Hi. I have to replace a roller of my boat trailer. I already bought a matching roller and was ready to replace it: then I found out it wasn't a bolt holding a bar that goes through roller. Some kind of round cap-looking thing was on the ends. Will someone help me how I can replace a roller on my boat trailer? The trailer says "Tee Nee" and I believe it is the maker of it. I have 21ft boat on it.

Felk list their larger roller trailers here. That may have the info you need

http://felks.com.au/trailer/multiroller-trailers/

Almost all trailers use the same wiring. White- ground, brown-running lights, and yellow and green for the turn/stop lights. I hesitate to say which is left and right. Here in Florida it is one way. The trailers I have had sent down from the Midwest are the other way. Not hard to test and match to your vehicle.

Since your boat is fiberglass, you can use either rubber rollers or red soft poly rollers. Aluminum boats can use rubber rollers as well as blue hard poly rollers.

I wouldn't recommend purchasing a boat trailer that has issues with rust.While you may get a good deal on it now, you will more than likely end up needing to replace it much earlier than you'd like to.
One more thing, check that the hitch on the trailer is tight so that you can haul your boat safely. You don't want to be causing any accidents while driving with your boat in two because your boat has detached from the trailer.

I did same reciently for a Nolex 25. Easiest is to measure and copy someone else's trailer.
Would suggest putting boat on the hard , measure the width between mudguards on your trailer ( you want the boards as close to the guards as you can) halve your number , measure same out from centreline of yacht and up to hull from ground. Transpose measurements to trailer.
Hardest part is guessing the correct balance point ( distance from centre of axles to winch) this is so much easier if you have one to copy.
Try to leave everything adjustable in order to tweak once your boat is on the trailer.
Remember the centre rollers need to carry most of the weight, not the boards.

Different states have different laws. In states that charge trailer plates by Weight, you need to pull the Trailer over a scale and show the weight receipt. If the Boat has to stay on the trailer, pull both and subtract the weight of the boat from the total weight. You can find the Boat weight online.

In states that charge a flat fee for Trailer plates, its much simpler. You can also go to a Vehicle Registration center and get a form for the registration. But you need to call ahead to find out if Police or Highway Patrol can verify the Hull# or Trailer ID.

I have some tips I learned from finding a trailer for my 27 foot cruiser. Really, you can find deals in this economy that make rigging a trailer from scratch too much work.
You need to find the loaded weight of your boat and where the hull needs support from Carver. Your trailer needs to hit the "Chines" correctly, meaning the bunks have to be adjustable to the contours of the hull.
The bunk supports can fit outside, inside, or on top the frame rails Mine started on top of the rails and were converted to the torsion axles, requiring new supports.

The axles need to support enough weight and State laws will say how many axles need brakes. Your choice of electric or hydraulic. The bunks should be made of Cypress, but synthetic decking could be cheaper. Your tires should Load rated D or better and 15 to 16 inch wheels, not 14 inch because of the weight.

There are numerous Boat Salvage yards listed online.
There seems to be a "thing" about the region the boats are used. Some places have orphaned trailers everywhere and others are always married to a trailer.
I have seen Boatyard liquidations with ridiculously cheap trailer prices. Use the internet and look.

I had the same problem with my 2002 Silverado last summer when I first bought my boat and was getting the trailer ready to go. Like an idiot, I rewired the boat trailer on that side before I decided to look at the owner's manual. The pickup has separate fuses for right and left side of trailer. They're located in the big box in the engine compartment. I replaced the 10 or 15 size fuse and haven't had a problem since. Hope this helps!

Float on style trailers are designed with immersions depths and vertical guides to allow the boat to be driven onto the trailer. But not at full throttle, only enough power to move the boat over the bottom rollers/guides. Some trailers are designed to have the boat winched onto the trailer. For this style, you drive to boat to a starting point and then use the winch to pull the boat the remaining distance. These sometimes have a release mechanism and hinge/pivot point to allow the back of the trailer to drop below the normal towing position to make recovery easier. As the boat is winched into position, the weight of the boat will cause the trailor to pivot and return to the towing position.

Float on style trailers are designed with immersions depths and vertical guides to allow the boat to be driven onto the trailer. But not at full throttle, only enough power to move the boat over the bottom rollers/guides. Some trailers are designed t