Cracked seat mount on an otherwise rust free truck...wtf?

[AJMBLAZER]

Was crawling under The Blazer last night taking the running boards off. Noticed the rear outside passenger front seat mount has a nice crack running out from it on two sides. The truck isn't rusty. What rust there is barely qualifies as surface rust. Fatigue maybe?

What's the proper way to fix this? I can't weld so I'll be having someone else do it but wanted to know if there were any tips or tricks beyond just welding it up.

 

[yellowK20]

Super common my 90' K5 cracked there also and it was a rust free texas truck my guess is from people leaning back in the seats.

Plus the flat surfaced that K5's have isn't really the best for strength

 

[yellowK20]

oh to fix it I just drilled out the end of the cracks and then welded it up and then made 12gauge reinforcement plates top and bottom where the seat bolts went through kinda like what they do with rollcage plates spreads the load out a bit

 

[AJMBLAZER]

Thanks, I'll talk to my friend the body guy.

 

[cdoggwsu]

Same deal with mine, 98% rust free and the drivers side rear mounts had literally punched completely through the floor. I took it to the local machine shop; they beefed up all of the mounts with wider 1/4" plates and welded it all up for about 80 bucks.

 

[AJMBLAZER]

Maybe we had the same guys owning our trucks at some point, who knows?

 

[michael0584]

Maybe we had the same guys owning our trucks at some point, who knows?

Well they owned mine too then, cause both the drivers side and passenger side of my 87 are all cracked up.

 

[tRustyK5]

Very common, it's plain old fatigue with the root cause being not enough rigidity in the area to prevent the normal movement from fatiguing the floor.

Not much to do other than adding thicker mount areas to spread the load and firm up the floor area.

Rene

 

[AJMBLAZER]

Yeah, my buddy talked to our super-welder-guy friend about it yesterday and he says it's totally fixable. I might see him today about it and do some brainstorming about it and the rockers on Big Ugly.

 

[JOES89K5]

cracked floor

I recently seen a post on criags list pittsburg area a company selling steel channel floor supports 18 guage assorted lengths fairly priced. They were being sold as such to strenthen floors on older vehicles. several of these used on areas would do the job.You can have them welded in any direction.

 

[AJMBLAZER]

We were supposed to fix it today but some stuff came up and our weekend was filled anyways.

We're going to weld some plate to the floor after filling the cracks. Not sure how big of pieces but it will be either some 3/16" I have sitting at his shop or some 1/4" he has. Should we put a 4" wide strip in for the rears and the fronts or just individual large pieces like 4"x6" under each mount?

 

[JOES89K5]

cracked seat mount

I would probably weld it to part of the metal plate which bolt from seat threads into. this would stop floor from flexing.Then some longer pieces from that to distribute the load throuht the rest of floor.

 

[AJMBLAZER]

We fixed the seat mounts yesterday. Welded some 3/16" plate on top of the humps the seat mounts sit on and welded up the cracks. Passenger side outer rear seatmount was not only cracked up but the whole assembly was pushed down below the level of the rest of the floorboards. My buddy got a bottle jack on it and punched it back up in place. He also fixed the two cracked and rusty spots on the tailgate at the edges of the window channel.

Rhino Lining is next!