2001 f150 super crew 5.4L triton, type U trans, shifting problems
#1
06-27-2014, 08:55 AM
Join Date: Jun 2014
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2001 f150 super crew 5.4L triton, type U trans, shifting problems
I have this truck with 160,000 has been dealer serviced by previous owner with not reported problems until now.
Going from P to D it does not get into gear until I give it a little gas then it bangs into gear, after that no problems until I stop or slow way down, at which time it doesnt downshift until I give it a little gas and it bangs into gear again.
The problem started one week ago with it taking a second or two to engage D from P, then it took like four or five seconds, now it just wont go into gear unless I raise the rpm's then it bangs into gear.
Transmission fluid is bright red, smells good, no leaks.
On another note the engine light came on several months ago and with a cheap scanner I read the codes as 171 174 which I believe indicates lean on banks 1 and 2, I will work on getting this remedied but I cannot connect the two issues.
Need my truck desperately so any help would be greatly appreciated.
Going from P to D it does not get into gear until I give it a little gas then it bangs into gear, after that no problems until I stop or slow way down, at which time it doesnt downshift until I give it a little gas and it bangs into gear again.
The problem started one week ago with it taking a second or two to engage D from P, then it took like four or five seconds, now it just wont go into gear unless I raise the rpm's then it bangs into gear.
Transmission fluid is bright red, smells good, no leaks.
On another note the engine light came on several months ago and with a cheap scanner I read the codes as 171 174 which I believe indicates lean on banks 1 and 2, I will work on getting this remedied but I cannot connect the two issues.
Need my truck desperately so any help would be greatly appreciated.
#2
06-27-2014, 10:06 AM
sounds like a sealing ring issue and/or the forward clutch is slipping.
I just rebuilt a 4R75 with same issue.
When I removed the front pump, I found the pump stator and reverse clutch drum were seized together. I had to use a 80ton shop press at my buddies tractor shop to get the pieces to separate.
Once separated, I found the metal sealing rings on the pump stator had cut grooves into the reverse clutch drum and the stator support bushing was badly worn.
Further inspection of the reverse drum found the snap ring that holds the intermediate mechanical diode one way clutch on the drum was bent and about to fail.
The mechanical diode one way clutch also showed evidence of something making contact/rubbing on the top race.
On the inside of the reverse drum, with the clutch pack removed, it was discovered the piston return spring was cracked in half.
The entire reverse drum went into the metal scrap bin. I updated the factory snap ring that holds the one way clutch on to a spiral ring with a cage, it won't be coming off any time soon.
The forward clutch outer piston lip seal was brittle with a 3" section of the sealing lip missing.
The forward clutches were worn to the point the cross hatch was gone and just starting to burn (note the dark ring towards the inner edge of the clutches)
The wave plate/spring that sits between the clutch piston and bottom steel plate was completely flat.
The low/reverse accumulator piston is steel with molded rubber, the rubber was brittle and basically broke into pieces when removed from the transmission.
The overdrive servo snap ring was broken and a royal pain to remove. I finally got it removed and found the last missing piece hiding in the valve body. The new aftermarket snap ring is hardened to resist breaking, it's black in color.
I just rebuilt a 4R75 with same issue.
When I removed the front pump, I found the pump stator and reverse clutch drum were seized together. I had to use a 80ton shop press at my buddies tractor shop to get the pieces to separate.
Once separated, I found the metal sealing rings on the pump stator had cut grooves into the reverse clutch drum and the stator support bushing was badly worn.
Further inspection of the reverse drum found the snap ring that holds the intermediate mechanical diode one way clutch on the drum was bent and about to fail.
The mechanical diode one way clutch also showed evidence of something making contact/rubbing on the top race.
On the inside of the reverse drum, with the clutch pack removed, it was discovered the piston return spring was cracked in half.
The entire reverse drum went into the metal scrap bin. I updated the factory snap ring that holds the one way clutch on to a spiral ring with a cage, it won't be coming off any time soon.
The forward clutch outer piston lip seal was brittle with a 3" section of the sealing lip missing.
The forward clutches were worn to the point the cross hatch was gone and just starting to burn (note the dark ring towards the inner edge of the clutches)
The wave plate/spring that sits between the clutch piston and bottom steel plate was completely flat.
The low/reverse accumulator piston is steel with molded rubber, the rubber was brittle and basically broke into pieces when removed from the transmission.
The overdrive servo snap ring was broken and a royal pain to remove. I finally got it removed and found the last missing piece hiding in the valve body. The new aftermarket snap ring is hardened to resist breaking, it's black in color.
