JRAY1944 Report post Posted April 8, 2019 I have a Chevy 2500HD with an Allison transmission. The color of the fluid is an odd color that I have never seen so I am wondering if I have a potential problem getting ready to show up. The fluid has a milky consistency and is yellow/tan in color. Is this normal? Thanks in advance for everyone's help. Jim Share this post Link to post Share on other sites
hermanmullins Report post Posted April 8, 2019 Jim, Welcome to the Forum. Fluid will change color at times what I do is smell the fluid. It will smell burnt if bad. You can really tell by the smell. Others may have other test. Good luck, Herman Share this post Link to post Share on other sites
campcop Report post Posted April 8, 2019 You might have a leak in the trans cooler that is allowing antifreeze into your trans. https://www.freeasestudyguides.com/atf-pink-milky.html Share this post Link to post Share on other sites
wildebill308 Report post Posted April 8, 2019 If you want to know what is going on and the condition of your transmision I would send a sample to Blackstone Labs. https://www.blackstone-labs.com/?session-id=gid5ju45lgwkiynzjz03ie45&timeout=20&bslauth&urlbase=https%3A%2F%2Fwww.blackstone-labs.net%2FBstone%2F(S(gid5ju45lgwkiynzjz03ie45))%2F Bill Share this post Link to post Share on other sites
manholt Report post Posted April 8, 2019 Herman is a great sniffer! Devil made me. Do not try the taste test! Is there any visible scum? That too could be coolant/water. Share this post Link to post Share on other sites
five Report post Posted April 8, 2019 Tom Johnson is retired from Allison, and was instrumental in developing Transynd. Order a kit from his company, send a sample, and they will send a detailed report on every part of your transmission fluid. I do it once a year. JG Lubrication: https://www.jglubricantservices.com/ Share this post Link to post Share on other sites
hermanmullins Report post Posted April 8, 2019 3 hours ago, manholt said: Is there any visible scum? That too could be coolant/water. Good point. Herman Share this post Link to post Share on other sites
richard5933 Report post Posted April 8, 2019 If you have a commercial truck repair center in your town they can probably run a test on a sample while you wait, at least for water. In my experience, milky oil often indicates water mixing with the oil. Share this post Link to post Share on other sites
rayin Report post Posted April 9, 2019 8 hours ago, campcop said: You might have a leak in the trans cooler that is allowing antifreeze into your trans. https://www.freeasestudyguides.com/atf-pink-milky.html That's my opinion also. The transmission lines connected to the engine radiator are not for cooling, their purpose is to heat the tranny oil quicker for better tranny performance. I once had that happen, I disconnected both lines and fabricated a connector line for them. That old 1976 Allegro class A(on Dodge chassis) was still that way 10 years later when it was sold, tranny still operated properly, just took longer to reach the normal temperature range. Share this post Link to post Share on other sites
wolfe10 Report post Posted April 9, 2019 Actually, the lines from transmission through radiator are for BOTH faster heating to operating temperature when cold AND for cooling under high-temperature situations in the transmission. Share this post Link to post Share on other sites
wildebill308 Report post Posted April 9, 2019 Did you have a temperature gage on the transmision? If not how do you know what temps it ran at? Bill Share this post Link to post Share on other sites
manholt Report post Posted April 9, 2019 I remember that my 1987 Barth, had both Oil/Coolant temp gauge's, but not transmission. Before that, none had Oil/transmission temp gauge, just coolant, non of them had Allison! With the exception of the Barth, they where all Dodge chassis! Share this post Link to post Share on other sites
campcop Report post Posted April 9, 2019 If the cooler is leaking, you can also look in the radiator. If fluid made it there, there will be an oily sheen on the water. Share this post Link to post Share on other sites
garyreed Report post Posted April 9, 2019 How is the oil level? low, overfull or correct? was the trans warm. If low, air will also appear milky. If overfull, could be antifreeze. Does the color resemble the color of the antifreeze? Gary Share this post Link to post Share on other sites
wolfe10 Report post Posted April 9, 2019 Bottom line-- DO NOT DRIVE UNTIL THIS IS PROPERLY DIAGNOSED. It takes only a little antifreeze circulating through the transmission to cost you a new transmission. Share this post Link to post Share on other sites
rayin Report post Posted April 12, 2019 On 4/8/2019 at 10:25 PM, wolfe10 said: Actually, the lines from transmission through radiator are for BOTH faster heating to operating temperature when cold AND for cooling under high-temperature situations in the transmission. How much cooling can occur when the radiator coolant is at/near 195°? My 02 Chevy Duramax dually has a separate transmission cooler in front of the radiator. Share this post Link to post Share on other sites
manholt Report post Posted April 12, 2019 My duramax on a 07...worked the same way as my coach, when my Allison temp shows 205, drop to 5th gear and it will cool off. Share this post Link to post Share on other sites
