If you have a bagged s-series, you know theres that pain in the ass triangle plate on the drivers side (both sides on newer blazers) with bolts hanging down that not only hold you up from laying frame but get caught on everything and end up getting completely destroyed. Well these bolts hold your transmission crossmember in the frame, so tearing them up isnt the best idea for the integrity of your truck.
What people typically have done in the past is got in there with a big ass drill bit or die grinder and just tear up the holes in the frame, trying desperately to widen them enough to slide the bolt heads up as well fit a socket on them to tighten em down. This method sucks, mainly because the areas surrounding the holes in the frame are reinforced with steel so it doesnt collapse.
What I have been doing for quite some time is using allen key bolts. You only need to drill out the first outer layer fo the bottom frame rail, then just stick the allen bolt in and youre done. This howto will show you just how easy it is.
Heres the plate that I'm talking about. The small 13mm bolt on the crossmember itself is not needed and not replaced. The other two bolts on the frame are what we will be modifying. Most S10s have the bolts facing down with threads sticking even further below the frame however this blazer has them pointing up. It doesnt matter either way.
Remove the small 13mm bolt from the crossmember, as well as the two longer bolts from the frame. Most of the time the head of the bolt is 13mm and the nut is 15mm but I've come acorss some nuts being 13mm as well. At this point we can see where we need to operate, the bottom frame rail.
Get a 9/16" or 5/8" drill bit and drill out the two holes in the bottom of the frame. I prefer to use a step bit or unibit, it cuts a lot faster and is much shorter than a standard bit.
The idea here is to just drill out the bottom of the rail. Once you drill it large enough you will see the reinforcements inside the frame and the edge of the hole will be even with them. However the hole only needs to be 9/16" to get the bolt in there so as long as you go that big youre good. The top of the frame rail has the same design, and that is left alone because the shoulder of the bolt will use that lip to hold the crossmember in place.
Here are the holes drilled out and a cross section diagram of the frame showing how its built and what youre trying to achieve.
This is what youll need to pick up from the hardware store.
2 - 3/8"-16 Socket head Allen key bolts, 1-1/2" long
2 - 3/8"-16 nuts
2 - 3/8" flat washers
2 - 3/8" lock washers
The head of these bolts uses a 5/16" allen key. Make sure to buy socket head bolts because the button heads are much too wide to fit inside the frame.
Stick a bolt on the head of the 5/16" allen key and feed it up into the frame. Place a flat washer, then lock washer and finally the nut onto the threads of the bolt and hand tighten. Do the same for the other side. Get a short 9/16" socket with 3/8" drive ratchet and tighten them down snug. If you cant hold onto the allen key to get it tight enough, employ the use of some pliers or something. The allen keys that fold up are useful in this situation because they have the longer handle.
And thats it. Some s-series still have other issues with the crossmember itself being too low, but just about all of them have this problem with this plate and now you know how to fix it.
[HowTo] Trans Crossmember Plate Mod on S-Series
Linear Mode
