Which fluid to use in a v730

[Geom]

Hey guys,

We continue to make some progress with the engine rebuild.
When we had the engine apart, the transmission was drained and inspected.
Now that we're putting it back together, there is question about what fluid to use.

When we originally got the bus, the previous owners had been using Delo 400 straight 30 oil.
We have always used that and have not had any problems.

Now that we're reassembling everything the shop is saying that Allison recommends dexron 3 ATF.

I'd like to get your thoughts on which to use.
Is there a reason to use one vs the other?
Is there an advantage?
They don't care which I put in there, but would like to know soon so they can move forward.

Thanks in advance,
George

[luvrbus]

I use 15/40 in the V730 or 740 lot to select from in way of oils for a Allison

[uncle ned]

I agree with Clifford.  I started with straight 30 wait but changed to multi-weight because I think it stands the heat changes better.

uncle Ned

[Geom]

Thanks Clifford and Uncle Ned.
I realize this is might be opening a can of worms (not at all my intent), but is there a reason to use motor oil vs ATF? Or is it pretty much the same for this application?

Thanks George

[bevans6]

I guess my question is do you want to run a mix of ATF and 30W oil?  As I understand it (which admittedly is not great) just draining the fluid leaves significant amounts of fluid inside the torque converter, etc, and you need to actually fill and drain three or four times with the new fluid to get a reasonably complete fluid exchange - unless you can drain the torque converter as well as the lines and the cooler.  Dexron III is indeed the standard duty on highway recommendation, in my Allison book at least, but they also recommend C-4 fluids for severe duty and off-highway.  Most 15W-40 diesel engine oils are actually Allison C-4 approved, or so it seems from a few minutes looking.  There is a note that Allison C-4 is an obsolete specification.  Allison TES-439 is listed as the current equivalent specification for off-highway severe duty use, and most of the fluids that come up are heavy duty 15W-40 engine oils.  The interweb implies that ATF is not as tough duty as engine oil.

In your case, since straight SAE 30 is recommended for use in ambient temps above 95 degrees, I would follow the lead and go with a 15W-40 Allison approved engine oil, just to maintain some compatability with any engine oil that's left in your system.  But that's just my thought, I'm no expert.

Brian

[luvrbus]

Runs cooler and shifts smoother either will work though sorta like the ice cream flavor deal, lot of people use ATF just because of the color red on the ground they know it's the transmission leaking

[Lin]

Yup, Clifford-- I loves my rainbow leaks!

[Geoff]

I use a 10w-20 in my V730.  Sold in pails as "universal transmission and tractor hydraulic oil".  Works fine, and gives you a multi weight oil instead of Dexron which is only 10w.  Some people run the 15w-40 engine oil, but the oil I mention is for transmissions.  $40 bucks for 5 gallons at Sam's Club.

--Geoff

[brmax]

This might strike a few interested, they list the 439 spec and it could be an option.
http://www.phillips66lubricants.com/documents/conoco/power_transmission_fluid/Con%20PowerDrive%20Fluid%20TDSw%20787307.pdf

In some ways I might have tried a lot more oils, but first had to carry warranty obligations.

The military decided to test many times first I recall in the eighties with one oil for logistic reasons and so 15-40 was chosen. I believe it worked in all but Detroit 53's and that was a good answer because they were trading many of them out.

As long as we can keep the oil temp way! down and have some clutch benefits we should be good.

Floyd

[Geom]

Thanks for the help and input, all!

I went ahead and decided to use 15w40 in there. Since we'd been using the 30w oil so far with zero problems (fingers crossed  ), I didn't really want to change to some completely different thing (ATF) and have it mix with what might still be left in there.

Plus based on others' experience and knowledge it seems that 15w40 would work better anyway (allowing for multiple viscosity and heavier duty).
And as long as it's a supported oil in there, I'd rather just carry two oils on board (the 40w for the engine and 15w40 for trans and PS)

Thanks again!!
George