high mileage 4l60e pan drop or cooler line

[jalikaria24]

hey guys, my truck has 4l60e with 240,000km on it. i dont know the previous maintenance history but i am 99.9% sure my mechanic did a pan drop on it about 4-5 years ago. i dont know how many km' that is but i was thinking of just putitng some new fluid in just so its maintained for the rest of its life. so i was thinking at this age, should i do pan drop or cooler line flush? i wouldnt mind paying for all the new fluid because atleast i know its maintained! secondly, i assume it had dexron iii regular in it its whole life, so is it BAD to switch to fully amsoil synthetic? or is that fine?

or what fluid would you say is best for this?

thx!

 

[HyundaiAbuser]

do a fluid exchange through cooler lines and after pumping the last bit out before adding new fluid drop the pan and change filter. Im sure you wont have any problems with amsoil but if you want a cheaper route maxlife works great along with valvoline dex/merc. Just last week i helped a friend of mine with his 04 sierra do a fluid exchange with maxlife and so far all is well but there are a lot better anecdotes on this website than that.

 

[krismoriah72]

No idea what year yours is, but on my 2003 4L60E there are two types of gaskets, deep pan and shallow pan.

I have a deep pan with a drain.

Perhaps do a pan drop and install a deep pan with a drain?

Mine has a new filter and magnet cleaning 40K miles ago, and two drop and fills of Maxlife ATF

Currently 274K miles on original trans.

 

[GON]

Second Kris thought on Maxlife.

You can always do the slow drain through the filler stick. I have done it many times on Chevy transmissions, super clean, super easy. Just takes some time. I use a under bed storage container for fluid connection, they are very large, to hold the eight plus quarts, yet shallow so the draining collection is lower than the transmission. Do this three times, your fluid will be vast majority replaced.

 

[Kbuskill]

I changed my fluid in my 2008 Suburban LTZ with the 4L60E transmission through the cooler line.

It had just under 200K miles on it at that time.

I used Wolf's Head full synthetic Dexron VI fluid and it took approximately 16 quarts to flush it completely.

I never bothered to drop the pan. The truck has 247k miles on it now and still runs and shifts beautifully.

 

[eljefino]

If it's before the mid 2000s I'd run whatever Dex 3 fluid in it... Maxlife being a top contender.

I would drop the pan, gets lots of silt out of there and you can stick a new filter on there. When you see the clutch dust you'll be happy you got it out.

 

[jalikaria24]

any clue what the mechanic probably used 5 years ago? i assume it was dex 3 but i heard dex 3 got discontinued, if he ran conventional dex 3 then im probably gonna stay with that cuz i heard its bad to switch to synthetic way later in life? he only did a pan drop so the 6 quarts could have been dex 6 if it was recommended back in 2015-2016 ish for a 2003 4l60

 

[Kbuskill]

Originally Posted by apollo18
any clue what the mechanic probably used 5 years ago? i assume it was dex 3 but i heard dex 3 got discontinued, if he ran conventional dex 3 then im probably gonna stay with that cuz i heard its bad to switch to synthetic way later in life? he only did a pan drop so the 6 quarts could have been dex 6 if it was recommended back in 2015-2016 ish for a 2003 4l60


Dexron 6 has been around since 2006 and is backwards compatible with Dexron 3 so it's highly possible that Dexron 6 was used.

 

[Donald]

If you do a cooler line flush without dropping the pan you have no idea on condition of the filter. Best to do both.

 

[clinebarger]

4L60E's will run on just about any Dexron ATF including the universal Dex/Merc fluids.

 

[jalikaria24]

great thanks for all the replies everyone, i will do cooler line and pan drop to change the fluid.

sorry to beat a dead horse but im so confused about the fluids

every tranny builder on ls1 tech and etc say never to use synthetic for a 4l60e but gm switched the fluid to dexron 6 which is semi synthetic when made by ac delco and then full synthetic if made by anyone else?

so is it fine to run full syn dex 6 or is it best only to run the semi delco one

 

[clinebarger]

Got a link? I would be very surprised that a experienced builder would make such a claim!

Whether or not synthetics are worth the price vs return......That could be debated 'til the end of time!

If you want to run Amsoil (That's recommend for Dexron III or Dexron VI applications).......RUN IT! It WILL NOT harm your 4L60E!

 

[jalikaria24]

https://ls1tech.com/forums/automatic-transmission/659508-synthetic-yes-no.html

this is just one thread i found so many mroe with all the tranny builders commenting and recommending regular conventional dex 3

 

[kschachn]

Originally Posted by apollo18
https://ls1tech.com/forums/automatic-transmission/659508-synthetic-yes-no.html

this is just one thread i found so many mroe with all the tranny builders commenting and recommending regular conventional dex 3

It is not based on factual information however. DEXRON III fluids were permitted a higher level of shear-induced viscosity degradation than DEXRON VI, shear stability is part of the DEXRON VI specification. In addition the oxidation resistance of DEXRON VI is higher which is an important property of any ATF. DEXRON VI is in every way a superior specification to the old (and no longer licensed) DEXRON III specification.

I use DEX VI in my ancient old BMW and if it works in there then it will work elsewhere.