How to tell if frame has been replaced on a Gen1

you had a good fix for that problem?

 

Safe T Cap two pieces.....local rep in Maryland $1,800

 

you got me thinking now about figuring out some kind of insulator between the cat and the frame, it seems the heat may like to keep the winter slop nice and slushy inside there?

 

Knock yourself out, but I highly doubt it.... it's just moisture, salt, and crappy metal from Toyota.

 

Thanks everyone for you insight. Called Toyota and was told that the frame was replaced 6 years ago. I did check myself and looks good. No scale but there is light rust on some surfaces,e will deal with that soon. If I can make this Taco last for two years I`ll be happy.Going to go thru all fluids in the up coming weeks. Over all truck looks in very good shape. I like the fact the all of the fluids that should be used are off the shelve. Coming from German cars in the last 18 years most fluids that I use are somewhat hard to find. I have to order them. The last truck I had was 98 Ranger 4x4 that took care of me very well for 15 years until the frame went south. Looking forward in learning much more about my truck. Looks like I found a good place to help with my learning curve. Thanks to everyone again.

 

It's an internal problem. You see, this type of frame is called a boxed frame and while this type of frame is a blessing (because is it much stronger than an open "C" frame), it is also a curse as it does rust from the inside out

the leaf spring area is the first place where the frame will start to rust and rot. Does from the inside out and when you see it on the outside, it is already too late. You'll notice, this is where the "boxed" portion of the frame ends, as it transitions to a "C" frame under the bed. I believe this is where crap and moisture gets trapped, initiating the rust fest. The portion of frame under the bed can also rust out too, despite being an open C frame as there is some kind of reinforcing butresses in there that traps moisture and debris

as for the CAT and the gas tank areas, rusts from the inside out too but I don't know why really. There is nothing to trap debris and moisture there. These areas are just commonly rusted through on bad frames

but I have my little idea of why there is moisture in the frame even if you never went driving in water. It's a phenomenon called condensation. When switching from hot to cold and cold to hot temperatures (the change of seasons, basically), it does create moisture in the frame. Not enough to make your frame rust as it will evaporate eventually, but when mixed and trapped with dust and debris inside the frame, it does not evaporate and it makes it rust, rusting through over time if the dust/debris clumps are not cleaned. Add the winter salt and chemicals to the mix and it accelerates the process tenfold

down south, you guys don't have season changes as brutal as up here, that is why the inside of frames may be dusty or have debris in there, but the inside of the frame is in good condition. Very little to no moisture gets trapped in there due to the absence of the condensation phenomenon
Or course, if you drive or park in a pond, that's a different thing...

rustproofing inside the frame will prevent moisture buildup on the inside while rustproofing the outside will protect it from the winter salt and chemicals

 

I just noticed rubber plugs in a 1994 Toyota Pickup frame.
Located just behind the front wheels where ,(on my 2003 Tacoma) the frame hole is perfectly positioned to catch all the water splashing up from the road.
My Tacoma has the same holes, but no plugs? Maybe buying some would help cut down on moisture in the frame.

 

The main issue with the Tacoma frame (1st gen especially) is actually quite opposite - not enough drain holes. Comparing this our trucks, the 3rd gen frame looks like a Swiss cheese (the same I see in my 5th gen 4Runner). The issue with the frame starting to go bad at the front leaf spring mount is that all dirt and water is pushed inside the frame from the front (by the front wheels splashing) and from the top (where the C-channel converts to boxed frame) pushed by the rear wheel splashing. And in that spot there is a just one tiny drain hole that can be easy plugged by accumulated mud.



For comparison my 5th gen 4Runner has multiple drain holes that will let dirt out of the frame



Of course the bad metallurgy is a big factor too.

 

This is the part number for the frame plugs I mentioned above.
https://board.marlincrawler.com/index.php?topic=102383.0

This is the part number as of 2019.
90950-01642 Frame Plugs, I'll be shopping
for some soon