Windscreen Wipers On Self Destruct!

[davidlexusls400]

Hi and thanks to all those amazing people who have given me such excellent advice.

I have yet to find an answer to this quite serious problem on my otherwise silent LS400:

The wipers do not always seem to remember that there is a part position during operation and annoyingly strike the stop below the line of the windscreen during when in position 1 2 or 3.

If the rain is light, then the wipers work perfectly - most of the time!

Then when in continual mode (position 2) and with heavy rain, the wipers go absolutely mad and whack the windscreen pillar with such violence that they bounce backwards, only to bounce back up when they hit the horizontal stop position (below the higher stop position).

The noise is alarming and will become a problem if I am driving more than a few miles.

Is this something that Lexus have introduced to keep awake the slumberful motorist?!

Please can anyone offer any advice as I really love this car and would hate to become like Bail Fawlty with his Austin/ Morris 1100/1300 and be convicted of corporal punishement!

Many thanks and am sure that someone can help me!

David

[steve2006]

Hi,

Given that the wipers are hitting both the park position below the bonnet line and the side windscreen trim this would suggest excessive wear in the mechanical links allowing sloppy movement.

The actual sweep area is determined mechanically and is fixed so the only adjustment you can make is the wiper arms position.

To check for excessive movement in the mechanism stop the wipers in mid sweep using the ignition key to cut power when in the correct position then gently lift them from the screen and see if you have any movement in the arms/links by moving them left to right.

There are various bushes in the mech but these may not be available as spare parts the exploded diagram suggests the whole linkage/motor assy may have to be replaced.

If this is the case I would go the s/h route, if you PM Benfur he may be able to supply.

Edit Just thought of another possible cause make sure the wiper arms are pushed fully on the spline drives and tightened on to the correct torque as the arms may be slipping on the splines and momentum is carrying them too far.

[benfur]

Hi,

Given that the wipers are hitting both the park position below the bonnet line and the side windscreen trim this would suggest excessive wear in the mechanical links allowing sloppy movement.

The actual sweep area is determined mechanically and is fixed so the only adjustment you can make is the wiper arms position.

To check for excessive movement in the mechanism stop the wipers in mid sweep using the ignition key to cut power when in the correct position then gently lift them from the screen and see if you have any movement in the arms/links by moving them left to right.

There are various bushes in the mech but these may not be available as spare parts the exploded diagram suggests the whole linkage/motor assy may have to be replaced.

If this is the case I would go the s/h route, if you PM Benfur he may be able to supply.

Edit Just thought of another possible cause make sure the wiper arms are pushed fully on the spline drives and tightened on to the correct torque as the arms may be slipping on the splines and momentum is carrying them too far.

Thanks Steve

Yes I have a motor in good order if your interested

can supply the arms if their splines have worn too

Thanks

Benfur

[davidlexusls400]

Hi,

Given that the wipers are hitting both the park position below the bonnet line and the side windscreen trim this would suggest excessive wear in the mechanical links allowing sloppy movement.

The actual sweep area is determined mechanically and is fixed so the only adjustment you can make is the wiper arms position.

To check for excessive movement in the mechanism stop the wipers in mid sweep using the ignition key to cut power when in the correct position then gently lift them from the screen and see if you have any movement in the arms/links by moving them left to right.

There are various bushes in the mech but these may not be available as spare parts the exploded diagram suggests the whole linkage/motor assy may have to be replaced.

If this is the case I would go the s/h route, if you PM Benfur he may be able to supply.

Edit Just thought of another possible cause make sure the wiper arms are pushed fully on the spline drives and tightened on to the correct torque as the arms may be slipping on the splines and momentum is carrying them too far.

HI Steve,

That is excellent advice, thanks. This is a nasty problem with the car, that needs fixing before I do any long trips. I will do as you mention and get a second opinion at my local garage.

Kindest regards and with gratitude!

David

[davidlexusls400]

Hi,

Given that the wipers are hitting both the park position below the bonnet line and the side windscreen trim this would suggest excessive wear in the mechanical links allowing sloppy movement.

The actual sweep area is determined mechanically and is fixed so the only adjustment you can make is the wiper arms position.

To check for excessive movement in the mechanism stop the wipers in mid sweep using the ignition key to cut power when in the correct position then gently lift them from the screen and see if you have any movement in the arms/links by moving them left to right.

There are various bushes in the mech but these may not be available as spare parts the exploded diagram suggests the whole linkage/motor assy may have to be replaced.

If this is the case I would go the s/h route, if you PM Benfur he may be able to supply.

Edit Just thought of another possible cause make sure the wiper arms are pushed fully on the spline drives and tightened on to the correct torque as the arms may be slipping on the splines and momentum is carrying them too far.

Thanks Steve

Yes I have a motor in good order if your interested

can supply the arms if their splines have worn too

Thanks

Benfur

Hi Benfur,

That is excellent news and may well take you up. Tomorrow I will do a bit of fiddling and see if I can assess the problem, following Steve's practical advice. I will then let you know what I will need to fix my 400.

Very many thanks,

David

[davidlexusls400]

Hi,

Given that the wipers are hitting both the park position below the bonnet line and the side windscreen trim this would suggest excessive wear in the mechanical links allowing sloppy movement.

The actual sweep area is determined mechanically and is fixed so the only adjustment you can make is the wiper arms position.

To check for excessive movement in the mechanism stop the wipers in mid sweep using the ignition key to cut power when in the correct position then gently lift them from the screen and see if you have any movement in the arms/links by moving them left to right.

There are various bushes in the mech but these may not be available as spare parts the exploded diagram suggests the whole linkage/motor assy may have to be replaced.

If this is the case I would go the s/h route, if you PM Benfur he may be able to supply.

Edit Just thought of another possible cause make sure the wiper arms are pushed fully on the spline drives and tightened on to the correct torque as the arms may be slipping on the splines and momentum is carrying them too far.

Thanks Steve

Yes I have a motor in good order if your interested

can supply the arms if their splines have worn too

Thanks

Benfur

Hi Benfur,

That is excellent news and may well take you up. Tomorrow I will do a bit of fiddling and see if I can assess the problem, following Steve's practical advice. I will then let you know what I will need to fix my 400.

Very many thanks,

David

Hi to everyone

I would like to publicly thank BENFUR who sent me a replacement wiper motor and other bits at great prices. He also sent me a note of how to fix the offending item - am absolutely amazed at the service, thanks. All now working as Lexus intended and will turn to BENFUR again for any other bits that fail!

Many thanks again

David

[benfur]

Hi,

Given that the wipers are hitting both the park position below the bonnet line and the side windscreen trim this would suggest excessive wear in the mechanical links allowing sloppy movement.

The actual sweep area is determined mechanically and is fixed so the only adjustment you can make is the wiper arms position.

To check for excessive movement in the mechanism stop the wipers in mid sweep using the ignition key to cut power when in the correct position then gently lift them from the screen and see if you have any movement in the arms/links by moving them left to right.

There are various bushes in the mech but these may not be available as spare parts the exploded diagram suggests the whole linkage/motor assy may have to be replaced.

If this is the case I would go the s/h route, if you PM Benfur he may be able to supply.

Edit Just thought of another possible cause make sure the wiper arms are pushed fully on the spline drives and tightened on to the correct torque as the arms may be slipping on the splines and momentum is carrying them too far.

Thanks Steve

Yes I have a motor in good order if your interested

can supply the arms if their splines have worn too

Thanks

Benfur

Hi Benfur,

That is excellent news and may well take you up. Tomorrow I will do a bit of fiddling and see if I can assess the problem, following Steve's practical advice. I will then let you know what I will need to fix my 400.

Very many thanks,

David

Hi to everyone

I would like to publicly thank BENFUR who sent me a replacement wiper motor and other bits at great prices. He also sent me a note of how to fix the offending item - am absolutely amazed at the service, thanks. All now working as Lexus intended and will turn to BENFUR again for any other bits that fail!

Many thanks again

David

Thanks David

Glad to help

Maurice

Benfur

[steve2006]

Excellent news it good to get a result but please what was the cause of the problem and what was the cure?

[davidlexusls400]

Excellent news it good to get a result but please what was the cause of the problem and what was the cure?

Hi Steve,

The problem appears to be a badly worn nylon bush that allowed far too much movement in the arms. In other words they failed to stop at each sweep! Benfur sent me a replacement wiper motor, which allows a little movement, but the wipers now operate perfectly! I now have a second hand wiper motor available with oval nylon bush!

I had a local garage carry out the work and with instructions from Benfur, it was a straight forward and inexpensive job. The result is a complete transformation and how the previous owner managed like this is completely beyond me. The impact on each sweep was truly alarming!

Hope this helps and best of luck.

Kindest regards,

David