Bearing Hub - The inside story

[Opera House]

I had to replace a front bearing hub on my 97 with 145K on it. Best price I could fine for replacement was a Timken (same as factory) for $140 with a new sensor. I had questions about the internal construction so I pressed the old one apart on a 20 ton press. Probably took less than 10 tons to open it up. Supported the three hole mounting flange and pressed from the back on the spline shaft. It easily popped apart with the speed gear mounted on the back bearing. Shields popped out without damage. Wheel side bearing was slightly damaged with contaminated grease, what there was of it. No reason why you could not press it back together.

It is obvious that this damage could have been prevented with greasing halfway in its life. There is no reason why the speed sensor can not be pulled out and greased through that opening. Some conical adaptor on the grease gun would work nicely. One word of caution. These sensors do not come out easily because of rust and you should be prepared to buy a new hub if it snaps in the hole. As long as you don't go wild with pressure and speed the seals should not pop out. Wheel side shield obviously gets more wear.

Something you might think about when doing brakes at 70K or more. Both bearings are conical roller bearings and the torque spec for the shaft nut is to keep the bearings from seperating. No pictures, this is Theatre of the Mind.

CAUTION: It is probable that sealed bearings contain polyurea grease because of the long life properties. These are not compatable with the more common lithium greases. One of the results is the grease thins several grades lower and causes bearing failure. Check the contents of your grease first.

 

[V8BoatBuilder]

Opera House, where did you purchase the Timken Bearing/Hub?

Also, is there a way to do this without a press?

 

[Opera House]

The sensor is 0.72" deep and has a diameter of 0.38". There is an O ring 0.2" from the top of the sensor. This is the short section that rusts and may cause sticking when you try to pull the sensor out. The sensor mounts with a single bolt. I am going to turn down a short 1/2 long section of brass with a fitting on one end and an O ring mid section. This will keep grease form squirting back out on me and allow the tolerances to be quite loose.

There is very little reason to dissasemble the bearing. Greasing should be all you need to do if you catch it early enough. You would not be able to replace the internal custom bearings that are pressed onto other sub sections. Basically it is just like the older Explorers except more compact without reserve grease sections. The front seal by this time is open enough to allow air to escape ans some grease slowly. If I had had this information two years ago, I could have saved a lot of money.

I purchased the bearing TIMKEN #SP450200 from a local store that is part of the PARTS PLUS network. I buy from about 5 stores (including Autozone and Advance) and prices can vary quite a bit. Pays to shop around.

 

[V8BoatBuilder]

Opera House, thanks for find this out about the bearings. Since it's preventative maintence, I'd like to try greasing mine before replacement.

Could you please post a procedure as to how to inject the grease into the bearing, ie: what to look for, what to dissasemble, where to insert the needle.

Thanks,
Aaron

 

[jasonb]

aaron.. check this out..

http://www.explorerforum.com/forums/showthread.php?s=&threadid=77262&highlight=bearings

 

[V8BoatBuilder]

Jason - that's awesome. Thanks.

 

[Opera House]

As much as I wanted to build something

I found an oversize thread zerk fiting in the junk box. Just slightly smaller than the hole and a single wrap of tape made a nice fit. You could also do this with a smaller zerk and a flat washer. Then you just press in, pump, and spin the hub once and a while. Ideal would be to have a second person spin the hub while you are applying pressure.

 

[m4grunt]

Opera House - - Is there any way to replace JUST the bearings in the hub assembly? I have the Timken part number and various manufacturer cross matches to that part number, but I have yet to find someone that sells the bearing. THANKS!

 

[Rick]

Post the Timken part number for the bearing. I'll see what I can find.

 

[m4grunt]

The Timken part number is 200S....I'll get the other cross numbers posted shortly.

 

[lonestar]

Try a bearing house. All you need is the bearing number. It might not be Timken, but bearings have standard numbers.

Autoparts store just want to sell the whole assembly.

When I heard people buying entire hub assemblies for $150, I wondered why you couldn't just replace the bearing. It may take some more work and a press, but it sounds like it is possible.

 

[m4grunt]

I have been told that the Timken 200s is proprietary to Ford Explorers and that the bearings cannot be sold individually due to liability concerns. I think that's a bogus sales ploy, but that is the line I have been given.

 

[lonestar]

Try these...

The original bearing part number is NSK 6200Z, which crosses to a Timken 200S or an *** 6200.2ZR.C3

Dead Link Removed

 

[m4grunt]

Lonestar - Thanks for posting that link. I found that site a couple days ago and didn't write it down or copy it.

Has anyone had any luck finding a source for these bearings? Don't want to come off as "pushy", but $10-$12 per hub as compared to $170 per hub? Hummmm. I think I'll try the bearings first!

 

[Opera House]

It is a lost cause

My original intention was to see if the inner and outer bearings were the same. This might allow me to buy a new hub and make a second good one from parts of the two old ones. The outer bearing is the most likely one to be damaged from dirt and higher pressures. Unfortunately the inside bearing axle sections are not identical. Individual rollers can be switched between the two. If you could purchase these bearing sections, there is not enough space to grab onto the bearing and press it off. There is a possibility that the sensor gear could be pressed off without damage but this bearing is not likely to fail first. The outside of both bearings is machined out of the housing and can't be pressed out like on a brake rotor. If there is doubt on the bearing condition the hub can be pressed apart, inspected and pressed back together.

So, if there is any real damage, the hub isn't rebuildable. An oversize thread zerk fitting with a wrap of tape works great to grease these from the sensor hole. It easily builds enough pressure to push grease out of the front and back seals. My old hub is still good enough to make a great rotary weld table out of it. Think prevention.

 

[Rick]

Here is a source for the bearings.

http://www.commercialbearing.com/product.htm?pid=151993


In Berea, OH you can try Rit Bearing at 1-800-555-6292. Ask for John.

 

[Opera House]

Something lost in translation?

Is that just a general source? The hub housing certainly doesn't have the pictured bearing in that link.

 

[jimbo74]

hmmmm.... maybe something to look at... my moms 96 seems to have a good amount of vibration in the wheel at all speeds.... its got like 156k on it...... i was thinking maybe it was normal becuase there is a front end always spinning even if in 4x2 but im wondering about bearings now......

 

[Rick]

Re: Something lost in translation?

Originally posted by Opera House
Is that just a general source? The hub housing certainly doesn't have the pictured bearing in that link.

I agree. This is what I found out. The NSK 6200Z and the *** 6200.2ZR.C3 both have inner diameters of 10mm. Obviously not the correct diameter for a spindle. I don't know where those numbers came, but they aren't the correct cross match for the Explorer wheel bearing.

Is the original bearing a Timken tapered roller bearing? Is that the 200S?

 

[V8BoatBuilder]

I purchased a new hub/spindle/abs sensor module for $165 at PepBoys. It was made by some random company, but does have a Timken bearing inside. I will get the number off it shortly.

I also pulled both front wheels and attempted greasing the current bearing. I found there was still grease inside, but not much. I was able to remove both left and right ABS sensors and inject grease untill it oozed from the outside seal. It never oozed from the inside.

Front Hub Assembly, ABS Sensor

Here are some shots of the new assembly (yet to be installed)

2nd Gen Front Hub: Side View

2nd Gen Front Hub: Outside(Wheel Mounting Surface)

2nd Gen Front Hub: Inside (Showing Timken Bearing)