4l60e soft shifting dramas!!!
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4l60e soft shifting dramas!!! Hey all i have a 60e in the shop behind a ls1 and am suffering from soft shifts... originally came in with no 3/4. r&r'd and found 3/4 clutches shagged as usual. o/hauled tranny and it went for about 20,000 km before dropping 3rd and 4th again. once again o/hauled and suspected poor piston sealing and leaking 2-3 checkball (fitted blanking plug into case). refitted and this time tranny went for about 100km (not 100,000, just 100km) before dropping 3rd and 4th. clutches are burnt but not signifigantly enough to suggest this is the cause of loosing the gear completely. o/hauled again and fitted. line pressures are as follows- Idling, P-50psi,Reverse-70psi,Neutral drive 1,2,&3-50psi. stalled up- Reverse-300psi, drive-220psi....more than enough. the problem im having is all shifts are soft as butter and slight flare up on 2-3 under moderate throttle. i know the clutches are just going to die if i give it back to the customer like this... 
i have replaced all seals, all gaskets all clutches, boost valve with sonnax o-ring seal one, drilled boost vavle to 60thou, tried fitting a valve body for differnt box to elinate a leaking pressure valve ect ect only to have the same result. all signs point to the pump...im failing to see what the problem with the pump can be, i suspect maybe the cresent is sticking. obviously it has a new slide ect. it is a 13 vein rotor as well which should pump some kick *** pressure.. im running out of ideas with this thing HELP!!!!!!!
i have replaced all seals, all gaskets all clutches, boost valve with sonnax o-ring seal one, drilled boost vavle to 60thou, tried fitting a valve body for differnt box to elinate a leaking pressure valve ect ect only to have the same result. all signs point to the pump...im failing to see what the problem with the pump can be, i suspect maybe the cresent is sticking. obviously it has a new slide ect. it is a 13 vein rotor as well which should pump some kick *** pressure.. im running out of ideas with this thing HELP!!!!!!! 
Does this trans have a shift kit in it. The pressures at idle seem a bit low to me. The one thing to do is to see what happens to the pressure when the trans shifts. If its falling off and not maintaining you have a pump problem or an internal leak. Have you cleaned the mass air flow sensor? I have seen these cause pressure issues and it might be something to check. Vince
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yea i have cleaned the maf sensor very thouroughly. there is a wire with slight damage to the maf due to serpentine belt coming off one day i assume, the wire has maybe 1-2 bare strands its in no way broken on not contacting which leads me to belive it should be fine. do you know of any ohms readings i can check throught the maf? just pulled tranny out again and checked pump clearence, perfect. there is no eveidence to sugest a sticky slider either. pressure ramps up to about 110+ when accelerating but quickly falls away back to 50 when engine load is reducing. its seems to hover around 50-60 during shifts. it does not increase upon upshift...is this normal? im als o wondering if these have any other control issues with the VPS?? although if im taking main line pressure from the test port is this affected by the VPS? or is this purely the pressure at which my pump is pumping? all my sealing rings to the input drum are fine i have fitted new moulded pistons. good news is the clutches are not burnt this time, and are showing very very minimal slippage on the steels. i am still failing to see this as a valve body control issue as i have fitted a seperate valve body and having the same dramas it seems 1 in a million chance that both valve bodies suffer from the same leaking valves. 
