View Full Version : wheel hubs/bearings

11-04-2008, 11:59 AM
quick question - How do you tell if your wheel hubs/bearings are bad? I know my suspension needs replaced, and while I am at it, I wanted to check these as well (1991sc). Also, do they make a rebuild kit for them, or do you need to buy a whole new hub assembly? Would bad hubs in the back create wheel hop?

11-04-2008, 03:46 PM
>How do you tell if your wheel hubs/bearings are bad?

If they have 100,000 miles, they're due.

Lift the wheel(s) off the floor and check for lateral runout/freeplay. If you find any, consider replacement. Make sure that any found freeplay isn't from other components such as the upper/lower ball joints in the control arms.

RockAuto has fresh hub/bearing assemblies. The 'extended life' non-adjustable design discourages simple bearing replacement.

11-04-2008, 04:38 PM
like this one? This will be my issue as finding play, because all my ball joints/control arms are shot. What are the effects of bad wheel hubs?



11-04-2008, 04:42 PM
if your hub berrings are bad you would hear a growling noise when driving.

11-04-2008, 04:52 PM
Sorry, I could have been more helpful before - the typical way to check is to get the wheel/tire off the floor, and to load it to one side at the very bottom, and then set a micrometer on one side of the lower tire edge, to zero. Next, unload the wheel and take a reading. Finally, opposite-load the wheel and read again. The sum of both readings is the total amount of play. If the tire wheel is heavy, you may have to pull at the bottom and push at the top at the same time to make full movement. Lock the wheel and use a pry bar if you're not hefty enough to persuade things to move.

An exact specification for how much freeplay is too much is hard to agree on when it comes to this type of bearing design. A new bearing/hub assembly would not have any noticeable play. Thus, it follows that any noticeable play indicates wear.

I work from the point of view that if the freeplay can affect the toe, then it is too much. This means the car must be on a machine, and moves the check out of the realm of DIY at home.

So what do do...? The fallback metric then becomes mileage. How many miles are on the current hub/bearing assemblies?

If known, and more than 80k miles...consider replacement (regardless of play) if a total frontend overhaul is being done.
If not known, you, the owner of the car, have to make a judgment call based on budget, time and common sense.

Most alignment shops are happy to check the car if they think you'll eventually be back and willing to pay for an alignment. If the shop offers a warranty, it is in their interest to first make sure the car can take one, otherwise the odds are they'll being repeating the labor, at their expense, if you come back with a complaint.

Of course, some shops with less-than-admirable ethics can try to scare the owner by claiming such-and-such parts need replacing or an alignment won't help...this is one reason to go to a national chain or shop - and another reason to do your own checks at home first.

>What are the effects of bad wheel hubs? (I assume you mean hub/bearing assemblies)

pulling to one side when driving and/or braking
unusual tire wear

Note the above list can occur in various combinations and come /go depending on road surface, temperature, car load, driving style, etc. Some may not surface at all, yet bearing condition/wear could still be contributing to others.

Wheel hop in the rear (if deemed related) is usually a combination of bad bearings and worn suspension in general. I can imagine severely bad bearings causing dramatic results, but in this case, there would be no question about them being trashed.

>like this one?

Are you equipped to service your own bearings? Are your hubs still serviceable? Bearings come as an assembly with the hub for a reason. Don't forget fresh nuts :)
If the cost seems high, consider how long they last...the cost is less than a penny-per-mile over a normal service life.

11-04-2008, 07:30 PM
what do you think about these?

http://www.worldsuspension.com/ShopByVehicle.epc?q=1991-FORD-Thunderbird--Sc-V6--3--ci--3.8l--F/i--Supercharged--Vin--R--sc-Steering/suspension&yearid=1991%40%401991&makeid=28%40%40FORD%40%40B&modelid=5579%40%40THUNDERBIRD+SC&[email protected]@V6-232ci+3.8L+F%2FI+Supercharged+Vin+R+(SC)@@11866&[email protected]@Brake%2FWheel+Bearing&[email protected]@Front+Wheel+Bearings+and+Seals&mode=PA

fresh nuts? Oh you mean the crush nuts? I have to take out my rear anyways - I know this is off-subject, but I have heard of people using the drivers side axle in the back for the pass side (I guess the bar is thicker?). I have one laying around - should I put that one in? Does it make a difference?

11-04-2008, 09:06 PM
>what do you think about these?

Fine, I guess, if you have the tools to press them in/out properly and know how to check/prevent any spin in the hub.

>I have one laying around - should I put that one in? Does it make a difference?

Are you bustin' axles, or just looking to beef up?

Measure one against the other and use a beefier one if you have cause, but just remember, if you make one item less prone to taking a beating, you'll risk moving the load to another component that may be much more expensive and difficult to service. In addition, the heavier an axle is, the more torque it takes to spin it. Who knows if two heavy ones would amount to any kind of power loss at that point...

J dot Miller
11-04-2008, 09:09 PM
You can press the rears. Not sure about the fronts...

11-10-2008, 09:32 AM
so if I read this right - for the rear, you only need the bearing, and not the hub/bearing combo? My pass. rear bearing is shot (there is play in and out of the wheel when on the ground!), and I need to replace this asap - just trying to figure out what I need, as I have never done anything with bearings before... I assume rockauto is the best/cheapest place to get one?

11-10-2008, 09:44 AM
Our FAQ on the main page has some info on rear bearing replacement: