Rebuilt 4l60e now having 2-3 and pos. 3-4 shift

[mrfister77]

I broke my trans after about 18mo after purchase. It is a level 3 Raptor with 600 hp/tq rating. It is in a 2002 Silverado ext. cab 2wd 5.3 with heads cam etc. except intake TB. Anyway, the input drum exploded, I contacted the company and was assisted in buying all the necessary parts w/ the ATSG manual. after first attempt I had no rev. nor would it roll back in rev or neutral. Took it back apart and found w/ builders advise I stuffed way too much of that trans goo in the check balls and didn't let the trans warm enough to dissolve it. put it back in and was great. After driving longer maybe 100mi or so it started doing it's prob. 1-2 is great, 2-3 is like neutral let off gas it shifts into 3 give it gas goes right back to N. It will do this as many times as you want until shifted down
to 3. then does fine. it also does the same thing on 3-2 as well until shifted into 3. I upgraded all the parts pin-less pistons, everything except the input drum, the input drum is hardened, I just didn't go w/ the Sonnax Smart drum. I've searched on here for days and tried several different tunes. I'm posting a couple of those including the one that's in it, Also some scans.

[mrfister77]

Here are some scans. Thanks so much for any help.

[mrfister77]

I'm guessing it's more than likely builders error. I just thought I'd take a shot in the dark. I'm sure I forgot to do something, I have no short term memory. After 3-4 sentences into a conversation the first 3 are gone. It took me 8-10 weeks to rebuild this trans. b/c of this. I know I shouldn't have tried to, but being a soldier my whole life I don't know how to except defeat, or how to quit. Thanks to everyone who looked at my post. Hopefully 3rd time's a charm.

[jason k]

It's possible you cut the sealing rings on the input drum when u put the pump in Does it shift normal when u manually shift it. Did u air check the clutches in the input drum before u assembled it?? Is the pan full of friction material?? The reverse boost valve in the pump if leaking can burn out the 3/4 frictions very quick if it's leaking also and it's very common

[mrfister77]

Yes it does shift fine manually. Yes I air checked every time the manual said, according to my notes. I have had the pan down twice and the fluid and pan were perfect, no metal or material of any kind. I also used the pinnless accumulator pistons (3) can they get cocked and stuck in their bore?
Thanks so much for your help.
1 more thing, the line pressures are smack in the middle of the ATSG guidelines.

[jason k]

the pinless are so tall its virtually impossible for them to become crooked the only thing different when manually shifting is the overrun clutches are applied in manual 3 and 4 and in overdrive they aren't did u make sure the foward sprag locks in the correct direction?? shouldnt be an electrical problem both shift solenoids are commanded off for the 2-3 shift in either range od or manual shift did u use the sonnex boost valve with o ring seals?? cant stress enough the importance of the boost valve not leaking also every valve has to drop in and out of their bores clean and dry with no problems meaning if u flip the valve body upside down the valve should just come out but if they are too loose fluid wont stroke them its a very tedious process

[wyochimneysweep]

one-way clutch not holding?

[mrfister77]

Yes I did use the Sonnax boost valve, Yes the forward sprag is correct. The valve slid out smooth and steady, but did not "fall" out or slide quickly as if loose in the bore.
I am wanting to confirm it is not an electrical prob. I was unaware of or missing. Thank you for that.

I don't know about the one way clutch. What is it and how can you tell/test it.

I'm thinking as well as most of y'all that I should've had a pro do this. I thought I could save some $$, only at this point it may have been cheaper.

Thank you for your help.

[jason k]

The one way clutch is a sprag. It has 2 The forward and the low ,sprag. you would need special fixtures and and torque meter of some sort to test themthey will freewheel in one direction and lock and hold up to a specific amount of torque and then slip in the other direction. A 4l60 holds somewhere around 300-400 ftlbs I think.....