Dark Tranny Fluid...again

[epa1775]

So I was checking my tranny fluid yesterday and it was a dark red again. Not pink like it's supposed to be. I had the tranny flushed 6000 miles ago. Any ideas as to what could be causing it, big tires maybe? I' hoping the torque converter and clutch plates aren't going out. If they are how much does this run to fix? Thanks as always.


Pete

[DA BIG ONE]

So I was checking my tranny fluid yesterday and it was a dark red again. Not pink like it's supposed to be. I had the tranny flushed 6000 miles ago. Any ideas as to what could be causing it, big tires maybe? I' hoping the torque converter and clutch plates aren't going out. If they are how much does this run to fix? Thanks as always.


Pete

Appears to be overheating, or poor quality fluid that can't keep up. Flushing trans is ok if pan filter is good and not causing any flow restriction. Suggest you collect real time temp data on transmission and flow pressures.

Clean out any debris in trans cooler plates and fins, between radiator, ac condenser, and or IC of you have one.

[epa1775]

Thanks for the fast response. I don't think it's overheating. I live in Salt Lake City now and it's been cold since I got here in October. Most days it doesn't even heat up during my hour drive to work in the morning. How do I go about collecting real time temperatures.

Thanks,

Pete

[cowboywildbill]

If it is transynd, it is normal for it to get dark. Just a thought. I would get a fluid analysis done. That may shed some light. As for real time temps you could use an infared tester and aim it at the pan and then the lines. It should read within 20 degrees or so of the factory gauge. The return cooling line should read a little lower if the cooler is working.

[DA BIG ONE]

Any aftermarket scanner will give you the temp reading within transmission.

If you think tq converter clutch is going then pull pan to see and change out that filter too.

I read somewhere herein that these torque converters like 1700 rpms and above when loaded, but I also see GM sells as an option 3.42 gear sets in diesel applications which puts the loaded torque converter well below 1700 rpms..............So, thinking tq conv can take a real good beating and survive.

Good luck!

[DmaxMaverick]

Any aftermarket scanner will give you the temp reading within transmission.

If you think tq converter clutch is going then pull pan to see and change out that filter too.

I read somewhere herein that these torque converters like 1700 rpms and above when loaded, but I also see GM sells as an option 3.42 gear sets in diesel applications which puts the loaded torque converter well below 1700 rpms..............So, thinking tq conv can take a real good beating and survive.

Good luck!

Only 3.73 for the Duramax/Allison combos. The 8.1L/Allison could be 3.73 or 4.10. No 3.42 for the HD/3500's. The torque converters are generally very reliable at stock power levels. If the torque converter slips, it will throw a code and SES/limp.

[DA BIG ONE]

Only 3.73 for the Duramax/Allison combos. The 8.1L/Allison could be 3.73 or 4.10. No 3.42 for the HD/3500's. The torque converters are generally very reliable at stock power levels. If the torque converter slips, it will throw a code and SES/limp.

Whoops, Thinking 4L80e here.