More wiper woes

[MKTR]

Hi All,

My TR4 windscreen wipers are working fine (ish) as they sort of clear the rain and they do self park correctly.  However, I have noticed that the drivers-side wiper arm flaps up and down when I am driving at speed.  The arm is tight against the screen but I can move the wiper about an inch without there being any resistance from the drive rack.  It is not turning on the spindle, so I am suspecting the wheel-box.

It is not something that I have noticed before and so I am wondering if I am worrying about something that is not a problem; but if it is - whether the wheel-box is the culprit.  Perhaps I need to try turning the drive cog 180 degrees as mentioned on other threads relating to wipers?

Thank you in advance

Mark 

[RogerH]

Hi Mark,

you shouldn't have that much slack.

Have you at any time removed the rack, turned it 180' and put it back.

If not then do this.  The action of the rack and the angle of the wiper action is such that only half the rack gets worn.

So - remove the blades. Pull the rack out (do not touch the blade spindles) flip the rack over and re-insert.

You could mark the spindles before removing the rack. The mark should return when the rack is re-inserted.

 

Roger.

[MikeF]

Hmm...I suspect by now the rack has already been turned and probably more than once.

My wipers were totally useless on purchase. I replaced the rack and replaced the wheelboxes with tr6 types being a bit beefier. They now do a full sweep and park properly no freeplay. But are still pretty useless.  Rain-X  works better.

Mike

 

[peejay4A]

You’ve eliminated everything except the motor itself then.  I can’t empathise with the frequent complaints about poor wipers on TRs. Mine are fine at both speeds - nothing special, just in good nick and my old TR6 wipers were fine too. 

 

[RogerH]

11 hours ago, MikeF said:

Hmm...I suspect by now the rack has already been turned and probably more than once.

My wipers were totally useless on purchase. I replaced the rack and replaced the wheelboxes with tr6 types being a bit beefier. They now do a full sweep and park properly no freeplay. But are still pretty useless.  Rain-X  works better.

Mike

 

Hi Mike,

 in using the TR6 wheelboxes with the original TR4 set-up did you find your sweep or speed different to normal. The TR6 WB has a smaller (I think)  diameter.

 

My TR4A wiper was quite poor, even after a decent rebuild. So last year I fitted the TR6 (14W) motor and it is npw like a modern system.

I used a 95 degree wheel in the motor and kept my fairly new TR4A WB's - the various wheel diameters maintained the blade sweep (and increased the torque slightly).

 

Roger

[trchris]

Hi roger 

how easy is it to replace the 4a wiper motor with a 6 ? as mine isn't great either and have been pondering if this would be a good swap

Chris

[RogerH]

Hi Chris,

 not too difficult.

The 14W motor, a 95 degree gear wheel,  a 35927  2 speed switch     from these folk https://www.s-v-c.co.uk/category/wiper-systems-and-part/

The connector lead https://www.moss-europe.co.uk/shop-by-model/triumph/tr5-6/electrical-system/wipers-washers/windscreen-wiper-system-tr5-6.html  from MOss

You need to mount the motor so that it is solid on the bulkhead. The original mounting plate is not used.

I replaced my pull switch with the above toggle.

 

With the 95 degree wheel and the 4A wheelboxes you get a good slow speed with stacks of torque. The higher speed  would be god for serving tennis balls.

Roger

PS - this may be good reading  https://www.s-v-c.co.uk/wiper-systems/

 

Wiper switch.doc

Edited July 15, 2019 by RogerH

[AlanT]

I should probably stay out of this.  But somehow I can't resist.

I've now rebuilt getting on for 200 wiper-motors and so I know about wear in them.

For every 4 thou of wear in the motor bearings, crank-arm bush, rack teeth and wheelbox gear the sweep angle increases by one degree.

The brass bush in the crank-arm and the main bearing for the gear often have 10 thou each. That's five degrees of sweep and about 1in movement at the blade tip.

Of course if one blade is worse than the other it must be the rack-teeth and wheelbox not the motor.

Good NOS racks are easily available and just push in so this has to be the first thing.

I make new brass bushes for the crank-arms and can refit the main Oilite bearing for the big gear.

I've got NOS DR3A motors that will get put into TR4A spec.  Also a TR6 motor for "research purposes".

The TR6, 14W type is really a cost reduced design to replace the DR3A.  There was a big saving because of the use of a permanent magnet for the field generation rather than a wound coil.  This is a good thing for long-term reliability also.

But elsewhere the cost reductions might result in long-term problems. 

The rack-slide is a plastic insert rather than cast encastre brass. The brush plate is SRBP or Paxolin.  The self-park switch is plastic too and not really serviceable.  It has a lot of internal parts with not very good registration and retention.  You will see brush-plate and park-switches offered on eBay and these are usually far-east repro,

 

 

 

 

 

 

 

 

[MKTR]

Thanks All,

I will try the rack turning and see how I get on.  I also have a spare used one somewhere I can try.  If not I will do the devilish task of checking the wheel boxes.

Presumably the back of the wheel box would not have come loose and caused the same effect?

 

Mark 

[Geko]

Another good read here

[peejay4A]

That explanation doesn't apply to TR4/4A wipers.

[MikeF]

On 7/14/2019 at 9:27 AM, RogerH said:

Hi Mike,

 in using the TR6 wheelboxes with the original TR4 set-up did you find your sweep or speed different to normal. The TR6 WB has a smaller (I think)  diameter.

 

 

Roger

Roger, 

Sorry for late response, been "off air" for a while. For the courtesy of a reply:

I can't answer your question because the wipers didn't. They mostly whirred and twitched a bit with minimal back and forth, Soon after I replaced the original motor with a TR6 type as my original failed.  I was tempeted by the idea of two speeds and was optimistic that I would solve the poor wiping performance as I had got them sweeping back and forth properly. In practice  there is no real benefit in the higher speed as the wiping performance is poor at any speed. I have tried several types of blade, with no perceptible benefit. If anyone has any advice in the area would be good to hear it. Changing the motors was a relatively simple job. Puzzling the wiring from motor to autojumble switch was harder.

 

Mike

[RogerH]

Hi Mike,

a number of people suggest the PIAA silicone blades work very well compared to the normal rubber type.

Halfords do single lengths - one length should do two arms. Revington also do them cut to size.

 

Roger

[MikeF]

thanks Roger I'll give it a bash! Plenty of opportunities coming up I think

 

[tim hunt]

Mike,

+1 for PIAA blades. Price can be prohibitive vs normal blades so I did some research and found that a 525mm PIAA Super Silicone Wiper Refill could be purchased from www.tdcautomotive.com for £14.79 including shipping. The TDC model number is SKR52E. The refill comes in a 6mm wide plastic backing strip, the correct width for the original TR4 or 4A blade carriers. If it is carefully cut exactly in half it provides two blades of the correct length for our cars. The 525mm refill comes with locking notches near one end of the plastic carrier. You just need carefully to cut matching notches on the other half you have cut off. The end jaws on the blade holders locate in these notches while the refill should be a sliding fit in the other jaws, which can be gently reshaped if necessary. These silicone blades deposit a hydrophilic film on the screen that causes water to bead; they are quiet in use, heat and ozone resistant with the promise of long life. I used them for the first time on last October's Club Triumph Round Britain Reliability Run. We didn’t encounter really heavy rain and I had treated the screen with Rain-X as belt and braces so only needed the wipers when travelling below about 45mph. I found that they cleaned the screen superbly, far better than any blades I have found to date and I consider they are well worth the premium price.

Tim

[Deggers]

+1

Did much the same for my 3A in 2014. On the road all year round, in sun, rain and snow. They work well, and haven't had to change them since.

Here's the forum thread link : "Tex wiper blade replacements"

Cheers, Deggers