Hi folks, im stuck with a funny thing.
I drive a 97 P30 7.4 454 MPI 4L80E Motorhome.
My transmission has times it works just perfect.
and then i cant get the 4th to stay in.
it does not set any codes that i can read. but it sort of kills OD in 4th and if i do a code reset it tries and fails again.
if its in that fault mode, with foot on the pedal i have rpm for 3rd gear, downhill coasting/engine brake i have rmp for 4th gear, no gear change inbetween.
if i lock it to 3rd and lower, it works just like normal, including 3rd lock up.
the 4th TC lock up comes and goes, even on WOT (wide open throttle) it easily pulls the engine down, if its applied.
Im a bit over full on fluid right now, as i had issues with the transmission on inclined driving. no matter if up or down. on a certain rpm it would open the clutch of the gear selected or what ever lower gear it was in. like at 3000 rpm uphill in 1st it would just open the 1st clutch. downhill on a different rpm it would do the same. (that's how i cooked my brakes on the drive down into death valley, all rebuilt now, but that was a pain)
there are no fault codes set. (trans related, other do show up, just had a dead MAF, and the replacement did over report and throw two rich codes, but that's fixed now)
i heard about the broken neck filters and the diagnosis to overfill. did that and the 1-3 netraling problem was gone. so i dropped the pan, and changed the filter. pan was clean. magnet got a tiny bit of residual, was at 57,000miles. and surprise surprise, the filter was not broken.
how ever i only got like 4 quarts of oil out of the pan, and did read 13.5 are supposed to be in it and 50% should come out if you drop the pan. so i filled it with about 2 gallons. and it worked perfectly. over land. no interstate.
lazer i found that the fluid level should be as high as the valve body, so basically the pan full minus what the valve node replaced in the pan. i didn't check if my dipstick is right. its an extended dip stick all the way to the radiator due to motorhome configuration.
when i went back into long interstate driving, my open clutch neutraling on mountain driving in 1-3 was gone and still is, but the lock up thing for the 4th is still there. once in a while.
yesterday on a smooth I84 salt lake to boise i had hours of perfect operation, almost hundreds of miles in 4th and it did shift on all hills and no hick ups, today on the bumpy I84 after Boise into Oregon, i had to go to 3rd all the way cause it was neutralizing in cruise control up into the limiter and then being pulled down again on re-engage non stop.
As said I changed filter and filter neck seal, right filter for the pan and the seal is good. Im about an inch over full, but it does not foam up. no foamy oil on the dipstick.
i do have an odb reader, ultragauge MX1.3. but cant figure out how to see transmission data. however i see the tpms is rock steady, engine temp is plausible and pretty steady at 93c, uphill 102c and downhill on engine brake with heater on full it slowly cools off to 87c
brake switch works, it kills reliable the cruise control that also works perfectly. so its not stuck on.
I'm absolutely at a loss.
when i had the pan off i checked for loose wires or pinched stuff, nothing. from how it looked ive been the first to ever be in there.
whats your take on this?
im heading towards Seattle, any good 4L80E shop up there that could hook a decent computer to my car and take a look what the PCM is commanding vs the tranny is actually doing?
Thanks
Manny
pictures show my odb ultragauge mx while troubleshooting the new and faulty MAF
I drive a 97 P30 7.4 454 MPI 4L80E Motorhome.
My transmission has times it works just perfect.
and then i cant get the 4th to stay in.
it does not set any codes that i can read. but it sort of kills OD in 4th and if i do a code reset it tries and fails again.
if its in that fault mode, with foot on the pedal i have rpm for 3rd gear, downhill coasting/engine brake i have rmp for 4th gear, no gear change inbetween.
if i lock it to 3rd and lower, it works just like normal, including 3rd lock up.
the 4th TC lock up comes and goes, even on WOT (wide open throttle) it easily pulls the engine down, if its applied.
Im a bit over full on fluid right now, as i had issues with the transmission on inclined driving. no matter if up or down. on a certain rpm it would open the clutch of the gear selected or what ever lower gear it was in. like at 3000 rpm uphill in 1st it would just open the 1st clutch. downhill on a different rpm it would do the same. (that's how i cooked my brakes on the drive down into death valley, all rebuilt now, but that was a pain)
there are no fault codes set. (trans related, other do show up, just had a dead MAF, and the replacement did over report and throw two rich codes, but that's fixed now)
i heard about the broken neck filters and the diagnosis to overfill. did that and the 1-3 netraling problem was gone. so i dropped the pan, and changed the filter. pan was clean. magnet got a tiny bit of residual, was at 57,000miles. and surprise surprise, the filter was not broken.
how ever i only got like 4 quarts of oil out of the pan, and did read 13.5 are supposed to be in it and 50% should come out if you drop the pan. so i filled it with about 2 gallons. and it worked perfectly. over land. no interstate.
lazer i found that the fluid level should be as high as the valve body, so basically the pan full minus what the valve node replaced in the pan. i didn't check if my dipstick is right. its an extended dip stick all the way to the radiator due to motorhome configuration.
when i went back into long interstate driving, my open clutch neutraling on mountain driving in 1-3 was gone and still is, but the lock up thing for the 4th is still there. once in a while.
yesterday on a smooth I84 salt lake to boise i had hours of perfect operation, almost hundreds of miles in 4th and it did shift on all hills and no hick ups, today on the bumpy I84 after Boise into Oregon, i had to go to 3rd all the way cause it was neutralizing in cruise control up into the limiter and then being pulled down again on re-engage non stop.
As said I changed filter and filter neck seal, right filter for the pan and the seal is good. Im about an inch over full, but it does not foam up. no foamy oil on the dipstick.
i do have an odb reader, ultragauge MX1.3. but cant figure out how to see transmission data. however i see the tpms is rock steady, engine temp is plausible and pretty steady at 93c, uphill 102c and downhill on engine brake with heater on full it slowly cools off to 87c
brake switch works, it kills reliable the cruise control that also works perfectly. so its not stuck on.
I'm absolutely at a loss.
when i had the pan off i checked for loose wires or pinched stuff, nothing. from how it looked ive been the first to ever be in there.
whats your take on this?
im heading towards Seattle, any good 4L80E shop up there that could hook a decent computer to my car and take a look what the PCM is commanding vs the tranny is actually doing?
Thanks
Manny
pictures show my odb ultragauge mx while troubleshooting the new and faulty MAF
