Nylon Sealing Rings


New Member
Nov 1, 2005
I have built a "few" transmissions since my teenage years, and I am very comfortable in working with the metal style of sealing rings found in these earlier transmissions. However, I am a bit unsure of my skills when it comes to the nylon sealing rings that are being used in the later transmissions. I suppose that these rings are a bit easier on sealing surfaces, but I have questions on the proper way of installing them (and subsequently resizing them). I have seen specialized tools to resize these little jems, all at a cost that could choke a horse :(

I would appreciate any imformation that can assist me in the "care and feeding" of this type of seal, as I will be going through a 1987 200R4 very soon.

Thanks :)


Crude but cheap. I use black electic tape to wrap around them--continuing to draw it tighter. Changing tape untill I get it to size. On the center support, once you get close you can drop a drum on it to finish the sizing. Same on the input shaft and forward drum, get it close and then finish on the part it fits.
Try it for yourself to see if teflon rings are for you. Air check the direct servo and listen for leaks. Then air check with iron rings. For me, teflon woudln't air check worth a damn, leaked like a sieve. So I went with iron.
When I installed my teflon rings, I used a hose clamp with the inside diameter lined with a wide zip-tie, smooth side facing in, and just a tiny bit shorter than the final diameter I wanted to resize to so that as I tightened the clamp, the tie would not overlap and create a smooth surface. It works really well, and is easy to do.
they seal better in some places and not others.if you are looking for installation methods as you state youll be working on one get our 200 page gm2004r trans mnaul.it covers the rings ,theory ,tech,principles of operation,step by step overhaul,converter tech and theory,hydraulic charts,diagnosis by symtom,pressure tests,interchange ,vbody and governer tech and codes etc.
i use a peice of an old quart of oil,Cut a nice round strip a few inches wide and wrap it all the way around and then some,Tightan a hoce slamp around each one,or one ata time and lst sit for 5 minutes or so,Then test fit the drum
Thanks All :)

I thank you all for your replies. I have to say that I like the old style metal rings a LOT better :) however, I realize that engineers only change things because somthing better comes along :rolleyes:

chris718, does this manual you speak of contain imformation on what locations that you CAN use metal rings, and where you CAN NOT use them? As the metal rings tend to not seal well in some areas, is the amount of leakage serious enough to compromise proper functioning of the transmission's componants? and can this leakage be compensated for?

Again, thank you all for your imformation.

A guy I work with ,who used to manufacture them told me they sized all thiers with a HOT water bath. I tried it on my second set, (after ripping my first set) and it worked great to get them on!
Mart Urbanski
Martin U said:
A guy I work with ,who used to manufacture them told me they sized all thiers with a HOT water bath. I tried it on my second set, (after ripping my first set) and it worked great to get them on!
Mart Urbanski

Good Tip! I twist them a bit then install, and immediately resize. Use plenty of vasoline while installing. I use sheet aluminum cut with tin snips with a hose clamp to initially resize. Input shaft rings can be then resized using that old stator with stripped splines as a resizing tool. Center support rings are resized using the sheet aluminum and hose clamps then the direct drum for final resize. Forward drum rings, same AL and hose clamp technique, then insert the forward drum into the direct drum to resize. Right now I have a stacked totem pole (top down) of center support, direct drum and forward drum on the workbench resizing the rings. The old stator is in the vice with input shaft pointed downward resizing the input rings. Next time I will give the hot water technique a try...
If the inner bore surface (where the rings seal) of the direct drum was worn, and you did not want to replace the drum, I would go with plastic over iron.