Rear axle bearing.. To replace or not?

r854rnr · 01-17-2006, 12:07 PM

ok, the machine shop said that they are sealed bearings and I should replace them. The reasoning he gave was that the axle lube will deteriorate the bearing grease and cause the to dry out and die. Is this true? The bearings aren't the cheapest part of the job, so I was hoping to avoid replacing them. Should I just bite the bullet and replace them anyway?

Has anybody done the rear axle seals and not changed the bearings?
I've read the writeups and it sounds ike most people just replace the inner seals. I'm doing both and I have found minimal info about the bearings. Any help is appreciated.

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surf4runner · 01-17-2006, 12:43 PM

could be worth doing, depends on the mileage, which is...?
(still) sealed bearings should be fine for many many miles

r854rnr · 01-17-2006, 01:04 PM

oops, my bad. My mileage is about 93K.

4Crawler · 01-17-2006, 01:17 PM

If the inner seal leaked and let gear oil get to the wheel bearing and oil was leaking through the bearing seals, then yes, the bearing grease has likely been washed out (BTDT). If no oil has gotten to the bearing, then it is up to you on replacement. Should run 200K pretty easily on the wheel bearings. If it feels tight, then keep it in there. You are trading off the cost of the bearing vs. a future cost of the bearing plus the labor to change it (which you are already paying for with the seal R&R).

Unhappy99 · 01-18-2006, 07:14 AM

Lets see....the arguement is that the diff oil has washed the grease out of a SEALED bearing? This is a new use of the word 'sealed' which I am previously unfamiliar.

Replace the bearing when its worn. Mine lasted 160K miles, and two or three axle seals.

Localmotion · 01-18-2006, 07:19 AM

Quote:

Originally Posted by Unhappy99

Lets see....the arguement is that the diff oil has washed the grease out of a SEALED bearing? This is a new use of the word 'sealed' which I am previously unfamiliar.

Replace the bearing when its worn. Mine lasted 160K miles, and two or three axle seals.

just bite the bullet and replace it.

4Crawler · 01-18-2006, 08:40 AM

Quote:

Originally Posted by Unhappy99

Lets see....the arguement is that the diff oil has washed the grease out of a SEALED bearing? This is a new use of the word 'sealed' which I am previously unfamiliar.

Replace the bearing when its worn. Mine lasted 160K miles, and two or three axle seals.

Well, seals are not perfect. There are two axle seals and two bearing seals in play here. Gear oil is inside the axle housing. There is the seal where the axle shaft leaves the housing. If it fails, oil can get past it. If the o-ring that seals the axle to the housung fails, you get oil leaking oil leaking out between the housing and the brake backing plate, no real harm done. Next in line are the seals on the wheel bearing. If oil works its way past the bearing seals (they are no different than the seal on the axle shaft, a rubber lip attached to the outside of the bearing that rides on the inner race to keep grease in), then oil mixes with the grease, thinning it. The thinned grease/oil mix can work its way past the other bearing seal and ultimately through the outer axle seal where it leaks out inside the rear brakes. If you have oil leaking there and it has been leaking for a reasonable amount of time, that oil must be coming through the wheel bearing. And along with the leaking oil, there must be some of the wheel bearing grease. I have seen it happen and have replaced bearings because of it.

leebee · 01-18-2006, 01:08 PM

i will second rogers posting, it happened exactly that way on my 93. when we got the bearing off the axle, there was NO grease what so ever left in the bearing, the seals were gone as well. ive done both of mine, at different times. the drivers side was a piece of cake but the pass side had to be cut off. no amount of pounding on 1" plywood would budge the bearing. my hands were aching for several days afterwards.

lee

Unhappy99 · 01-19-2006, 07:11 AM

The outer seal is nothing but a dust seal, not intended to keep in fluid. The bearing does not make a good seal to the axle housing, nor to the hub. Diff fluid leaks from the inner seal, goes between the bearing and the axle housing and hub and on out.

Mason Dixon · 03-12-2006, 08:23 AM

is the bearing pressed on?

4Crawler · 03-12-2006, 09:12 AM

Yes:
- http://www.4x4wire.com/toyota/mainte...axle/oil_seal/

BruceTS · 03-12-2006, 12:19 PM

Once the inner seal (axle housing and axle shaft) leaks, oil start going through the sealed bearing on the axle shaft washing out the thick grease. If you replace the axle seal, the bearing will no longer have sufficent lubrication and will prematurely fail. Now if there isn't too much play in the bearing, you can simply re-pack them. I used a small nail head to pry off the seal on the bearing, then use a thick moly bearing grease, pack in as much as possible and re-install the seal.

jeremys73 · 03-13-2006, 06:14 PM

drive it til the wheels fall off

01-17-2006, 01:04 PM	#3 (permalink)
r854rnr Registered User Join Date: Jul 2003 Location: Oakdale, MN Posts: 279	oops, my bad. My mileage is about 93K. __________________ Kevin Black 1998 4runner SR5 4wd http://www.cardomain.com/memberpage/760675

01-17-2006, 01:17 PM	#4 (permalink)
4Crawler Contributing Member Join Date: Jun 2002 Location: SF Bay Area, CA Posts: 7,828	If the inner seal leaked and let gear oil get to the wheel bearing and oil was leaking through the bearing seals, then yes, the bearing grease has likely been washed out (BTDT). If no oil has gotten to the bearing, then it is up to you on replacement. Should run 200K pretty easily on the wheel bearings. If it feels tight, then keep it in there. You are trading off the cost of the bearing vs. a future cost of the bearing plus the labor to change it (which you are already paying for with the seal R&R). __________________ 1985 Toyota 4Runner SR-5, 22REC engine, dual t-cases, 4.88 gears, dual ARBs, 33x10.50 BFGs or 35x12.50 MTRs r.c.brown@ieee.org TruckEditor@tlca.org Project: 4Crawler 4Crawler OffRoad Gettin'Off 4WD Club

01-18-2006, 07:14 AM	#5 (permalink)
Unhappy99 Registered User Join Date: Sep 2003 Location: Albuquerque, NM Posts: 381	Lets see....the arguement is that the diff oil has washed the grease out of a SEALED bearing? This is a new use of the word 'sealed' which I am previously unfamiliar. Replace the bearing when its worn. Mine lasted 160K miles, and two or three axle seals. __________________ 03 Dodge Ram 2500 CTD...its amazing Ex: 1999 4Runner JT3HN86R1X0199261...Now somebody elses Karl Malone Toyota 'Certified' POS Legendary Toyota quality is exactly that: A thing of legend. Defective fuel gauge - 'Certified' Defective brake rotors - 'Certified' Defective axle seals - 'Certified' Defective heater diverter - 'Certified' etc. etc. etc.

01-18-2006, 01:08 PM	#8 (permalink)
leebee Contributing Member Join Date: May 2004 Location: marlbank, canada Posts: 2,450	i will second rogers posting, it happened exactly that way on my 93. when we got the bearing off the axle, there was NO grease what so ever left in the bearing, the seals were gone as well. ive done both of mine, at different times. the drivers side was a piece of cake but the pass side had to be cut off. no amount of pounding on 1" plywood would budge the bearing. my hands were aching for several days afterwards. lee __________________ 93 sr5 v6 auto, 4x4 Photos http://s866.photobucket.com/albums/a...albumview=grid there are quite some attractive ladies on here with Toys. (compliments of ironmike) ifsc 3(.0) http://tlca.org www.of4wd.com www.sontt.com

01-19-2006, 07:11 AM	#9 (permalink)
Unhappy99 Registered User Join Date: Sep 2003 Location: Albuquerque, NM Posts: 381	The outer seal is nothing but a dust seal, not intended to keep in fluid. The bearing does not make a good seal to the axle housing, nor to the hub. Diff fluid leaks from the inner seal, goes between the bearing and the axle housing and hub and on out. __________________ 03 Dodge Ram 2500 CTD...its amazing Ex: 1999 4Runner JT3HN86R1X0199261...Now somebody elses Karl Malone Toyota 'Certified' POS Legendary Toyota quality is exactly that: A thing of legend. Defective fuel gauge - 'Certified' Defective brake rotors - 'Certified' Defective axle seals - 'Certified' Defective heater diverter - 'Certified' etc. etc. etc.

03-12-2006, 08:23 AM	#10 (permalink)
Mason Dixon Registered User Join Date: Jul 2005 Location: Huntsville, Alabama Posts: 797	is the bearing pressed on? __________________ http://www.sectalk.com/images/graphi...ds/alabama.gif 2000 4Runner SR5 4x4 Sport

03-12-2006, 09:12 AM	#11 (permalink)
4Crawler Contributing Member Join Date: Jun 2002 Location: SF Bay Area, CA Posts: 7,828	Yes: - http://www.4x4wire.com/toyota/mainte...axle/oil_seal/ __________________ 1985 Toyota 4Runner SR-5, 22REC engine, dual t-cases, 4.88 gears, dual ARBs, 33x10.50 BFGs or 35x12.50 MTRs r.c.brown@ieee.org TruckEditor@tlca.org Project: 4Crawler 4Crawler OffRoad Gettin'Off 4WD Club

03-12-2006, 12:19 PM	#12 (permalink)
BruceTS Contributing Member Join Date: Nov 2003 Posts: 2,317	Once the inner seal (axle housing and axle shaft) leaks, oil start going through the sealed bearing on the axle shaft washing out the thick grease. If you replace the axle seal, the bearing will no longer have sufficent lubrication and will prematurely fail. Now if there isn't too much play in the bearing, you can simply re-pack them. I used a small nail head to pry off the seal on the bearing, then use a thick moly bearing grease, pack in as much as possible and re-install the seal.

03-13-2006, 06:14 PM	#13 (permalink)
jeremys73 Registered User Join Date: Dec 2005 Location: North America Posts: 490	drive it til the wheels fall off __________________ 1998 TOYOTA 4RUNNER 3.4l \| Auto \| eLocker

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