Dextron V1 in High Mileage 4L60E
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Staging Lane
Joined: Aug 2013
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Dextron V1 in High Mileage 4L60E Hi guys, I bought a 2003 Suburban with 140K a year and half ago for a donor vehicle for my project S10. When and if I ever get it going I want to flush the Dextron 111 out of 4L60E tranny for Dextron V1. I heard flushing out old transmissions may loosen up clutch material and may cause slippage. Am I asking for trouble or should I go for it? The oil is dirty and I have to do something. Any help advice would be appreciated.
If it has not had the trans flushed every time during fluid exchange, I would avoid doing it. It can dislodge material built up in the passages and converter, clogging the tiny oil holes leading to burned clutches or complete failure.
I would drop the pan and change the filter and fluid, this method may only drain about 40-50% of the entire contents of fluid in the trans. There is a method of removing the oil cooler lines from the radiator and connecting one cooler line to a hose which is in a 5 quart jug and the other cooler line in a empty bucket. This method allows the old fluid the run out into the empty bucket and siphon the new fluid out of the 5 quart jug, this keeps air out and is a safe way to exchange all fluid. You can switch it to Dexron VI, the newer fluid meets and exceeds Dexron III. I was told Dexron VI has better friction modifiers and is Synthetic or Semi-Synthetic. GM Made the switch to Dexron VI late 2005 and recommends to use the newest Dexron Fluid in your transmissions (At least "E" Electronically Controlled Transmissions) as long as it is compatible with the previous Dexron Fluid.
In early 2006, all Licensing for Dexron-III expired and was not renewed. Which means it is no longer Mandated or Inspected by GM and may not be the exact specs or approved formulation as before. It can still be purchased by most auto parts stores labeled Dex/Merc ATF. GM has replacement fluids for all Automatic and Manual Transmissions as well as Transfer Cases that used Dexron-III.
I would drop the pan and change the filter and fluid, this method may only drain about 40-50% of the entire contents of fluid in the trans. There is a method of removing the oil cooler lines from the radiator and connecting one cooler line to a hose which is in a 5 quart jug and the other cooler line in a empty bucket. This method allows the old fluid the run out into the empty bucket and siphon the new fluid out of the 5 quart jug, this keeps air out and is a safe way to exchange all fluid. You can switch it to Dexron VI, the newer fluid meets and exceeds Dexron III. I was told Dexron VI has better friction modifiers and is Synthetic or Semi-Synthetic. GM Made the switch to Dexron VI late 2005 and recommends to use the newest Dexron Fluid in your transmissions (At least "E" Electronically Controlled Transmissions) as long as it is compatible with the previous Dexron Fluid.
In early 2006, all Licensing for Dexron-III expired and was not renewed. Which means it is no longer Mandated or Inspected by GM and may not be the exact specs or approved formulation as before. It can still be purchased by most auto parts stores labeled Dex/Merc ATF. GM has replacement fluids for all Automatic and Manual Transmissions as well as Transfer Cases that used Dexron-III.
Last edited by 07NBSChevy; Apr 25, 2017 at 02:16 AM.
If it has not had the trans flushed every time during fluid exchange, I would avoid doing it. It can dislodge material built up in the passages and converter, clogging the tiny oil holes leading to burned clutches or complete failure.
I would drop the pan and change the filter and fluid, this method may only drain about 40-50% of the entire contents of fluid in the trans. There is a method of removing the oil cooler lines from the radiator and connecting one cooler line to a hose which is in a 5 quart jug and the other cooler line in a empty bucket. This method allows the old fluid the run out into the empty bucket and siphon the new fluid out of the 5 quart jug, this keeps air out and is a safe way to exchange all fluid. You can switch it to Dexron VI, the newer fluid meets and exceeds Dexron III. I was told Dexron VI has better friction modifiers and is Synthetic or Semi-Synthetic. GM Made the switch to Dexron VI late 2005 and recommends to use the newest Dexron Fluid in your transmissions (At least "E" Electronically Controlled Transmissions) as long as it is compatible with the previous Dexron Fluid.
In early 2006, all Licensing for Dexron-III expired and was not renewed. Which means it is no longer Mandated or Inspected by GM and may not be the exact specs or approved formulation as before. It can still be purchased by most auto parts stores labeled Dex/Merc ATF. GM has replacement fluids for all Automatic and Manual Transmissions as well as Transfer Cases that used Dexron-III.
I would drop the pan and change the filter and fluid, this method may only drain about 40-50% of the entire contents of fluid in the trans. There is a method of removing the oil cooler lines from the radiator and connecting one cooler line to a hose which is in a 5 quart jug and the other cooler line in a empty bucket. This method allows the old fluid the run out into the empty bucket and siphon the new fluid out of the 5 quart jug, this keeps air out and is a safe way to exchange all fluid. You can switch it to Dexron VI, the newer fluid meets and exceeds Dexron III. I was told Dexron VI has better friction modifiers and is Synthetic or Semi-Synthetic. GM Made the switch to Dexron VI late 2005 and recommends to use the newest Dexron Fluid in your transmissions (At least "E" Electronically Controlled Transmissions) as long as it is compatible with the previous Dexron Fluid.
In early 2006, all Licensing for Dexron-III expired and was not renewed. Which means it is no longer Mandated or Inspected by GM and may not be the exact specs or approved formulation as before. It can still be purchased by most auto parts stores labeled Dex/Merc ATF. GM has replacement fluids for all Automatic and Manual Transmissions as well as Transfer Cases that used Dexron-III.
