Camper Trailers Tech Tips

Jockey Wheel Inspection





jockey wheel inspection


Because of their placement placement, jockey wheels are subject to a great deal of dust and road grime. Foreign particles find their way into the mechanisms of the jockey wheel and in particular cause corrosion and pitting of the ball race and its cup washers – components that take the load when you wind up the front of the camper trailer. This wear results in a grinding, rough feel as you turn the handle. Also the jockey wheel may not turn as easily therefore moving by hand will be difficult to manoeuvrer it.

By replacing the worn or pitted ball race and the jockey wheel bearings, the trailer can be made to feel like new again. You might also consider a way to keep moisture out of the mechanism if the device is left outdoors for prolonged periods.

To start with, the main part of the jockey wheel consists of three parts
1. Outer tube
2. Inner tube and yoke
3. Winding thread (Acme Thread) and pressed nut (Acme Nut)

step by step

01 I had to raise the front of the camper trailer on a bench (previously used for potted plants). I did try to leave it attached to the car and just remove part of the jockey wheel, but found it would be easier to take it completely off the drawbar.
Note: At this stage it may have been better to remove the whole jockey wheel from the trailer and place it in a vice. However, I chose to just remove part of unit and leave the bracket and main tube attached to the trailer.

02 To inspect the bearings and Acme Thread I had to remove the winding handle. This is done by using a parallel punch to knock out the “Dowell Spring Pin”. The pin is seen in the photo below in the centre of the winding handle head, the handle needs to be free of the unit to begin the service.

03 I don’t own a parallel punch, so I ground back a thick nail removing the point and smoothing it off to have a flat end (burnish the burrs from the edges) to tap out the dowel spring pin. The punch must be a near fit for the hole in the handle.
I also had to make a larger punch to remove the axle from the wheel housing described later) but below are the two tools for the job.

04 Once an end of the dowel spring pin is protruding, it may be possible to grasp it with pliers to extract it. Keep a record of the roll pin size as you will need to put a new pin in the hole – don’t re-use the old one as it may be a ‘looser’ fit whereby it may dislodge causing your handle to fall off.

05 Now the jockey wheel’s inner tube can be removed from the outer tube.

WARNING – if you do not take off carefully, the balls from the bearing may dislodge all over the ground therefore requiring you to purchase a new bearing. In most cases you may need new bearings.

06 At the top of the core assembly and sitting above the acme nut are a series of washers and bearings called the ‘Thrust Bearing’. It is made up of a bearing ring containing balls which is sandwiched between two ball race washers. A nylon tube is placed in the centre of the three parts and helps to centre it over the acme thread. The whole unit sits at the top of a thick washer which is welded to the acme thread. Below is the remains of the thrust bearing which, when taken out of the tube, dislodged many bearings although I suspect some had previously fallen out of the housing.

Below is a close up of the main ball washer and the damaged race washer with a split in it. I could only locate 9 of the 12 balls therefore I decided to track down a couple of new bearings (one as a spare and one to install).

07 I sent an email to the manufacturers of the jockey wheel ‘ARK’ to enquire about how to best service the unit and take it apart. They responded stating “You will notice a small indentation on the inner tube, this is where the nut is held in place, you can pop the nut out with a hammer and screw driver and pull it apart from the inner tube”.

Once your winding thread and pressed nut is apart, you will need to clean the grease off and inspect for any damage or burs that may stop the jockey wheel from winding. If all is good completely grease the thread with a good quality marine grade grease and replace back into the inner tube and reverse your steps of assembly.

Below is a close up of the indentation on the inner tube. I put the whole unit in a vice and tried to remove but was not able too. I feared that if I hit with too much force that I may damage the tube, nut or myself so quit while I was ahead.

08 I wound the acme thread out as much as it would go (there is a ‘welded nut’ on the base to stop it winding out fully which is good to know – stops the jockey wheel being fully wound off the trailer). I cleaned the old grease and dirt off the thread with a solvent (grease remover purchased from some auto store). I then liberally applied a liberal amount of automotive wheel bearing grease (Timken Hi Temp Premium is the product I already had) then wound it back into the inner tube. At the base of the inner tube is a 20mm hole to which I applied more grease to a small piece of dowel and inserted it through the hole and tried to grease the bottom end of the acme thread.

09 Obtain a new upper bearing set to replace the worn and gritty or completely damaged set. Apply a liberal amount of grease to the new bearing set and assemble it on the shaft.

10 Next is to remove the two cotter pins from the axle. You will need to use pliers to straighten then then gently knock them out from the axle. Take off the washer and try to push he whole axle through the yoke housing, through the wheel and out the other side. I found that the one of the wheel bearings was preventing the axle from being pushed through an had to knock it out using the larger punch which I had made earlier (see photo in point number 4.

Below is the better of the two bearings and it was very loose but the internal core did remain in place on this bearing. It was rusted and split on the other which I found is what prevented the axle from coming out of the housing.

11 Now I had the complete yoke free so I could inspect it for damage. I rubbed it with ‘00’ size steel wool soaked in kerosene and polished it a bit and took off some of the surface rust and weld splatter.

You will also see a hole which I drilled into the inner tube a couple years ago – it matches a similar positioned hole in the outer tube so when they are aligned in the upright position (i.e. when camper trailer is being towed), this prevents the wheel from moving and bashing against the ’A’ frame of the trailer. I insert a 10mm cuphead bolt though the holes.

12 Follow the above steps in reverse to reassemble the jockey wheel. The only part that I didn’t replace was the bracket itself or the spring which is contained on the swivel part. Note – this may not apply to people who have removable jockey wheels that are inserted within a ‘clamp’ type system on their drawbar.

13 To extend the life of the bearing if the camper trailer is left outside in the weather, I found the following two suggestions on the internet;
1. slot a can and place it over the jockey wheel to stop water entry.
2. Cut a 150mm length of 40mm pvc pipe, buy a 40mm end , then cut 10mm wide slot length ways so it will fit over the handle. glue the end on and no more water can get into the working area. hope this helps.

parts list

I sourced the following bearings from ‘Statewide Bearings’ in Brisbane and suspect that the same parts numbers will be available at any bearing store;

  • Thrust Bearing NSK item No 51203 - $15.47 each

  • Wheel bearing – no name branded on it but listed on invoice as K35110F UNGROU item No J2210F – I was told that these bearings are the ones to replace wheelbarrows and wheel-trolleys and are pretty common. - $7.42 each.

  • Roll pin is 5/32 diameter and 1 ½ inch long (sorry, inherited a set of assorted roll pins and they are imperial sizing hence the ‘old’ measurements). Think that converts to 4.2 x 37mm according to my callipers.

  • 2 x 50mm long cotter pins

  • Timken Automotive wheel bearing grease – premium hi temp grease.

Note: ARK state they have spares available but I couldn’t see them on their website. The email sent stated the following available;

  • Complete swivel bracket

  • Winding handle

  • Thrust bearings

  • Wheel bearings

Their email address is

I also sourced a company in Brisbane that do spares but they were closed for the Xmas holiday break - All Trailer Spares – 605 Toohey Road Salisbury 4107 (07 3277 2802)

  • 91515 – Spring

  • 12161 – Thrust Bearing

  • 12154 – Acme Nut

  • 12130 – Shaft Acme thread for jockey wheels up to 320mm thread travel


thanks to Matt Stone for this article


february 2013