Talk Morgan Forums Morgan Sports Cars Maintenance & Servicing Wiper drive

Help please!
The centre wiper on my 2006 Roadster has stopped!. Narrowed it down the 'rack' &/or the 'wiper wheel box'.
It seems there are two types of wheel box, 32 or 40 teeth.
Before dismantling everything, would anyone know what type would be fitted to a 2006 S1 Roadster?

It seems odd only one failed. Is the gear that moves on the rod loose i.e. is there a nut you can tighten?

Sounds like the connection somewhere between that specific wiper arm and the inner drive cable. Ought to be some of the following:
Connection wiper arm - splines at the spindle. Not likely, but check.
Connection splines - spindle. I think the splines are screwed onto the spindle, then locked with a hex grub screw. Could it be loose?
Defect wheelbox, the spindle is not moved by the inner drive cable.
Defect inner driving cable.
Cannnot be anything in the wiper gear box, as long as the other two arms are moving.
If you look at CarBuilderSolutions' website, they have all these items, but I can't see any 32 vs. 44 teeth versions of the wheelbox. Might be a good idea to contact them about the wheelbox.

It sounds like a wheelbox problem if the outer 2 wipers are working.

There are 2 nuts on the wiper wheelboxes backplate behind the dash that hold the wiper rack to the wheelbox drive wheel. You will have to remove these to look in side (and the nut on the outside of the car if you replace the wheel box).

Its likely that the wheel isnt connected to its shaft or alternatively the splined wiper fitting that the wiper attaches to has come away from the shaft. Car builder solutions or Melvyn Rutter will have the wheelboxes.

Have no idea as to the wiper kit fitted to your Morgan though have messed about with wipers on older cars over the years.

I might start by lifting the wipers clear of the screen and checking for free play on each of the wiper arms by rocking it left and right, if there is an issue of excess free play on any one arm compared to the others then it might be worth removing the arm on the suspect arm and checking the splines in it and on the driving wheel, I have seen these stripped to some degree.

The arms can over time size on to the driving spindle, and can be difficult to remove. There tends to be a small spring clip arrangement holding the arm to base of the drive wheel that requires to be prised and held back to allow the arm to be released.

The wheel boxes can suffer worn driven teeth where they run on the rack drive wire , dependant on the degree of arc there may be enough good teeth to disengage the wheel from the drive and rotate the wheel to present the non worn teeth to the drive.... Also if the drive wire has suffered wear, it too could be disengaged and rotated to present the unworn section to the teeth of the driven wheel in the wheel box..

Hope I have not muddied the water.

Thank you to everyone for the responses & suggestions.Having already done the basic checks as suggested above, it seems the wheel box is the most probable cause for the failure; will have to drop the dash & physically check the number of teeth before ordering.

Just a quick update; I had e-mailed gomog from their web site on Friday & posed the same question. Lorne responded very promptly, but advising that he didn't know.
However. for information, he has just replied & confirmed it's 32 teeth.

What a friendly and helpful community!

A further update, & for general information; not only do the correct number of teeth have to be specified, (32) but also there are two lengths of shaft available for the Wheel Box! The correct length to suit the Roadster is 65mm, this turns out to be the same as fitted to a TR6.
Replacement fitted today; www.angclassiccarparts.co.uk; now have three working wipers, just in time for this weeks MoT!
Thanks for all the replies & suggestions.