oldzy

Just to confirm that when replacing the outer axle seals (#712146) that they are supposed to stick out a bit from the axle tubes? How far are they supposed to stick out though? 4mm or so?

Also... the original bearing retaining plates with the raised tapered lip end hold those outer axle seals in correct? I guess the concern (if there is one) is that a 'flat' aftermarket bearing retaining plate would put too much pressure on the seal/bearing/collar?

Aftermarket on left... original on right.

monzaz

There is a crush to the seal outer most edge...I have never had any issues with the retaining plates yet. The SEAL will hang out past the backing plate slightly...1/16" or so and should be the rubber part making it crush-able. IF you are using a DISC brake kit the seal will be about 1/8"- 3 /16" past the tube end. YOU will need a spacer plate to take up the distance using DISC BRAKES. DRUM they will bolt right in.

Jim

oldzy

The garage put two backing plate gaskets on each side... one on each side of the backing plate (or both gaskets on one side of the backing plate - not sure). So 4 gaskets used in total.

Whether that is correct or not I don't know... but they said it was b/c the seal stuck out too much.

monzaz

Well I hope you do not drive it for a few hundred miles and start to have end play issues. ??? Like I said not had any issue to date with the plates. Sold a ton to the Buick guys. Please keep an eye on them for the first few hundred miles and be sure they are still tight(end play that is)...After that if you have NO issues I am sure it will be fine for a good long time. Jim

oldzy

Jim... the garage did not use the retaining plates you sent me... they used my originals with the tapered end/slots. They also did not use the National seals... I picked up some Timkens instead. They were the same width/size though.

Now I know there was originally ONE backing plate gasket on each side... but they (the garage folks) figured it (the outer seals) stuck out a little too much, and decided on using a 2nd gasket on each end.

monzaz

Well I guess all we can do now is cross the fingers.

oldzy

Well if this is such a big deal... I will remove the drum brake crap (ie. springs, brackets, etc.), or pull the axle out, and remove ONE backing plate gasket. ****.. prob just loosen the 4 nuts/bolts... then rip one out by hand. Done.

I don't see how one extra stupid thin little backing plate gasket is going to make a difference either way. Is it like a head gasket or something and makes a huge difference if it is a thousands or whatever thicker? I mean there is the powdercoating layer on the outside of the axle tube as well... is that a prob? Perhaps I could tighten the 4 nuts/bolts even tighter squishing those 2 gaskets into a paper thin layer... will that make things all good and stuff??

monzaz

I will leave it be - I do not know if it was you hung up on the specs or them??? I am just trying to help.

The metal ribbing seal is covered in rubber for a reason...There is a slop factor to the seal...IT gets crushed.. I just do not want to leave too much room for the seal NOT to be properly pushed against the tapered bearing...It is the only thing that stands in the way of failure for the bearing and the seal. You have 3000+ lbs. in turns transfering weight...

It is in. Let it ride. I am sure they got it right... As you said how hard can it be? Right?

AGAIN I personally apologize for any headache I caused here. If I did not care I certainly would not be answering these threads for You and everyone.

Take care and hope the Holidays treat you well. Jim

oldzy

Not me... them (the garage guy... the expert)... saying it stuck out too far. My question is... how far is too far (5mm too far... 10mm too far)? They figured 'too far' based on using the 'flat' retaining plates, and that using those plates would destroy the bearings once tightened. Then I brought my original tapered retaining plates in... and they said all was well... along with the 2 gaskets on each side as mentioned though. Who knows... perhaps the aftermarket gaskets are paper-thin... and TWO aftermarket gaskets are equal to ONE original gasket.

I am going back there to confirm all this again b/c I am almost getting the impression they figured the outer seal should NOT be crushed at all, not even a little bit.

How far (in mm, inches or whatever) does the outer seal actually stick out normally from the axle tube? 1mm? 2mm?

tx

/rant

Yellowstatue

That seal should be about flush and the retainer plate does not push on the seal whatsoever...the lip faces outward...the seal is pressed into the tube and that is what holds it in, period... don't worry about the two gaskets in there, it's marginal at best...

monzaz

Quoted 'the retainer plate does not push on the seal whatsoever'

This is wrong information on the Tapered bearing... Period. If you go buy this info you WILL have a A9 tapered bearing failure. You might as well just use the 2146 seal then.

I will not let this information go with out stating the correct info. I am sorry. I can not with good conscious let that happen... At least it is on the record.

Jim

507OLDS

The seal,whether it be the 712146 or the 2146,not only acts as the seal to the end of the axle tube,but it also puts a preload on the tapered roller bearing,giving it a firm seat.If there is ANY play or slop in there,then the bearing is not fully seated onto the race,thus riding on a partial surface,and it will also want to pull the seal away from the shaft surface,causing oil to leak.
The A-casting 8.5" 10-bolts can get away with the thinner 2146 seals,but the O-casting 8.5" 10-bolts definitely need the thicker 712146.I put the thicker 712146 in ALL of them for this reason.I do NOT concern myself with the backing plate gasket,unless it is for that certain resto purist,that wants it in there.In the situation where the seal sticks out a little,and I mean a little,I torque the backing plate bolt,and it will start to bend the retainer plate.The center is pressed against the seal,and the 4 corners are pressed against the backing plate.I have disassembled many factory,unmolested rears,that had this done in the first place.This way,the bearing is seated,and the backing plate is firmly mounted.

Run to Rund

The factory service manual, pp. 4B-11-15, has drawings and information to complement the advice in this thread.

HWYSTR455

Can you post that page? I'm going throught this right now, trying to figure it all out.

As far as I can tell, the factory retaining plates' 'tapered lip' does nothing when it comes to crushing the seal, because the tapered area is past the edge of the seal. The edge of the seal will get crushed the same with either plate.

When I took my rear apart, the axle bearing is a one piece bearing, and not the tapered A9 or SET 9 two piece, tapered/race style. The shop who did my rear used the A9 or SET 9 bearing/race, and that's what has me concerned. Anyone have the part numbers for the one piece bearings?

From what I understand, the thinner seal is for the one piece bearings, and the thicker seal for the tapered set. Can anyone confirm this?

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