4l60e rebuilt but just lost reverse
4l60e rebuilt but just lost reverse Around 15k miles on trans since rebuilt . Reverse started acting funny a few weeks ago . Kinda jerky /jumping at lower rpms in reverse. Started acting like it was slipping but jerky feeling at lower rpms but when it tached up it would take off spinning in reverse. Parked the truck for about a week and tried it today and its like its almost in neutral. All forward gears work fine and shifts great . Any possible ideas what we ould cause this?
TECH Fanatic
Joined: Jan 2015
Posts: 1,114
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From: Fort Worth, Texas
4L60E's don't have a dedicated Reverse Boost Valve like a 700R4.
Check the 3 8mm headed bolts that hold down the Support Plate under the rear of the Valve Body.
Other than that.....You can check pressures in Reverse, Tear the unit down & see which frictions are Burnt/Distressed (Lo/Reverse or Reverse Input).
Check the 3 8mm headed bolts that hold down the Support Plate under the rear of the Valve Body.
Other than that.....You can check pressures in Reverse, Tear the unit down & see which frictions are Burnt/Distressed (Lo/Reverse or Reverse Input).
I wouldnt think itd be clutch related seeings transmission only has less than 15k miles since it was rebuilt . That and reverse was working somewhat before the truck sat for only a week . Now its just like its in neutral.
Moderator
Joined: Aug 2010
Posts: 7,323
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From: Ann Arbor, MI
Getting a new trans after 394,000 miles sounds like a good plan; even with a recent rebuild, that is incredible longevity.
Just to address the "reverse boost valve" - many people still call the boost valve in the 4L60E by that older name.
We had a thread here last year where the OP reported no Reverse and it turned out his boost valve had indeed popped out. However, IIRC that was shortly after a rebuild which indicated the boost valve's snap ring was probably not installed correctly.
Just to address the "reverse boost valve" - many people still call the boost valve in the 4L60E by that older name.
We had a thread here last year where the OP reported no Reverse and it turned out his boost valve had indeed popped out. However, IIRC that was shortly after a rebuild which indicated the boost valve's snap ring was probably not installed correctly.
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Verdad Gallardo TECH Fanatic
Joined: Jan 2015
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From: Fort Worth, Texas
EPC Boost & Reverse Boost are built into one Boost Valve assembly with 2 separate reaction areas. The Boost Valve assembly is in the Pump Cover that is accessible with the pan removed, You need to check pressures before messing with the Boost Valve.
Moderator
Joined: Aug 2010
Posts: 7,323
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From: Ann Arbor, MI
Yes, the "boost valve" can be accessed with just removing the pan. It is located in the pump in front of the valve body and held in with a round plate and a snap ring. On the driver's side.
The stock parts look like this:
Generally the inner-post pressure regulation valve does not fall out easily.
The stock parts look like this:
Generally the inner-post pressure regulation valve does not fall out easily.
Registered User
Joined: Jan 2018
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Boost valve I'm having the same issue - no reverse - but only when the its warm. When its cold it will work fine. If the boost valve has slipped would this happen? It has a new torque converter and pump which is why I'm questioning the boost valve.
Moderator
Joined: Aug 2010
Posts: 7,323
Likes: 529
From: Ann Arbor, MI
The reverse circuit does feed through and press on the boost valve to increase line pressure as needed in Reverse.
So a stuck or seriously leaking boost valve could lead to your loss of Reverse, but this is rare. Although I do remember one thread where the boost valve fell out after a rebuild.
To get the correct diagnosis you need to connect a pressure gauge and get the values in Park, Reverse, Drive and when blipping the throttle in Drive.
So a stuck or seriously leaking boost valve could lead to your loss of Reverse, but this is rare. Although I do remember one thread where the boost valve fell out after a rebuild.
To get the correct diagnosis you need to connect a pressure gauge and get the values in Park, Reverse, Drive and when blipping the throttle in Drive.