[twitchee2]

So a little back story here. My sister drives 2007 V6 Sport 4wd with 155k on it. A couple weeks ago she was driving up in sequoia national park with a friend and the A/T temp light kicks on and she gets the Christmas tree of lights on the dash. Calls me panicking. Says she was driving at ~10mph following traffic up winding roads in 100*+ heat. I tell her to pull over and let it cool and keep the revs up, it will be fine. I will change the fluid when she gets home. She lets it cool for 30 minutes an finishes the weekend trip of ~800miles.

Fast forward to today I finally got a chance install the new B&M trans cooler I ordered so this wont happen again and flush the system. Keep in mind, as far as I know, the ATF has never been changed in 150K miles so shame on us for that, but that is besides the point.

We got the cooler mounted up and ran all the lines, drained the ~3.5 qts from the pain and filled it back up with fresh fluid, old stuff was pretty bad, not horrible but bad. Unhooked the return line so we can pump the old stuff out and flush the system.

Start the truck, 5s of idle no fluid flowing out of the coolers yet. 10s, still nothing. 30s, still nothing. Shut it down, double check everything and put an extra quart in the pan, maybe it was really low. Start it up again, still nothing. Let it idle for 1min, nothing. Put it in gear and goes in gear so it has oil but nothing is flowing through the coolers.

Started following the plumbing and taking things apart as we go. Pulled off the input into the factory water to oil cooled in the radiator and look what we found:



It appears to be a plug from the original packaging, from the factory maybe? It looks like a purpose built plug for that location and it fit very snugly in there and obviously impeded all the flow.

We learned the transmission has an internal bypass so in the event your external coolers become plugged, you can still drive. And you can drive for a long, long time.

We we dumbfounded to find that and VERY surprised the trans had not destroyed its self.

This is the ATF that came out:


Anyone else ever had this issue?

[AuSeeker]

So are you saying your sister has own her T4R since new?

I find it hard to believe that it was left in there from the factory but anything is possible and would seem to be the case if she has owned it since new and the radiator has never been replaced, if she hasn't had it since new then a previous owner maybe had to replace the radiator and whoever did the work left the plug in there.

That all being said I can envision how it was left in there, usually the type of plug placed in the threaded holes to keep debri out has a flange of sorts on it make it easier to remove the plug, if when trying to remove it the flange detached then it possible that the person thought the plug was completely removed, especially if the person was inexperienced.

On another note this testifies to how "bulletproof" these transmissions are.

[waypoint]

That is bizarre. My '07 was bought used, but poorly maintained. Very unlikely the trans had been serviced previously. I removed the trans cooler upper hose at the radiator last year to flush it...didn't find any such plastic plug. Fluid pumped out just fine with the engine idling.

I'm wondering if that plug was a manufacturing process dust cover that somebody forgot to remove on the assembly line...

[twitchee2]

Originally Posted by waypoint

That is bizarre. My '07 was bought used, but poorly maintained. Very unlikely the trans had been serviced previously. I removed the trans cooler upper hose at the radiator last year to flush it...didn't find any such plastic plug. Fluid pumped out just fine with the engine idling.

I'm wondering if that plug was a manufacturing process dust cover that somebody forgot to remove on the assembly line...

What you described for flushing was exactly what I expected. I am suspecting a Friday or Monday AM build and the dust cover wasn't removed!