Lets talk about teflon rings.

[Steve V]

So are they really needed in the 200 4r? I know CK's book says yes. Some other builders on this site list them in there build sheets. I have used them. But see some respected trans guys saying the iron rings are just fine on the center support.

What about the fwd drum,needed or not.

Input shaft,yes or no.

They are known to leak with an air test,but they seal with fluid.

Opinions? Thanks!

 

[GNeric]

I have used both solid teflon and iron rings on my 2004R builds since I first found out about the solid teflons and had nothing but good luck with both designs. Never had extra wear from switching from one to the other. When air checking, I put oil into the circuit and even thought it is not "up to temp" fluid, they seal up and I don't have pressure issues. One I am freshening up, that I built 3 years ago, has the 4L80 rings on the center support and everything looks absolutely great. Still seals against the drum and center support. This is a unit that has a stock fwd drum and not dual fed but nothing turning colors or burning. My supplier gets me the solid rings that go on the input shaft and I do all three there and the two on the fwd drum as well.

 

[jakeshoe]

Teflon seals contain glass filler. The glass filler eats aluminum. They work great on an iron or steel surface. Think of factory applications, the 200-4R being one. They installed teflon seals in all the other locations but not on the aluminum center support.

On the center support location of the 200-4R, the rings "run" with the drum, and spin on the center support for the most part.

 

[87GN_70GS]

When I rebuilt my trans with 100k miles on it, there was no discernable wear on the support from the factory iron rings.

I look at it this way, if it doesn't leak with air, there is no way it will leak with fluid. We all know the viscosity of fluid is many times that of air. But due to this property and just because it leaks with air, I think it is wrong to assume it will not leak with fluid. I think it will leak "some" - and "some" means more than with iron rings.

 

[turbo nasty]

IMO the iron rings can take heat better.