Oil seak "swelling" fluid that really works?

[Rapidrob]

I have a two speed transmission that is 90 weight oil filled that even with new seals, leaks around the seals. The shafts are not the problem. The movement of the shafts side to side cause the oil to weep out. The shafts have to move in order to change gears.
I've seen there are fluids you can add to the oil to swell the seals.
Do these fluids work?
Would going to a still thicker oil help slow the leaks?
Would going to a grease be a better idea? or would the gears starve for lubricant?
I've added a "high cling" oil but it did not help.

 

[Rapidrob]

After the massive replies, I tried the Lucas Oil Treatment. So far it seems to work a little bit. The leak is less but still there.

 

[Mike T]

Hey, Rapid. I used the Lucas too. I had a slow drip of the pinion seal in my 1971 Chevy Nova. As a temporary measure I put maybe a 1/4 cup in the differential and it stopped the drip.

I used BelRay motorcycle fork oil with "Seal Swell" too and that worked.

Mike T

 

[ugmold]

I heard ATP AT-205 was a good product, was thinking about buying some myself.

 

[jeep2003]

I would consider John Deere Corn head grease. Its like half way between oil and grease works nice for gear boxes

 

[JKautoFab]

personally id try heavily greasing the seals and shafts. if it doesnt get better, id take the seals to napa and look for a replacement. do the new stock seals have that spring inside the lip to hold it tight to the shaft?

 

[rollin2]

If you put new seals again,soak in brake fluid about 1 hour before installing them.makes em swell just a bit.

 

[danford1]

rollin2 beat me to it. Brake fluid works.
I've used it many times over the years. I had some power steering leaks on cars. No money to get the steering rack replaced. I added a couple ounces of regular Dot 3 brake fluid to the power steering reservoir and it stopped the leak. I did that on more than one car
You have to realize this isn't a permanent solution. It stopped the leak because it swells the rubber a bit. That means once the swelled rubber wears down, you now have a leak again. Adding more brake fluid doesn't help anymore...

Danford1

 

[PAP]

Berryman's B-12 chemtool, found at your local auto supply.

 

[minibikegi]

Lucas oil conditioner is very thick, I use it in a gear box mixed with 90w.. like said about cornhead grease. I bought new seals,teardown etc. No signs of wear using the lucas blend. Still leaks with new seals,even double lip ones. The gear box was never machined perfect. You cant get them old c/r seals most times. Make sure that the gear box can vent-good?

 

[minibikegi]

I have 4 of the same gear-box in same machines, one leaks more than the others and is in the best physical/mechanical condition. I wondered about a big felt washer, kinda like a battery post protector? just to contain the mess of oil?

 

[neo71665]

Cheap quick fixes rarely work and are rarely cheap in the long run.

If you need something to make it the last few miles home to correctly fix it then go ahead and dump whatever snake oil in it. My short time doing mechanic work (15-20 years) those temp fixes being used as a long term fix more often than not causes more problems. I've seen coolant stop leak clog up radiators, heater cores, and engine blocks. The seal swelling stuff doesn't just choose the bad seal and swells it up, over time they will go back down making every seal leak. The junk that is supposed to stop trans from slipping swells the clutches and wears them faster.

Sometimes it's just poor design and nothing can be done about it. A good example is some old british cars the carbs were so bad they leaked gas no matter what. The factory solution was to install a drip pan under the carbs to catch the gas and direct it to a hose to drain to the ground. (try to get that to fly today lol)

 

[minibikegi]

That's exactly what I found was my sprocket hub was out-of round, no seal ever gonna work. Im just using heavy fluids that still can be dependable.

 

[Rapidrob]

It's that time a year again to get the old Trail King ready to go mountain climbing. The two speed shifter gear box seals on my scooter do not last a year due to the sideways movement of the driven gear and the dust and grit out here. A real pain to change out. I tried a high cling additive to the 90 weight oil to no avail, and the seals still weep making one heck of a mess to clean up after a run.
I did find an oil that goes into a jelly when disturbed by the gear motion called Omega 690 but at 80 dollars a liter plus shipping from England it is just not worth it.
Jeep2003 posted here awhile back to try John Deere Corn Head Grease ( corn head is a type of combine transmission) that has most of the properties of Omega 690 gear oil for much less. For some unknown reason you can buy it on-line for tens of dollars less including shipping than you can at the dealer/ tractor supply.
Walmart had the best deal with free shipping to boot. The other online "dealers" had great prices of 4 bucks a 14 once tube but had stupidly high shipping charges of over 20 dollars for one tube! I was born at night,but not last night!
The videos of this grease in action and how well it clings to the gear teeth under stress is impressive. I can clearly see that this grease will keep my bikes gear box running coolly when I running in the boonies as any help would be hours away if needed.
Thanks again for the replies and the link Jeep2003 I do appreciate it.