Trans speedo cable O ring needed

[rumblefish360]

Sorry about the sideways picture.

I'm looking for an "O" ring to seal the speedometer cable in the adapter. This would be the left, or bottom as currently pictured "O" ring. Any tips to anquality part & place?

 

[gkent]

Available over the counter at many places. Try some place that sells industrial hose and fittings. I'd be surprised if both cost you more than 50 cents.

 

[khryslerkid]

O-rings are like bearings, seals, light bulbs, they're universal.

Recently I needed a o-ring that was thicker than any parts stores had. I just happened to be in Lowes and went to the plumbing section with the sink faucet parts. Rows of o-rings in different sizes. They measure by inside, outside, and width.

Useing a caliper is the best way to measure for one. Measure the diameter of the groove in the housing, measure the width of the groove in the housing, measure the hole in the transmission. That will be the size you need. Anything smaller stretches the o-ring and changes its size. Anything larger can pinch and cut the o-ring.

Also any transmission shop has a good assortment of them. I had a local shop give me two that I needed.

 

[rumblefish360]

Thanks guys. I was worried about how evil the trans fluid is with its ability to leak past places other liquids do not which is why I said a quality seal. I just don't want to do this twice or more.

 

[oldbee]

Got all those seals last summer because mine was seeping, trans shop gave them to me free out of an opened seal kit for a GM trsnny(!). They all fit beautifully.

 

[PurpleBeeper]

Thanks guys. I was worried about how evil the trans fluid is with its ability to leak past places other liquids do not which is why I said a quality seal. I just don't want to do this twice or more.

Hey Rumble, I have to disagree with Kryslerkid on this one. All O-rings are not created equal. Just think of how many different "rubbers" that they're made of....NBR, HNBR, viton, Teflon, silicone, etc, etc.

Krysler kid is correct on how you measure them however. How big/thick is the o-ring that will fit.

All of these polymers ("rubbers" or "plastics" if you will) have different properties. Some are hard, some are soft, some are stretchy, some take high temp well, some take low temp well, etc. Each of these polymers also has a group of chemicals that they will resist & others they will be dissolved by. I'm going through this right now with some parts store O-rings I used on my power steering which dissolved in 2-days and started leaking again. (the parts store O-rings' rubber didn't resist p/s fluid).

There is definitely some overlap with chemical resistance, so for a particular fluid you might be able to run 2-3 different types of rubber O-rings and still be OK.

Here's an example for "Type A" transmission fluid. Sorry it doesn't line up very well, but each rubber is "graded" by how well it resists each chemical (e.g. transmission fluid)

http://mykin.com/rubber-chemical-resistance-chart-6
Nitrile EPDM Neoprene SBR Silicone Butyl Polyacrylate Hypalon Viton Polyurethane Fluorosilicone Aflas Kalrez
Transmission Fluid Type A 1 4 2 4 2 4 1 2 1 1 1 X 1

Here's a link to a better chart: http://www.mossrubber.com/pdfs/Chem_Res.pdf
E= excellent
G= good
F = fair
C = conditional (e.g. not very good)
X = not recommended
blank = not tested

Again for "type A" transmission fluid (I think that's mineral oil based trans fluid and is chemically similar to Dex/Merc.... I think, haven't checked).

The second chart is showing that you can use:
1. CPE
2. Nitrile
3. Nylon
4. Teflon (aka PTFE - not very soft)
5. Urethane
6. Viton (aka "fluorosilicone" - probably the easiest for you to find - common auto gasket material)

Hope This Helps!

 

[gkent]

Well you can rhyme off all the rubber grades you want but the selection in o-rings is somewhat more limited. I think you'll find that your choice will be limited to a standard rubber o-ring or a viton o-ring for high heat applications and totally unnecessary for the use in question.

 

[rumblefish360]

Thanks, I'll be swinging by my tranny guys shop in a day or two. He wants to see the wife's Cuda he built the trans for. He was super stoked to see it when it was done. Well, I'm down to some wheel fitment and alignment issues as well as painting the hood so it'll have to do for now. LOL

I'll bring in the parts to show and ask. He SHOULD have one in hand .... I think.......

 

[rumblefish360]

@PurpleBeeper

Thanks for the list. This is where I was asking about a quality O ring. While I can go to horrible freight for an box of them, I'm not so sure transmission fluid would play nice with it. I'm certainly not interested in doing it twice! LMAO!
I have had enough of that early on!

@Stanton. What is OK for use and what is overkill for use maybe two different things, prices, grade, long lasting, etc...
Doesn't make a hill of beans difference when the trans is leaking fluid from the speedometer cable. Still need a seal, a seal is a seal as long as it lasts.

2 cents for a rubber ring and $2 for some expensive place selling the latest material in O rings, what's the difference? For sure a $1.99 maybe a huge increase percentage wise, but, a clean driveway and NOT pouring trans fluid more in all the time is all I'm after.

 

[PurpleBeeper]

Well you can rhyme off all the rubber grades you want but the selection in o-rings is somewhat more limited. I think you'll find that your choice will be limited to a standard rubber o-ring or a viton o-ring for high heat applications and totally unnecessary for the use in question.

Actually, those are all o-ring rubbers from o-ring manufacturers....check out the links. While it is true that the parts store have much fewer options AND it's also true that Viton will cover "most" automotive needs (+ HNBR for Air conditioning) you can get 2/3 of that list from McMaster-Carr or Granger if you need them. Seriously, the "unknown hard-rubber" I got at Advance leaked in TWO DAYS...."sometimes" it matters.