Greetings:
My dad just bought a great running 2000 GMC Sierra 1500 2WD 4.8 V8 with the infamous 4L60E transmission. It has 183K miles on it and no maintenance history is known. The trans shifts fine and the fluid looks fair but not burnt, but I'd like to service it and/or do things to ensure that it will last (especially with that transmission's somewhat checkered reputation.) This truck will get light utility use and probably won't see more than 5-7K max a year. It does not appear to have the factory towing package (no external cooler). For all I know it has 183K on the original trans and fluid (?!)
I have been reading about the 4L60E box here and in other places and there are so many opinions on what to do in a case like this that it makes my head spin. My thought was to start off slowly with a pan drain through the drain plug (5 quarts or so) and refill with fresh DexIII for now and run it until the spring (probably 2000 miles or so). Then, I would pull the pan, change the filter, do a cooler line flush with either Valvoline Max Life fluid or Dex VI and add an external stacked plate cooler at the same time.
I have also heard that there are general problems with control valves and servos that wear out on these that can be changed while the pan is off. I am not sure if I should touch these or not as I understand that changes were made to these units over the years and I don't know if the 2000 model year has those specific problems. I have also heard that tweaking line pressure, adding a Corvette-style servo, etc. can actually hasten the breakage of known weak parts like the sun shell, etc.
As always, thanks for any feedback.
Andrew S.
My dad just bought a great running 2000 GMC Sierra 1500 2WD 4.8 V8 with the infamous 4L60E transmission. It has 183K miles on it and no maintenance history is known. The trans shifts fine and the fluid looks fair but not burnt, but I'd like to service it and/or do things to ensure that it will last (especially with that transmission's somewhat checkered reputation.) This truck will get light utility use and probably won't see more than 5-7K max a year. It does not appear to have the factory towing package (no external cooler). For all I know it has 183K on the original trans and fluid (?!)
I have been reading about the 4L60E box here and in other places and there are so many opinions on what to do in a case like this that it makes my head spin. My thought was to start off slowly with a pan drain through the drain plug (5 quarts or so) and refill with fresh DexIII for now and run it until the spring (probably 2000 miles or so). Then, I would pull the pan, change the filter, do a cooler line flush with either Valvoline Max Life fluid or Dex VI and add an external stacked plate cooler at the same time.
I have also heard that there are general problems with control valves and servos that wear out on these that can be changed while the pan is off. I am not sure if I should touch these or not as I understand that changes were made to these units over the years and I don't know if the 2000 model year has those specific problems. I have also heard that tweaking line pressure, adding a Corvette-style servo, etc. can actually hasten the breakage of known weak parts like the sun shell, etc.
As always, thanks for any feedback.
Andrew S.