Auto Reverse not working - Page 4

charliee · 03 June 2018, 08:09

I’m no trailer expert and have just played “spot the difference”. Part 6 looks different.
On the right hand end of part 6 there are 2 horizontal metal plates of different lengths. Alko show the shorter of the 2 in the upper position whereas you have it in the lower position in your photo.
I have no idea if it’s significant but it’s point of difference.

charliee · 03 June 2018, 08:19

Have you referred to The Sbs manual, it’s quite detailed and refers to the auto reverse function a lot
http://www.northernexposurerescue.or...e%20Manual.pdf

beamishken · 03 June 2018, 18:52

Looking at that picture and all the rust i think id invest in a new set of shoes that right hand side shoe looks like the lining is set to detatch at the top due to rust under the lining.
It also looks like the lining is not true to the shoe at the top
Id say new shoes strip and clean all the slipper assembly, make sure everything that should move does move and plenty of lubrication anywhere the shoes touch anything else

paintman · 03 June 2018, 22:28

Looking at the two pics you've posted & the relationship of the shoes position to the rim of the backplate.

The shoes on the Al-Ko pic. The bottom is near to the rim of the backplate & as you look along the shoe the gap between the backplate & the shoe looks like a nice taper getting further from the rim as it goes towards the top.
Your pic looks as though the top is much closer to the rim than the bottom & instead of a nice smooth taper there's a bigger gap in the middle.
Suggests either the shoes are wrong or the way they're set up is wrong.
It would be easier if you'd posted a pic of the same brake as the Al-Ko viewed square on so the two pics could be directly compared.

If that's black waxoil over the mechanism I agree with the post above about removing it & greasing it instead. Waxoil is good stuff but goes hard & isn't going to help slidy things slide.

Has auto-reverse ever worked properly on this trailer - either with the old shoes or these that you've fitted?

beamishken · 03 June 2018, 23:52

If you go back to post #5 at the start of the thread I think Pikey Dave hit the nail on the head

Pikey Dave · 04 June 2018, 10:13

Quote:

Originally Posted by beamishken

If you go back to post #5 at the start of the thread I think Pikey Dave hit the nail on the head

I think I might have a couple of sets of brand new shoes on the shelf in the garage + bearings, all surplus to requirements, I'm sure an arrangement could be reached[emoji6]

Jeff · 09 June 2018, 11:14

Did you ever resolve the issue Sargen ?

smallribber · 09 June 2018, 18:18

Part 6 is on the wrong way round

Also I think Dave got it right in post 5. If you have had them off so many times why not give then a good clean up and replace the knackered shoes

paintman · 09 June 2018, 21:21

Quote:

Originally Posted by Bigplumbs

Part 6 is on the wrong way round

?
The two pics are effectively mirror image & parts are oriented the same way in both - the thin end of Part 6 is one the same side as the adjustment wheel on Part 1.

Sargan · 09 June 2018, 22:18

Quote:

Originally Posted by Bigplumbs

Part 6 is on the wrong way round

Also I think Dave got it right in post 5. If you have had them off so many times why not give then a good clean up and replace the knackered shoes

Maybe you missed original comments ... it had had full service, complete clean of all components thorough clean of back plate, drum. Wash all old grease out of bearing, replace with new grease, new grease seals and then reassemble, and set brakes up correctly (in terms of show to drum gap.)

I have now replaced all the shoes ....

Reset brakes at least 1/2 doz times - even had guys who have like me had boats 30+ years check and they agree brakes set correct.

It is not fixed ........... so currently have to use winch to get trailer up my drive.

I had a Qualified Engineer come take a look ....... he seems to think that the brakes are applying finer in FWD (I agree) and when they go backwards they start applying as soon as coupling moves the 'S pawl' (fixed to brake rod) but instead of the brakes tripping out with rear movement the coupling continues its movement and applies so much pressure when reversing up hill the brakes will no trip.

When reversing up drive the weight is fully on back axle only.

We have tried putting play in rod to change the point at which is starts acting on Bowden cables ... but even with 75mm of play brakes still lock on.
With that much play the rod is sagging badly, and would rattle terribly.

As a reminder the 3 x Al-Ko set up guides and Indespension manual all state after adjusting shoes, with coupling fully forward (brakes not activated) rod should be adjusted to have zero play.

Best thought currently is coupling is somehow faulty and over travelling and hence over driving brakes when reversing ..... but unaware of any adjustment.

JimRib · 09 June 2018, 23:00

Is you hitch damper in good condition ?

beamishken · 10 June 2018, 02:36

I know you dont want to run with loads of slack in the rods but if you've now replaced the rusty shoes for new ones and it still doesnt work then id back off the rod further in small increments until you can reverse then check if you have brakes going forward (only as a test)
The mechanism in the drum is designed to put a little slack in the system after the initial grab rotates the shoes rearward. There are 2 possibilities
A) the shoes are not rotating and releasing
B)they are rotating and initially releasing but the travel in the cable is such that it takes up the slack in the system induced by the shoes collapsing as they rotate rearwards.
My next stop would be adjust the rods until you can reverse if you then have brakes going forward your drums are working if you have brakes in neither direction then the drums arent working.
Once you determine if its drums or a travel issue you can concentrate on the hitch/damper/actuating rods or the internals of the drums

charliee · 10 June 2018, 08:40

After a month of trying and multiple adjustments and obvious frustration I suggest you hand it over to a professional to sort, pass the hassle downstream and pay! Persumably you can’t put the boat in the water either.

smallribber · 10 June 2018, 08:59

As I said on a previous thread you need to stop tinkering and do something positive that will work.

Is it possible to change the breaks out for Knott brakes in the same hub.
or
get a hand winch to winch the whole lot up your drive
In my view you are just trying the same thing over and over again

Sargan · 10 June 2018, 09:12

Quote:

Originally Posted by beamishken

I know you dont want to run with loads of slack in the rods but if you've now replaced the rusty shoes for new ones and it still doesnt work then id back off the rod further in small increments until you can reverse then check if you have brakes going forward (only as a test)
The mechanism in the drum is designed to put a little slack in the system after the initial grab rotates the shoes rearward. There are 2 possibilities

Once you determine if its drums or a travel issue you can concentrate on the hitch/damper/actuating rods or the internals of the drums

I have not been able top get to a point where adding slack makes it work.
Added loads ..fon't forget any slack I add also affects normal braking.

Sargan · 10 June 2018, 09:17

Quote:

Originally Posted by Bigplumbs

As I said on a previous thread you need to stop tinkering and do something positive that will work.

Just can't find anything that makes it work ...

I did mention earlier cannot change backplates they are welded onto stub axles - not bolted.
New pair of Axles around £1600

>In my view you are just trying the same thing over and over

Agree as the advice is same thing over & over .... i.e. set brake shoe gaps they are too tight, or add more slack ..
Tried everything suggested here.
.... even though explained what has been done - still get told to do the basics.

I do have an electric winch in my garage ... so that currently used to pull boat up the drive.

paintman · 10 June 2018, 09:35

Does autoreverse work OK on level surface or does it have the same problem no matter the angle?

The coupling has been mentioned. I don't know if it makes any difference but is its weight range appropriate for the weight of trailer & load?

If all else fails then consideration to some device for stopping the coupling pushing back may be the only solution. Been mentioned earlier & was common before autoreverse. Was a metal lever that hinged over onto the neck of the coupling & stops the brakes working. If you DO go that route you must remember to take it off as it will stop the brakes working in normal driving.

Sargan · 10 June 2018, 10:07

I have no way of knowing if autoreverse is working ‘on flat’. As there might not be enough rolling resistance ... i.e. I start reversing, coupling starts compressing,it may be that trailer then starts rolling before it gets compressed enough to apply brakes.

I did have once when reversing on launch site brakes locked on reversing, but pulled fwd 1/2m then it reversed OK ...

neil.mccrirrick · 10 June 2018, 15:38

Do you know how many wheels are locking? If the trailer is weighted on two wheels more than the other two there may not be enough friction to make the shoe slide and by the time the bar is fully locked they will be locked on

Sargan · 10 June 2018, 17:37

When I start reversing up drive all the weight is on rear axle ... i.e stern of boat.

In fact for first couple of metres the wheels on front axle due to height of tow hitch don't touch ground .... after first 2m all 4 wheels back in contact

Not particularly steep drive, just a slope at the start

It is the rear axle wheels that lock up for sure, if I put in low ratio I can force trailer to moves - and rear wheel skid, showing brakes are locked on.

I am sort of thinking more & more the coupling is 'over driving' so instead of being light touch and the auto reverse kicks in ... it has full car force , and locks the shoes solid.

If I drive fwd ... brakes release and trailers rolls fine.