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[ksd]

Gentlemen :
 How do I trouble shoot the wiper drive system? I know my motor is good. I suspect that the driver's side wheelbox assembly is bad but wonder also about the drive cable. The passenger side wiper runs great but the driver's wheelbox/wiper slips or pops out of gear so to speak.  Is it the gearbox or the cable? I don't look forward to replacing a wiper gearbox but think that's probably the problem. Anyone out there have any ideas based on their experience? Thanks KSD

[charley fitch]

The drive cable is not really a cable at all.  It is more like a linear gear that runs through the wheel boxes where a circular gear then mates up with it to turn the wiper stem.  If you are having a problem with just one wiper especially the driver's side, then the 'cable' should be okay as would be the wiper motor.  So what you need to do is have a look at the gearbox that is found behind a small cover under the dash.  The biggest problem is just getting into position to work on it.   And of course the driver's side is harder because of the steering wheel.  I am guessing that it could be something as simple as the gearbox has become loose on the cable and needs to be repositioned and tightened down.  They are really extremely simple in design.  Like I said the real problem is the access.

Charley Fitch 

[herald948]

I second Charley's advice...and yes, access is possibly the worst part. It is quite possible that the gear for the one wiper is worn. Good news, though, is that the typical wiper only works through about 110-120 degrees of arch, so it might be possible to remove the wiper arm, loosen the cable, and then rotate the gear by about 180 degrees to what then likely will be clean and unworn gear teeth. Then reassemble.

[ksd]

Herald946
   When you talk about loosening the cable to rotate the gear in the wheelbox assembly will this be done at the wheelbox? I'm having a difficult time visualizing this as I haven't gained access yet and can't find a good illistration of an actual wheelbox to see how it's put together and might come apart. Maybe when I get under the dash and pull the cover it will become obvious.
 Thanks to you and Charley and all the others that make this forum such a great source of tech advice and info. KSD

[charley fitch]

Yes it is done at the wheelbox.  The wheelbox is simply two pieces of metal that enclose the gear that connects to the actual wiper and the cable runs through the wheelbox.  The screws that hold the wheelbox together are what also hold and position the cable against the gear.  Under the dash you will find a plate the gives you access to the wheelbox. 

Charley Fitch 

[ksd]

 Thanks Charley:
 Also want you to know that the rear spring installation went well and I'm back on the road again with a much better riding TR4 thanks to your advice  and  encouragement. KSD