Wiper Flip - Need Help

[FL911SC]

Greetings one and all,

1979 911SC

Request: Any tips or tricks to get the wiper drive arm back on the motor shaft after moving it 180 degrees.

The problem: I attempted to switch my wipers from at rest on the left to at rest on the right. This is a project in the 101 Projects book, however since I had some of the gauges out, I attempted this from inside the car. The wiper arm was difficult to get off the motor shaft, but I got it with the help of screw driver. I moved the assembly 180 degrees, however now I cannot get the wiper arm back on the motor shaft.

Details: As mentioned, I had some of the gauges out and proceeded with this from inside the car rather than going in from the frunk. It needed a screw driver to pop the arm off the motor so I knew it wouldn't be that easy to get it back on, but I had no idea it would be this hard.
I have placed the arm back on the motor shaft and moved it slightly back and forth to ensure the splines are lined up. Simple hand pressure to push it down doesn't result in anything. I put the washer and nut on hoping as I tightened the nut, it would push the arm down. However what happens is, as resistance is met while tightening, the whole thing (motor, arms and all) begins to rotate, which leads to the nut being covered by the arm and assembly and the nut not tightening. You will note in the picture that there are no threads exposed out of the nut, so I know it is not near tight enough.

I am hoping someone has a tip for pressing the arm down onto the motor shaft.

As always, thank you!!

Keith P.

[OffCamber00]

Odd indeed. I don't recall having that issue when i flipped mine years ago. Do you have another hand free to brace the arm to prevent it from rotating as you tighten the nut? Have you tried to pop off the nut and re seat it to make sure its threaded properly and not cross threaded and causing the arm movement you are describing? You may need to attack this from inside the frunk.

[FL911SC]

Mat,
Yes, I have removed the nut, and arm, several times to make sure everything is seated correctly. As well, I can start the nut by hand to help ensure is isn't cross treaded.
As for bracing it, I have tried several things, from holding it by hand to using zip-ties to hold the "arms" together. Nothing works.
This would be very difficult, but maybe of yours didn't fight you like this, perhaps I need to clean the splines.

Any other thoughts are appreciated.

[OffCamber00]

the only other thing i can think of is to loosen the bolts on the supporting bracket just enough to get the arm cinched down and then re-tighten.

[fintstone]

Try putting an open end wrench of the appropriate size on the arm (as it it was nut) to hold it in place when you tighten

[WMontald]

I swapped mine months ago (911 T 2.2 1970)
You do not need to close the gap as in your picture
The strut is conical and therefore fixing the arm is limited trough it's shape.

When connecting you just need to make sure that arm is at 5° from center, this avoids heavy force on it when motor is engaged.

[FL911SC]

Fintstone - that is a good idea and I will try it. Space is very limited but I think I can make work.

WMontald - I did notice the motor splines were conical, however since the arm was all the way down when I took it off, I figured it should be all the way down when I put it back together. As it sits, I am not comfortable with the lack of thread engagement at the nut, so I would like to get the arm pushed down a little more on the motor shaft. I will tighten it until I am un comfortable with the torque/force being applied and stop.

Your tip about off setting the arm is interesting. Does it matter if it is forward or backwards from center?

I will probably not work on this, this evening. The frustration is clouding my judgement. I tried to remove the blower motor in the frunk last night and that never happened. The article in the 101 Projects was worthless for this project and I never got it to budge let alone come out. So I am going to take a night off, think about it, and tackle it again tomorrow.
If there are any more tips or ideas in the mean time, I do appreciate them.
I will update the post with progress and the final solution, whatever it is.

Thanks,
Keith

[76FJ55]

I think there is a clip that you can see in your picture just above the plastic bushing which holds the motor assembly together. If you didn't see the gap there before you removed the arm it is because you weren't looking for a gap. You do not want to close that gap. If you manage to force the arm down that far and close that gap you will put those bushings into compression and cause binding in the motor.

I swapped mine shortly after getting my 84. Then I drove it in the rain and subsequently swapped it back.

[fintstone]

I had to go out and see for myself....since I did this so long ago. Checked my '74 (where the fresh air system is already apart). I switched this one from under the dash about 10 years ago. I also looked at a spare removed from an earlier '74 (also converted). I switched that one similarly about 20 years ago. There is indeed a gap in the second (not much in the first). It appears to me that as long as the nut is tight and you have a lock washer as shown in your photo, you are fine. See photos from various angles below for reference. The first two photos are from the wiper sys currently installed in car (taken from the frunk). Second set (remaining 6) are from the previous car...removed but not disassembled. Both worked well:

[FL911SC]

Originally Posted by 76FJ55

I think there is a clip that you can see in your picture just above the plastic bushing which holds the motor assembly together. If you didn't see the gap there before you removed the arm it is because you weren't looking for a gap. You do not want to close that gap. If you manage to force the arm down that far and close that gap you will put those bushings into compression and cause binding in the motor.

I swapped mine shortly after getting my 84. Then I drove it in the rain and subsequently swapped it back.

You may be right that I just didn't notice the gap that was there, however I am 100% it was tightened down more than it is now, simply because I could see threads at the top of the nut. I am happy you pointed out that there is a clip or bushing at the bottom, if I do get the arm down a little further, I will be sure not not to push it against the top of the motor.
Thank you!!

PS, you have me very curious about this working in the rain. That said, I do try not to drive in the rain since it is a Targa and not water tight. I will say the biggest reason for the swap is that I auto-cross and having the wipers our of the way will help with visibility.

[FL911SC]

Originally Posted by fintstone

I had to go out and see for myself....since I did this so long ago. Checked my '74 (where the fresh air system is already apart). I switched this one from under the dash about 10 years ago. I also looked at a spare removed from an earlier '74 (also converted). I switched that one similarly about 20 years ago. There is indeed a gap in the second (not much in the first). It appears to me that as long as the nut is tight and you have a lock washer as shown in your photo, you are fine. See photos from various angles below for reference. The first two photos are from the wiper sys currently installed in car (taken from the frunk). Second set (remaining 6) are from the previous car...removed but not disassembled. Both worked well:

Thank you for the photos!!!
The second set looks just like what I am looking at now. It is good to know that a gap that large, and no threads showing at the top of the shaft, can be correct, or at least work.
I also took a look at the on-line tech article for this project here on the Pelican site. I noticed in their photo that there is also a gap.

I think for me, I will re-set the stop position;
Remove the shaft once more, then reinstall it to off set it 5 degrees as noted in a previous post;
Put the new split washer (lock washer) on;
Then add a drop of blue lock-tite to the threats, then install the nut.
I will tighten it as much as is reasonable, and hope for the best.

Thank you again!!

And Thank You to all!!!

[fintstone]

Like you, I rarely drive mine in the rain. The only difference in performance I see is that the initial pass is slightly delayed (as it comes from the other side) so you need to turn them on a second or two sooner. Of course that assumes wiper tension is good and your blades are fresh.

[AG81]

Flipped mine about a year ago. Haven't driven in the rain in 4 years.

[76FJ55]

Originally Posted by fintstone

Like you, I rarely drive mine in the rain. The only difference in performance I see is that the initial pass is slightly delayed (as it comes from the other side) so you need to turn them on a second or two sooner. Of course that assumes wiper tension is good and your blades are fresh.

That was my initial thought too, however that is not the only negative. What you will find if you drive yours in the rain, the wipers swing to an almost horizontal position on both sides, which pushes a mass of water to the bottom of the windshield. With the wipers parked on the drivers side this mass of water is forced to the outside edge of the windshield and rolls off the side into the rain gutter. With the wipers swapped to the non-driver side, at the end of the cycle when the wipers park, the airflow over the car will push this mass of water up the windshield creating streaks/streams, which pass right in front of your visible path. in an effort to eliminate the streaks and regain visibility the only solution is to cycle the wipers, which again places the water at the base of the windshield and the cycle repeats itself.

[FL911SC]

I wanted to close this out.
Thank you again to each of you that replied, it helped a lot and I appreciate it.
I removed the arm from the motor one more time and offset it about 5 degrees as recommended. I don't know how to measure that, so I guess it was about one spline.
Then I put a lock washer and a drop of blue thread lock on, then got the nut as tight as I could. I then connected the battery and rotated the arm such that the short end stopped at the opening in the dash where the clock goes. This allowed me to put a 12" adjustable wrench in and hold the arm while I gave the nut a final tightening.
I never did get the gap to close, but I know it is tight. I would prefer to have better thread engagement at the top, but there is no point in breaking something.
I have included a photo of the final gap.
Thank you again!!!

[fintstone]

Thanks for the followup!

[WMontald]