Teflon sealing ring question

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Duane

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Just finishing up a rebuild on my late 80,s 904.
I purchased a Teflon sealing ring kit from A&A trans and I have noticed that the thickness
Or the width of all the rings in the kit a significantly thinner that the metal ones I took out. Do I have the wrong year or is this normal for the Teflon ones to be thinner.
Cannot say that I recall seeing this before and the A&A catalog seems confusing.
The diameters look right, just not the width.
Can anyone shed some light.
Thanks

Duane
 
Sounds wrong to me. I would think a softer sealing ring would need some sort of lateral support.
 
Duane said:
Just finishing up a rebuild on my late 80,s 904.
I purchased a Teflon sealing ring kit from A&A trans and I have noticed that the thickness
Or the width of all the rings in the kit a significantly thinner that the metal ones I took out. Do I have the wrong year or is this normal for the Teflon ones to be thinner.
Cannot say that I recall seeing this before and the A&A catalog seems confusing.
The diameters look right, just not the width.
Can anyone shed some light.
Thanks

Duane
Click to expand...

Depending on what "significant" is it could be normal for teflon rings as the function they use to seal is a little different than steel rings.
Teflon rings rely on being "blown closed" by fluid instead of tension like piston rings.
If the tapered ends (scarf cut) seems to line up ok in the bore they go in it shouldn't be a problem.

If I may give you a hint from experience if I may.
I always bent the tips of the rings just a little to make sure the very tip didn't stick out and get cut off on assembly AND lube pack the ring grooves completely to keep the rings in place until they are in the bores they will be living in.
(just two hints to keep from having a pressure loss from a cut ring):D

I'll tell you an odd thing I found out about teflon rings a long time ago.
They wear the metal they are in contact with more than steel rings do.
Weird huh?
 
Trial beast, some are a glass reinforced polymer and that may be what you have seen?
 
TrailBeast said:
Depending on what "significant" is it could be normal for teflon rings as the function they use to seal is a little different than steel rings.
Teflon rings rely on being "blown closed" by fluid instead of tension like piston rings.
If the tapered ends (scarf cut) seems to line up ok in the bore they go in it shouldn't be a problem.

If I may give you a hint from experience if I may.
I always bent the tips of the rings just a little to make sure the very tip didn't stick out and get cut off on assembly AND lube pack the ring grooves completely to keep the rings in place until they are in the bores they will be living in.
(just two hints to keep from having a pressure loss from a cut ring):D

I'll tell you an odd thing I found out about teflon rings a long time ago.
They wear the metal they are in contact with more than steel rings do.
Weird huh?
Click to expand...
Interesting about the wear characteristics. I was reading the Carl Monroe book the other day and it says that if using an aluminum front drum( like I am) the best rings to use to minimize wear to the drum are stainless stator rings because Teflon rings remain stationary and stainless will spin with the drum.
Also the poster after you mentioned glass in the Teflon. Tcs told me that as well. The glass type Teflon will wear my aluminum drum.
He said there are two types of Teflon rings. I agree about how you think Teflon rings seal. They have no tension. The fluid pressure blows them into position.
Thanks
 
TrailBeast said:
Depending on what "significant" is it could be normal for teflon rings as the function they use to seal is a little different than steel rings.
Teflon rings rely on being "blown closed" by fluid instead of tension like piston rings.
If the tapered ends (scarf cut) seems to line up ok in the bore they go in it shouldn't be a problem.

If I may give you a hint from experience if I may.
I always bent the tips of the rings just a little to make sure the very tip didn't stick out and get cut off on assembly AND lube pack the ring grooves completely to keep the rings in place until they are in the bores they will be living in.
(just two hints to keep from having a pressure loss from a cut ring):D

I'll tell you an odd thing I found out about teflon rings a long time ago.
They wear the metal they are in contact with more than steel rings do.
Weird huh?
Click to expand...
Found this article online
gmay99p22
 
Just did a 904 friday with teflon sealing rings.....everything air tested good...
 
they seem to be....and i pack them in with vasoline...actually only replaced the pump sealing rings...

I will see if I have anymore of the teflon and steel rings in the box of rings...lol...
 
70aarcuda said:
they seem to be....and i pack them in with vasoline...actually only replaced the pump sealing rings...

I will see if I have anymore of the teflon and steel rings in the box of rings...lol...
Click to expand...
I posted a link a couple posts back. That article says Teflon are substantially thinner by design. It's a good read. Not too long.
 
VOETOM said:
Trial beast, some are a glass reinforced polymer and that may be what you have seen?
Click to expand...

That very well could be.
I know I have seen them cut some pretty good grooves in cast drums and governor supports where cast rings didn't.
 
Sterling said:
I think A+A lists two different thickness teflon rings for a 904.
Click to expand...
Yes you are correct. The catalog list a wide version for the stator only.
I just bought the kit and there was no option for a wide version.
Now I don't know if I have the wide ones or the narrow or what the difference is performance wise. But thanks for pointing that out to me.
 
In all the rebuilds over the yrs. I've only replaced steel rings with Teflon rings twice and both times they were real close to the steel ring width they replaced. I'm sure if you call Rick at A&A he'll be able to get you on the right path
 
fishy68 said:
In all the rebuilds over the yrs. I've only replaced steel rings with Teflon rings twice and both times they were real close to the steel ring width they replaced. I'm sure if you call Rick at A&A he'll be able to get you on the right path
Click to expand...
Thanks for the reply. I have air tested both drums with the Teflon rings and they appear to work great. The rings are .030 thinner than the steel ones. After reading the link to the article I posted, I believe they are thinner by design.
 
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