oil and trans fluid recomendations

[mccarlk]

hi the big day will hopfully be coming this week end , after a long year of sourcing parts and putting the old beast together hopfully its going to start, I'm running a 8v71ta with a 644 auto, what oil and trans fluid should i run, 15 40 rotella and dextron?

[jackhartjr]

Can't speak to the trannsmission.
On the oil it needs to be Chevron Delo 100, 40 weight or a similar low ash I think it is 'C-2' rated oil.
O'reilly's Auto parts can order the oil.
You do not want a multi-vicosity oil, needs to be single weight 40.
The reason for the low ash oil is that it helps prevent soot on the valves!
The archives should be full of info on the oil.
Jack

[buswarrior]

Synthetic in the transmission, if you have a few dollars kicking around.

Heat kills transmissions. Busnuts with gauges faithfully report a 10 degree F drop in tranny temp after the switch to synthetic.

Ditto about Straight Weight 40, low ash engine oil.

Delo 100, Exxon XD3, Shell, PetroCanada, you may have to order it.

Your Detroit needs the right lube. The label or spec sheet will specifically state it meets DD requirements for the 2 stroke engines, or don't buy it.

Who has that good link to examples of the engine internals if run on Multi-grade oil? Was it at tejas coach?

It's a lot more important than just soot on valves.

happy coaching!
buswarrior

[wildbob24]

I believe this is the link to which you refer:

http://www.tejascoach.com/tips.html

[luvrbus]

use the 15-40 for the transmission if you already have it works good.
Check your local Wal-Mart for the Tech brand it's made by Citco and comes in 40W and meets DD specs and sold in Canada so my Canadian friends tell me.    good luck

[Gary '79 5C]

Is there any problems with changing an Allison (644) for dino oil to synthetic with regards to the internals of the transmission ?? I am sure mine has never seen synthetic in its 30 years.

The temp drop has definite value in lengthing the life of the unit, I will consider for next trans fluid change.

Thanks

[Ed Hackenbruch]

Check with an Allison dealer. When i had my 644 changed over to synthetic  i know that they had to drop the pan and put in a different style of baffle plate i believe. The whole change over only cost an extra 200-300 bucks over a regular service, and with a difference in the service interval, (4-5 times longer) pays for itself as soon as you would normally need another service.  And of course there are the added benefits of running cooler and  shifting smoother.

[Ed Hackenbruch]

Almost forgot, my info sheet for the 644 says that it takes 15 quarts of Dexron or Dexron II.  Also it looks like it was a different type of sump filter or screen that they put in rather than a baffle.

[luvrbus]

Guys, don't think for a minute the synthetic oil will solve your heating problems as good as it is.
If you have a heating problem to begin with it will be the same just takes a little longer.  
These transmissions are design to run at 160 to 220 degrees normal and will run hotter for short periods and will last using 15/40 , ATF or others.
I use Cat  TO-4 in my 740 and have for years not even interested in changing over to synthetic.
You double filter the transmission and they will run cooler and the oil changes go over the recommend 50,000 miles.
My transmission runs at 180 ( no extra cooler only factory) on flat or mountains no difference and I have my first Allison to see shift any smoother than mine it's all in the trimmer valves.
I think the synthetics are best for the electronic transmissions thats what it was design for but I am not going to waste big bucks for synthetic oil in the HT transmission. just my way YMMV        


good luck

[gus]

I think Jack means CF-2.

Not trying to be a SA, but that is the one I use which happens to be Rotella-T, 40 wt.

[brando4905]

Be careful with the synthetic, I changed the oil in my 730 to syn. and had to replace transmission 1500 miles later. Can't say for sure wether it was the fluid change or not, but it was working fine before that!

[TomC]

The big misnomer that people have about synthetic, is that it is a cure all for an ailing transmission.  If you have a worn transmission with questionable clutches, then putting in a more slippery oil-like synthetic will spell the demise by allowing the clutches to slip even more.  If you have a world transmission, then synthetic is the suggested fluid for it (it is standard now on Allisons from Freightliner).  If you have an older Allison, especially one with many miles on it, I wouldn't suggest synthetic-it can cause slipping, and with the smaller molecules, you can discover leaks that weren't there before. Good Luck, TomC