Seized trans pan bolts

My new to me 07 DC had a trans issue. Good new is I found the problem and is cheap - (S2) shift solenoid. Bad news is even with lots of heat, I snapped 6 of the 12 bolts. Pretty sure these haven’t been touched since 2007. I am pretty good with rusty fasteners on cars, but these m6 bolts were like pot metal. I gabe up and drilled one out and will just use a nut on top or if there is enough meat left a heli coil. Can do the same with the other 4. However one of them is either a blind hole or goes into the area inside the junction with t case. I have heated it, soaked it, and even welded a blob on theend to really heat it and it willNOT budge.

looking for some tips on how to get these out. I really need to get that one in the blind hole out. Drilling for a helicoil is tough with such a long bolt. Very hard to drill straight.

thanks

 

@Joe333x had the same issue. He might know how to get it out.

https://www.tundras.com/threads/my-transmission-pan-adventure.110777/

 

What was you initial problem that required S2 solenoid?

 

Also how did you apply heat? Torch does not always help, you better be using inductive heater. Or TIG welder. Get it glowing red and it will move.

You may skip drilling that one bolt out if it's not in the corner and use a thick metal plank with holes for the neighbor bolts, to apply equalized pressure to the pan in the spot where one bolt is missing. Or get a drill guide like



If you manage to clamp it somehow...

 

some good advice here, thanks. I welded the blob on with a mig and doubt the bolt got red hot. I did this one the driveway and don't have enough cord to get the tig all the way out there. I will first hit it harder with the mig and see if it goes. Will then make a drill jig and see if I can drill it out clean enough for the heli coil. otherwise will make a bar to support.

 

clunking during shifts (i.e. very hard shifts) from 1-2. Had P2714 & p0756 codes. S2 was giving me 70 ohms instead of 11-15 and would not move with 12v. I cleaned out the SLT and it ohm'ed in spec and had snappy performance with 12v. I used the sonnex guides to see which solenoids are used for each gear. The two used for 1 are the SLT and the S2. The ecu applies both for hte shift and then it observes a failure via speed difference between input and output sensors. It doesn't have a lot of detailed feedback, so it points the finger at both suspects, but that doesn't necessarilly mean both failed to operate and cause the problem.

You can not assume a bad solenoid from these codes though. It could have many other elements between the solenoid and the clutch/brake that the solenoid activates. I got lucky with my case, as it is dead simple to fix, excluding the seizing bolt issue.

 

I read that. Mine are much worse than his. On the one that I drilled, I STILL couldn't get it out with an easy out. The handles on the tap holder actually bent and if i went any further, I would have snapped the extractor. They are seized to a level that I have never seen in many years of dealing with rust belt cars. The aisin engineer that decided to save a few dollars on the casting by using through holes should seriuosly be reprimanded. Through holes on aluminum casting using steel bolts is a major no no with smaller sized fasteners. No issue in Arizona, but a serious problem in the rust belt. Galvanic gorrosion is greatly accelerated with the aid of a saline solution (i.e. conductor). THe other issue is the spacers in the gasket. It is nice to keep gorilla mechanics from over compressing the gasket, however, it creates an area for corrosion to form at the pan side of the bolt case interface. This style of gasket should be reserved for valve covers and NOT stuff under the car.

 

I've drilled them to the point only the threads are left in the hole. You have to be careful to get the bit as centered as possible and not drill at an angle. I have 2 post lift so working under cars is much easier. I just kept going larger diameter bits until I could just see the aluminum from the housing showing. At that point I used a pick to get the remaining steel threads out of the hole. There's not much metal left so it bends easily. I then chase it with a tap. I've had much better luck doing that than trying to weld a nut onto the broken bolt or using an easy out.

 

I have no codes, but my 2019 has a subpar 1-2 compared to all other gears, which are pretty smooth. 1-2 on wife's Sequoia with the exact same powertrain is very smooth, too. I may need to drop the pan and check that S2.

 

define sub par. not likely the solenoid. more likely wear in the valve body or clutch plates. Non linear solenoids, like the shift solenoids generally either open/close or not. Could be intermittent, but typically nothing in between open and closed. the linear ones (slu/slt) can cause partial problems. They use PWM to provide variable movement. i would do a zip kit instead. if it feels like slippage I would check pressures. Could also be wear on the A clutch plates.

 

Thanks for the tips

 

Jolts while cold. No slippage. Feels like super-early engagement, when engine power reduction window commanded by TCM did not happen yet, so clutches lock with more torque coming from the engine than required.

It is doing it from mile 200 when I got it. ATF has been replaced 3 times (drain&fill 4-6 qt at a time). There was zero wear anywhere in transmission at 200 miles. If it was my Volvo, I would do transmission adaptation. Maybe need to figure it out how to do adaptation in Tundra.

Definitely not a big deal. I've had my share of transmission problem, this one is not a major concern yet.

 

Mine has done this from day one if I’m really granny pedaling through stop and go traffic. Feels like there’s an awkward point where vehicle speed and engine load and RPM are low but the transmission still wants to go into 2nd gear. It’s a pretty noticeable thud.