Main Seal Oil Additives

[crash-harris]

I'm going to need to get to an oil change when I can, so the question arises...are main seal additives worth it in our engines?

I have some oil on the starter and I know the rear main will only get worse, but the front main is the one that leaks most, leaving about a 2" or less stain under the truck overnight (not damp). I've used rear main seal additive in the oil in my gasser before, but the seal was too far gone for it to have any effect (gasser leaves close to a dinner plate size wet spot after driving it).

So is it worth it with the main seals just now starting to leak? Any specific one to use? Any recommendations for oil?

I'm currently planning on getting a FL-1995 filter and using motorcraft synthetic blend (red jug), and I have a jug of Delo in the back floor that I've been topping off with every now and then. I had previously been topping off with Rotella, but after reading a thread here, I switched and it doesn't seem to use or blow out as much.

 

[franklin2]

They just have a chemical in them that attacks the rubber and makes it swell. If you don't want to fool with changing the seals, why not try it. It might take a little while for it to work if it can.

 

[crash-harris]

They call it "reconditioning". Just didn't know if the IDI's have anything against it or if the soot would affect an additive's performance or functionality.

I would love to just change the seals, might see how much extra it would be for the shop that will be doing the SMF to replace the rear main while they're in there. From what I've read, replacing the front means pulling the engine. Guessing that's due to the oil pan. I just don't have the tone to park it at my rents place to borrow the "MF hoist" (Massey-Ferguson 1040 with a front loader, lol).

 

[typ4]

The upcharge for a seal replacement while clutch is out is 30.00 plus parts in my local shops. You do not need to pull the engine to do a front seal.

 

[crash-harris]

That good news. If the front seal cab be replaced in-frame, then I'll probably be able to get that done next spring or so.

I'll probably pay the shop to do the rear main while the flywheel is out. In still not happy about letting someone else work on my vehicle, by time demands are too great.

But the original question still remains, and does anyone recommend a specific brand of seal repair additive to use? It'll be about a month before I can get the stuff for the oil change. Bills and wedding venue deposit this month...along with more fencing crap, but that's half done now!

 

[franklin2]

Pick your own snake oil, I have never used a engine sealer. I have used Rislone to quiet engine lifters and it works. I have also used Lucas "transmission fix" and I have seen it do miracles also.

The big problem you will run into with the front seal is a grooved seal surface on the balancer. Easy enough fix though, they have repair sleeves that you drive over the balancer surface to repair it and get rid of the groove. Just something to look out for and expect when doing it.

 

[crash-harris]

I'll look for a seal that has a repair sleeve with it when I go to do the front. I know they package them worth the seals for the rear a lot.

 

[Golden Helmet]

But the original question still remains, and does anyone recommend a specific brand of seal repair additive to use? It'll be about a month before I can get the stuff for the oil change. Bills and wedding venue deposit this month...along with more fencing crap, but that's half done now!

I'm on mobile so I can't post a link, but I used "AT-205" in my Lincoln when the oil filter adapter started leaking. It seemed to stop (or significantly slow) the leak, I haven't checked up on the car recently but I haven't noticed any fresh stains either. Beats the hell out of trying to replace that seal, working on that POS car is a nightmare.

 

[icanfixall]

The rear seal is a double lip synthetic material and it works with a speedi sleeve very well. Both Ford and International sell the exact seal. The forn is done in frame easily. Clean off the dirt up front and see the 3 welded on nuts. That fits the tool that will press in the new seal. Use a speedi sleeve on the damper shaft too. Remember that front seal does not ride on the crank. It seals off the damper shaft. Also make sure the shop uses some rtv on the keyway area or oil WILL LEAK past that keyway and washer. Just a dab on the end of the keyways and the washer

 

[crash-harris]

So on this topic, I'm looking at rear main seal kits from autozone. What's the best material to use, a rubber or Teflon seal?

 

[Dsl_Dog_Treat]

Replacement rear main seal part #F2TZ-6701-A. Should also come with the repair sleeve for the crank.
Autozone has been starting to cross over to National seals #3894v and is a Viton seal but IIRC doesn't come with the repair sleeve.

 

[crash-harris]

They don't, you have to buy them seperate. Looks like only 2 from rock auto come with the repair sleeve, but you have to buy the cover gasket seperate.

 

[crash-harris]

So any suggestions on whether to use rubber or teflon?

And shouldn't teflon be installed dry?

 

[crash-harris]

Also make sure the shop uses some rtv on the keyway area or oil WILL LEAK past that keyway and washer. Just a dab on the end of the keyways and the washer

Are you talking about the rear main here? I've been searching for pics online, but can find anything about a keyway on the back side of the crank (nor have I ever encountered such).

And if I cross reference F2TZ-6701-A worry Autozone, I get a totally different looking seal than if I search for "rear main seal". F2TZ-6701-A goes in the cover...is there actually a seal between the crank flange and the block/pan???

 

[riotwarrior]

Keyway = front of crank