Swapping to synthetic trans fluid ?????

[Beedee]

Hi Guys
I posted on the 6.5 forum but never got any replies back, so thought that i would try here and the drive train forums.
I have a 98 with a 6.5, auto. I bought some TranSyn to swap the trans oil out to. A friend of mine, who worked in a shop that service allison tranys on busses, ect warned me off of it saying that my tranny would start to leak. I only have 180,000 km on the truck.
Any one have any experiance with this or any thoughts.
I just bought a Arctic Fox 22 GQ, truck tows it well, It is time to change the tranny oil again, and i want to put the TranSyn in, but am a little leary about springing a leak or two.
Thanks for any help
Brian

[rustyk]

I replaced the standard trans fluid in my motorhome with Mobil synthetic along with the upgrade to the Mag-HyTech pan about 8K miles ago. I've experienced no leaks in the 4L80E tranny (an HD rebuild).

[Beedee]

Thanks Rusty
I got a pretty good response in the drive trains forum.
I'm going to swap it over and see what happens.
Brian

[MikeC]

Beedee,

I flushed my '96 Burban, '06 DMax and '07 DMax by finding the line coming back from the radiator and pouring in a quart for every quart that came out.

It takes about 17 quarts but you are assured of almost 100% synthetic when you are done. Do a search here, someone has posted the process.

Mike

[rustyk]

I now have about 15K mile on the synthetic, and still no leaks nor need to top off...

[Robyn]

The sad part is that there is not a drain plug on the converter like in the "OLD " days.
The converter holds the vast majority of the fuild in the system.
As you pump the old out and the new in you are going to get a fair amount of mixing of the two products as they enter the converter.

The converter aslo acts like a giant centrifuge and traps a buttload of junk in the nooks and crannies of the blading. The only issue I would have of swapping to the Synth from standard is that most likely you are not going to have a 100% fill of Synth even after doing the flush through due to the mixing effect that occurs as the converter fills and empties during the refill/flush process.

This process is fine when using the standard dino oil but will the two different materials get along with each other when mixed.
What does the manufactures written material say??

Another issue I worry about when changing oils in the tranny is that all the friction materials are mostly a paper product and are soaked with petroleum based oil and then if the oils are swapped what does this do to the friction quality of the clutches.
Every trans manufacture has certain specs for the fluid depending on the composition of their clutch and band lining.

Just my 2 cents worth

Robyn

[rustyk]

The sad part is that there is not a drain plug on the converter like in the "OLD " days.

Robyn

I'm with you there! There's somewhere in DEE-Troit (and environs) an idea that one doesn't need to "change" fluids. Just stick a bit more into the Thing, and all will be well.

When I replaced the stock tranny pan with the Mag Hy-Tech, I ended up replacing the residue with synthetic, then doing the whole fluid replacement again (just to be sure). It would have been a whole lot nicer if the damned torque converter had a drain plug. But then, that would've cost GM, what - $1.25?

[DA BIG ONE]

I replaced the standard trans fluid in my motorhome with Mobil synthetic along with the upgrade to the Mag-HyTech pan about 8K miles ago. I've experienced no leaks in the 4L80E tranny (an HD rebuild).

How many x-tra qts does new pan allow? I've been thinking of a changeout, I use their 14 bolt ff cover and very happy w/product and the x-tra capacity.

[Craig M]

There are a couple of different products, but most are 3 or 4 quarts.

[rustyk]

I don't know what the difference is, but the Mag-Hytec pan on the 4L80E takes 9.5 qts.

[1999GMC]

There is a bulletin from GM saying you can use dexron V instead of Dexron III in any trans that used Dexron III. So I went with a deep aluminum pan and changed to the Dexron V which is full synthetic.