4L60e issues after rebuild

[NickTransmissions]

I am not familiarized with the wet pressure test procedure.

4L60E / 700R4 Forward Drum Inspection; 3rd Gear Slipping and Failure

 

[Tataocb]

4L60E / 700R4 Forward Drum Inspection; 3rd Gear Slipping and Failure

I did perform that test and there were no bubbles.

I am now testing it after having rebuilt both input and reverse drums as well as the pump. I stacked both drums along with the pump, flipped the whole assembly over and did an air. Checked through the pump holes, and I can still feel air coming out of the tip of the input shaft.

I also tested 2 other similar assemblies out of 2 other transmissions, and they all seem to blow a little bit of air out of the tip of the input shaft. So I am starting to wonder if it is normal and I just had never noticed it before?

 

[NickTransmissions]

I did perform that test and there were no bubbles.

I am now testing it after having rebuilt both input and reverse drums as well as the pump. I stacked both drums along with the pump, flipped the whole assembly over and did an air. Checked through the pump holes, and I can still feel air coming out of the tip of the input shaft.

I also tested 2 other similar assemblies out of 2 other transmissions, and they all seem to blow a little bit of air out of the tip of the input shaft. So I am starting to wonder if it is normal and I just had never noticed it before?

I've never noticed it either but will let you know tomorrow if i can hear/feel some air coming out of the snout when i take apart the 700R4 and wet pressure test the input drum.

 

[Tataocb]

I've never noticed it either but will let you know tomorrow if i can hear/feel some air coming out of the snout when i take apart the 700R4 and wet pressure test the input drum.

I decided I would continue with the reassembly since the other 2 drum and pump assemblies had similar results. When I got to the point where I air checked using the test plate there was a bit of air coming through the tip of the input shaft but nowhere near as much as it was before. So I assume the new sealing rings corrected that behavior.

 

[NickTransmissions]

I decided I would continue with the reassembly since the other 2 drum and pump assemblies had similar results. When I got to the point where I air checked using the test plate there was a bit of air coming through the tip of the input shaft but nowhere near as much as it was before. So I assume the new sealing rings corrected that behavior.

You'll know for sure once it's back in the vehicle...no news is good news in our biz...

 

[NickTransmissions]

I decided I would continue with the reassembly since the other 2 drum and pump assemblies had similar results. When I got to the point where I air checked using the test plate there was a bit of air coming through the tip of the input shaft but nowhere near as much as it was before. So I assume the new sealing rings corrected that behavior.

I did a wet pressure test and air check of a 700R4 drum today (this one had the tcc ball capsule in the snout removed) and there was absolutely no air coming out of the snout of the input shaft. I also checked a 4L60E drum that I threw together with what I had laying around in the shop and air-checked it as well...No air coming out of the snout.

 

[Tataocb]

@NickTransmissions - I come again in search of help. I rebuilt a 2007 4L60e and everything air checked fine. The buyer reused their old torque converter and replaced the transmission cooler lines. He installed it the first time and said it was leaking from one of the cooler lines, by the fittings on the transmission. He replaced the fittings and then it started leaking out of the front seal. He replaced the front seal and then it started leaking out of the vent tube. It will not stop leaking. He has added almost 2 quarts of fluid to get it to the correct fill level and it still leaks. Other symptoms are that after he turns on the engine, when he shifts into Reverse or Drive, the engine will die. After about the 3rd attempt, it will stay running. He says it shifts through all the gears, but the shifts are a bit rough/bumpy (all of them from what I understand). His old transmission that he exchanged had run low on fluid because it leaked out of the transmission cooler line where it goes into the fitting on the transmission.

I thought he might have overfilled it, but if after letting it run for some time it leaks enough fluid to where more needs to be added, then that tells me that is probably not the case. Apparently, the leak does not stop even after it runs low.

My next thought is a bad torque converter (I should probably be stricter about only selling along with a new converter) since he is also experiencing issues where it shuts off when put into gear and it bumps when it shifts gear.

The other possible cause I can think of is that the transmission cooler could be clogged (since he replaced the lines), causing it to overheat and spill fluid.

I reused the wiring harness so maybe the TCC solenoid is faulty, causing it to shut off when put in gear some of the time. Considering his old transmission also leaked fluid, it leads me to believe he might have a bad torque converter or clogged cooler more so than an issue with the transmission.

What could cause this behavior if it was an issue with the transmission? Is there any way to test the pump for cross leaks? He will probably end up bringing it back and I might end up giving him a full refund since I doubt he will want to spend more money on a new torque converter and cooler. He is convinced those are fine. So I am looking at what to check for once I get it back.

Thanks for any insight you can provide.

 

[NickTransmissions]

@NickTransmissions - I come again in search of help. I rebuilt a 2007 4L60e and everything air checked fine. The buyer reused their old torque converter and replaced the transmission cooler lines. He installed it the first time and said it was leaking from one of the cooler lines, by the fittings on the transmission. He replaced the fittings and then it started leaking out of the front seal. He replaced the front seal and then it started leaking out of the vent tube. It will not stop leaking. He has added almost 2 quarts of fluid to get it to the correct fill level and it still leaks. Other symptoms are that after he turns on the engine, when he shifts into Reverse or Drive, the engine will die. After about the 3rd attempt, it will stay running. He says it shifts through all the gears, but the shifts are a bit rough/bumpy (all of them from what I understand). His old transmission that he exchanged had run low on fluid because it leaked out of the transmission cooler line where it goes into the fitting on the transmission.

I thought he might have overfilled it, but if after letting it run for some time it leaks enough fluid to where more needs to be added, then that tells me that is probably not the case. Apparently, the leak does not stop even after it runs low.

My next thought is a bad torque converter (I should probably be stricter about only selling along with a new converter) since he is also experiencing issues where it shuts off when put into gear and it bumps when it shifts gear.

The other possible cause I can think of is that the transmission cooler could be clogged (since he replaced the lines), causing it to overheat and spill fluid.

I reused the wiring harness so maybe the TCC solenoid is faulty, causing it to shut off when put in gear some of the time. Considering his old transmission also leaked fluid, it leads me to believe he might have a bad torque converter or clogged cooler more so than an issue with the transmission.

What could cause this behavior if it was an issue with the transmission? Is there any way to test the pump for cross leaks? He will probably end up bringing it back and I might end up giving him a full refund since I doubt he will want to spend more money on a new torque converter and cooler. He is convinced those are fine. So I am looking at what to check for once I get it back.

Thanks for any insight you can provide.

Why are you reusing things that should be tossed? All electronic/electrical parts should be put in the trash and replaced with AC Delco, Rostra, Delphi or Borg Warner components. Its begging for a comeback when that stuff is reused (esp 2006+ 4L60Es with TSS).

Same with the converter, which is where the problem is. Never reuse any of that stuff. I say this countless times in all my videos and on here/elsewhere.

Always provide a new converter, build it into the price and inform the customer up front. If the customer insists upon reusing his old one, decline the job. It's not worth your time/money/stress/headaches, etc.
That converter contaminated a freshly built unit, not to mention the customer likely didn't flush his system out so even more contaminants.

My warranty becomes void if that stuff isnt done, and I can always tell.

Never let customers steer you in the wrong direction or force you to take unnecessary risks because they want to be penny-wise and pound foolish...

 

[Tataocb]

Why are you reusing things that should be tossed? All electronic/electrical parts should be put in the trash and replaced with AC Delco, Rostra, Delphi or Borg Warner components. Its begging for a comeback when that stuff is reused (esp 2006+ 4L60Es with TSS).

Same with the converter, which is where the problem is. Never reuse any of that stuff. I say this countless times in all my videos and on here/elsewhere.

Always provide a new converter, build it into the price and inform the customer up front. If the customer insists upon reusing his old one, decline the job. It's not worth your time/money/stress/headaches, etc.

That converter totally contaminated a freshly built unit, not to mention the customer likely didnt flush his system out so even more contaminents. Now you're going to be rebuilding it all over again.

My warranty becomes if that stuff isnt done.

I agree. Customers coming back with issues can get stressful depending on their personality, and having to open up a transmission more than one is frustrating and no fun either.

Thanks for the insight.

 

[NickTransmissions]

I agree. Customers coming back with issues can get stressful depending on their personality, and having to open up a transmission more than one is frustrating and no fun either.

Thanks for the insight.

You're welcome, hopefully you can salvage it without having to refund the entire job.