03 F250 5.4 auto 4x4
Any suggestions on a good material for the trans dipstick tube o-ring?
I ordered a tube from rockauto, ring was missing on the first & second they sent, no one seems to stock the ring alone.
I'd like to avoid rubber as I'm sure it'll degrade in short order & the job will have to be done yet again.
Look up Viton O rings. You should be able to find some. They are green.
Unfortunately every kit I've found indicates silicone or an unspecified "synthetic rubber" in the fine print. Most I've seen are red, one had a green option (both shown below) for a buck more but I think they might just be using a different color additive as they also have purple.
I'd buy a single one but I'm unsure of the exact ID/OD/thickness needed.
This is the only green set I could find but it's nitrile rubber:
https://www.amazon.com/dp/B08XYXVJLB/ref=cm_sw_r_awdo_TGSRH7PZKZ1P9BQ34KPH
This is rated to 248°, claims to be oil resistant :
https://www.amazon.com/dp/B09LDD7PP2/ref=cm_sw_r_awdo_V6THMDFPRZMQA2PC1QSC
@doc From everything I've seen and researched the "green" rings are generally NBR70 or nitrile rubber ORINGS with a max operating temperature of 250 F. I find these in kits advertised for automotive AC lines. Most of the Viton ORINGS come "brown" in color, some may be in black, but primarily brown. Please don't feel I'm attacking you in any way whatsoever. Not at all. Just stating what I've seen researching and buying various O rings throughout the year. Amazon primarily shows them this way.
Awesome, thanks!
Crazy they charge that much for a single seal but not much I can do about it given the market unless I want to use J-B weld😄
Just an addendum, I was looking at viton & all that are avertised as such seem to be either silicone or "synthetic rubber" of unknown types, would silicone rated for 250°F cut it or look for something else?
@russelljkelly81 I realize these questions are a few years old now in 2026 but just in case anyone lands here via a search as I did. NO. You definitely DO NOT want to use "silicone" ORINGS with anything oil related. They will degrade, breakdown quickly, absorbing the oil and swelling. I've seen it plenty of times. Viton would be best based on its high operating temperature of 400 F and it's ability to withstand harsh oils and chemicals. But if 250 F will suffice, a much cheaper alternative is NBR70 Which is a general usage oring found in evety size and all over the place. Viton is much more expensive and more difficult to locate, usually requires you or your place of purchase to order the correct size.