OMC Shift Rod O-ring 301877

[Buccaneer]

Anyone know the dimensions of OMC shift rod O-ring 301877.
As long as I have an order started at McMaster’s, I thought
I’d get this O-ring as well, if possible.
I found this photo, and guessing it’s

1/4" ID,
1/8" thick
1/2" OD

Can anyone confirm? If not, I can tear apart the LU and do some measuring.

Also, in some cases McMaster offers "soft" (for better sealing in low pressure systems)
"hard" for better wear resistance, and "Military" grade O-rings.
What’s ya’lls thoughts on this?
Thanks!

Prepare to be boarded!

[fisherman6]

Buc,
The last time I measured one it seems that it measured a bit over 1/8" thick cross section. A little under 1/4" I.D. McMaster may have something that will work. I have been using Metric O-rings 6mm ID x 4.5mm CS in 70A durometer Buna N. I buy my O-rings from theoringstore.com. These are about $0.23 each and I usually buy a 50 ct. bag. They are a little tight, but work well if you make sure there are no sharp edges on the shift rod and use plenty of lubricant when you push the shift rod thru. Once they are together, they seal up nicely. I can send you a few to try if you like.
-Ben

OldJohnnyRude on YouTube

[frankr]

quote Buccaneer:

Anyone know the dimensions of OMC shift rod O-ring 301877.
As long as I have an order started at McMaster’s, I thought
I’d get this O-ring as well, if possible.
I found this photo, and guessing it’s

1/4″ ID,
1/8″ thick
1/2″ OD

Can anyone confirm? If not, I can tear apart the LU and do some measuring.

Also, in some cases McMaster offers “soft” (for better sealing in low pressure systems)
“hard” for better wear resistance, and “Military” grade O-rings.
What’s ya’lls thoughts on this?
Thanks!

I just went out to measure some OEM o-rings and found my caliper battery dead. But doing the best I could by other means, I would say you are correct. 1/4 x 1/2 x 1/8 nominal. Actually a tad bigger for squeeze.

Quite confident they are 70 duro.

[Buccaneer]

Thanks Frank! I was digging around in the garage and I think
I found a "used" shift rod O-ring. The OD measured about
.575 and the ID fit on the shift rod snug.
Perhaps they’re sold "over-size" from the stated dimensions
so they actually seal.
I had problems with my veneer calipers too…… my eyes
have a hard time matching up the little lines anymore!
Was thinking a digital one would be nice, but then again,
batteries and 30 below don’t work out in MN, lol.

quote FrankR:

quote Buccaneer:

Anyone know the dimensions of OMC shift rod O-ring 301877.
As long as I have an order started at McMaster’s, I thought
I’d get this O-ring as well, if possible.
I found this photo, and guessing it’s

1/4″ ID,
1/8″ thick
1/2″ OD

Can anyone confirm? If not, I can tear apart the LU and do some measuring.

Also, in some cases McMaster offers “soft” (for better sealing in low pressure systems)
“hard” for better wear resistance, and “Military” grade O-rings.
What’s ya’lls thoughts on this?
Thanks!

I just went out to measure some OEM o-rings and found my caliper battery dead. But doing the best I could by other means, I would say you are correct. 1/4 x 1/2 x 1/8 nominal. Actually a tad bigger for squeeze.

Quite confident they are 70 duro.

Prepare to be boarded!

[chris-p]

Someone did a pretty detailed write up on these in an Outboarder….cant for the life of me find that article though. I have boxes of Outboarders…anyone what issue that was in??

[Buccaneer]

I give all my read "Outboarder" mags to my uncle, so no help there,
but I did order some o-rings from McMaster’s, and will post back
if they fit correctly.

quote Chris_P:

Someone did a pretty detailed write up on these in an Outboarder….cant for the life of me find that article though. I have boxes of Outboarders…anyone what issue that was in??

Prepare to be boarded!

[chris-p]

Did you order these? Dash #202

1/4" ID, 1/2" OD, Actuals 0.234" ID, 0.512"OD, Durometer 70A (Medium) ASTM D2000, SAE AS568, SAE J200 -20° to 250° Black 100 9452K183 $3.42

[jerry-ahrens]

For the labor that it takes to do it over again, if it leaks, it may not be worth substituting this O-ring…. I’d hate to have to do the job twice. Just my humble opinion..

[chris-p]

Very true Jerry. I have never tried anything but OEM here myself. Curios to see how they hold up after time and a pressure test? I know the Sierra ones are wider than the OEM ones. Even the newer OEM ones are slightly different than if you were to find some NOS ones.

If I were to buy some from McMaster I would likely go with these:

Chemical-Resistant Soft Viton® Fluoroelastomer O-Rings

Gearcase is pretty low pressure application. This softer, chemical resistant material would be better than a plain old o ring possibly. Especially since they would be subject to constant contact with gasoline from the top of the o ring.

[Buccaneer]

Yes, I ordered Dash 202 Mc Masters, but I presume one is included in the LU seal
kit I ordered from you today, so I’ll compare when I receive both.
BTW, still waiting for total cost and payment info.
Thanks.

quote Chris_P:

Did you order these? Dash #202

1/4″ ID, 1/2″ OD, Actuals 0.234″ ID, 0.512″OD, Durometer 70A (Medium) ASTM D2000, SAE AS568, SAE J200 -20° to 250° Black 100 9452K183 $3.42

Prepare to be boarded!

[Author]

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