What trans fluid?

[iweb]

Ok I know its not a K5 but I need help. What tranny and transfer case fluid is suppose to go into a 2002 GMC 2500 4x4 with 4L80E tranny and hand shift transfer case?

I get dextron 3 from some people, dextron 6 from others, and a guy that builds trannys for a living said that it takes a special synthetic fluid that only a GM dealer sells.

The tranny takes to a count of 5 or 6 to move once I put it in Drive. The tranny builder guy said the rubber somethings in the tranny were hard so I should get a bottle of tranny repair and put in it. There are a bazillion to choose from, any suggestions?

Whats the truth?
Thanks.

 

[iweb]

I have a 87 K5 Blazer if that helps getting help here??

Dipstick says to use Dexron 3, went to 3 stores and there is no Dexron 3. Valvoline that replaces Dexron 3 and mercron, Dexron 6 that replaces Dexron3, Dexron 5, Dexron 6 full synthetic. Any idea what I should use?

 

[StevoandaRedK5]

As far as I know, Dexron 6 will replace Dexron 3 with no problems. I believe they rate it similar to the DOT ratings for brake fluid. Hopefully someone will confirm for the both of us

 

[Kjunky5]

What is the fluid level?

If the dipstick says to use 3 than you can use 6 or 3. 6 is the new stuff but is backwards compatible. Do not use 5, it's not backwards compatible. Don't over fill the trans. Keep it at full. The rubber seals inside the trans are soaked in atf. There is no way they could harden unless it sat empty for a long time. Any tranny additive is just a temporary band aid if that. However there are some that work but not for what you need it to do. I'm talking about friction modifier additive for dex/merc 3 to make it compatible for honda trannys. Not a mircle trans repair in a bottle.

 

[Happyjohn]

ALLDATA states to use Dexron III, However, Dexron VI is good also.

 

[4xcrazy]

i've been told that the "level" grading on the Dexron/Mercon is just a rating, they make changes to it, then label it the next number up, it's all compatible. It says to use Dexron III on it, because that's all that was available at that time.

i believe it's just called Dex/Merc now or even Mercon.

 

[iweb]

Cool thanks guys, really appreciate it. Off to get 6. We changed the filter and had to replace the adapter between the tranny and transfer case so we are replacing the fluids too. Amazing all the wrong info out there at Autozone, Checker, Wal Mart, etc.

 

[Kjunky5]

i've been told that the "level" grading on the Dexron/Mercon is just a rating, they make changes to it, then label it the next number up, it's all compatible. It says to use Dexron III on it, because that's all that was available at that time.

i believe it's just called Dex/Merc now or even Mercon.

5 is not backward compatible

Edit: nevermind, I'm thinking of brake fluid.