I'm installing a shift kit soon, so I figured I'd put in aluminum accumulator pistons too. I found 2 different kinds on ebay, which ones do I need? Small pin or pinless?
1) Aluminum no name small pin pistons from Oregon Performance Transmission
2) Sonnax pinless

Also, do I need both the fwd and the 1-2, or just one? If so which one?

EDIT: I read that the sonnax 1-2 piston will also fit the 3-4 piston? So if I wanted to replace all the plastic pistons in my tranny, I would buy 3 aluminum ones, right? One fwd and two 1-2 (also 3-4)?

 

Anyone???

 

Yes you need both if they are plastic and usually are. Forward and the 1-2. I've never installed the pinless style. They are suppose to be an improvement... actuate smoother, no binding and seal better due to no chance of leaks around the pin.

Digging through some pictures.
The 2 60e's I've done this pistion (3-4?) has been metal


This one has been plastic (1-2)


Then the plastic forward servo. This is where the pinless can be used.

 

K thanks! So I need a pinless foward and just a normal aluminum 1-2?

 

Yes that sums it up nicely. Pinless is optional.

 

Ok Thanks!

 

I would just get the aluminum pistons for both. Just my 2 cents. Vince