March 26, 2006

By: Mark Harris
Website: http://www.bearing-n-bearings.com

Boat trailer wheel bearing steel bearings maintenance & preparation for new season

The Frostbite season will soon be ending in late March, so April is an ideal month to prepare your boat for the next sailing season. I will break down the different jobs into 6 areas so that you allocate sufficient time to each job spec:-

Road Trailer & Launching Trolley

Many of us forget where we leave our road trailers from season to season not to mention proper examination of tyres, bearings and moving parts. Many of the trailers I have seen over the years would not pass an N.C.T. if there were such a test for trailers. It is illegal to tow a defective trailer and since a trailer is considered as part of the car when towing it could invalidate your car insurance in the event of an accident.

You should spend a complete day checking the following:-

Tow hitch:- make sure that the moving parts are free and the hitch closes correctly when it engages the car’s tow bar. Free any moving parts with Rocket WD40 and if it continues to stick spend some time taking the hitch apart and thoroughly cleaning the rusty gunge and grease with sandpaper and white spirits, regrease and reassemble. Ensure that the 2 bolts securing the hitch to the trailer are not loose and if badly corroded replace with a sharadised or galvanized set of nuts, bolts and washers. As a precaution you should consider attaching a chain and metal circular loop to the trailer so that in the event of hitch failure the trailer does not separate from the car. Most modern trailers have this device fitted.

Stress cracks:- The trailer should be examined for any hairline cracks at the weld and stress points and be immediately repaired by a competent welder and primed with galvanizing paint. Pay particular attention to Rapide trailers back extensions, which are prone to cracking due to their close proximity to the road. This should be checked after every long journey.

Bearings:- You should examine the bearings of each wheel by jacking up each side and rotating the wheel quickly with both hands. The wheel should rotate freely and should only stop when it gradually loses it’s own momentum. If you hear a slight rubbing or grinding noise it is time to replace your bearings. In any event the bearing assembly should be dismantled and thoroughly cleaned with white spirits or grease detergent and checked to see if there has been any wear on the bearings or marks on the axle. Before reassembling, check to see if the innermost gasket has worn and replace if necessary since this is where most of the lubricating grease escapes. Remember that fast rotating bearings with no grease will overheat and become so hot that they will seize which will result in the wheel shearing off. Regrease and reassemble the bearings. When tightening the castle nut, do not over tighten the assembly; you should only tighten just enough so that when you shake the wheel from side to side any play has stopped; you should then loosen the castle nut half a turn (this is the correct play achieved on the wheel after doing this) and insert the split pin into the castle nut. After 5/10 miles towing see if the wheel play has increased; tighten the castle nut quarter/half a turn so that the slackness is similar to when you first assembled the castle nut and released it by half a turn. This is required to allow the bearing assembly to bed in. You should have a hub dust cover for each wheel and when you have assembled the bearings squirt grease into this cover and attach to the hub, additional grease can be forced through the grease nipple with a suitable grease gun. It is important to keep dust covers on the hubs since it will eliminate the risk of grit, debris and water mixing with the lubricating grease, which will cause damage to the bearings. You should always carry a spare dust cover and set of bearings, can of grease and split pins in your kit bag.

Fitting bearings is a skilled job and the D.I.Y. saving is negligible when one compares getting them professionally fitted by a company such as Blackrock Trailers who provide an excellent service.

Suspension: Most trailers have indespension units fitted while a few of the older type have a torsion bar. It is not exactly a clear science when these should be replaced since they are a sealed unit. You should jump up and down each side of the units and ensure that there is sufficient up and down movement so that any uneven road services will not result in the suspension units bottoming out. They should last at least 10 to 15 years and a replacement pair costs approx. £60. There are about 6 different load ratings so make sure you purchase the correct type to suit your all-upright boat and trailer weight.

Tyres: The best size tyres are the 20" 4 ply variety; they rotate at slightly more speed than the average car tyre and have the same 4-ply rating and do not overheat. Most of us have the 16" variety that rotate at twice the speed of the car wheel and frequently overheat and blowout. If you have 2 ply tyres, throw them away and replace them with 6 ply. 2 ply have a speed rating of 30 mph while 6 ply have a much higher speed rating you should never park tyres on grass for a prolonged period since the acid in the grass will perish the rubber. Check the tyre for wear the same as you would a car and most trailer tyres require to be inflated to 35 lbs but check manufacturers recommendation. Always carry a spare tyre and foot pump on a long journey.

Cradle: It is important to ensure that the cradle is correctly attached to the launching trolley; any loose bolts should be tightened since they have been known to puncture a hull when they come adrift. A large surface area cradle properly aligned to the shape of the hull will offer great protection since the load will be evenly distributed across the surface area of the hull. Remember that the pressure exerted on the hull when trailing can be as much as 140 lb per square inch on a poorly shaped cradle, this is similar to the Riverdance cast dancing on your hull and will therefore cause permanent damage. You should avoid using carpet on your cradle since the pile attracts grit and pebbles and will damage and scrape you hull. You should resurface the cradle with neoprene type material, which can be stuck with an impact adhesive.

Tying the boat down: You should consider purchasing a pair of ratchet tie down straps which are available in McQuillans of Capel St. at a reasonable price. Make sure that the webbing for these straps are at least 2" wide since they will spread the load evenly when tightened. Avoid using ropes to tie down your boat since they are prone to loosing and will chafe and damage the boat. Ensure that the boat continue to be attached to the trailer by attaching a piece of rope to the forestay deck attachment and tie the other end to the trailer; there is a tendency in fireballs to slide backwards when trailed so this will prevent this happening. Make sure that you have a tailgate light board with at lease 6 metres of cable; they only cost £20 in a motor factors. The only way of attaching this type of light board to the boat is with shockcord and it would be wise to make up a ¾" wooden board with a pintle and gudgeon for easy attachment to the boats transom. Some sailors while trailing prefer to support their mast at 2 points i.e. on the trailer mast support and at the tailgate while others keep the bottom of the mast inside the boat at the aft cockpit and the other end of the mast support. I have a tendency to prefer the latter option since if any fittings come loose on the mast they will fall into the boat rather than onto the road. If you prefer the first option you should put a mainsail sausage bag tied around the mast to avoid loosing fittings or purchase a customized mast cover.

About The Author:

Mark Harris is a successful author and regular contributor to http://www.bearing-n-bearings.com.  Keep things running smoothly with ball bearings, roller bearings, ball thrust bearings and tapered bearings.