Wiper arms

[Tom Grant]

Hello everyone.

Need to fix the slack I have in the wiper system as the wiper arm keeps hitting the gutter under the windscreen! 
 

im wondering if it is slack in the wheel box and spline or if it’s the wiper link inside the wiper motor. If anybody has experienced this before and knows where it would have slack first that would be appreciated. Or if it’s easier just replace the whole lot to be sure? 
 

Thanks 

Tom

[Peaklander]

First check is the splined thing that the wipers slot onto. It is secured to the spindle with a grub screw. Mine were always working loose until I used a smidge of threadlock. This is on a 300TDi 110. Don't know if this is the same fixing across the range.

So with the wipers parked, just grab a wiper arm and see if it moves on the spindle.

Edited December 15, 2020 by Peaklander
Clarity

[western]

Replace the splined adaptors, STC987 grub screw type.

 

mine were slack, I replaced both splined adaptors & made sure they grub screws were tight on the spindle flat face, no more slack.

[paime]

Is there a modification that can be made for those grub screws? They're always the first thing to rust up and never seem to be able to get a robust grib on the spnidle.

[western]

There were another set of adaptor RTC4480 with small bolts instead of grub screws, no longer available, superseded by the STC987 version with grub screws.

[Glue]

In the past I've drilled them out and retapped to M4(?). The grub screws were then replaced with BZP hex head set screws. It's not ideal from a cosmetic point of view, but I found it easier to torque the bolts up than faffing round with a (tiny) allen key.

HTH

[landroversforever]

I'd replace the tiny little grub screws with some stainless ones, and go slightly up in size.

[western]

There isn't much clear material to increase the thread diameter, it quite close to the rear edge as it is. 

[Snagger]

Some thread lock on the grub screws should not only keep them tight, but prevent thread corrosion from permanently seizing the screws., but stainless screws would be a good little change too as they’ll be harder and can’t wear on their tips, gradually becoming slack.

[landroversforever]

3 hours ago, Snagger said:

Some thread lock on the grub screws should not only keep them tight, but prevent thread corrosion from permanently seizing the screws., but stainless screws would be a good little change too as they’ll be harder and can’t wear on their tips, gradually becoming slack.

Whilst the threadlock helps the corrosion, its not going to stop the tiny hex in the end corroding  

[paime]

Many an allen key has been lost to those wee s*ds!

[landroversforever]

1 hour ago, paime said:

Many an allen key has been lost to those wee s*ds!

My hex key survived.... it just acted like a drill in the grub screw  

[Snagger]

20 hours ago, landroversforever said:

Whilst the threadlock helps the corrosion, its not going to stop the tiny hex in the end corroding  

A little dollop of grease will.

[Tom Grant]

So I’ve bit the bullet and replacing the whole assembly and changing the wheel inside of the wiper motor this should hopefully eliminate the slack issue! 
 

thanks to everyone who came up with suggestions. A great community!