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Message |
Geobus (4108gmc)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Wednesday, November 24, 2004 - 3:55 pm: | |
After many days of looking at my coach, I agree, there is no good way to build a heavy duty hitch. So I intend to go a little overboard on a lighter duty hitch, just in case I have a bigger load than expected--leaves a little room for error.
This is the best I came up with and plan on installing it in my GMC 4108 this long weekend.
Since I don't think it is a good idea to tie directly into the bulkhead, for each side of the coach frameI thought I would try to make a frame extension that drops down from the upper coach frame, behind the bulkhead. To do this I would start by installing a vertical 2x8 channel iron that is side bolted to the rear of the upper 5x8 coach frame, since my muffle is now back by my engine. To give it support I indtend to put a support at about a 45 degree angle, which would mount on the 2x8 at about 20 in. below the upper coach frame and mount on the upper coach frame at about 20 in. infront of the rear bulkhead, making a right triangle. In addition, the bottom of the 2x8 drop would be bolted to the bulkhead, next to the cradle mount. I think the 2x8 iron with the bracing would likely take the push/pull for a light trailer, mounting to the bulkhead gives it a little more support.
To get to the hitch from the 2x8 drop, I plan to use 2 in. square tubbing that basically follows the engine cradle support. However, to stablize it at the bumper I will need to fasten to the rear of the cradle or the bumper's subframe.
Its likely an overkill but hopefully it will minimize the push and pull on the engine mounts on the bulkhead and on the lower radius rods. It looks like the lower radius rods could handle it but on my setup there doesn't appear to be any good way to fasten into the lower radius rod brackets, without possible corrupting them.
As always, thanks for the help.
Have a great Thanksgiving. |
darisb
Rating: N/A
Votes: 0 (Vote!) | | Posted on Wednesday, November 24, 2004 - 4:19 pm: | |
Check out the hitch on my 4106. The URL is http://www.freewebs.com/darisb/4106/hitch.htm
Regards,
Daris |
Gary McFarland (Gearheadgary)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Wednesday, November 24, 2004 - 4:25 pm: | |
Do you have any good pics of the engine cradle area?
Hint: When describing something like this, I use the terms "Fore" and "aft", so a place that is closer to the front of your bus from a certain point of reference is "Forward". So our frame location is "Forward" of the bulkhead (Not behind).
Although you will want a diagonal brace, you are going to have more problems with lateral loads, but a horizontal crossmember between your verticals should do it. 8" is way overkill (also, there is no specific flange size in channel, but rather a weight rating). I would use 12# (Twelve Pound) 6" channel.
I would (Did) get a commercial hitch and make your extension frame fit the commercial hitch.
I would use the 6" heavy channel for everything.
Sure would be nice to see a pic.
Gary |
John that newguy
Rating: N/A
Votes: 0 (Vote!) | | Posted on Wednesday, November 24, 2004 - 10:16 pm: | |
What do you plan to tow? |
Geobus (4108gmc)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Wednesday, November 24, 2004 - 11:10 pm: | |
To Daris:
Thanks again. I have looked at your setup a few times. My lower frame is a
little different so it is a problem fastening in front of the bulkhead.
To Gary:
Thanks for the response.
The 6 inch sounds a lot more user friendly. I guess I was also thinking of
trying to beef up the bulkhead a little.
Often you hear stories how they could use a little more support. As I get a
little further, I will take a photo and send it off for you to see.
To John that newguy:
For now I would like to tow my small trailer. It is under 3000 lbs, probably closer to 2500. Its TW is about 100 to 200 lbs. Maybe I am underestimating it but I am not too worried about the small trailer. However, someday I would like to use my 17 ft trailer with dual torsion bar axles. It is rated for 10,000 lbs but I never had that much on it. I don't think there is any good way to extend the frame on the coach to take a load over 5000 lbs. So the hitch I am building is being built for loads less than 5000 lbs and TW of less than 500 lbs. If I wanted to go over that I think I would install a "Tuff Tow" wheel assy. on the front of the 17 ft trailer to keep the TW below 500 lbs. I am guessing the vert. drop with the 2x8 steel is an overkill but it appears that it will fasten nicely to the upper frame member of the coach and butt up against the front of the bulkhead. This way I can also bolt it to the bulkhead for additional support.
Thanks and have a great Thanksgiving. |
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