.

[GaryR]

Originally Posted by BK911

Wow, I guess I am in the minority here. I def agree with the aint broke don't fix it rule. But if I am spending north of 1k to replace the entire front end, I just couldn't sleep knowing I reused 17 year old $20 bearings. In fact, if I replaced the front bushings I would do the rears too. And while I had the banannas off, I would put new rear bearings too. Maybe that's why I am broke?

I'll join that minority, they are a wear item like it or not.

[tharbert]

Normally, I would say "just change them." But since yours are only 33 years old and on the plus side of 100K miles, they are probably fine. You can just look and see they are fine.

+1 Replace em'. They are a very common size and available here or at your LPS.

Include new grease seals. That'll set you back another $15. Cheap insurance.

[KTL]

That's exactly my point. The fronts are cheap and you can replace them at any time in the future without affecting your suspension work. The "while you're in there" term is more appropriate for something like rear suspension bushings, where you'd be messing up your alignment if say for instance you decided to only do the spring plate bushings now. When you decide to replace the trailing arm pivot bushings (which seemed in okay condition at the time) in the future, you'll be re-doing work you've already done. Whereas the wheel bearings don't even have to be messed with at this time.

To each his own. But I disagree that the front wheel bearings are a no-brainer as long as you're doing the suspension. Especially on a street car. These bearings are very robust and last a LONG time. Fresh grease is all they need to go for many many miles. A simple visual inspection will tell you whether or not they need replacing on account of neglecting re-grease them over the years.

Just make sure you do the front bearings right- heat the hub for ease of driving the race out. It's very easy to cock the race in the hub if you don't install a cool race into a heated hub, and then that simple $20 while you're in there job all of a sudden just caused you a nice headache.

[rwest]

Hi Kevin,

If I understand correctly, waiting to do the bearings if or when they go won't be any harder or more expensive than when I'm working on the susp this spring. Is this right? I'm planning on replacing all the bushings front and rear, so I'm guessing I'll have trailling arms and front hubs seperated from the car, making it easy to bring to a good machine shop(letting them take the risk!)

Thanks for all your, and everyone else's input, Rutager

[KTL]

The front hubs are easy to take on & off and doing the suspension work is completely independent of the front hubs, despite that you have to take the hubs off to get at the suspension ball joints. But when you go to do the front bearings later, you don't mess with the suspension whatsoever. All you have to do is remove the brake caliper and then reove the metal grease cap. With the grease cap removed you'll find the pinch-nut on the spindle and it's simple to remove.

The rear bearings are actually easier to do with the trailing arms installed because when the trailing arms are left installed onto the car they afford you something (the chassis) to hold the trailing arm while you press out and press in the bearings and the hub/axle assembly. Pressing the bearings is probably same level of difficulty whether the trailing arms are in or out of the car. But removing the hub requires some slide-hammering and the chassis does a better job of "vise-ing" the trailing arm than does a bench vise.

However, the rear inboard bushings are much easier to do with the trailing arms removed. I'd recommend doing these bushings with the trailing arms removed so you can work on them on your workbench vise and drive out the old bushing retainers.

[rwest]

Kevin,

Thanks for the extra information, I'll be replacing the trailing arm bushings, so will do them on the bench! I also plan on replacing the A-arm bushings too. I'm figuring on removing them from the car also, is this the best way too?

Rutager

[GaryR]

Originally Posted by rwest

Kevin,

Thanks for the extra information, I'll be replacing the trailing arm bushings, so will do them on the bench! I also plan on replacing the A-arm bushings too. I'm figuring on removing them from the car also, is this the best way too?

Rutager

Yes. While off you can refinish the A-Arms, do the ball joints and tie rods if they are old or boots shot. Heat on the bushing covers and a twist, they pop right off.