Trailer porpoise while towing.

[beeker]

Need a remedy for trailer porpoise. Using extende cab chev.pulling single axle trailer with 3100 lb 185. Im second owner and boat has always been on this trailer and appears to be set up correctly. Boat extends about 8 inches past bunks at the rear. Does have room to move front roller/crank fwd some. Had dual axle with other boats previously and no problems. Does someone have a solution to this problem . Afraid strap is going to break or bunks split. Other note,good shocks on p.u. Thanks

 

[Westie]

Im second owner and boat has always been on this trailer and appears to be set up correctly. Boat extends about 8 inches past bunks at the rear. Does have room to move front roller/crank fwd some.

Having the boat extend 8" past the bunks is not set up correctly. The end of the boat should be even with the end of the bunks.
What is your tongue weight, it sounds like it may be low.

 

[beeker]

Thanks for the reply.not sure of tongue wt.,but will check. Is there a percentage of total wt.? Like 10%

 

[outlaw32]

need to have boat against front roller. So need to understand tongue weight like stated below and adjust boat and front roller so boat is against it.

 

[Lazy Daze]

If it's the trailer that came with the boat from Sea Ray, the transom should NOT be sticking out past the bunks. If you have the bow eye snugged up tight underneath the roller (should always be tight), then something has been changed. As Westie said, too much weight aft (which provides too little tongue weight) will cause swaying. I assume you mean swaying (left to right), not porpoising (up and down). However, very, very little tongue weight can also cause bouncing on the draw bar.

 

[beeker]

No, trailer pulls with no sway at all But porpoises up/down front to back when you pass over a swell or dip in road like at an intersection crossing at 50 60 mph on two lane road

 

[Lazy Daze]

Most likely, you're just keeping the speeds low enough and haven't experienced the sway, yet. Or, there's "just" enough tongue weight to limit the sway. It's a pretty normal thing, though, to experience (and the porpoising) when there isn't enough tongue weight.

 

[beeker]

Going out this w/e ,I'll ck the tongue wt. ,and adjust boat
further onto the trailer and re- ck tongue wt. Thanks ,all info is greatly appreciated

 

[Cincy Aquaholic]

Depending on the number of axles you should have 7-10% as your tongue weight I believe. I have one of these weigh safe hitches because i tow alot and use a cargo trailer for hauling my RZR and gear and I like to make sure the weight distribution is right..

https://www.weigh-safe.com/

 

[GJarrett]

+1, tongue weight too low. Needs to be 7%, up to 10% okay with lighter boats and tow vehicle capable of handling the tongue weight.

 

[NotHerDecision]

I was also told 10-15% tongue weight. Keep this in mind as well. I think it's probably a lack of tongue weight but it could be worn rear suspension on your truck.


Sent from my iPhone using Tapatalk

 

[GJarrett]

I also grew up using 10-15% as a guide, but that was for much lighter trailers than the boat/trailer I am currently hauling. Our boat did not have a trailer when I went to buy it so I had a trailer custom fit for it to tow it home. The guy who set up the trailer had something like 30+ years experience and set it for 7% tongue weight. I had a lengthy discussion with him about that, but it does make sense for heavier trailers. My boat is 6,500 lbs on the trailer; 15% would put a half ton tongue weight on my SUV which there is no way I would be comfortable doing that. I've now towed for four years and several thousand miles and at 7% it behaves wonderfully and has never even begun to try to sway.

If the OP has a 3,100 lb load I agree 10-15% will work just fine. No way the boat should be hanging off the bunks like that; move the bow roller up to allow the transom to line up with the bunks and it will probably fix the problem.

 

[beeker]

Thanks guys will move roller ,adjust boat and ck tongue weight. I'll let you know.

 

[Leardriver]

My complaint with single axle trailers is that they are noticeably more bouncy.

 

[Espos4]

I agree with the heavier tongue weight. That is a relatively light boat for a full size pick up truck. 15% will give you 450 or so lbs on the tongue which can be easily handled by your truck.

 

[beeker]

I agree with the heavier tongue weight. That is a relatively light boat for a full size pick up truck. 15% will give you 450 or so lbs on the tongue which can be easily handled by your truck.

 

[beeker]

Took it out this past w/e, moved front roller
assembly forward when loading the boat
Bunks now end at transom
This increased tongueweight and improved towing. Thanks for everyone's input