Replaced the stock shallow pan with an available "deep" pan and also replaced the OEM trans fluid with Allison's TranSynd full synthetic fluid. Even if you don't go with the deep pan, I highly recommend switching to TranSynd.


http://onramp.uscom.com/%7Ehoot/cars/duramax/gmc/allison/allisunder.jpg

Some instructions... (http://onramp.uscom.com/%7Ehoot/cars/duramax/gmc/allison/allisonflush.htm)

Here you see the difference between the old shallow pan and the new deep pan. Also take note the filter screen is different.

http://onramp.uscom.com/%7Ehoot/cars/duramax/gmc/allison/allis7.jpg


If anyone is inclined to do a full writeup on this procedure we would appreciate it. It would be added to the FYI section. Edited by: hoot

Good topic Hoot!!! Here is a pic for those worried about ground clearance and how low the pan sits.


http://www.dieselplace.com/forum/uploads/Deep_Pan_Installed2.jpg

By the way here are the part numbers for the deep pan, internal filter and replacement external filter for those that don't know.


Deep Pan ...... 29536522 List $48.87
Screen/Tube (Deep Pan).... 29536891
External Filter........ 29539579


Bob

Is that a drain plug at the right rear corner of the deep pan?

Is that a drain plug at the right rear corner of the deep pan?

Yes it is. The shallow pan has one also.

why change the pan to the deep one???

The deep pan holds an additional 3.2 qts. The extra capacity helps keep the tranny temps down by allowing more fluid into the system. I think they said it also helps the fluid last longer because there is more fluid to get heated up, so it does not stress the fluid as bad. I could be a little off on that last statement, but it sounded good to me!! hehehe


BobEdited by: 4x4man

what is the purpose of changing pan depth ???

Yes I relize that it holds more oil what is the main advantage of this.

rock - Think of it this way: Put a cup of water in a teapot and see how fast it boils, now put a gallon in the tea pot, and see how long it takes. Obviously the cup will boil faster than the gallon. Same principle: more fluid, longer it will take to get hot, extended tranny fluid life, extended Allison life. http://www.dieselplace.com/forum/smileys/Big Smile.gif


Too be honest, after I did the change to the deep pan and transynd, I didn't see that much of a difference in tranny temps, but the synthetic will handle the heat better than dino.

the rock,

Two main advantages and 4x4man and smitty stated them.

More fluid gives longer fluid life.

The larger pan has more outside surface area which helps cool the fluid.

You didn't ask about TranSynd fluid. Allison recommends it in med duty applications. Synthetics handle a greater range of temps without getting too thick or thin.

The best part is the cost. The pan is only $43. The entire job costs like $200. It's well worth it considering a tranny goes for $7000.

Hoot If you ever need a tranny I want to be your supplier ...


Mac http://www.dieselplace.com/forum/smileys/Evil Smile.gif

Well I meant what GM charges for it. I know you can get worked ones for what $4500 or so?

Another thing you may want to do. Change the spin on/off transmission filter every (or at most every other) engine oil change.


You can get them at most Allison dealers for under $9 and the amount of ATF souldn't break you. I bought a dozen spin ons for $104.41 including tax. ($8.17 each) I change mine every 10,000 miles, and I will be doing a complete flush every 30,000 miles.


I spent $256.97 for 5 gallon of TranSynd and 12 filters. So if I changed the filters every 2500 miles and a complete flush every 30.000 miles, it would cost less then one penny per mile. Cheap maintenance if you ask me.