Clunking mechanical overide brake unit.

[Paikea]

Another question for Huey and any others with experience of mechanical over ride brakes.. (Gee we make use of the experts on this site)

My trailer coupling is extremely noisy. It clunks when going over bumps and when slowing down. Drives me nuts!

The coupling is the standard mechanical over ride unit, the bar is a Hayman Reese.

The square part of the actual tongue that carries the towball is a little loose in the square receptacle part of the bar. My last 4WD had a nut welded onto the bottom of the square receptacle which held a bolt that could be tightened up to take out any up and down play. Nothing like that is fitted to the current bar.

Question; is it ok to weld a nut on the bar and take up the slack in the square bar that way?

Also, could the noise be coming from too much play in the coupling. I have never seen one pulled down but I understand that there is a cylinder in there that compresses when the trailer moves forward under braking. The noise is worse when braking.

Thanks for any help.

Cheers

Paikea

[VViCKiD]

Hi Paikea,

Mine seems to do the same. But when I slow down REALLY slowly, it doesn't seem to happen to me.

I always thought that was the norm (only had my boat for a year).

Has this only started happening recently ?

Cheers

[Crossfire63]

I would strongly advise against doing any welding on the bar unless you've got a Tig Welder or use hydrogen free rods as it may cause Hydrogen embrittlement at the site of the weld which will later crack.

There isn't a cylinder inside the coupling, rather a large spring which may be weak or broken.

Make sure the coupling is correctly adjusted to the ball by backing off the lock nut on the top of the coupling and tightening the locking screw.

Make sure the cable on the brakes is correctly adjusted, you may have too much play in the cable

[Fab1]

Agree with crossfire, you can also use shims to take some of the slack up from the tongue or drill and tap some holes with a bolt.

You can also use steel wedges hammered in to take up the slack.

Sent from my GT-I8730T using Tapatalk

[Crossfire63]

Or another alternative if everything else checks out OK, if it bothers you, if you know a handy machinist (like ME) he could hard face the tongue on the goose neck and then mill it down so its a snug fit into the bar.

Also climb underneath and make sure the bar is correctly tightened to the frame. Done quite a few repairs to frames caused by poorly fitted and maintained towbars

[Paikea]

Thanks all, I will pull the coupling apart and have a look at the spring. That would seem to be the best place to start.

Cheers

Paikea

[Flickn Mad]

Crossfire has it covered, my trailer brake cables were stretching due to flex in the trailer when tilted up for storage. the override would then travel full length and not bring the brakes on hard enough. if you pull the manual leaver up to activate the brkes and measure the distance from the back of the lock nut to the leaver and compare that distance to the travel available at the front end it should give you an idea of how much if any cable adjustment is needed. I hope this doesn't sound like jibberish.

[grandad]

If it's an old female coupling, it may be a 2" fitting, and will rattle with a 50mm ball.

[Paikea]

Hi Grandad.

Checked the ball and coupling today. Both 50 mm.

Holding the tongue I can rattle if from side to side and backwards and forwards. I have one of those locking pins and I don't think they are as close a fit as the one supplied with the bar. Will change the pin back to the original to start with.

I do believe that the square part that goes into the bar socket needs building up at both ends. Problem is, even a little bit of corrosion and its impossible to get the square part out of the bar without a big hammer and a lot of effort. (been there, done that)

I don't like shims for reason that they are unlikely to stay there. Rather build the square section up.

I like your idea Crossfire but you are a little far from Cronulla. However I do know of a local guy who does a lot of Tig and Mig welding so he should be able to do it. What type of welding wire should he use?

Thanks all, much appreciate your input and advice.

Cheers

Paikea

[Crossfire63]

Just a standard wire for mild steel. He'll need to check the female side with a set of bore gauges to make sure its square. If its worn or flogged out there's every chance it won't be square.

i then build the male section up to 1mm O/S on all sides and then mill it back with a 50mm face mill bit to .25mm clearance all over which will give you .5mm clearance tapered to the dimensions of the female section. I also redo the hole for the locking pin to the correct size.

Its a bit of mucking around, but cheaper than a new goose neck, also a new goose neck will only improve the situation marginally if the female side of the bar is severely worn

[Paikea]

Thanks Crossfire, your advice is much appreciated.

Cheers

Paikea

[Paikea]

if you pull the manual leaver up to activate the brakes and measure the distance from the back of the lock nut to the leaver and compare that distance to the travel available at the front end it should give you an idea of how much if any cable adjustment is needed.

I could not find anyone who would do the welding/machining as suggested by Crossfire so I ended up welding two nuts each on the bottom and one side of the square tube (after drilling holes to allow the bolts to go through onto the gooseneck) fitted the bolts with lock nuts and screwed them tight which stopped any up and down or sideway movement. Hope that it stays that way when we do a few K's.

Also fitted a new coupling/override breaking unit from Alco, rated for 2000Kg it should remove any rattles from the coupling.

Now for the $64.00 question? What should the gap between the back of the override brake rod and the actuating lever be?

I have adjusted it so that it is approx 50 mm, is that aok or should it be greater?

I think that I have done all that I can to remove the rattles/shocks, will find out when I take the boat to Ulladulla after Easter.

Cheers

Paikea

[Flickn Mad]

I hope I make some sense here, The length of shaft between the coupler( part that goes on the towball) and the body (the block that is bolted to the trailer)has to longer than the gap between the back of the large nut on the back of the shaft and the actuating lever when the leaver is pulled on hard( the hand brake position)

If this is not set up correctly the coupler will contact the block under braking causing reduced breaking and a thud felt through the tow vehicle as the coupler impacts the block.

My suggestion would be to have as little as 10 mm gap at the back of the nut to the activating leaver when the brake is off and the trailer hooked up to the car.

I found out the hard way that my trailer flexes when stored propped up at the front, stretching my break cables to the point my breaks were running full stroke without any effective breaking.

Take note, I am presuming your over ride breaks work the same as mine.

I hope this is off some help and makes sense.

If in doupt a quick break test on a back road may be a good idea before u hit the way free.

Edited April 15, 2014 by Flickn Mad

[Paikea]

Yep, I understand, will check it out tomorrow.

Cheers

Paikea