Sam ColesSee other Advice articles filed in ‘General motorhome advice’ written by Sam Coles
One of the most widely used leisure door steps is the Thule Omnistep.
It comes in either manual or motorised form – this article deals with the motorised version.
It relies on aluminium extrusions sliding inside nylon bearings, all of which are exposed to the hostile environment normally found beneath any motorhome.
Although there is a bottom plate, contaminants such as grit, dust or road salt can get between the load-bearing extrusions and the bearings.
Thule advises that the step linkage should be cleaned and lubricated regularly.
Despite regular cleaning and greasing, my step has become reluctant to slide in and out.
The grease on the runners has attracted both dust and grit.
This article explains how to deal with a recalcitrant step – the work should take no more than a couple of hours.
What you’ll need
- 13mm angled hex ring/open-ended spanner
- 13mm socket plus 6” extension
- Large and medium Pozidrive screwdrivers
- 1” paintbrush
- ¼” flat-bladed screwdriver
- Receptacle to wash parts in
- WD40, if required
- Loctite thread lock
- PTFE dry lubricant spray
The main aim is to keep disassembly to a minimum.
As I clean and reuse existing bearings, I have not had to remove the step assembly from the ’van, avoiding the need to disconnect supply wires to the motor and step-travel-limit switch.
Initially, at least one end of the vehicle should be raised to allow access to the lower part of the step.
A word of caution!
I used a pair of sturdy ramps under the front wheels with the handbrake fully on, first gear engaged and bricks to the front and rear of the back wheels.
If a jack is used to raise the ’van, it is essential to support it on vehicle stands capable of taking its weight.
Working with the vehicle still on lifting jacks is very dangerous.
First, take out the two screws securing the bottom cover plate before removing it – this reveals the activation arm and the nylon slider.
Engage the in/out switch until the step is fully out.
Using a flat-bladed ¼” screwdriver, remove the circlip and washer from the end of the square driveshaft protruding from the motorised gearbox.
Pull the lever downwards off the square drive section (some penetrating oil may be needed).
The step will now be free to slide further out than normal, allowing access to the rearmost self-tapping securing screws on the side extrusions.
Removing the step
Using a large Pozidrive screwdriver, remove these six screws. This will release the tread part of the step and the two end caps.
Push the two step supports back into the main housing.
The main step assembly is attached to the underside of the ’van by four 13mm nuts and bolts at the four corners of the main frame.
These should now be removed, allowing the step assembly to drop (take care not to damage the wires running to the motor and limit switch).
Inspection and cleaning
Support the front of the step assembly on the ’van bodywork while dropping the rear, to allow the step slider assembly to be slid out of the back of the main frame.
Then, temporarily suspend the rear of the main frame back in position, using one of the securing bolts.
You will now have access to all of the rotating and sliding parts of the step for inspection and cleaning.
Any severely worn or broken parts will need to be replaced.
As the build-up of grime is, in this case, based on lithium grease being used as a lubricant, I used paraffin as a solvent, brushing it well in.
A clean sweep
Keep changing the paraffin until no more grime is washed out (three lots in my case), then wipe dry.
Check that the rear slider travels the full length of the runner and the activation lever rotates on its pin.
Before reassembly, spray the two side extrusions and the rear slide bar with PTFE dry lubricant and allow to dry – this lubricant is less likely to attract road grime.
Putting it back together
Reassembly is the reverse of the procedure outlined above, with the following provisos.
When replacing the six self-tapping screws holding the step centre section in place, apply Loctite thread lock to the threads.
I had the added complication of two threads having been pulled by whoever last took the step apart.
I overcame this by buying longer self-tapping screws (No 14 x 40mm A4 stainless steel), so an extra 5mm could bite into fresh aluminium in the step centre.
Make sure the wires supplying current to the motor are secured well outside the activating lever operating arc of travel.
If the entire step assembly is being replaced, all that needs to be done is to remove the four securing bolts before lifting the assembly clear, having cut the wires to the motor.
Make sure the new step wires are securely connected to the existing wires with a waterproof joint (I recommend soldering and heat shrink insulation) once the new step is bolted in place.
Finally, ensure that you join red to red and black to black, otherwise the step switch will be operating in reverse!