Rear Diff, Gasket or FIPG?

[TeCKis300]

Factory and FSM call for gasket. Many prefer FIPG. Seems like there's two camps on this.

Which do you prefer and why?

 

[silverhorse]

i have always used both

 

[Oakleyguy]

Haven't opened up the rear diff on the 200 but I'd just stick with the FSMs direction.

 

[bloc]

If you use both make sure you recheck the torque spec after a few hours.

In the dozen or so times I had third members out I never had any leaks or other problems with the bare gasket, as long as both surfaces are spotless and the housing straight. RTV helps when the housing has been tweaked.. as I eventually figured out was the case with two of my axles.

 

[619TOY]

I do both as well. I don’t know if the 200 calls for different, but I believe I used the factory Toyota orange. There are people that will argue that if you omit the gasket, you change the angle of the axles into the third member. How much if any effect that has is usually where the argument escalates

Do yourself a huge favor and pull all the studs, clean and loctite them while everything is apart. Nothing sucks worse than having them start to back out after everything is reassembled and you have a few thousand miles logged

 

[TeCKis300]

All great points. I'm partial to the FSM and I have a gasket in hand. Also have Toyota orange FIPG. There's rock crawlers out there that seem to believe FIPG is more robust of a seal for 3rd members when abused against rocks. I don't recall hearing many leaks if any on these boards.

 

[KLF]

I've never pulled a third from a 200, but I've done many many on older Cruisers and minis. I always pulled all the studs, cleaned them up, ran a die down the threads, then Loctite red when putting them back on. Don't forget to pay attention to where the longer stud goes. Very thin coat of RTV (your choice, I preferred the Permatex stuff in the cheez-wiz can), then a gasket, and a very thin coat of RTV on the face of the diff. The gasket makes removal next time much easier, as it just tears apart, then you can easily scrape the RTV off the surfaces with a razor. A quick polish with a Scotch Brite biscuit in a whizzer, and you're ready to re-install.

 

[TRAIL TAILOR]

Only time I ever use silicone is if the diff and/or housing face is damaged. Only done this 2 times in 70 or so installs over the past couple years. OEM gasket for the win for me.

J

 

[TeCKis300]

OEM gasket in hand. OEM gasket it is.

Thank you guys.

 

[OSS]

While there may be more than one way to skin a cat, (or seal a diff) when in doubt - Never- try to outsmart Toyota engineers. Follow the recommendation in the FSM

 

[TeCKis300]

Definitely different ways to skin a cat. Sometimes the choices may be best for other considerations. Manufacturability or assembly considerations.

The front diff is sealed with FIPG. It is somewhat different in that it's a more complicated interface, made of aluminum, and a sideways clam shell. I think importantly, it can be fully assembled and sealed off the car in an orientation that allows the mating surface to be cleaned and free of contamination while assembling.

Contrasting with the rear that is steel, but also in a configuration that requires sealing to be done in an orientation and manner that could be difficult to clean, and be consistently repeatable without oil contaminating the mating surface.

This difference can be seen in the FSM as a gasket is forgiving of oil residue.

I guess the reason for my question is I've heard rock crawlers feel the diff is more stable and seal more robust when done with FIPG. With almost steel on steel contact, the assembly is overall more stable and better reinforced at the mating surface. Vs a gasket, no matter how thin, potentially allowing flex between the components, and compromising the seal. I do have a couple rock gouges in my diff, but I don't particularly off-road in that manner really.

Perhaps these thoughts might be useful for others deciding how to skin this cat.

 

[bloc]

I just don't see any indication the stock setup isn't working for us so far. Keep in mind the crawlers are sometimes running locked 37's or bigger with a ton of traction on an 8" chunk (though they are lighter). Plus not relying on a gasket that is easy to tear on install for a trailside repair, but a tube of RTV that everyone has in their toolbox is a benefit. And, my observation has been they usually don't care about some oil weeps, so if the surface isn't perfectly clean it's not as big of a deal.

Also the decision not to run a gasket in the front could have to do with carrier preload. I'm sure that setting would be extremely sensitive to gasket squish.