GT6 Mk2 Wiper Motor Gearing

[Josef]

I’ve opened the wiper motor (Lucas 14W round can type) from my Mk2 GT6 to find a 100 degree gear. I’m pretty sure this is not correct, the motor is 73 date stamped so I can know it’s not the original one. Question is, what gearing should it have? I’ve seen claims of 115 degrees, and 130 degrees, both without quoting any source of information. The car is in bits so not like I can just give it a go and see what the sweep is like!

I do have my Mk3 Spit with the same wiper spacing, but the older style DR3 motor, so don’t know if comparing with the gearing in that is actually valid. I’d be pretty sure it isn’t given the gear wheels are different designs. 

[Colin Lindsay]

That's the Lucas 14 PMDC motor?

Possibly it should be 130 degrees, but you can buy replacement gears very easily. Work out how much extra sweep you need and adjust accordingly. 

Back in the day I used three or four old gears and marked the position on my Mk1 screen before photographing it for future reference:

[Josef]

Yeah, the later type Lucas permanent magnet motor. I know you can buy replacement gears, but they’re about £20 plus each so I don’t want to have to buy more than one! I have learned the degrees marking on the gears can’t refer directly to the sweep at the wipers though as wheel boxes with different numbers of teeth were available. This makes me even more doubtful that the gear ratios between the DR3 and 14W type motors can be directly compared.

[johny]

Several of the 14W offerings on ebay say theyre suitable for GT6 mk3 and indicate 105º gears. To back this up Rimmers offer the same motor but with one gear for mk1 and another for mk 2 and 3 but unfortunately dont say angles...

[Josef]

Canley’s list two gears for the mk2 (as NLA though). They’re marked up as RHS and LHS. The former part number corresponds to the 115 degree gear found in the landrover Defender 90/110 motor and the latter to the gear various places list for the TR6 and MGB. Not sure what RHS and LHS refer to though. The GT6 wiper motor was always on the same side regardless of the steering position, and as far as I can see the wipers always parked on the right side.

[Peter Truman]

Didn't later Heralds have their wiper spindles at different locations on the windscreen surround so presumably different wiper sweep areas

[johny]

Yes surely wipers have to be differently position on lhd and rhd cars so that the drivers side can be wiped right up to the A post...

[Pete Lewis]

one good place for wiper spares is

https://www.s-v-c.co.uk/categories/stafford-vehicle-components-washer-wiper-systems

Pete

 

[Colin Lindsay]

10 hours ago, Peter Truman said:

Didn't later Heralds have their wiper spindles at different locations on the windscreen surround so presumably different wiper sweep areas

The late Heralds moved the position of one wiper (passenger side in UK) so that it's now outside the washer jets rather than in between, so they could use the wiper system common to the other models in the Triumph range; any difference in sweep was compensated for by using different wiper wheelboxes with more teeth. 

[Josef]

I have found what looks to be a definitive answer on some other forum. Summary is that the late US Spec Spit Mk3 (1969 on), GT6 Mk2 / Plus, TR6, and Landrover Defender (pre 2001 ish) all used a 115 degree gear 517646. 

[Colin Lindsay]

1 hour ago, Josef said:

I have found what looks to be a definitive answer on some other forum. 

"The spacing of the wheel boxes is only an optical indicator for the changes in the wiper mechanism."

Hmmm... that's like saying the wipers waving to and fro is only a visual indication of the fact that they're working.