I work hard to keep my Barth maintained. We have a big trip planned for this summer so it went back into the shop to have a few things maintained and repaired. While in there it was discovered that the transmission cooler is just starting to develop all leak. It I s an issue of rust and will need to be replaced. I checked the Cummins manual that came with the bar and it shows a picture of the cooler but no information on it. I am going to attach a couple of pictures and was wondering if anybody had any information that would help me to locate a replacement part.

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2nd picture from the Cummins manual. This cooler uses engine coolant circulating around a core with transmission fluid flowing through it. I am Unfamiliar with this sort of cooler, but it has been working well. With the exception of traveling at very slow speeds in traffic during warm weather. Under those conditions the transmission tends to overheat. Any help that any of you have regarding this would be appreciated. Thank you in advance.

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Infromation here.

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I have applied for a folder for you also to put your pictures in.

Bill what transmission do you have? If it is a 4 speed Allison, it may heat somewhat at low speeds because the torque converter isn't a lock up type and they will run hotter at lower speeds.

Where is it leaking, is it coolant or trans oil? Pictures are too large but certainly there is a lot of rust on the outside of the heat exchanger. That green connection hose also looks suspect!

What temperatures do you see at low speeds and higher cruise speeds?

Hi Ed,

The cooler is not leaking yet, but there is a damp spot appearing on the end near where the hose and clamp are located. The transmission is an Allison 647. As you mentioned it is a 4 speed. My plan is to have the transmission fluid changed and replaced with synthetic fluid. I will include an additional picture that shows that spot. I was told by Cummins recently who researched my transmission and said that the temperature range should be 197° to about 240°. When running slow in traffic I have seen it get up close to the 240° Mark, but that does not happen very often. Normally it runs from just under 200 to about 215.

I apologize, I do not know how to size the pictures appropriately to post on this website.

Rust is becoming an issue with some of 1” square tubing used in the lower frames. I will be repairing some of those issues in this particular service call as well as the maintenance items that need to be taken care of prior to my upcoming trip.

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That looks like an easy job to build a replacement if it is just a tube inside of a can. Two stainless steel tubes with welded bungs and caps. If anyone has an old one they don’t care about I’d like to take it apart and see what might be required to duplicate it.

quote:

Originally posted by Tom and Julie:
if it is just a tube inside of a can. Two stainless steel tubes with welded bungs and caps.

Tom, It is not a tube in in a can but a honey comb configuration inside of a can. I call it a heat exchanger.

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I am using your suggestion for further investigation of my heat exchanger. I have purchased the color dye for the transmission. I will look for the dye in the antifreeze.

quote:

Originally posted by Bill G: I apologize, I do not know how to size the pictures appropriately to post on this website.

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Bill G: Please check community announcements for some picture posting tips.

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Your folder number is 0159. Good luck.

quote:

Originally posted by Bill G: Rust is becoming an issue with some of 1” square tubing used in the lower frames. I will be repairing some of those issues in this particular service call as well as the maintenance items that need to be taken care of prior to my upcoming trip.

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I have replaced a few of the J tubes on my Barth. Click Here

Changing the oil in the transmission will not change the oil in the torque converter. Need to do it about 3 times to get most of the old oil.

quote:

Originally posted by Gary Carter:
Changing the oil in the transmission will not change the oil in the torque converter. Need to do it about 3 times to get most of the old oil.

Gary, you are Correct. I drove my Barth about 500 to 1000 miles between transmission oil changes. The MT 647 Allison holds 5 gallons. Buy the five gallon pail. Rusty has posts here for the Allison specifications.

Allison MT 547 Transmission Series 1100 Shell and Tube oil cooler. A heat exchanger, transferring heat from the hot transmission oil to the cooler antifreeze surrounding the tubes.

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