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Discussion Starter · #1 ·
I've been towing my #3500 car with tools etc. in a 24' enclosed trailer with 2008 Escalade.Last time out trans temps were rising to the 210-215 range in stop and go highway construction traffic.At one point when accelerating from stopped the engine was up to 4000 rpm and trans wouldn't shift.I hit the tow mode button off and it shifted.I put it back in tow mode and had no more issues there or returning home but I'm concerned. Vehicle has only 11,000 miles but fluid smells slightly burned.Called the dealer to schedule having the fluid and filter pm'd for peace of mind and they laughed because of the low mileage and new Detron VI fluid 100,000 mile interval.Any suggestions?
 

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If there was an issue, a code should store. 2008 Has the 6 speed ?? IIRC, the 4L60 & 4L80 had a overtemp code and wold defalt to max line pressure and shift real hard. I would bet the new trans woild have something similar.
 

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Discussion Starter · #5 ·
If there was an issue, a code should store. 2008 Has the 6 speed ?? IIRC, the 4L60 & 4L80 had a overtemp code and wold defalt to max line pressure and shift real hard. I would bet the new trans woild have something similar.
When On-Star sends a monthly Vehicle Diognostic report for engine/ transmission it says "diagnostic complete no action needed" would a stored code show on that report ?
 

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MCMIKE said:
When On-Star sends a monthly Vehicle Diognostic report for engine/ transmission it says "diagnostic complete no action needed" would a stored code show on that report ?
Yes.

Dexron VI is absolutely BADASS fluid. You've got the 6L80 or 90 trans, it should be fine. It shifted when you took it out of Tow/Haul, because the commanded shift point is lower when it's not on. DON'T tow that thing out of T/H mode, you'll cook it.

You said 3500 Lb car...what's the total GVW of your trailer, tools, tires, cooler, cart, etc.? That's the real number. You may well be close to max.

210 is hot, but not too bad. It's the stop and go that's killing you. Shifting up and down is what cooks the fluid and kills it. If you get out on the road, I'm guessing it cools down?

Do yourself a favor, talk to a tech at your dealership. Find out if they have a machine that will do a 20 or 25 qt fluid exchange. Getting ALL the fluid out is what's important. A 15 or 16 Qt service won't cut it. And only doing a pan drop is a waste of time.
 

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Yes.

Dexron VI is absolutely BADASS fluid. You've got the 6L80 or 90 trans, it should be fine. It shifted when you took it out of Tow/Haul, because the commanded shift point is lower when it's not on. DON'T tow that thing out of T/H mode, you'll cook it.

You said 3500 Lb car...what's the total GVW of your trailer, tools, tires, cooler, cart, etc.? That's the real number. You may well be close to max.

210 is hot, but not too bad. It's the stop and go that's killing you. Shifting up and down is what cooks the fluid and kills it. If you get out on the road, I'm guessing it cools down?

Do yourself a favor, talk to a tech at your dealership. Find out if they have a machine that will do a 20 or 25 qt fluid exchange. Getting ALL the fluid out is what's important. A 15 or 16 Qt service won't cut it. And only doing a pan drop is a waste of time.
I would have to agree with ya. you better check the real GVW of your rig. also hopefully its not killing the sprag like in the 4L60's and the 65's. At my work we would recommend a external cooler on top of your stock one.
 

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I know GM stopped putting auxiliary trans coolers on a lot of the 1/2 ton trucks a few years ago. Might want to ensure that you have one. I had to add one to my 2003 Avalanche. Got the factory setup and it works just fine. It comes with the lines, cooler, and mounts.
 
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