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COE Class a p-30 motorhome frame question

Discussion in 'Off Topic Hot Rods & Customs' started by Homer41, Mar 13, 2020.

  1. kscarguy
    Joined: Aug 22, 2007
    Posts: 1,612

    kscarguy
    Member

    Worst parts of my design are my battery location under the cab, and the fuse box behind the seats. Too hard to access either. Going to move them.
     
  2. Homer41
    Joined: Nov 19, 2019
    Posts: 103

    Homer41

    Thanks for the insite. Dave
     
  3. I think having the steering box outside the frame may not make a difference on a GM COE? I used a 1980 Chevy 2 ton stepvan P30 frame. I'm guessing that in a motor home, like a stepvan, you sit over the left wheel, so the column is off-set left of the box. So GM added a short dbl u jointed shaft to lean left from the box to align the column. So you should be able to use that same short shaft & lean it to the right to align with the column.
    If he will be widening the cab, that brings the column over a little closer also?
    I really like everything about using the 1980 P30 frame on my 1939 Chevy COE. The rails are 100% identical to my original 1939 frame rails. only difference is the front independent suspension & yes, the box is outside the frame.
     
    RMR&C likes this.
  4. Homer41
    Joined: Nov 19, 2019
    Posts: 103

    Homer41

    Hi Old School, I talked to you over on the bolt. What engine are you using? Will you have enough room to keep it in the original location? I am thinking of just widening the fenders. Dave
     
    Last edited: Mar 30, 2020
  5. RMR&C
    Joined: Dec 26, 2009
    Posts: 4,940

    RMR&C
    Member
    from NW Montana

    Thanks for your reply on the subject! We need someone with actual experience....
    I'm trying to help in a general sense, but my truck was built somewhat differently.
     
  6. Hi Dave, OK, this is a long version, LOL.
    I have a 1989 Corvette L98 motor & trans, but everything else is still 1.1/2 ton. I am doing some crazy stuff to my 39 build also. Actually I think it was 1941 or 42 that Chevy added a little more leg room in the Cab, just changing the floor a little, but Cabs are all the same from 39 to 46.
    Just by accident I picked up my frame not knowing that it was the best frame for my project. Not till I pulled my Cab off the 39 frame that I realized that the 1980 frame was 100% identical to my 39 frame rails. Just different front suspension.
    Here is were everything goes crazy, first I air-bagged the front. Then boxed the rear & C notched it 3" over the rear axle. Your frame rails are 7" tall, so boxing it & lousing 3" is still stronger than the open 7" frame. Then I added 4 air bags in the rear, 2 behind & two in front of the 1 ton dully rear end. Then I took the motor & moved it back just behind the front axle cross member & dropped it as low as possible to the ground, leaving 2" clearance from the ground when the truck is as low as it could go, just for safety. Now is were the first problem came in. Lowering the motor that low you will need to build your own engine / trans & rear end mounts lower also. They don't make mounts for this. Remember that the rear-end can not be higher than the trans, going down the road. I also added 4 link rear suspension.
    Your cab sits on a 10" pedestal. I tossed the pedestal & made a sub frame, that hangs between the frame rails, not on top, & it's hinged in the front so the cab tilts all the way forward. My back Cab mounts are 4" tall putting my floor 4" higher then the frame rails. The motor is far back enough that I was able to lay the radiator down in the frame in front, giving clearance to miss floor when tilting forward. " I still have the original floor " Now the suspension, the cab & the radiator is in.
    Next, I'm hoping your motor home ch***is had hydro boost brakes? My step van did & that will be the best & easiest brake system to use in a COE. The master cylinder/hydro boost will mount length wise on your 41,s firewall just like on the motor home / step van as mine was on. Every bit of the system all the way to the swinging brake paddle. You will use everything, the dash support brackets you will need also.
    Brakes are done, now for the steering. If you are keeping your cab on the pedestal above the frame you should have plenty room with a short U jointed shaft bringing the linkage back over the frame rail to meet the steering column.
    If you plan on going the rout I went, all bets are off, LOL. Still using the hydro boost, because of my Cab tilts, I have to change the master cylinder to a remote filler style, putting the brake fluid canister through the firewall & mounting it under the dash. The Cab has to be down to check the fluid, LOL.
    Also, because my Cab is lower & much closer to the frame rail, my steering box is only 4" under the front corner of the floor, "I still have the original floor" & because the Cab tilts, the column & linkage must follow the Cab. I am using parts of the original short column shaft for that application also.
    I am probably giving you to much info, not knowing what way you plan on setting up your drive train. I needed to get my Cab as close to the ground as possible. I'm 65 & with a left prosthetic leg & knee. So my bottom step is 2" off the ground, making it easier to climb up in the dang think, LOL. Then I can air it up to go.
    I also did a few other crazy thinks. My wheel base is only 101" now. Shorter than a Dotson PU. I am putting a removal goose neck trailer ball in the middle of the bed. With 10,000 lb of air suspension in the rear & dully wheels, & 5,000 lbs of bags up front, I want to be able to haul an old goose neck trailer some day.
    Dave, look at my photo album & you will see some of the stuff I'm doing...
    Darrell
     
    Last edited: Mar 31, 2020
    vintage56 and RMR&C like this.
  7. Homer41
    Joined: Nov 19, 2019
    Posts: 103

    Homer41

    WOW! Amazing! I don't plan on going to that extent! Great info and thanks again! Dave
     
  8. Dave, there are plenty of ways to go. Widening the Cab & narrowing the fenders seems much harder than anything I would tackle. You could go front wheel drive. To me that would be the coolest car hauler. Air bag it & you won't even need ramps to load your cars on. You need room for the long legged kids, add a sleeper & cut the back wall out & the sleeper becomes your back seat. That will also give you more Cab room for your legs. Then you can move the motor under the sleeper & you have the best of all worlds.
    I checked out other COE's on the Internet for over a year before I knew what I wanted to do. It has been about 7 years now & I can finely see it getting close, maybe a couple years more, I'm very slow. I also have never done anything like this. I had to learn to weld & I have had no help with ideas or weather my ideas would work. So many of my ideas had to do over once or twice. It's amazing but once I do something wrong, I can see the right way to do it, LOL.
    If you spoke with me before on this subject, I probably advised you to purchase a running driving donner, set your Cab on the ch***is & the hardest part is done. A GM step van, like a big bread truck or moving van, or UPS type truck would work perfect. You will save money & time in the long run, & replacing worn parts is much easier to order years later when you forget what the worn part came off.
    Good luck & just have fun building your dream truck... Darrell
     
  9. Homer41
    Joined: Nov 19, 2019
    Posts: 103

    Homer41

    Thanks again Darrell!
     
  10. Ha Dave, Getting the Cab to tilt properly, it mostly depends on were you put the hinges. As the Cab tilts forward, anything lower then the hinge will tuck under & go back toward the tires as the Cab goes up. Because my truck sits so low, my hinges had to be the lowest thing that moves. My bumper had to be mounted to the hinge also & it sticks out past the hinge & fender so it had to be ****ed in as close as possible. My bumper is tucked just under the grill closer to the fender than the grill it self.
    A lot of the problems I am dealing with, you won't have. Having my Cab so low in the frame, the fender is just 1/2" in front of the steering box. I wish my Cab was still 1" farther back for the wheels to be centered right. If my Cab was higher in the frame it could go back more. Also, all the wiring, the brake lines, fuel lines hydraulic lines & anything else that goes up to the cab must go all the way forward in the frame & be able to flex & have extra to shift as the Cab goes forward. I have no room because my Cab is so low & close to everything. I also had to find the narrowest radiator I could find. I have 1/2" clearance so the Cab can tilt over it. Even if you don't want to go tilt, you may need a narrower radiator than is in the motor home? But you don't need to worry about having room in front of the motor for a radiator. As I said earlier, the 1985 P30 frame rails are identical to the one under your 41 COE.
    If I had kept my Cab on the original pedestal & not wanted it to tilt, everything would have been an easy transfer from the newer frame to my 39 Cab.
    Things like the radiator & master cylinder, first I made a cardboard box the size of them to make sure there was room before & drilled holes or made brackets. If you get A running driver donner truck, you will have no problems.
    "Let me correct my self", I used a step van frame, I don't know if thinks like the steering box were moved on a motor home?
     
  11. Homer41
    Joined: Nov 19, 2019
    Posts: 103

    Homer41

    Wow, lots more things to think about, thanks for the help. Dave
     
  12. Dave, years ago I spoke with a COE builder in LA that said he used to use P30 truck donners, but he switched to Isuzu trucks for donners. I didn't look into it because I like to stick with all GM. But he also looks for drivers as donners.
     
  13. Homer41
    Joined: Nov 19, 2019
    Posts: 103

    Homer41

    I want to stay GM also. Dave
     
  14. I had a 1990 Isuzu NPR. Its track width was way to narrow for my Autocar. Dodge pick-up was just right.
     

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