Rear Wheel Bearings :(

[gtyates]

Well I finally got bitten by the rear wheel bearing bug. What a pain!! Both bearings were bad. Main symptom I had was noise, though about a month a go I developed an occassioanl "sway" feeling in the rear end. I finally had my wife drive the truck and me follow her, and when doing this I could actually see the left rear tire wobble a bit at the same time she was feeling the "sway" while she was driving. I had a shop do all of the work (not mechanical myself). Total for both rear bearings and a 4 wheel alignment was $1228, including sales tax. Truck only has 85k miles, though it is a 2004. It is our weekend/travle vehicle. This is actually our first real repair on it, so I guess I can't complain too much, but what an EXPENSIVE issue to have due to a bad design!! And related, the shop I use had trouble diagnosing because when I initially brought the truck in they put it up on the rack and everything was solid, no wiggle in the tires, nothing. But after a month of it getting a bit worse (and me leaving them some notes of the symptioms we were having)they were finally able to see the wobble when the truck was on the rack and they were running it. Left bearing was toast, right was not far behind. Venting over now. lol!!

 

[imp]

This is actually our first real repair on it, so I guess I can't complain too much, but what an EXPENSIVE issue to have due to a bad design!! And related, the shop I use had trouble diagnosing because when I initially brought the truck in they put it up on the rack and everything was solid, no wiggle in the tires, nothing. But after a month of it getting a bit worse (and me leaving them some notes of the symptioms we were having)they were finally able to see the wobble when the truck was on the rack and they were running it. Left bearing was toast, right was not far behind. Venting over now. lol!!

I personally dislike the way today's wheel hubs are designed, from an Engineering standpoint, but I feel it a bit unfair blame the design itself. The glaring difference with these hubs is that the two bearings on each are placed "back-to-back", which makes them far less structurally sound than spacing them farther apart. Nonetheless, many last up into the 150K+ mile range, or more.

Regarding the shop finding no descernible movement when manual force was applied, bearings often are found to be close to "terminal" without "wiggle". To illustrate, I'll show it again:

This view shows the inner race of one of my hub's bearings, galled at it's center, but still having enough unspoiled surface at either side of the ruin to allow the rollers to roll over the spot without the bearing crumbling completely away; that would have eventually occurred. The vehicle was driven several thousand miles after the noise was first noticeable. Note that NO wiggle was discernible. imp

 

[mikeinri]

That's a very labor-intensive job, because so much stuff needs to come out. The parts aren't terribly expensive, making it tempting to DIY. That's about the mileage I had when mine started to make noise. I got more time than you before I also got the wobble. Very scary when it gets to that point.

Mike

 

[ponkotsu]

I personally dislike the way today's wheel hubs are designed, from an Engineering standpoint, but I feel it a bit unfair blame the design itself. The glaring difference with these hubs is that the two bearings on each are placed "back-to-back", which makes them far less structurally sound than spacing them farther apart. Nonetheless, many last up into the 150K+ mile range, or more.

Regarding the shop finding no descernible movement when manual force was applied, bearings often are found to be close to "terminal" without "wiggle". To illustrate, I'll show it again:

This view shows the inner race of one of my hub's bearings, galled at it's center, but still having enough unspoiled surface at either side of the ruin to allow the rollers to roll over the spot without the bearing crumbling completely away; that would have eventually occurred. The vehicle was driven several thousand miles after the noise was first noticeable. Note that NO wiggle was discernible. imp

Mine were way worse than that at 148k, but had absolutely no play. Just noisy and annoying. I think they can actually go for a really long time like that before finally completely coming apart. Driving at city speed, I think they would go practically forever.

 

[Nc2099]

i had the same issue.... but it wasn't even close to over 400 dollars to get changed out.

 

[gtyates]

I appreciate the replies so far. I guess what frustrated me so much about this issue is that on my '96 and '97 Explorers I went close to 150k miles on each and NEVER had a bearing problem. Overall we are happy with this '04, actually paid cash for it back in '08, just the cost to do this repair is a bit high!!

 

[ponkotsu]

I appreciate the replies so far. I guess what frustrated me so much about this issue is that on my '96 and '97 Explorers I went close to 150k miles on each and NEVER had a bearing problem. Overall we are happy with this '04, actually paid cash for it back in '08, just the cost to do this repair is a bit high!!

If you use good bearings and they are installed correctly it should be good for another 150k. If both rear bearings went out early, sounds like driving condition issues. Rough rough, lots of towing, etc. The tranny and the wheel bearings are the weak points on these trucks. I've heard that from a few pros.

 

[gtyates]

If you use good bearings and they are installed correctly it should be good for another 150k. If both rear bearings went out early, sounds like driving condition issues. Rough rough, lots of towing, etc. The tranny and the wheel bearings are the weak points on these trucks. I've heard that from a few pros.

I agree with those comments totally, but this truck of mine is basically a highway cruiser!! No towing, no off-road, and other than running a little above 80 on the interstate, no hard driving. lol!! But I have seen plenty of other discussion on here of early rear bearing failure, so something about either the design or the bearings themselves is a bit weak on this generation of the Explorer. Mainly this thread was just me venting!!

 

[imp]

If you use good bearings and they are installed correctly it should be good for another 150k. If both rear bearings went out early, sounds like driving condition issues. Rough rough, lots of towing, etc. The tranny and the wheel bearings are the weak points on these trucks. I've heard that from a few pros.

Just what is it that makes "pros" so much more knowledgeable than the rest of us? imp

 

[gtyates]

I will add these comments. Apparently our 12 year old son had noticed the "wobble" even before we did. A few months back we were heading out and starting getting into this Explorer. He asked "do we have to take mom's truck today"? We asked him why. He said riding in the back seat at times was upsetting his stomach. We had not noticed anything except it was noisy from the rear at that point (but this truck has ALWAYS had some rear noise since we bought it with 30k miles. Noise early on was the OE BF Goodrich tires. 85k now btw). It took about 2 more months of driving before we noticed the wobble, and also the noise got noticeably louder. So, if you have kids saying that they feel funny riding in the back of your Gen. 3 Explorer and you are noticing some rear end noise, you might be getting close to the bearing problem. But again, this thread was mostly for me to vent a little, but I hope some of this helps someone else diagnose a similar problem. I only pray that this is not the beginning of major issues with this truck.

 

[slayer_of_fords]

I have heard and personally experienced that torquing to 200 ft lb factory spec is too much. Had a shop install a Timken rear wheel bearing and it went out at 15k and had the wobble bad. Installed a new Timken myself and only torqued to 170 ft lb and it is good so far at about the same mileage. Maybe it was a bad one from Timken but I doubt it.. Ball joints are a pain on these trucks. They last but they are a PITA to replace..

 

[ponkotsu]

I have heard and personally experienced that torquing to 200 ft lb factory spec is too much. Had a shop install a Timken rear wheel bearing and it went out at 15k and had the wobble bad. Installed a new Timken myself and only torqued to 170 ft lb and it is good so far at about the same mileage. Maybe it was a bad one from Timken but I doubt it.. Ball joints are a pain on these trucks. They last but they are a PITA to replace..

Fastener torques are really not a good indicator of how tight something is. (Believe it or not) Thread efficiencies can vary from 10% to 90% depending on the condition of the threads and what lubrication is used. The idea of torquing a bolt is to get it tight enough to stretch it a little so it has a preload, but not break it. So for example if a bolt has a torque spec of 60 ft/lb dry, and you torque it with some grease or never seize on it, you are likely to break the bolt. If the same bolt is rusty and dry, that 60 ft/lbs might be barely enough to overcome the friction of the threads. That's why engine head bolts usually spec the torque by something like, 1/2 turn after snug, or something similar.

Having said that, 200 ft/lbs for a nut that large is actually a pretty low torque. And when you torque it, it's basically just squeezing the two hardened steel inner races together, metal on metal. It seems highly unlikely that you could apply enough torque to deform or damage the inner races.

The most common cause of early bearing failure is sloppy technique when pressing them in. Most mechanics do not know how to properly press in a bearing. If after pressing it in, and it isn't silky smooth and silent, you did it wrong and it will fail early.

 

[imp]

Fastener torques are really not a good indicator of how tight something is. (Believe it or not) Thread efficiencies can vary from 10% to 90% depending on the condition of the threads and what lubrication is used. The idea of torquing a bolt is to get it tight enough to stretch it a little so it has a preload, but not break it. So for example if a bolt has a torque spec of 60 ft/lb dry, and you torque it with some grease or never seize on it, you are likely to break the bolt. If the same bolt is rusty and dry, that 60 ft/lbs might be barely enough to overcome the friction of the threads. That's why engine head bolts usually spec the torque by something like, 1/2 turn after snug, or something similar.

Having said that, 200 ft/lbs for a nut that large is actually a pretty low torque. And when you torque it, it's basically just squeezing the two hardened steel inner races together, metal on metal. It seems highly unlikely that you could apply enough torque to deform or damage the inner races.

The most common cause of early bearing failure is sloppy technique when pressing them in. Most mechanics do not know how to properly press in a bearing. If after pressing it in, and it isn't silky smooth and silent, you did it wrong and it will fail early.

You are well-versed and understanding of the principles involved in the torqueing and tensioning of threaded fasteners! A refreshing thing to find among forum members. However, I plead to take issue with your consensus of torque not affecting bearing function. Think for a moment, if you will, about a plain, old, front wheel set-up with two tapered roller bearings whose outer races are confined within either a rotor hub, or drum, where the bearings' "running fit" is determined by a nut threaded onto the axle shaft. How tight did you make those nuts? About 5 Lb.-Ft.? Less? What about 200 Lb.-ft? Just a thought..... imp

 

[ponkotsu]

You are well-versed and understanding of the principles involved in the torqueing and tensioning of threaded fasteners! A refreshing thing to find among forum members. However, I plead to take issue with your consensus of torque not affecting bearing function. Think for a moment, if you will, about a plain, old, front wheel set-up with two tapered roller bearings whose outer races are confined within either a rotor hub, or drum, where the bearings' "running fit" is determined by a nut threaded onto the axle shaft. How tight did you make those nuts? About 5 Lb.-Ft.? Less? What about 200 Lb.-ft? Just a thought..... imp

You're comparing apples to watermelons. The old type tapered bearings relied on the torque of the nut to set the bearing preload. The rear bearings on the EX have a precision ground race set that does not depend on the torque. The races bottom out on each other and the preload is preset at the factory. They need to be torqued tight enough so they don't squirm around, but the upper limit is really limited only by the strength of the bearing race material, which is pretty damn strong.

 

[imp]

You're comparing apples to watermelons. The old type tapered bearings relied on the torque of the nut to set the bearing preload. The rear bearings on the EX have a precision ground race set that does not depend on the torque. The races bottom out on each other and the preload is preset at the factory. They need to be torqued tight enough so they don't squirm around, but the upper limit is really limited only by the strength of the bearing race material, which is pretty damn strong.

You are, of course, correct. I had forgotten the details surrounding these newer bearing "packages". The variable involved in establishing correct "crush" amount on a yieldable crush washer, or the stacked height of a solid shim instead, has been eliminated, thus allowing the installer to tighten to a much less critical specification.

Glad you brought this out! My apologies for being so insistently stupid. Now, if only those pesky pinion bearing preloads could be thus covered..... imp

 

[mikeinri]

The most common cause of early bearing failure is sloppy technique when pressing them in. Most mechanics do not know how to properly press in a bearing. If after pressing it in, and it isn't silky smooth and silent, you did it wrong and it will fail early.

Interesting. Where can we learn more about the proper way to press a bearing?

Mike

 

[mjp3262]

Wow, they really soaked you for that bearing job. Best bet is to do them yourself. I bought Timken bearings online for $75 each and $30 per axle to have old bearings pressed out and new ones pressed in. It's worth being without the vehicle for the extra day it takes to remove and replace them yourself. Just make sure you Torque them correctly and they'll last.

 

[n2audio]

Wow, they really soaked you for that bearing job. Best bet is to do them yourself. I bought Timken bearings online for $75 each and $30 per axle to have old bearings pressed out and new ones pressed in. It's worth being without the vehicle for the extra day it takes to remove and replace them yourself. Just make sure you Torque them correctly and they'll last.

I don't like to comment just to criticize a shop for making money, but I was thinking the same thing. $1200 for a pair of rear bearings is

National bearing was about $50, and I paid $50 at the machine shop for the press work, and the guy wired up my e-brake shoes while he was at it.
I'm a pretty slow worker at stuff like this - I think it took me 3-4 hrs to disassemble (some stuck stuff) and 2 or so to reassemble, plus an hour at the machine shop.

 

[gtyates]

Yes the $1200 was high, but that did include the 4 wheel alignment and the sales tax (over 9% in my area). So the actual rear bearing job was about $1000 of it. But hey, I am willing to pay for it to get it done correctly. And besides, mechanical work is not my talent. I prefer things like income tax work. My frustration is the fact that @85k miles the bearings were shot on a truck used mostly for vacation travel!!

I don't like to comment just to criticize a shop for making money, but I was thinking the same thing. $1200 for a pair of rear bearings is

National bearing was about $50, and I paid $50 at the machine shop for the press work, and the guy wired up my e-brake shoes while he was at it.
I'm a pretty slow worker at stuff like this - I think it took me 3-4 hrs to disassemble (some stuck stuff) and 2 or so to reassemble, plus an hour at the machine shop.

 

[zpn_by]

...My frustration is the fact that @85k miles the bearings were shot on a truck used mostly for vacation travel!!

I hear you, particularly for this price. But back in the day, it wasn't unusual to ahve to replace worn bearings on the front of my old mustangs (87-90) at about 40,000 miles. Granted this is an apples-to-watermelons comparison, but at least you got 85,000 out of it. My front bearings are going on my 02 EB, and I've got 96,800 on my truck now. I'm not working right now so I'll be driving as-is for now, but I figure I have about another 10,000 before they are shot.