AT545 replacement

[Ghrasshopper]

Hello I have a 1983 Thomas with an AT545 and a DD8.2 I recently burned up my AT545 and I need my bus back on the road. Unfortunately I had to leave it in Idaho and go to Oregon while I get things figured out. I havnt been able to find an external filter. I have read some do not have them. Do some also not have coolers? I don’t see one or am I over looking it? The parts dealer has insisted this model has both and the remaned also does. Also I’m trying to replace my modulator cable to be sure it’s in shape. How do I determine which one I have? Thanks I’m advance.
Ghrasshopper

[magnakansas]

Most likely the cooler is also the radiator. you will find a hose from the transmission, goes to the radiator and then another hose goes from the radiator back to the transmission..... I have seen one bus, the hose went to a coolant/oil cooler then back to the transmission....

From what i have seen in pictures, the filter for the transmission is inside with that oil pan.... and might also have a filter between the transmission and oil cooler... helps to keep crap out of the oil cooler.....

because you never know what has been done, it is possible there is not an external filter, even if there is supposed to one.

william

[Ghrasshopper]

Thanks Magna that helps a lot.

[Booyah45828]

Are you replacing the trans? Or what is the nature of your questions? If you burned up the clutches in your current one, replacing the fluid and filter likely won't fix anything.

As magnakansas said, the cooler is in the bottom tank of the radiator. Some can have an additional air to oil cooler mounted in front of the radiator.

There should be an internal filter/screen in the pan, and an external filter in one of the cooler lines. The external filter should look like and oil or hydraulic fluid filter. The internal filter doesn't need replaced unless the trans is being overhauled.

The modulator cable options are typically because of different lengths of the cable. So remove the old one and measure it to see what you have. Honestly, as long as it's intact and moves freely I wouldn't bother changing it. Just make sure it's adjusted correctly when installing the new transmission.

[Ghrasshopper]

Thanks booyah the transmission started whiring before it shifted. I drove maybe two blocks like that replaced the internal filter and fluid but it did not stop whirring and there were metal shavings in the pan. I didn’t know I had an external filter and that was probably the problem but from what I understand metal shavings means rebuilding it anyways. I am not at my bus and have a friend looking at the transmission today. I’m looking at a remanufatured tranny and want to make sure I have all the nessasary parts and pieces in line to get this done and back in my bus ASAP. I didn’t think I had an external filter or a cooler but I must have been mistaken about that. I am mechanically inclined but have no idea about transmissions especially big automatic transmissions. Since I am out of state working I will have a shop install it and I guess I will just ask them to check the modulator cable. I just don’t want to spend the money on a tranny and burn it up. Thanks for all the information. I really appreciate it.

[Booyah45828]

Shavings in the pan typically indicates rebuild/replacement. So you're correct in doing that.

My external transmission filter is on the outside of the right frame rail, a little ahead of the front axle.

If you have shavings in the pan, make sure someone flushes the cooler and lines before you install the fresh trans. They make cans of commercial solvents for this, but any solvent coupled with an air nozzle on a compressor can do the job. Make sure to clean it both ways. You'll want it spotless.

If the shop is good/competent, they'll make sure the modulator is working and adjusted correctly after install before letting you have it back.

You'll have soft, low rpm shifts if it isn't.

[Ghrasshopper]

Thanks the shop I’m using is legitimate and they do a lot of the commercial work in the area so I’m sure they will do things right but I’ll double check that they flush the cooler and check the modulator cable. Thanks for the help. It’s been a life saver.