Turned 200K This Week Now Trans is Leaking?

[JBlakeman]

Hey all... just turned 200k on my truck this week with no issues transmission wise until yesterday. We had a 3 hour drive and once we returned home noticed underneath a fresh leak. Upon investigation is bright red transmission fluid that seems to be coming out of a vent hole at the bottom of the bell housing just north of the pan. Leak dries up as truck cools off however I'm now concerned that this might be something major (torque convertor or something else... ). I've kept up on fluid / filter changes, outside of a double deep pan and temp gauge no other modifications and have ran Royal Purple ATF +4 since I purchased the truck 8 years ago.



What's next... thoughts on what it might be.....



Thanks,



Jon

 

[mwilson]

Hey all... just turned 200k on my truck this week with no issues transmission wise until yesterday. We had a 3 hour drive and once we returned home noticed underneath a fresh leak. Upon investigation is bright red transmission fluid that seems to be coming out of a vent hole at the bottom of the bell housing just north of the pan. Leak dries up as truck cools off however I'm now concerned that this might be something major (torque convertor or something else... ). I've kept up on fluid / filter changes, outside of a double deep pan and temp gauge no other modifications and have ran Royal Purple ATF +4 since I purchased the truck 8 years ago.



What's next... thoughts on what it might be.....



Thanks,



Jon

Look up on the left side, make sure you don't have a hole in the cooler line.



Thread here.....

https://www.turbodieselregister.com...4668-Trans-Cooler-Lines-Chafing-(Please-read)



Another one here...

https://www.turbodieselregister.com...regret-it-later)&highlight=transmission+lines



Mike.

 

[JBlakeman]

I took a quick scan of the cooler lines today. The oil to water cooler inside the left front fender is all good. Some rust is evident on the coolant lines however both rubber and metal lines are not touching / chafing and are dry. I do have some oil leaking from the metal to rubber lines leading up to the air to oil cooler close to the radiator though none of this is traveling back to the trans and seems minor (only wetness is on the frame right underneath the metal to rubber connection. The cooler lines on the driver side of the transmission are oily in film (thinking from the oil draft tube rather than trans oil... ) and the connections / line seem to be in good shape. Only remaining oily residue is on the pan itself, driver side of the pan, and red fluid (very little mixed oil here... ) on the bottom of the bell housing.

The trans air to oil cooler was replaced by Dodge under the Cummins warranty back in 2006 for a pretty constant trans leak at the radiator (same area that seems to be "slightly" leaking now); but it also then had a constant stream spraying out when running which is not apparent now.

 

[JJPage]

If trans is slightly overfilled, there is a vent hole up high in the bell housing that could be forcing fluid out when hot. Also make sure it is trans fluid, and not coolant...