i went to rubber and gasket place today for o-rings d30 ARB locker 27 spline 5.13

ARB says to use BS-133 VITON 75
the rubber and gasket store had 133 VITON 75
i called ARB and they told me it is "special" o-rings, that "BS" has to be in with the part number.

was actually comical. the store owner told me what he thought "BS" stood for.

anyways, does anyone know if i can use 133 VITON 75 or does it HAVE to be BS-133 VITON 75

the store owner gave me 2 of his o-rings and says yes it will work. ARB says no, his will not work.

 

I have worked on a lot of equipment. Manufacturer's always say that only their parts will work. It never seem to be true. I suggest trying the o-rings given to you by the store owner. An o-ring is an o-ring. As long as it is the same diameter and size, you shouldn't have any issue's.

My two cents

 

that's what the store owner said too. but i don't want to tear diff apart and the o-rings not work. i know manufacturers will do this and its all the same thing, but i'm hesitant. i'd like to do this one time only. i will probably call arb back tomorrow and get the price, if its not too bad, might just order from them.

i kinda want to order the arb o-rings and compare just to know for sure, but have to get price first.

 

well i ended up ordering 2 sets of o-rings from arb. only like $11. atleast when they get here i can compare the "BS 133 VITON 75" AND "133 VITON 75" hopefully see a difference. from what was explained to me, the newer style o-rings are a different shape to enable more sealing surface.

so come monday, i will compare, take pics, and let everyone know what i find.

 

received the o-rings today
D30 ARB locker 27 spline 3.73 and up

o-ring on left is "BS 133 VITON 75" (ARB PART# 160235)
o-ring on right is "133 VITON 75"

"BS 133 VITON 75" has ridges, more of a square shape to it
"133 VITON 75" is a smooth circle

so there are obvious differences in the two o-rings. correct o-ring for this setup would be "BS 133 VITON 75"

 

they look like they're made of different materials also.

 

The "square" shaped one is called a X-ring aka quad ring aka quattro seal O-ring. The round one is the classic O-ring. My ARBs came with quad rings. I ordered ARB replacements from Randys Ring and Pinion and they sent me O-rings. Either style will work.

ARB specifies Viton as the material for the rings. Viton comes in different colors, such as brown, black and clear. The D44 Quad ring is specified as BS136 Viton 75. What this means is its a Quad ring, size AS568A-136 with a durometer of Shore A 75. The D30 Quad ring is specified as BS133 Viton 75. I have found the D44 (-136) Viton quad ring from Amazon.com for $1.08 each. The D30 (-133) Viton quad ring happens to be $9.88 from Amazon. I don't know why Amazon want so much more for the smaller ring. You can get the classic O-ring shape in Viton from McMaster Carr (www.mcmaster.com). D30 rings (-133) is PN 5267T112 for $6.28 for a 10 pack and D44 (-136) is PN 5267T115 for $6.85 for a 10 pack.

The Viton quad rings (like came with my ARBs) are rather difficult to find in sizes -133 and -136. The Buna-N are very common and very cheap. McMaster has the D30 (-133) Buna-N quad rings PN 90025K262 for $13.45 for a 50 pack and the D44 (-136) Buna-N quad rings PN 90025K263 for $13.45 for a 50 pack. If you compare Buna-N and Viton materials on charts that show their characteristics, they are "similar" with Viton performing a little better. The major difference I can see is that Buna-N is good up to 250 degrees F and Viton to 400 degrees F. If someone has more information on the performance of Buna-N vs Viton in differentials please post a reply. Is the Viton really necessary, or is it a corporate game to make you buy their parts given the difficulty of finding the Viton parts?

I'm going to be pulling the differentials this weekend to replace the O-rings in both axles. I'll be replacing with the classic O-ring shape in Viton that I bought from McMaster. I think I'll have better luck with the O-rings now that I've found that my OBA was supplying air at around 110psi. Hopefully 85psi will work much better with the rings.