Wipers

[andy4]

My wipers which I assume are standard Marina from the doner cover an arc of 90 degrees and I want to increase this to sweep more of the screen. Searching this forum there is talk of swapping to allegro wheel boxes and a statement that these have 40 teeth instead of 32 in the marina. However if the number of teeth change surely they will not mate with the "rack" which must be designed for a different TPI. On SVC components website they sell parts of the wiper system, and on the page http://www.s-v-c.co.uk/prod_wipers.html#techie it talks about the gear wheel in the motor being changed to affect the arc through which it sweeps - this makes much more sense. It implies the gear wheel has a pin which is positioned at different distances from the center of the gear wheel, hence changing the sweep of the connecting rod. Anyone have any experience of comments ? I think changing the gear or the motor is the way to go, but worried about the wheelbox advice given on this site ....

[stevejgreen]

Re: Wipers

I am guessing Lucas wipers. From memory, standard Marina was 110deg. The gearwheel with crankpin shown on the svc website is available in several angular dimensions and specified as 90, 100, 110 and perhaps other angles. SCV should be able to help, I think they supplied mine when I changed it.
They are a straight swap over. It's possibly worth pulling the flexible drive out of its tube to check for lubrication. The wiper arms will need to be removed when you re-thread the flex as it will not go back in the same place.
When changing the angle of the drive make sure that the wiper blade does not hit the bodywork. The angle it travels through will be quite different when the screen is dry or very wet and you dont want to dig holes in the paintwork.

[lil_red_roadster]

Re: Wipers

I recently fitted 32 tooth wheel boxes from SVC (Marina is 38-40 I forget which)...and they make a huge improvement. My wiper motor (ex Mini) is fitted with a 120 degree gear wheel and with the new wheel boxes I get 120 degrees of sweep...before it used to be 90 degrees. Fewer teeth = more sweep.

As Steve says its also worth checking the flexi drive and wheel box connections...

[stevejgreen]

Re: Wipers

Just found my old gearwheel and crank pin. It's clearly stamped with the angle opposite the crank pin, giving you a starting point.
It must be easier and possibly cheaper to change the gearwheel than to change both the wheel boxes. Like Jez I cannot remember what the standard Marina fit was.

[dogoncrazy]

Re: Wipers

Allegro wheelboxs fit no problem. This one one of the first 'mods' I did on my old roadster.

[lil_red_roadster]

Re: Wipers

120 degree gear wheel available on eBay...
280426677828

[greyV8pete]

Re: Wipers

Some older cars use wheel boxes with a different number of teeth for each wiper, to tailor each wiper for optimum "sweep" of the screen area. Peter.

[andy4]

Re: Wipers

Having taken the cover off my wiper motor it looks like it has a 120 degree gear in it - my wipers don't sweep through 120 degrees ( more like 90 ) so I guess the next stage is to look at the wheel boxes - dash board out tonight :-) I am assuming everything on my car was from taken from a Marina, but of course as I did not build it originally, I don't know for sure.