4L60E trans problems

[a10zman]

I HAVE A 93 GMC SUBURBAN 1500 2WD. WITH A 4L60E TRANS. SHIFTS GOOD 1-2. 2-3 AND 3 SLIPS REAL BAD LIKE IN NUETRAL. I CHECKED THE TRUCK OUT WITH MY OTC4000 SCANNER AND GOT THE FOLLOWING INFO.....

CODE 72 OUTPUT SPEED LOSS

CODE 73 FORCE MOTOR CURRENT

CODE 79 TRANS HOT (ONLY AFTER DRIVING TO DIAGNOS)

CODE 81 TRANS SOL B FAILURE.

 

THE TRANS WAS REBUILT 50K MILES AGO AND HAS BEEN IN STORAGE AND NOT DRIVEN FOR 4 YEARS. WHEN STARTED 3 WEEKS AGO, IT RAN FINE. TOPPED OFF ALL FLUIDS AND DROVE FROM CHICAGO TO MICHIGAN ABOUT 140 MILES. IT RAN GREAT. PARKED IT. THEN TRYED TO DRIVE IT THIS WEEKEND AND IT STARTED ACTIN UP.

 

IM A MECHANIC ON HEAVY EQUIP SO AUTOMATIC TRANSMISSIONS ARE GREEK TO ME.

 

THIS TRUCK WAS MY GODMOTHERS WHO DIED OF BREAST CANCER AND ITS VERY SPECIAL TO ME.

 

THANKS,

DAVE

[Black02Silverado]

Dave,

 

I'm not a tranny person and hopefully someone will chime in and help.

 

You can always change out the fluid and put fresh in since the fluid has been sitting a while. Pennzoil makes a good ATF.

[Bish]

Could be as simple ad a bad solenoid or it could be cooked frictions which means a rebuild. The first code says there is slip in the trans. The second is one of the solenoids. The third will happen if the trans is slipping generating lots of heat. The third is another solenoid.

 

Having said all that, I would agree with the suggestion to change fluid. The solenoids could be stuck from sitting and a fluid change MAY help. Beyond that, I am not sure how you can test a solenoid to verify the cause. Where did you have it rebuilt? I had mine rebuilt due to slipping 2-3 shift at WOT. It wasn't slipping bad enough to set codes or overheat but I'm sure it would have given a little time. Frictions were pretty close to gone when FLT (Finish Line Transmission) tore it down.

[Loomis462]

if its only been 50k since the rebuild i doubt the clutches are wore out. I would guess a couple of solinoids have seized

[redrider2001]

From what I understand from a Tranny shop - When an auto tranny sits for a long time, the fluid drains to the pan and the frictions dry up and ruins the tranny... sounds like you may need a rebuild.

[a10zman]

ok, i did a total flush out. used a friends shift-rite fluid exchange machine. flushed it out, drove about 2 miles, no change, flushed again and still no change. any ideas

[mcreyaufmiller]

I would agree with redrider.Your fibers are probably dried out and damaged. For a real idea, take it to a tranny shop for an opnion.

[a10zman]

OK, I REPLACED 2 BAD SOLINOIDS IN THE TRANS, FOUND BAD BY COMPUTER. COMPLETELY DRAINED, FLUSHED AND CHANGED THE FILTER. STILL NO CHANGE, LOOKS LIKE IM BUYIN A TRANS NEXT WEEK. THANKS FOR THE INPUT FROM EVERYONE. ILL POST AFTER THE SWAP. ANYBODY IN SOUTHERN MICHIGAN OR NORTHERN INDIANA HAVE A 4L60E TRANDS THEY WANNA GET RID OF AT A DECENT PRICE? IF SO EMAIL ME AT [email protected].

Thanks,

Dave