jca

hi Guys, got a problem with a 4l60e we just rebuilt, it will shift 1-2 -3 but will not go in to 4th no matter what , we just did clutchs, seals, wider band, transgo stage 1 shift kit we reused the old converter and the customer fitted the box himself could it be as simple as the o-ring on the end of input shaft?, I'd be gratefull for any other input/ ideas. - thanks

Vince B

iTrader: (1)

I would probaby check the 4th servo seals and also the band clearance at the 4th servo. Also look at your check ***** to make sure that you have 7 in the valve body and one in the case at the 3-4 accumulator. The ring on the input shaft is for lockup so that would not effect 4th gear. It is used for the torque converter clutch. The only way this could be an issue is if you are missing LU and not 4th gear. I hope this helps you with that box! Vince

jca

Hi Vince/ guys, I pulled the sevo out today looked ok pretty sure i had the 4th gear pistion the right way round the seals look ok but are super tight in the cover but i compared against a know good box and they felt the same so i pulled the box out and the brand and drum has been slipping its nut off i read another post on here and it said if the sprag is in backwards it would smoke the band but i had all gears apart from 4th also the customer fitted it himshelf and decided 5litres of fluid was enough ( ********) ,it was down about 3 litres by the time i checked it (first thing i did) could the low oil level have made it slip enought to stuff the band he reckons he drove it stuff all?. regards Jason

Vince B

iTrader: (1)

Yes low fluid and or a sprag in backwards could cause this issue. Vince

jca

Hi guys, I pulled the box apart to day couldn' t really find any thing wrong apart a burnt band and shinny drum so I repaired that and rechecked the valve body all good i put it back in and have all gears apart 4th as soon as it trys to select 4th instant smoke starts to pour out the dip stick tube its could be stuffed its like the trans is trying to select 2 gears , I check the solenolds with the scan tool they all click on and off apart from the 3-2 downshift solenold it just pulses i tryed 2 other s/h ones i had laying around , same thing so i probed the wiring all the way back to pcm and it still dose it so i tryed another pcm with stock tune and dose the same , I check the operation of the solenold on 3 other cars in the workshop and they just turn on or off with the scan tool - could this solenold stop the trans changing in to 4th and burning up my band I air tested the servo with the valve body off and locked the drum in both 2nd and 4th I guess ther the two passages in find in the case?. There is also no fault codes present.
regards Jason

performabuilt

iTrader: (25)

If your burning the band on the 3-4 shift then there are only a couple possibilites.
Sprag installed backwards but that should also cause no movement on OD position from a dead stop. Or a cut or missing sealing ring on the input shaft causing the overun clutch to allways be on or cut or missing center seal on the forward clutch piston causing the same. No solenoid could cause this.