Transmission oil change

[stilly]

I have the 03 D/A with 110,000 miles on it. I am looking to change the transmission oil. Bought it with 100,000.

1) How does one know if you have synthetic or regular transmission oil in it?

2) How do you change the majority of the oil? I read that you can change a partial amount of the oil by removing the plug, but what about the rest?

3) Can I replace the current oil, synthetic or regular, with synthetic oil? What oil do you recommend? How about filters?

Thanks.

[DmaxMaverick]

Drain/fill only replaces about 1/3 of the fluid. You can flush about 95% of the fluid w/o a machine using the method(s) described in past posts. Try a search in this forum.

All Dexron fluids of the same rating are compatible, dino or synthetic.

If you want to change to full synthetic, do the full flush. The flush involves removing the "from cooler" line at the tranny and pumping it into a container with the engine running, and replacing the fluid during a shutdown. Please search for the threads for more details. It isn't hard, even if you do it solo.

[DickWells]

A GM tech guy told my son that your DM-A will have some of each in it. Said that Allison ships them with synthetic, and it gets changed to dino. Dealer or factory? I don't remember.
Your other answer is just as I did mine, back in December. It took 23 quarts to flush and fill mine. I ran it until I was satisfied that the fluid coming out was fressh and clear. I figure about 5-6 qts thrown away. I used full synthetic. Bought Amalie at the local parts store. Cheapest sythetic I could find. Yeah, I'm as cheap as the oil! Dunno, but it says on the can that it meets or exceeds all the requirements. And, I've towed for about 6,000 miles, since, with no cause for concern. Fluid still clean and transmission running VERY cool. You could spend 3 times as much for the other brand with an "A"! Yup, and I'll get more than one note in here, telling me that I get what I pay for. Oh, well, so be it.
Have at it, me says.
DW:)

[DmaxMaverick]

The trannies don't get shipped from the Allison mgf to the GM ass'y plant with fluid. Any fluid in them is from assembly and testing, but is drained before shipping. The trannies are serviced with dino ATF on the GM assembly line. Any synthetic fluid in them at time of delivery would be residual. I haven't heard of Allison using synthetic for assembly/testing, but it is possible. I don't think there would be any advantage in it, being GM just fills them with dino later. As cost-conscience as they (GM, Allison, and everybody else) are, it doesn't make sense. It is possible the assembly/testing fluid is a preservative type, and that could be synthetic, or partially.

[DickWells]

Sounds about right. My version of the story was at least third hand. We've always been told that the details change on every repetition, right?
DW:)

[77TransAm]

Last I heard, the Indy plant tests all transmissions with Transynd fluid. This is because Indy makes all 1000/2000/2400 series transmissions (for both GM and all other OEMs) on the same assembly line. If a customer orders a trans with Transynd, it cannot have any residual non-synthetic, so they all get Transynd.

I don't know how it is now, but back in '04 or so, the Baltimore plant was not using Transynd. This is because Baltimore only builds transmissions for GM pickup trucks, and GM pickup trucks don't use Transynd. Therefore, there's no need to have it on the assembly line.

Indy transmission serial numbers start with 631xxxxxxx
Balt. transmission serial numbers start with 632xxxxxxx

DmaxMaverick is correct about shipping with fluid, however. The transmissions are assembled and tested with no oil pan. The last steps in the factory are oil pan installation, external cleaning, and then packaging. Therefore, the only Allison factory fluid you will get is what is left in the torque converter and internal passages. The rest of the fill will be from the GM truck assembly line.

[FBJR]

Why on earth would they assm something like a trans costing thousands and ship without an pan to seal it up.
But it sounds about right as they do motors that way too :(
I understood to many claims on bend-dented pans.

FB

[77TransAm]

The last steps in the factory are oil pan installation, external cleaning, and then packaging.

That's the Allison factory I'm talking about, not the GM factory.

The trans goes down the line getting assembled (minus the pan), gets tested, gets a pan, gets cleaned, packaged, and then shipped to the OEM. It does not leave the assembly line without a pan.