2-groove or 3-groove accumulators

GRWeldon

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I'm about to order a rebuild kit and I'm wondering if it makes a difference if I put in 2-groove accumulators or 3-groove accumulators or is this something I have to disassemble to find out what I have to replace it with the same kind?
 
There should only be one correct design for the accumulator which is a seal bonded to the piston - no grooves and O-rings at all. I'm not sure what else "2 or 3 groove" designs might refer to... 🤔
 
The sonnax version has o-rings. It's overkill unless you have bore damage. I'd suggest the stock upgrade, but that comes with the superior kit iirc. The VB parts are great, but you need to inspect the bores of those valves in the vb.
 
Yes they offer different grooves.
If you can weld, grind, and measure and follow rebuild instructions you can figure it out.
 
Yes they offer different grooves.
If you can weld, grind, and measure and follow rebuild instructions you can figure it out.
Thank you for your comment. I have no idea why you took the time to leave it. No useful information contained within.
 
So after digging yesterday in transmission forums, I'm pretty sure the number of grooves pertains to the OD and/or the reverse servo. Seems that you must remove those pistons from the VB first and replace those components with ones that have the same number of grooves. The grooves are for identification only, possibly slight length differences? The grooves are at the top of the pin where it joins the piston.

I remember seeing them when I did the J-mod on my Cougar in 2005.

I will be doing a mild j-mod on this tranny, otherwise all else will be stock. Yes, I realize it may not last long, however, the original tranny in my 95 Cougar lasted over 266K and went to another Tbird after my timing chain broke. J-mod was done at 139K on that tranny and I replaced the TC with a new Mk.8 at that time.
 
Yes they offer different grooves.
If you can weld, grind, and measure and follow rebuild instructions you can figure it out.

I know a lot of welders, but none of them are capable of rebuilding a transmission ( except me of course .. 😉 )

possibly slight length differences?

Correct .. this is for proper engagement of the OD Band.
 
The only reason you would need the one with the orings is if the bore is damaged. The thing to check there, is the pin bore, and see of it's slopped out, It will leak, and will not hold. A slipping odband smokes the seals in the direct clutch. But there's no reason not to use the one with he o-rings. I'm using it in one of them. Dirtydog recommended those for certain applications.
 
The only reason you would need the one with the orings is if the bore is damaged. The thing to check there, is the pin bore, and see of it's slopped out, It will leak, and will not hold. A slipping odband smokes the seals in the direct clutch. But there's no reason not to use the one with he o-rings. I'm using it in one of them. Dirtydog recommended those for certain applications.
I did intend to use the OD pin with O-rings from Sonnax in my build, but I never mentioned this in my original post. Others did, possibly relating the grooves on the OD pin to O-ring grooves, I don't know. My research from several sources indicates that the O-rings on the OD pin assure a good seal IF the pin bore is less than perfect. I'm assuming mine is less than perfect!
 

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