Lost reverse today 2005 48RE

[Blakers]

I need some help. Today my truck lost reverse. Forward gears seem to shift fine. Everything has been ok up until now. Transmission fluid level is fine. Transmission was completely rebuilt last March and has always shifted very strong. I've owned it since late March and have never towed with it or abused it in any way. Thanks!

 

[CharlesinGA]

Low/Reverse band may have broken. You lose reverse, and there is a one way clutch for low in Drive, and the band applies in manual low, but the one way clutch catches it for low, and you cannot tell the difference. Lo/Rev Band is absolutely necessary for reverse however.

I had a 2ed speed band break in a Ford C4 one time, would stay in low until it got fast enough and went to 3rd.

Just an educated guess.

Charles

 

[Blakers]

Low/Reverse band may have broken. You lose reverse, and there is a one way clutch for low in Drive, and the band applies in manual low, but the one way clutch catches it for low, and you cannot tell the difference. Lo/Rev Band is absolutely necessary for reverse however.

I had a 2ed speed band break in a Ford C4 one time, would stay in low until it got fast enough and went to 3rd.

Just an educated guess.

Charles

Can the band be replaced without pulling the transmission?

only 7877 miles on it.

One thing I recall, one time last week I went to back into a parking spot at work and it seemed like it wasn’t fully engaging in reverse. It moved, but didn’t have much power. Then it was fine after that until this evening.

 

[sag2]

Band cannot be replaced in the truck. Don't know if this guy is any good, but pretty good teardown showing possible no reverse problems.

 

[promisedland]

Any chance the shifter linkage could be off?

The reverse band is a heavy piece, seems hard to believe it broke... very high pressure?

 

[CRodi]

Are you able to drop the pan and have a look for anything obvious? I had the exact same symptoms on my 47re with less than a thousand miles on a fresh rebuild. The transmission shop neglected to tighten down whatever this actuator type do hickey is. A bit of vibration and a few bumps and this piece fell right off. Sorry I don't have a before shot. It was sitting on the bottom of the pan in a transmission shop far from home.

 

[Grumpy8811]

this is a copy and paste.

quote
The rear band is applied in 1 and R range only.
The overdrive clutch is applied only in fourth gear. However the overdrive direct clutch and overrunning clutch are applied in all ranges except fourth gear.

Examples…
If slippage occurs in first gear in D and 2 range but not in 1 range, the transmission overrunning clutch is faulty. Similarly, if slippage occurs in any two forward gears, the rear clutch is slipping.
Applying the same method of analysis, one note that the front and rear clutches are applied simultaneously only in D range third and fourth gear. If the transmission slips in third gear, either the front clutch or the rear clutch is slipping.
If the transmission slips in fourth gear but not in third gear, the overdrive clutch is slipping. By selecting another gear which does not use these clutches, the slipping unit can be determined.

For another example, if the transmission also slips in Reverse, the front clutch is slipping. If the transmission does not slip in Reverse, the rear clutch is slipping.
If slippage occurs during the 3-4 shift or only in fourth gear, the overdrive clutch is slipping. Similarly, if the direct clutch were to fail, the transmission would lose both reverse gear and overrun braking in 2 position (manual second gear).
If the transmission will not shift to fourth gear, the control switch, overdrive solenoid or related wiring may also be the problem cause.

This process of elimination can be used to identify a slipping unit and check operation. Although road test analysis will help determine the slipping unit, the actual cause of a malfunction usually cannot be determined until hydraulic and air pressure tests are performed. Practically any condition can be caused by leaking hydraulic circuits or sticking valves.
Unless a malfunction is obvious, such as no drive in D range first gear, do not disassemble the transmission. Perform the hydraulic and air pressure tests to help determine the probable cause

 

[Blakers]

I contacted the guy who rebuilt it back in February, and he said it’s still under warranty. I drove it up yesterday morning. I don’t know all the details yet, but his first guess was a pin or snap ring came off the reverse band.
Later he called me and said it was low on oil and that the reverse band was cooked and he was going to check the clutches. The he texted me last night around midnight saying truck was ready, but he wants to keep it a couple days to drive it around and make sure it’s ok.
I can’t believe it was low on oil. I don’t check it as often as my engine oil, but I have never seen any leaks since I’ve owned the truck. I park on concrete and I’ve been under the truck at least 50 times since I bought it in March. Never a drip besides a seep from the drain plug gasket that will leave a film on your finger.
Anyway..,, I’m hoping this thing is fixed and reliable once he’s done, and not something I have to worry about forever.

 

[Ozymandias]

How do you check level?
Did it leak into the TC? That can happen if the seal up the mating flanges with RTV at install.

 

[Blakers]

How do you check level?
Did it leak into the TC? That can happen if the seal up the mating flanges with RTV at install.

You mean leak into the bell housing from the torque converter and get trapped in there? That truck doesn’t leak any fluids anywhere that makes it to the ground.

 

[Blakers]

Band cannot be replaced in the truck. Don't know if this guy is any good, but pretty good teardown showing possible no reverse problems.

Good video. Thanks for sharing.

 

[Ozymandias]

No I meant into the transfer case.

 

[Blakers]

Update and back on the road:
The culprit for no reverse turned out the be the shift lever that actuates the low/reverse band via the servo had bent. I have not seen pictures of it yet, but he kept the parts. He said he used the most heavy-duty parts he could find when he rebuilt it, and blames it on cheap Chinese parts.

He pulled the transmission apart and checked the clutches, which he said are ok. He drained the converter and filter, and replaced the oil with new. He wanted to keep the truck a couple days to drive and make sure it's ok. He drove it about 155 miles going to work and back two days, plus test driving through various situations. He returned it directly to my house last night after burning up almost 1/2 tank of fuel in testing.

He says he used the heaviest-duty part to replace the shift lever, and says it should be ok now. He also said the low oil issue he told me about before was not a cause of the problem. Personally I think most of that was a miscalculation.

I drove it to work today and it seems to shift fine. So, hopefully this issue is behind me now. I gave him $250 to cover the oil as a courtesy.

Thanks for your help!