My '67 Plymouth right rear wheel bearing is giving trouble. It appears that the outer seal has failed and is allowing gear oil to leak out onto the brake linings etc. I replaced this bearing, retainer and both inner and outer seals about 20,000 miles back because the bearing had worn out. I believe that at that time I purchased the parts from NAPA but I notice on their site that they offer only the bearing and the retaining ring but no seals. Is there a kit available that consists of the cup and cone bearing part as well as the retainer and both seals required? I am going to check with NAPA tomorrow but if anyone here knows of other sources, I would be interested. I also heard once of some type of "green bearing" which if I recall was a sealed type similar to the ones used on the Darts and Valients that some owners used on the Fury's and Polara's of this vintage. Any info here will be greatly appreciated. John
Green bearings are a sealed, non-adjustable style. If you use these, you have to replace both. Most speed shops can get them because they have to be used with a spool. They do work with a posi. or an open rear and they fit both 8&3/4 and Dana 60's.
Thank you for the responses. What is meant by a spool and if these green bearings are used, is a different inner seal required than the type originally used? John
The seal inside the axle housing may be leaking and if the spot on the axle where the seal rides is grooved, then the seal doesnt have to be driven in all the way.But it has to be straight. Have a driver made up to drive the seal made up with, and when putting the axle in, coat the splines with thickfiber type grease. This protects against cutting the seal.You mayalready know all thisbut in case. Also, the adjustment on the axle that has the adjuster (one side only) could also be off, allowing too much slack and causing the seal to leak, bearings to wear out prematurely etc, etcd. There s a amount of up and down play that is adjusted by the threaded adjuster wheel, and I can get you that spec if you dont have it...or a service manual for 65-72 mopars, any with a 8 3/4 will have the procedure.
The green bearings are ok for a drag car but are not the best for a street driven car that has to corner. The side loads on the bearing play heck with things and the spacer in the chunk, between the axles, also is designed for use with the side adjusted bearings to give you a lot less wear on the gears. Retainers also a factor.
Did you adjust the bearings after the replacement? If not, that's probably your problem. If you're starting over, get both "green" bearings, and your problems will be over. This is how 9" Fords were done for their entire production, and they are very reliable. It changes the bearings from tapered roller to ball bearings, and the center spacer no longer does anything, but you don't have to remove it. It is not possible to cause any additional load or wear on the gears by doing this.
Again thanks to all for the advice. Randy Routt, thanks for your offer. I do have a service manual a I'll refer to it for the installation. John
Another question here. Does the inner seal (the one inside the axle tube) prevent the gear oil from leaking out onto the backing plate and brake linings and the outer seal prevent the grease in the bearing from leaking out? I was planning on changing the bearing and both seals but I am thinking that maybe I could just replace the inner seal first and see if that solves the leaking gear oil problem. The bearing in there is not that old and was not making any noise. Any info here is appreciated. Thanks John
That's the plan.In a perfect world anyway. I had a 67 Sport Fury at one time and I liked it a lot. Dark green with white buckets...the Mopar Action website has a tech page that details some of the stuff about tapered timkens. But the service manual is so detailed even I can do the adjustment/setup. Oh yeah, a friend has a 67 Fury 3 fast top.the original owner gave him when he coiuld no longer drive.I still have a 65 Monaco a****st other stuff. I have a powerful hankering for a 67-68 Monaco fastback.So far I take az look at my projects and just say no
Call this guy Best in the business on Mopar rearends has green bearings or orginal tapered bearing Best price on Green bearings. If the car is driven a ton tapered may be better for street use lots of opinions both ways http://www.doctordiff.com/drivetrain/mopar-8-3-4/
Hey guys, Great info here Thanks so much. That guy at doctordiff lists both rear wheel bearings, seals etc for $65.00. I just paid $35.00 for the two seals for one side - OUCH!!! John
Just a opinion from my experiences. I was shop foreman for a Mopar dealer from 1968 thru 1971. You touched on what may be your problem. The 8 3/4 has both a inner and outer seal. The inner seal does in fact keep gear oil from getting to the bearing. If it allows the oil to get past ,the outer seal is not designed to stop it. Most people ***ume that the gear oil lubes the bearings, it does on a lot of cars but not the 8 3/4. I found out the rear bearings lasted a lot longer if in fact a SMALL. I said SMALL amount of wheel bearing grease was used to pack them ,You read SMALL amount didn't you. If the rear end lube isn't going to get out there what lubes the bearings? The axles have a end play adjustment with the adjuster on the p***engers side.The seal is in this adjuster and if you look at it you will see why it would not hold rear end lube.The threads on the adjuster will not hold anything lighter than wheel bearing grease. Now in my opinion the green Ball bearings are good for race cars but I would not use them on the street. The ball bearing gives very little side support compared with a tapered bearing. Another observation from me, it has been my experience that %75 of rear end oil leaks or seeps is due to the vent being plugged. I would make sure it is open before I went to far. Make sure the axle end play is correct.( you do not need to worry about outer seals and end play with the green bearings.)Just my opinion ,I could be wrong.
I agree 100 percent on all accounts. Also I have used Green Bearings on the.street but agree that they are better in a race car. I just built an 8 3/4 for a 65 and used Tapered. Also correct on the seals and lubrication. The 8 3/4 is an incredible rearend when properly setup and maintained.
Make sure the garter spring is still present in the inner seal. I have seen where they jumped out when that seal was installed. Packing the inner seal with stiffer grease before installing it helps keep that spring in place. Inner seal is the culprit if you have gear lube on brakes x2 on greasing the rear wheel bearings - that is their only source of lube make sure axleshaft endplay is set correctly
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