ATF Change on 2004 Buick Rendezvous

[radtech91]

I have a 2004 Buick Rendezvous that is greatly in need of a change. It still has the original ATF in it and I wanted to make a change to Valvoline Dexron VI Full synthetic. Will there be a problem since the old fluid will be the original and I will be replacing it with the Valvoline Full Synthetic? What I mean is will it need flushed or something? Or when I let the fluid drain will it all drain or will some get left over somewhere and get mixed in with the synthetic and cause a problem?

Does anyone understand what I'm asking?

 

[beast3300]

Yes I think I understand the question. Do a pan drop/filter replacement. It won't "shock" the transmission with all new fluid. The 4T65 trans will like a filter change with mostly new fluid.

 

[beast3300]

Don't use any flush additives or additives at all. Just drop the fluid, refill and drive on. The trans will be happy that way.

 

[ls1mike]

I totally agree with beast. I recently did my Buick Regal. Pan Drop filter change and about 8 qts of Dexron VI (Castrol kind) and it shifts nice and smooth with no problems.

 

[radtech91]

Ok thank you so much. I was gonna do the change but then some one said that it would cause problems having the Dexron III not completely and utterly out of the car and then putting the Dexron VI Full synthetic in. They said it wouldn't mix and then it would gum up or something. I'm glad I'll just be able to do the drop the pan change the filter and refill.

 

[beast3300]

No you will be ok. Similar to mixing a syn engine oil with dino or vice versa. Or even switching from one to another. No special procedure needed.

 

[radtech91]

Thanks! That is such a relief!

 

[beast3300]

Originally Posted By: radtech91
Thanks! That is such a relief!


Your welcome.

 

[SteveSRT8]

I don't believe the VI formula is a full synthetic.

Can anyone clarify?

 

[beast3300]

Originally Posted By: SteveSRT8
I don't believe the VI formula is a Full Synthetic.

Can anyone clarify?


No it's not required to be Full Synthetic to meet DEX6 specs. Some are blends and DEX6.