1977 D100

Q: can you swap a 1970 W200 rolling frame under the rest of a 77 D100?

D100 frame is rotting around the rear leaf spring attachment point on the passenger side. The front attachment point. There is an upside down cup shaped thing on the outside of the frame where the leaf spring attaches, and on the inside is the cross member. Around where those two things sandwich the frame is rotted.

The frame was like that when I got it 5 years ago $400 and I've just been watching it for any changes. I just helped my folks move some stuff and had a full load and about 15 hours of highway driving.

I noticed a little shiny metal about the size of the head of a pin at the upper part of the rotted area.

I did this swap in the late 70s .

The subject was a 76 w200 club cab and 75 d100

I cant remember anything that made it complex.

Its best to do a ton of measuring before you start.

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Yeah....Im the one who destroyed this rare, vintage automobile.....

1970 truck is straight front axle in both 4WD and 2WD. The steering is completely different from the later trucks. Swapping cabs isn't that bad if both chassis were meant to accept that type of cab, but the 1970 chassis used a completely different cab.

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Joshua

Thanks Sandy and Joshua,

New Q: Is there a low cost solution to extend the life of the truck frame?

Driving as-is costs nothing. I am just waiting for the frame to give, pull to the side of the road and call a wrecker to come scrap the truck.

I was thinking about bolting on a peice of metal to take some of the load, someone told me it was a dumb idea and I should get it welded by a professional.

Googled some advice from the professionals and they say you can't weld a frame because it creates a different temper and will crack, and you CAN'T WELD RUST. (they said that last part alot)

I talked to another guy who said to take another frame and cut out the part that you need and bolt it right onto the existing frame, do it on both sides.

so then I found this 1970 W200 frame and thought that it looks so good I don't want to cut it.

I might just run the truck as-is until it breaks, it may never break or it might break next week, and then I'll deal with it.

Anyway, thanks for the input, if anybody else has done something and had success for low $$$s, let me know. Thanks

Welding would be better especially if you can get a pro to do the job, technically if the weld is good it will be as strong as the original metal,
since this isn't a high end job TIG welding would be out of the question.
The weld could crack if it's at a point of flex or compression on the frame(but you can use thicker metal or reinforcing angels or pieces as needed), it's more likely if the metals are dissimilar (say like welding a piece of stainless onto a mild steel frame).

If the frame is rusted all the way through you can't weld on rust, but if you have a proper patch piece, you can cut the bad part out and over lap the new part and weld to good metal if the original frame isn't swiss cheese(you gotta wire brush and grind the base metal before welding any way).

I have a buddy that just played this game with two different generations of Chevy truck...he ended up mocking up the cab on the frame and doing some fab and welding to the frame then bolting the cab on it and going from there, if you don't have the experience and fab ability, it won't be cheap to try and convert.

-D.Idiot

If it were mine to fix I would grind heads off the spring hangar rivets and drive the rivets out of the frame. Pull the spring hangar and get to the damaged area. Cut the damaged section out of the frame and weld in the same thickness plate. Make the repair area larger than the spring hangar so that you can fish plate the repair section to the frame. Drill the patch and bolt the spring hangar to the frame with Grade 8 bolts. These aren't fancy heat-treated frames so the impact on the surrounding area will be minimal.

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Joshua

Can you post a photo of the damaged area? I have always been able to make cold repairs with reinforcement pieces for such damage that work well. One thing you need to watch for is that you do not create a space where water will get trapped and start the rust all over again. If you create over-lapping joints then find a way to seal it up and caulk it to keep out water. Good luck. This actually sounds like a fun project.

Sam

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Here's a link:

http://pinterest.com/gogyrl/shovelhead/

If that were my truck here in Gaithersburg, I would take it to my friend Tom Reed, who is a miracle worker as a welder. Is there someone near you who can do such things? It looks like it would be hard to make a cold repair there. That damage is in a pretty high stress location. Not only does it hold the spring perch, but there is pressure downward on both ends trying to split that metal apart in an upward direction where the spring is. I think it would help to get a cap on top of it all in some way to tie together the front and back halves over the spring perch. It is hard to see from those photos what is in front and in back.

The question comes down to whether to cut out all of the old stuff, and rebuild new there, or cap the old to reenforce what is there. Advantage of the latter is you keep the geometry and dimensions. Advantage of former is you get rid of rust entirely (for now).

Sam

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I was thinking of getting an identicle frame, cutting out a piece to span the wheel well arch, drill and punch out the rivets, and using 3M structural adhesive and grade 8 bolts to bind the piece to the inside of the existing frame. Cut the piece so it fits right inside the old frame. i was actually thinking if I did it just so, I might be able to leave part of the cross member on the new piece to reinforce that rickety structure also. maybe do both sides the same way. Or am I trying to think too much.

I do not think you are overthinking this. But, why not just get steel, make some patterns, take them to a good welder with a plasma cutter, and bolt that to your existing frame similar to what you are imagining with the old stock frame. I think I would be inclined to go outside your old rusted parts if possible. The value of the construction adhesive would be water proofing and not structural. I would not count on it to hold anything together.

Make your patterns from cardboard, figure how much stock you need, and maybe order it from McMaster Carr. Figure out how the stresses lie in the frame and make sure your patch can resist the twisting our bending forces.

To reiterate make sure your final construction does not trap water. It must either keep the water out, or let it drain adequately. Paint your finished product with POR15 to protect it as much as possible. ACtually, if you are using cold fasteners here, paint it all with POR15 before you bolt patches to it. And paint your patch before you bolt it on. Good luck.

Sam

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