Green loctite/bearing mount adhesive for rear main seal

Tue Nov 20, 2012 8:24 pm

I've got the '53 from geibes all split in the garage to fix the rear main seal. The old seal just pushed out with finger pressure

Has anybody tried the loctite/permatex bearing mount adhesive to deal with the poor fitting seal?

I was kinda hoping to get it buttoned back up tomorrow, but the alternative here seems to be sending the retainer out for machine work.

Re: Green loctite/bearing mount adhesive for rear main seal

Tue Nov 20, 2012 9:30 pm

I always stake all of my new seals into the retainer, it will last for another 50 years that way. Just my preferred method, eliminates machine work or buying a new retainer.

Re: Green loctite/bearing mount adhesive for rear main seal

Tue Nov 20, 2012 9:39 pm

I think you'll need to use some type of sealer on the bearing OD to keep it from leaking past the seal OD. The green Lok-Tite is a bearing mount and not a sealant. Staking in the seal as Brian said is a good idea but I think I'd use a sealer around the seal OD too. The green Lok-Tite might do the job or possibly silicone might also work.

Re: Green loctite/bearing mount adhesive for rear main seal

Tue Nov 20, 2012 10:04 pm

ricky racer wrote:I think you'll need to use some type of sealer on the bearing OD to keep it from leaking past the seal OD.


Rick, the inner part of the seal is what prevents any oil passage from the crankshaft---the OD needs no sealant. The issue with loose fitting seals is they can spin with the crankshaft.

Re: Green loctite/bearing mount adhesive for rear main seal

Tue Nov 20, 2012 10:11 pm

cubguy47 wrote:
ricky racer wrote:I think you'll need to use some type of sealer on the bearing OD to keep it from leaking past the seal OD.


Rick, the inner part of the seal is what prevents any oil passage from the crankshaft---the OD needs no sealant. The issue with loose fitting seals is they can spin with the crankshaft.


But, if the seal is loose enough to spin in the retainer, isn't it loose enough to let oil slip by as it passes through?

Re: Green loctite/bearing mount adhesive for rear main seal

Tue Nov 20, 2012 10:14 pm

Hengy wrote:
cubguy47 wrote:
ricky racer wrote:I think you'll need to use some type of sealer on the bearing OD to keep it from leaking past the seal OD.


Rick, the inner part of the seal is what prevents any oil passage from the crankshaft---the OD needs no sealant. The issue with loose fitting seals is they can spin with the crankshaft.


But, if the seal is loose enough to spin in the retainer, isn't it loose enough to let oil slip by as it passes through?


That is why I mentioned in my initial post that I stake it within the retainer housing---eliminates spinning.

Re: Green loctite/bearing mount adhesive for rear main seal

Wed Nov 21, 2012 7:25 am

Understand that you are keeping it from spinning, but isn't the area that is not staked still going to allow oil to seep between he OD of the seal ring and the ID of the retainer? Maybe I am over complicating this.

Re: Green loctite/bearing mount adhesive for rear main seal

Wed Nov 21, 2012 7:39 am

cubguy47 wrote:I always stake all of my new seals into the retainer, it will last for another 50 years that way. Just my preferred method, eliminates machine work or buying a new retainer.


cubguy47: Would you explain to me what staking a seal into the retainer means? What is the process? I've never heard of it. Thank you ahead of time.

Re: Green loctite/bearing mount adhesive for rear main seal

Wed Nov 21, 2012 8:31 am

Stanton wrote:cubguy47: Would you explain to me what staking a seal into the retainer means? What is the process? I've never heard of it. Thank you ahead of time.


Stanton, it is a similar process as what is done on the early style PTO bearings to hold them onto the PTO shaft.

After the rear main seal is pressed into the retainer, I use a small punch and very slightly deform the inner part of the outer rim of the retainer on the OD of the seal in 4 or 5 individual spots. This creates inward pressure on the seal and eliminates any slippage. For a visual, approximately where you see the small circular embosses on this photo from TM Tractor is about where I would stake it:

http://www.tmtractor.com/new/en/377fp.htm

Re: Green loctite/bearing mount adhesive for rear main seal

Wed Nov 21, 2012 8:36 am

Hengy wrote:Understand that you are keeping it from spinning, but isn't the area that is not staked still going to allow oil to seep between he OD of the seal ring and the ID of the retainer? Maybe I am over complicating this.


Mike, if you have engine oil reaching the OD of the rear main seal, then your seal is bad and worn and needs to be replaced, hope that makes more sense.

The staking procedure is not for creating a seal--only for permanently holding the seal in a fixed position.

Re: Green loctite/bearing mount adhesive for rear main seal

Wed Nov 21, 2012 8:36 am

Thanks, cubguy47. That clears it up.

Re: Green loctite/bearing mount adhesive for rear main seal

Wed Nov 21, 2012 9:06 am

Has anybody tried the loctite/permatex bearing mount adhesive to deal with the poor fitting seal?
Yes. During initial installation found the seal was so loose in the retainer that I could easily turn the seal. Used a hardening gasket maker and staked the retainer as described above.

Re: Green loctite/bearing mount adhesive for rear main seal

Wed Nov 21, 2012 10:15 am

I need to chime in on this. I’ve spent years as a district sales manager for Stemco. They manufacture seals and bearings for the trucking industry. Much of my time was spent training HD truck technicians in the northeast on proper seal installation and bearing adjustment. I’d like to point out a few basic things on seal installation.
Both the ID and the OD of a seal needs to be a snug flush fit. Both the OD and the ID of a seal is exposed to lubricants. I’m a wheel end guy and not an engine guy, but all the seal applications I’ve seen require the OD of the seal to be tight fit and contaminant free to prevent leakage. I agree that if a seal is spinning on the OD side, you’ve got big problems.
A clean bore with a tight fitting seal does not require sealant. If you have a bore with any imperfections and plan to install a steel OD style seal, Stemco recommends the use of Permatex 2B or equivalent on the OD. It is not recommended to use sealant on any seal that has a “rubber” OD. 2B is a semi hardening product and is resistant to petroleum based products. Regular silicone is susceptible to breakdown after time and does not handle heat or petroleum based products well. Always be sure if sealant is used, the excess sealant is forced away from the lubrication side of the application when the seal is installed. Any sealant based products are extremely abrasive. If you allow the excess to contaminate the wet side of the seal i.e. the lubricant, it will find its way to the seal lip causing premature failure. It can also float around and create havoc elsewhere. Never put sealant on the ID surface of a shaft! The staking of the seal to prevent spinning is really a last resort approach. The problem with the rear retainer is I have not seen a seal with the proper fit, so options are very limited. Also, always be sure not to “cock” a seal on installation. It is a good practice to seat the seal as long as there is a retaining area or seat to set the seal against. This assures it is square on installation. A cocked seal in a bore will fail early.
Again, this is basic rule of thumb on seal installation. There can be a few exceptions to this depending on how the seal is installed, but always be sure if sealant product is used, the excess product does not get forced to the west side or oil side of the application.


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Re: Green loctite/bearing mount adhesive for rear main seal

Wed Nov 21, 2012 10:39 am

Thanks tractordad for the explanation from the technician's standpoint. Many good points.
We all need to remember that seals are actually supposed to leak - they leak enough to lubricate the interface between the moving members but not enough to actually get past and result in a drip. If it's not a moving surface, it's OK to use sealers to ensure that the housing is sealed. The best sealers are the ones we've used for years on regular gaskets - Permatex, Aviation sealer, etc. I don't trust silicone as far as I can throw it.
Most good quality seals come pre-coated with a dry sealer like you see pre-applied on pipe threads or a rubber type coating. The ones that are plain steel that are not a drive fit into the housing can use some help. Those housing bores that are loose - add sealer to ensure leak free performance.

And to the original question - yes the green loctite (670 or 680)should have worked just fine for you. Those products are made to run in oil, seal up to 0.010 diametral clearance and hold like superglue.

Re: Green loctite/bearing mount adhesive for rear main seal

Wed Nov 21, 2012 11:29 am

Gary, good info, my staking method is just my personal preference as stated in my first post, I've staked on more rear seals on my Cubs than I can count, never had a drop of oil leak, you also have to make sure the retainer is flat and that the seal lip seats evenly against the lip inside the retainer as you mentioned, if this is done correctly it won't leak, regardless of whether adhesive or sealant is used, just my opinion.