New (used) IH 7500 Dump Truck purchase, modification & fix up

[Hay Dude]

I found a couple of old pics I had taken of a tailplate, two 1/2" NPT couplings either side for trailer air, center hole for electrical, bottom holes for a 50T air cushion pintle hitch and of course the D rings. If it's in your budget, the air cushion pintle saves a lot of banging, not cheap tho.
I've got the drawings I had made for subframes but unfortunately I no longer use nor have the software they were created in.


Sure, all you're effectively doing is moving the frame up 3", just treat it like the truck frame. Not saying there' isn't going to be some customizing but I can't see why it wouldn't be minimal.


As long as it's not paper thin and Swiss cheese, the subframe should bridge the bad area. The subframe is running front to back, so with the dump body dumping, the rear of the frame is partially in compression. Yes there is still some vertical load but the subframe will help spread it out.

Ideally yes that would be the cats ass but I don't think much of the idea of moving the hangers out the thickness of the plates.
You think they'll be able to be moved out with no problem with anything clashing?
View attachment 787311
View attachment 787312

Well, you’d have to build (4) plates for front and rear pairs of hangers, then you’d have to remove and replace U-bolts. U-bolts are only $50 each. To be honest, my existing U-bolts look pretty scary anyway.
The lingering question is: Is there a vertical alignment pin on top of the axle tube for the base for the springs? If there is, then what?

Another thought: I am also concerned about the rust spot compromising the frame not just from the standpoint of the dump body, but also the overall strength of the suspension.

I was thinking the inverted L idea-full length of frame from cab to end, would also make the frame appearance really nice (say for resale) nice glossy, smooth looking finish rather than painted over pock-marks????

Like a “2-fer” (strength and appearance).

I’m not overly concerned with weight since the truck is 41,780 GVWR.

You could hang the inverted L on the frame and the top of the frame would be nice & level, to…..even with the rust jacking opening.

 

[mrmikey]

The lingering question is: Is there a vertical alignment pin on top of the axle tube for the base for the springs? If there is, then what?

Like I had said, go to a dealer and see if the have a new hanger you can look at, only way shy of taking it apart, you're going to know for sure.

Another thought: I am also concerned about the rust spot compromising the frame not just from the standpoint of the dump body, but also the overall strength of the suspension.

How thin is it, any way to tell for sure? I know you had said it was rusty but there's thin.....and holy crap thinnnn.

You could hang the inverted L on the frame and the top of the frame would be nice & level, to…..even with the rust jacking opening.

That's a 12' sheet of plate to have sheared and bent, anyone close to you to do it if you go that route?

 

[Hay Dude]

Like I had said, go to a dealer and see if the have a new hanger you can look at, only way shy of taking it apart, you're going to know for sure.


How thin is it, any way to tell for sure? I know you had said it was rusty but there's thin.....and holy crap thinnnn.


That's a 12' sheet of plate to have sheared and bent, anyone close to you to do it if you go that route?

The best way I could describe the rusted are is it is inside the 6 bolt area where the rear spring hanger is. It looks like the outer piece of frame is about 50% rusted away. The inner piece of frame is fine. What concerns me is that area is under a lot of stress from the suspension hanger and it being the fulcrum of the the dump hinge/pins.

Maybe I am over-thinking this, but I feel like doing this now would be a lot cheaper than a big “UH-OH” later once the body is mounted.


The truck is at a welding & fab shop. They can build or do just about anything. I do what I can do, and they do the rest. Very nice people to work with.


Here is where the outer frame is thin (red box). A pile of asphalt sat in here for probably years, held in moisture and deeply rusted an area of the frame about the side of a fist.

 

[mrmikey]

What concerns me is that area is under a lot of stress from the suspension hanger and it being the fulcrum of the the dump hinge/pins.
Maybe I am over-thinking this, but I feel like doing this now would be a lot cheaper than a big “UH-OH” later once the body is mounted.

Ultimately it's your decision, I understand the , "pay me now or pay me later" decision you have to make.
I don't think there's a bad choice other than doing nothing. Looking back at the options we've talked about.....I'm leaning toward the shorten the crossmembers and put a doubler inside the frame.

 

[Hay Dude]

More info incoming. IH parts diagram does show a pin. not surprised.

I may have to reinforce from the inside as you suggest. I would lose the feature of covering the rougher frame with a smoother piece.

It would actually be a “tripler”

 

[Hay Dude]

So I did some more pausing and gathering information on the truck. Spoke with a company in Ohio that installs beds and we got to talking. The guy was very knowledgeable. He spent 20 years in the shop doing frame work and mounting dump bodies on trucks.

What he told me surprised me a bit.

He said he would not bother reinforcing the frame.

He said to cut the last section off of the outer frame that has the rust issue (it’s about 18” long), and simply butt weld a replacement piece in place of it, then put a set of 5/8” bolts on either side of the weld and call it a day.

This would save me a few thousand, but at the same time leave me with a truck with a 12’ dump body.
He suggested if I was on a real low cost budget to buy a 10’ bed and slide the rear axle forward.
They have a 2020 leftover 10’ BiBeau dump bed for $8,200 (normally they are $10,500)
12’ Bibeau dump bed is newer, so it’s $12,000.

So it comes down to about $4,000 more for the extra 2’ of dump bed.

I’m guessing the cost to slide the axle forward is a little more than the cost to butt weld the back pieces on and bolt them.

So here I am. Now I need to decide. I’d really rather have the full 12’, but $4,000 would go a LONG way towards pump, tank, PTO and cab controls……

Shop doesn’t have any 5/16” frame in stock, BUT I have frame on the front of my truck basically unused from when it had the engine driven pump.

 

[mrmikey]

From following this from day one and the way you've been talking about a 12' bed, I'd say go the 12' route. If you compromise and shorten up to 10' you're not going to be a happy camper and will regret not going 12' like you've wanted all along. It'll end up..wouldda.......coulda.... shoulda.

 

[Hay Dude]

From following this from day one and the way you've been talking about a 12' bed, I'd say go the 12' route. If you compromise and shorten up to 10' you're not going to be a happy camper and will regret not going 12' like you've wanted all along. It'll end up..wouldda.......coulda.... shoulda.

I know but…………4 GRAND is a lot of kabbage!

 

[Hay Dude]

The front piece of frame is not long enough.

 

[mrmikey]

I know but…………4 GRAND is a lot of kabbage!

Yup 'tis.... but is it gonna be more than $4k in aggravation LOL.

The front piece of frame is not long enough.

Ohh ffs . It wouldn't cost a whole bunch to have a couple pieces bent

 

[Hay Dude]

So what’s the opinion on cutting the bad piece out and butt welding an 18” piece on the outer back frame? No biggie with a double frame?

 

[mrmikey]

No biggie with a double frame?

No biggie in my books as long as it's done correctly. That 18" takes in the three bolts from the spring stop? You can catch the single existing bolt hole to bolt thru for the original frame and the spring stop will catch the add on piece.
Careful placement of either the mounts for the subframe if you end up using one, or careful placement of the guides for the body will help reinforce it as well

 

[Hay Dude]

I was planning on cutting roughly here
Just the outer frame. Inner should be fine.
All the spring hanger bolts would hold it, plus the weld, plugs the rear crossmember.

 

[civilian]

What if you went with that 10ft box for now. Don't shorten frame, just mount box at back of frame leaving 2 extra feet at cab. Keep looking for 12ft box. If/when comes available, buy it and install it on your 12ft frame. Just move hoist ram accordingly to fit 12ft box. Just my dumb thoughts. Jon

 

[mrmikey]

I was planning on cutting roughly here

Yup, better place than I had thought of. You've got the spring stop on the original frame and the perch on the new.
It looks as if the frame extension from the front would work, how much too short are they, can't be a heck of a lot. Although I 'spose an 1" or a 1'..if it's short it's short.

What if you went with that 10ft box for now. Don't shorten frame, just mount box at back of frame leaving 2 extra feet at cab. Keep looking for 12ft box. If/when comes available, buy it and install it on your 12ft frame. Just move hoist ram accordingly to fit 12ft box. Just my dumb thoughts. Jon

It's a viable option, a lot of work tho

 

[Hay Dude]

The shop can take 5/16” and bend it. I have to look at my overall budget, but if I went with a new 12’ I bet I’m looking at 18-19K. The leftover 10’ more like 15-16K.
I have some other farm tractor and attachment replaced expenses, so I have to be careful and think this through.

 

[Hay Dude]

What if you went with that 10ft box for now. Don't shorten frame, just mount box at back of frame leaving 2 extra feet at cab. Keep looking for 12ft box. If/when comes available, buy it and install it on your 12ft frame. Just move hoist ram accordingly to fit 12ft box. Just my dumb thoughts. Jon

Not dumb, but that would be extremely expensive. I want to do this just once and get it behind me. Too much time invested in buying things, shipping, mounting, etc.
I have another piece of equipment we are trying to fix that could be $2,000 or $10,000. We don’t know yet. Once I know, I can finish the truck.

 

[4570Man]

I’m not following everything you say, but do you mean buying a dumptruck bed with a subframe?
Wouldn’t that mean a scissor hoist instead of a tele hoist?

Don‘t have a problem with that type of hoist, but always thought they were inferior.

I don’t understand fully the rest of what you speak of with the cheek plate….
Will adding a typical pintle plate help strengthen? I think so, but wanted to mention I plan on doing that too

Scissor hoist only get a bad rap because they’re typically too light duty. Powering them with battery pumps doesn’t help. The beefy ones like the one in the middle of this picture are the best ones available for a single axel truck.

 

[mrmikey]

Scissor hoist only get a bad rap because they’re typically too light duty. Powering them with battery pumps doesn’t help. The beefy ones like the one in the middle of this picture are the best ones available for a single axel truck

I've never liked them because of the massive amount of force pushing almost parallel to the length of the body until it's partially up. Look at the size of that cylinder in the second from bottom pic, 10"± or so diameter. For the sake of a couple of degrees, when that loaded body is down, its almost totally horizontal, the mechanical force pushing back when the body is down must be unreal.
I'll take a telescopic cylinder any day over that kind of a setup, that's just my opinion and the experience I've had with them LOL. As the expression goes, opinions are like a$$holes, some stink some don't .

 

[4570Man]

I've never liked them because of the massive amount of force pushing almost parallel to the length of the body until it's partially up. Look at the size of that cylinder in the second from bottom pic, 10"± or so diameter. For the sake of a couple of degrees, when that loaded body is down, its almost totally horizontal, the mechanical force pushing back when the body is down must be unreal.
I'll take a telescopic cylinder any day over that kind of a setup, that's just my opinion and the experience I've had with them LOL. As the expression goes, opinions are like a$$holes, some stink some don't .

I never liked dog house built in the front of the bed of my last truck. It made loading logs hard and it’s also where dirt would start sticking the worst. A telescoping cylinder provides zero sideways stability to the bed and the whole job falls on the bed pins where a scissor hoist helps with stability. My current truck has duel telescoping cylinders mounted half way down the bed without a buildout in the top side of the bed. It works but it can’t dump the bed as steep as other options could.