I've got an old car with a 96 Impala motor and trans in it that was throwing a code (think it was 1870, valve body wear) so I bought a reman valve body off shiftrighttrans on ebay and did the sonnex purple springs and pinless accumulator piston for the 1-2 (and maybe the 3-4, can't remember tbh).
This has been a fair number of miles ago and the codes gone and it shifts fine for it's age and miles, except the 1-2 shift.

So at light throttle, just meandering around, it's okay. Little firm maybe, but it's not objectionable. However if you get anywhere near 1/2 throttle the shift firmness ramps up fast, like half throttle will bark the tires pretty aggressively.
The other shifts seem to be as expected at the same throttle position, upshifts, downshifts, all acceptable. But that 1-2 at any kinda throttle much past 1/4 feels like it's going to break something.
I used the purple sonnex springs as they recommended and installed both the pinless pistons as their instructions called for. Other than swapping for a stock 1-2 accumulator to see what effect it has, is there anything
else I can check or look at? I don't think it's line pressure or TPS or such since it's fine otherwise and shifts alright at light throttle, but I also don't know if it did this before I did the valve body and such.

 

Going back to the stock accumulator is probably the only solution, The kit you installed is intendedto do exactly what you have.

 

Is it really? Sonnax seemed to think the purple spring and pinless accumulator were just reliability, not performance related.
Can I try a true stock spring maybe?

 

Go back to the stock 1-2 accumulator.

 

I didn't find the Sonnax Pinless 1-2 accumulator very firm at all. Makes me wonder if something is wrong in the housing. Might it be so worn that the piston is jamming in it?
As others have suggestion, you might just want to get a new housing and install a stock 1-2 accumulator piston and springs.

 

The type accumulator in and of itself has little effect though the sonnax does limit travel a tiny bit, The springs have the biggest effect on things. Since the spring is working against torq signal oil stiffer softens weaker firms. Opposite the 700r4 which works the other way .

 

Ok, I can do that. These are all mostly the same right, this one okay?

 

You should not need to replace the housing just put the stock spring back in

 

One more question, on this era 4l60, the 1-2 spring goes into the accumulator housing, then the piston goes ON the spring, right?
I've seen it both ways, pretty sure I did the single sonnax spring in the housing with the piston on top of it but it's been awhile ago.
I never found a straight answer on which models/years have which, even in the ATSG books.

 

93-94 used the 700R4 accumulator line up 95 & up used the piston against the plate. They put 3 different housings in it and multiple spring setup's.
I'm a little late to this party. I just went through this with a guy. He insisted on the Sonnax pinless kit and their spring. He took the spring out and is happy now!

 

I don't know why everyone has such a hardon for the pinless kit. It's the internets solution to fixing a 4L60/E

 

I really don't get the pinless, I understand the concept but I have seen the plastic ones at 200k look like new, But like many things it is a selling point people like many things. Like rolerizing yes in some things it is useful like rear of case on the 80e but at same time you see these plastic washers with 200k or more miles look like new which tell me for the most part they do nothing but act as bumpers. But again, selling points the perception of getting more.
best money really spent in a 60e are good frictions addressing hydraulic issues a things like the reinforcement collar.
Other things which are good seling points But mostly useless IMO 4th billet servos , perhaps ok if you are gonna tow in OD but realistically the weak link even there is the the 3-4 clutch not the band and WOT shifts to 4th well no matter what servo its a big demand 30 percent gear change under the highest stress levels possible between air resistance and ratios it's probably never a great idea they are pretty though I actually even when i use the stock 4th servo chuck it in the lathe and clean it up looks as nice as any aftermarket when done take about 5 minutes.


As for the OP Iam still leaning to the vb accum getting intermittently stuck

 

As a guy without a ton of trans experience but a pretty decent mechanic otherwise, the pinless pistons look like a superior design for not a lot of money. Whenever I'm into
anything I like to upgrade or fix a problem before one exists if I can. I'm completely open to this not being a problem in this case, you can't believe everything you
read on the internet after all. I ordered a new GM accumulator housing spring and piston, will stick that in and see how it acts. Would be really nice to be able to
use all of first gear without the rear getting squirrelly when it shifts .. lol

 

Ok, ordered a new GM accumulator housing with a stock piston, it did not come with springs, so I need them since I have no idea what was in the trans the other year when I had it open.
As near as I can tell, and this is a lot more annoying to figure out than it should be, I need a 8685655 orange inner and a 24209794 violet outer which will be 96 Impala SS spec, which
is what the trans and motor are out of and the car it's in weighs about as much, so.

Anyone correct me if I'm wrong on these please, I'd like to get this stuff installed and done this weekend so I'm scrambling around ordering stuff.

 

​​​​​​mid-90s B-bodies would have come with a type 2 housing and would only have a single spring setup (8685655).

if you have a newer type 3 housing you will need to get a 2 spring setup. I would try 24220145 (inner) & 24219942 (outer). This is stock for 1500 silverado/suburban/express. remember, stiffer springs = softer shift in this instance. be careful about using type 2 springs in a type 3 housing (or vise versa) the spring can coil bind and end up braking after awhile.

 

The new housing is a type 3, are the two springs I ordered for type 2 or 3? 8685655 and 24209794 inner/outer

 

did you read my post at all?

 

Yes, I don't think you read mine though.
I bought the new, as in current production type 3 housing, the one that I linked above off amazon.

I listed the PN's of the springs I bought, which I got from a GM parts site by looking up a 96 Impala SS and they also came up on Summit racing for the same application.

My ATSG book makes mention of the late housing using an oval wire external spring with the (thicker) plastic piston so as to avoid coil bind, but I can't find a list of part numbers that
say what a given spring is for. You mentioned not using type 2 (round coil) springs in a type 3 housing which jives with what I've read in the ATSG book, but I don't see any springs listed as "this is for type 1/2/3 housing"
for some reason. Just by color code, and no explanation of what color is what either.


I appreciate the suggestion of the Silverado springs but I'd like to know how they differ from the two PN's I ordered (which I can have in a day or two, it'll be into next week for the ones you suggested)
and if the outer spring 24209794 is in fact suitable for a type 3 housing. I *think* it is from photos online, but they can be deceiving.

 

both springs you listed are wrong for a type 3 housing. '794 isn't even for the accumulator being discussed.

 

Is this for a type 2 then? It looks oval rather than the earlier round coils.
https://www.summitracing.com/parts/a...09794#overview