Like a "Z", but on it's side. That way, like Issam said, the cut is not in one vertical plane...specifically the upper and lower frame flanges.
CK5
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budget beater - . . . HOLMES 220 single line boom wrecker install starting ..
- Thread starter sweetk30
- Start date
I am not trying to sound superior here.
I learned what to do from helping stretch semi trucks. The old guys doing it showed me lots. One even told me of a cabover he had seen that someone did a 90* cut at the bellhousing and didn't fishplate at all. It went for years and never a problem.
My point is that you may never see any difference in a Z cut, step cut, slant or fish mouth as long as you get it welded well, and don't beat the holy crap out of it, like overloading to high heaven!
I saw a 1 ton Chevy wrecker the other day that I would have fixed the frame, but the guy didn't even think twice before towing a step van, partially loaded with it.
I learned what to do from helping stretch semi trucks. The old guys doing it showed me lots. One even told me of a cabover he had seen that someone did a 90* cut at the bellhousing and didn't fishplate at all. It went for years and never a problem.
My point is that you may never see any difference in a Z cut, step cut, slant or fish mouth as long as you get it welded well, and don't beat the holy crap out of it, like overloading to high heaven!
I saw a 1 ton Chevy wrecker the other day that I would have fixed the frame, but the guy didn't even think twice before towing a step van, partially loaded with it.
It's not about being superior.
We do most of our work because we want the best but don't want to pay the price associated with the best.
You can get a straight cut to work, but we abuse our trucks and if you know of a way to get bullet proof result with a little more work wouldn't you want to do it?
I was trying to remember what it was called but a picture is worth a thousand words
Like this...
I understand what you are saying, but I know that what I have seen done to / with heavy haul trucks, and heavy wreckers is way more strenuous than what a pick-up goes through.
Anyway, the step cut that is being pictured is a good common way to go.
Beat you to it
Well it's debatable, the twisting our frame goes thru when going off road put a different strain on a straight cut. I have a couple of big rigs and the kind of loading they get is more vertical and I think you can get away with a good weld on a straight cut with good fish plates.
I bought a crew cab that had a cracked frame at the end of the cab and someone welded it and put a plate to reinforce it.
It cracked in the same place even through the reinforcement plate.
I'm not trying to endorse a straight, vertical cut. Never had anyone tell me that they would do that. That was merely something a guy witnessed.
And I wasn't referring to a regular OTR tractor. More weight... more twisting/pounding.
But yes the light channel frames under these are different.
This makes me wonder more of embrittlement in the frame by possibly too much heat in it.
The fishplate on the one picture doesn't spread the load enough, compared to what I was taught. And it puts too much weld heat in a couple if places. I was taught to make the plate big enough to go past the original cut. Less crossing of weld joints as well.
I was told not to fully weld the fishplate, also. Leave some places for movement. But this may depend on the design. Not sure.
And I wasn't referring to a regular OTR tractor. More weight... more twisting/pounding.
But yes the light channel frames under these are different.
This makes me wonder more of embrittlement in the frame by possibly too much heat in it.
The fishplate on the one picture doesn't spread the load enough, compared to what I was taught. And it puts too much weld heat in a couple if places. I was taught to make the plate big enough to go past the original cut. Less crossing of weld joints as well.
I was told not to fully weld the fishplate, also. Leave some places for movement. But this may depend on the design. Not sure.
I agree on this fishplate not being done right.
It was just posted with the other picture for reference.
ya I forgot about the Z-cut or step cut . . . this might even work good for me .
still have to make cardboard template of each and see what method works the best for getting rid of the chunky spot I have to cut out and give me the most solid section available of the 2 halfs when lined back up .
still have to make cardboard template of each and see what method works the best for getting rid of the chunky spot I have to cut out and give me the most solid section available of the 2 halfs when lined back up .
You can also make the different on each side based on the bad part of your frame.
placed my order with kirt @cybrfire from DIY4X for the beefy gooseneck hitch he builds . this will help tie the back end repair together on this truck . plug create a good tow point for a trailer .
cant wait to get this one . the last one was super beefy built .
look here for pics of the other one HITCH PICS scroll down for even more pics once page is loaded .
cant wait to get this one . the last one was super beefy built .
look here for pics of the other one HITCH PICS scroll down for even more pics once page is loaded .
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pics later 
. but the tail is back on the frame . and measured the plow machine frame to get here were she needed to be . got some clean up and back side welding but that can wait till later . also fish plates to add but that will wait till the DIY4X goose neck hitch is here and installed to make sure it clears .
now lunch and then i will remove the middle cab mount brackets and clean the frame and layout the cut lines.
. but the tail is back on the frame . and measured the plow machine frame to get here were she needed to be . got some clean up and back side welding but that can wait till later . also fish plates to add but that will wait till the DIY4X goose neck hitch is here and installed to make sure it clears .now lunch and then i will remove the middle cab mount brackets and clean the frame and layout the cut lines.
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were ready to this back together after dinner .
she is clamped / checked 4-5 diffrent ways / and ready to go .
got lots of pics to load later tonight .
this back together after dinner . she is clamped / checked 4-5 diffrent ways / and ready to go .
got lots of pics to load later tonight .
here we go today we converted a crew cab frame to a std cab frame .
i used the slant cut cause the left rail had some bad thin spots from rust and it worked the best to keep the most meat in the frame . pass side was 95% better than left side for some reason .
i used the slant cut cause the left rail had some bad thin spots from rust and it worked the best to keep the most meat in the frame . pass side was 95% better than left side for some reason .
so just a fyi for others . its the 3+3 emblem for the difference in length . remove the + and make it 33" . . . 
take the 33" out of the middle section between the front and back cab mounts and splice it back together .
i know most pics show the slant cut going the other way but some show it this way . i also asked a friend who use to do heavy truck repairs for years . he said no problem .
i still need to do the fish plate on the back side of each rail yet .
but i was able to verify in 5-6 diffrent ways how much to cut by taking measurements from the plow machine k30 frame sitting in the middle of the shop .
i figure for my first time doing major cut/splice work and taking my time i have 4-5 hr's in it with basic tools . only used a 4.5" grinder with cut off disk to cut . sand flapper wheel to clean up . around 20 pairs of vise-grips . and few scraps of steel to hold flat each half .
all in all i measured and give or take the frame might be out from end to end and left to right 1/4" and most of that i found was factory hanger placement .
take the 33" out of the middle section between the front and back cab mounts and splice it back together .
i know most pics show the slant cut going the other way but some show it this way . i also asked a friend who use to do heavy truck repairs for years . he said no problem .
i still need to do the fish plate on the back side of each rail yet .
but i was able to verify in 5-6 diffrent ways how much to cut by taking measurements from the plow machine k30 frame sitting in the middle of the shop .
i figure for my first time doing major cut/splice work and taking my time i have 4-5 hr's in it with basic tools . only used a 4.5" grinder with cut off disk to cut . sand flapper wheel to clean up . around 20 pairs of vise-grips . and few scraps of steel to hold flat each half .
all in all i measured and give or take the frame might be out from end to end and left to right 1/4" and most of that i found was factory hanger placement .
What's the significance of the football game of X' s and O's?
TreeFarm
Internet fabricator.
I'm willing to bet that 1/4" is straighter than my truck
