What did you do with your GMT400 today...or yesterday....

[Stoney]

I used to 7/16 in easy out on the end of a breaker bar to get mine out ..mine did the same thing..

 

[Will L.]

Steel bolt, aluminum transmission body. There has to be some special goo to stop the galvanic corrosion that is not going to let the bolts come out on accident.
Removing and cleaning the bolts and bolt holes every 30,000 miles would fix this issue but slackers like me don’t always do it.

 

[Big T]

Use on of these drive tools on a 1/4” torque wrench for install. Saves this headache in future. Hopefully it isn’t cross threaded.
I can’t imagine cold being issue because only 2 stuck but all others were ok- cold effects all of them.
OR, You could warm it up and those 2 come out easy. Heat gun? Small butane torch? Even a fireplace lighter with the flame on the bolt head?
View attachment 67800

I was using exactly that Allen tool on a 3/8” socket. Got one side of bolts off, but two in the front stripped and one in the rear started to. Did not go to the other side. Since I was not certain I could get the bolts today, I called it.

 

[Big T]

Steel bolt, aluminum transmission body. There has to be some special goo to stop the galvanic corrosion that is not going to let the bolts come out on accident.
Removing and cleaning the bolts and bolt holes every 30,000 miles would fix this issue but slackers like me don’t always do it.

Well I based the fluid change on mileage, but I had not been using the truck that much. I’ve put 20K miles on since 2016 per posts here and 10K of that in the last year. So at a 30K interval, those bolts have been in there for years and it was obviously a function of time. I had to break free most of them. I will pull one and get a grip of replacements, then go at it after it has been warmed up from running and apply a little more heat with a mapp gas torch. Just not this weekend.

 

[Big T]

There are also those stripped Allen bolt removers that thread down in to remove them:

Powerbuilt 240094 8 Piece Zeon Metric Hex Bit Socket Set - with use for Damaged Fasteners, Standard, Rusted, Rounded Bolts, Size from 3mm to 10mm



Probably go that route before using the drill and extractor.

 

[Will L.]

One of the things that turned me from average tools like craftsman (which you see I still own) to high end stuff is extractors, and sockets to deal with worn or rusty head bolts.
Snapon, Mac make some of the best extractors out there. For fair price instead of crazy high price sockets for regular bolt/nut- look up mac edge sockets. Made in Taiwan, but have a unique design that puts over half the force on the flat of the bolt. So they never strip and actually remove rounded of bolt no other one can and priced lower than craftsman. I kept asking them to make extractors for allens for your situation.

I would suggest looking at the hansen extractor set over those. In fact, hansen tap and die, and most all there small consumable tools are top quality and affordable price. Cost will be a be a little more but work so much better it is well worth it. They make many of the Mac, Snapon, etc items. But the reason I say Mac is they come with lifetime warranty when broken- even drill bits. So using them all the time- it is worth the pre-pay investment. If just occasional diy- get the Hansen.

 

[MrMarty51]

Shovel head Harley engine. Tappet filter screen under a steel, not pipe thread, bolt. Every time, that bolt would be seized in solid. Put a wrench on it and tear yourself and the bolt head to pieces. Several sharp rapity tap tap tap and that bolt would turn right out. Like nothing had been tje matter. That is steel bolt into aluminum engine crank case.
Oh yeah, I forgot, that tappet screen plug is steel, but, it has a screw driver slot.

 

[dbrannon79]

Most of those bolts are through hole type in the tranny. you might try squirting some PB blaster over the top side of the threads where the end is barley sticking through. drive it and keep squirting daily. when you get ready to pull the bolts give the bolt head a good couple smacks with a flat punch or the extractor you plan to use. that might give you some luck getting them out.

is that pan and bolts OEM or something aftermarket? only reason I ask is the design of the pan looks aftermarket where cheap grade 2 steel was used making the bolts and possibly why your seeing the heads strip. when you got new replacement bolts, make sure they are grade 5 and not made in china!

something that frightens me too is the use of MAP gas on the aluminum, if that pan is aluminum, be very careful. I'm sure you know that already, but my experience using MAP gas is it gets much hotter a LOT faster. could distort the aluminum mating surfaces or worse cause a crack.

 

[Big T]

Most of those bolts are through hole type in the tranny. you might try squirting some PB blaster over the top side of the threads where the end is barley sticking through. drive it and keep squirting daily. when you get ready to pull the bolts give the bolt head a good couple smacks with a flat punch or the extractor you plan to use. that might give you some luck getting them out.

is that pan and bolts OEM or something aftermarket? only reason I ask is the design of the pan looks aftermarket where cheap grade 2 steel was used making the bolts and possibly why your seeing the heads strip. when you got new replacement bolts, make sure they are grade 5 and not made in china!

something that frightens me too is the use of MAP gas on the aluminum, if that pan is aluminum, be very careful. I'm sure you know that already, but my experience using MAP gas is it gets much hotter a LOT faster. could distort the aluminum mating surfaces or worse cause a crack.

The vehicle came from the PO with that pan installed. I like it. Has a drain plug and a separate hole for a temp sender, plus additional capacity.

Every single bolt needed to be broken free, so there was some sort of electrolysis going on with the steel vs aluminum. That is what cause the bolts to strip. They were not inferior grade. Yes an impact tool would probably be best to break them free.

Did not know on the MAPP gas and aluminum. I will use the barbecue lighter after driving it. I think the extractors will get the job done.

Bolts I got were grade 5. Not sure of country of origin.

 

[dbrannon79]

@Big T when you do get the pan pulled, I am curious what brand or markings are on it. I like the contour of it and the fact it has a drain and port for a temp sender! I have been thinking about having a gauge in the cab for trans temp. that would be an ideal place for a sender.

 

[Big T]

@Big T when you do get the pan pulled, I am curious what brand or markings are on it. I like the contour of it and the fact it has a drain and port for a temp sender! I have been thinking about having a gauge in the cab for trans temp. that would be an ideal place for a sender.

I will look. Did you see that it has cooling fins?

 

[dbrannon79]

I will look. Did you see that it has cooling fins?

Yup! that I like too

 

[MrMarty51]

Grade 8 is better. Just My personal thoughts and experiences.
Oh yeah. That is a nice pan. Might be something to add onto My someday tooodooo list.

 

[Will L.]

Grade 5 to grade 8,
5 is slightly softer metal and will bend before it breaks.
8 is harder and holds more shear and tensile but will give no warning before failure.
Grade 8 is much harder to drill out if ever have to. Even using ez out is worse.
Going to grade 8 doesn’t hurt a lot if there is never failure. But failed ones, you are happier to use what is the required one. Holding on a pan- not much required...

 

[Husker6.5]

The pan is manufactured by PML. They currently run about $285. Recognized it right off the bat as soon as the pic was posted.

 

[Big T]

The pan is manufactured by PML. They currently run about $285. Recognized it right off the bat as soon as the pic was posted.

Nailed it:

PML GM 4L80E, 4L85E Late Model & Hummer, Deep Transmission Pan – CJC Off Road

 

[Husker6.5]

I laugh at how much PML charges, and how much their authorized dealers up charge to add a transmission temperature sender port. Like I can't drill and ⅛" NPT tap the casting boss myself for free, or use the ⅛" NPT pressure port on the side of the tranny, either!

 

[Stoney]

I was actually wondering how hard it is to do a temp sensor on the tranny.

 

[MrMarty51]

I was actually wondering how hard it is to do a temp sensor on the tranny.

Pressure port on the side of the transmission is where Mine is plugged into, or, it must be. It shore aint plumbed into the pan.

 

[Will L.]

That is nuts. It looks cool, and the fins will help loose a little heat- but if the fins helped that much, it would be stock on all the performance cars by mfr- a little aluminum isn’t that hard to make when they do block and heads from it.
Spend way less, and get way better function.
And several times it’s been explained that more transmission fluid in the pan/ entire system doesn’t help with lower temps. Yes it might take a minute longer to get hot, but then it will take same amount of time to get it to cool off back to normal temperature.

JEGS 60372: Transmission Cooler 18,000 GVW - JEGS High Performance

Transmission Cooler

www.jegs.com

https://www.summitracing.com/search/product-line/dorman-transmission-pan-drain-plug-kits/part-type/drain-plug-kits?fr=part-type&SortBy=Default&SortOrder=Ascending

There is tons of options available. This was fast grab online as examples.