Towing boat behind 5th wheel

[Brian_Shack]

I am biulding a hitch to tow my 23 ft jet boat behind my 24.5 ft 5th wheel.my boat and trailer weighs 7100lbs. I don't know the tongue weight but I can't lift it and it is very heavy. I thought of extending my boat trailer tongue a few feet but my neighbours thinks this will increase tongue weight? Thoughts please. I can't move the boat back farther on the trailer as this puts too much weight on the rear axle of the boat trailer.

[miked101]

FYI having the heavy vehicle behind the light one is a recipe for trouble.you will tonight that you heavy back trailer will cause you some fishtailing especially in bad weather

[tegu69]

Here you go.
http://www.youtube.com/watch?v=32kK7lQZSks

[Brian_Shack]

New controller installed $607.00 no improvement. Grr

[Brian_Shack]

Tried the close adjust didn't work. Went through everything again still nothing. Pinned another truck to it same year and model everything works fine. Ordered new integrated brake controller from ford be here tommorow.

[RAS43]

Since you mentioned new backing plates I assume you installed complete assemblies. There is a left and right assembly as well as front and rear brake shoes.
Another thought-you mentioned setting the shoes to just touch the drums. They may be too loose. I adjust until I can't turn the drum and then back off 5 clicks. That results in some drag on the drum from the shoes and my brakes work fine.

[Brian_Shack]

Drums but not self adjusting. All new all inclusive backing plates out. Set up so the shoes are just contacting the drums still no good. Ran a jumper from truck to trailer frame and from truck to trailer pin no change so I don't think it's a ground?

[RCMAN46]

I recently did brakes on my 5th wheel. The brakes were weak until I had put a couple hundred miles on the trailer then they were good as ever.

When braking in the new brakes be careful that you do not over heat them. Several high speed heavy braking for 5 seconds at a time with a cool down time between braking events.

This will wear off the high spots on the brake shoes.

[da_bees]

Assuming the 5er has drum breaks.
Due to "lack of exercise",self adjusters often fail to keep linings tight on all 4 wheels. Raise one wheel at a time and adjust breaks like we did before cars had self adjusters. It is also common for hold-down pins to break causing no breaking on that wheel.

[Brian_Shack]

Hitch is done pull a ken worth if needed. 5 pack springs using 2 mains from old set and 3 new. Re arced old 2 in hyd press. All new brakes and 10 ply tires. Now I can't get the brakes to work properly. The brakes are there but soft. Set them up regrounded no go. Hooked my stock trailer and I can lock up all 4 so it's not the controller. Any suggestions?

[Shadow_Grey]

My dad tows it to South Georgia every winter (Lake Seminole)...Last year he got out a little late obviously. This year he has a new 2014 Dodge 3500 to pull it with. My brother and I built the hitch for him

[P_Kennedy]

I tow a 23.5ft boat behind a 31ft 5th wheel and it pulls fine even though we are over length in Alberta. It sounds like you have river boat and the axles on the boat trailer are farther back than most which is good for towing. If it tows good behind your pickup it will be good behind the trailer. The welder can build a properly supported hitch frame which will add weight to your trailer but I think your running gear is going to be too light in the end. The added weight to the rear of the trailer is going to reduce the vertical weight on your kingpin.

[Brian_Shack]

Today went from 3 leaf to 5 leaf spring pack. 225/75/r15 load range e tires from the stock 205/75/15 load range d. 8"channel frame going to build hitch back from wheel centre, cross braced. Neighbour has built trailers for 30 years and has build a hitch to haul his 32' ocean boat with 5ft extended hitch behind his 13 ft camper does nice work and he is going to design and help build with me. He tends to overdue everything he builds. If you want to tow a ton he builds it to tow 25 ton so I'm pretty confident in the hitch. Don't know like was mentioned if the hitch on the fw can take it all. That will be the weak link in the chain.

[pbar34]

Brian - I tow a 21' Sea Ray (5,000 lbs total for boat and trailer) behind my 5ver and my biggest concerns for your situation would be in the following order:

1. How the hitch weight is distributed along the 5ver frame. Should be a long hitch subframe to distribute this weight almost to the rear wheels of the 5ver frame.

2. The spring shackles (a.k.a. spring hangers). Specifically, the rear shackles will take a lot more lateral load with your heavy boat and trailer. The shackles aren't known to be a strong point towing solo, much less towing doubles. With a 7100 lb. load pushing them laterally in turns, I'd want to beef up the shackles.

3. Springs themselves. You may need to upgrade at least the rear springs to accommodate the extra weight and twisting/lateral forces caused by the large boat.

4. King pin strength and overall frame integrity of the 5ver in this area. Lots of stories of cracked frames up in the king pin area. This is a scary failure since you can't easily inspect this before a trip and the failure will most likely be noticed while you are underway towing. With your heavy load and small 5ver, I'd be concerned here.

5. Hitch rating. You may be fine here with a 15-16K hitch already but its worth bringing up.

You are towing a large boat by single tow standards. In general, I'd feel a bit uncomfortable towing your doubles rig if the weather turns bad, high winds, etc. due to the high weight of your second trailer and the relatively low weight of the 5ver. But this is just my gut talking.


Good luck,
Phil

[laknox]

tegu69 wrote:

Brian Shack wrote:
I guess I should clarify the boat and boat trailer weigh 7100 lbs. the 5th wheel is 6040 lbs empty

So the caboose weighs more than the middle of the train, beautiful.

You tow an empty FW? 🙂 Bet the weights are near-equal, when ready to roll. That's a heavy, boat, though, and the frame on the FW needs to be beefed up all the way forward of the front spring hangar, IMO. Upgrading the tires and springs are a good start, but the frame issue really needs to be addressed.

Lyle