Hey guys, posted a few times on this but did not get a lot of responses so trying again. Have an 05 with 48RE that was rebuilt at 97k and again at 136k now 162k. Has a Precision Billet Converter with 65k in it and all new hard parts drums bands clutches steels etc with 30k on them. I live in Houston and daily temps are 90+ right now and my truck cools down fine until I get on the highway where my temps will go into the mid 190's at 70-75mph. Now i checked to see if my TC is locking by the 50-60 roll while looking for rpm and speed rise and or looking for a 500-700rpm when it locks and both are good so I do not believe TC is bad. I am almost positive that the trans was not flushed when rebuilt at 136k cause there was material in the pan and magnet at my last fluid and filter change. Truck shifts beautifully and cools down real well after sitting a few minutes. I have a few questions. 1)have replaced cooler and cleared thermostat at trans and check ball valve....could a clogged transducer and governor solenoid be giving false readings without throwing a code? 2) any other tests to check lockup on TC i could be missing?

 

I can't answer your questions, but can tell you 190 at 75 mph is pretty good.
My tranny runs about 105 degrees above ambient temp. It don't matter if I'm running light or towing the trailer. Were mine heats up is stop light to stop light. Especially towing when its hot outside.

I also have a billet torque converter with very large ports. Difference in my tranny and yours, is my locks the TC up in 3rd gear and shifts to OD locked up. When towing I manually shift it in OD since the pressures are to high and it bangs hard. Running without the trailer its shifts without the bang.

I have 122,000 miles on mine tranny and plan to either built it or get another one that's built after this travel season. We are currently up north with the trailer and don't expect to get back to Fl till late October. Change tranny fluid 35-40K miles.

I would like to remove the Thermostat in the tranny cooler line. I guess they want it to run in the 100-105 above ambient.

Please enter your signature info. Post shows this is your first post.

Dave

 

I agree with CoastalDav that your trans temps seem alright to me. I was wondering where you are monitoring the temperatures at on your transmission?
The most accurate area is the line coming OUT of the transmission and going BACK INTO the cooler.

If you are concerned about the current temps you can add an additional trans cooler to what you already have. Another suggestion is for you to add a "lock-up" switch to control the lockup of the converter. You can buy these or make one yourself.

You should be glad your temps are that low. On the new 4th Gen Dodge CTD CR 6.7 trucks the 68RFE transmissions run MUCH higher temperatures than that.

Hope that helps you some Sir.

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John_P

 

John and Coastal, thanks guys calms my mind a bit.

The gauge is hooked into the stock transducer sensor in the valvebody and read with edge monitor. On a side note i have a buddy with a 2012 and his trans actually runs around 140 highway....maybe the first 68rfe in the 08-09 ran hotter?

 

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TXC:

You are very welcome Sir!

 

The temp sensor for my gauge is on the outside of the return line from the TQ. It normally reads 160 on the highway at 70mph (TQ locked and trans in OD of course)