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Fri Jul 10, 2015 10:46 am

Hi

The right-hand wiper keeps overshooting the cab and the connecting rod pops off the ball joint.

The wiper spindle goes past horizontal when the connecting rod is reaches its furthest left hand position, so the rod tries to push it over the top on the way back. The spindle jams and the rod pops off the ball joint.

Should there be some sort of stop on the spindle to stop it travelling too far?

The motor is an early 6V motor (round rods), but the truck is 12V. I've ordered a voltage converter too.

Thanks

Andy

Fri Jul 10, 2015 11:12 am

After a closer look at the OACDP page, do I have the wrong shafts? The cranks on the back on mine are flat, the ones on OADCP look round. Are the flat and round cranks different lengths?

Crank...

Motor...

Fri Jul 10, 2015 11:56 am

What year is your bus?

WW sells a 55-64 12v conversion armature.
https://www.wolfsburgwest.com/cart/DetailsList.cfm?ID=113955811B

Here's pics of shafts/pivots:
https://www.wolfsburgwest.com/wolfsburg_new/electrical/bus_electrical/wiper_shaft.cfm

Fri Jul 10, 2015 12:16 pm

It's an October 56 build (so 57 model year).

Looks like the shafts are correct (for repros).

I may convert the armature to 12V, but the right hand arm overshoots even if I move the wipers by hand, so I'm not sure that the motor is the issue?

Fri Jul 10, 2015 12:25 pm

Is the arm in a good "home" position at the other extent of travel?
If not, adjust arm base on pivot shaft.
If yes... not sure what to suggest.

No travel stop at pivots.... would jam motor.

Fri Jul 10, 2015 12:33 pm

Ahh :?: Good idea. I'll check in the morning.

Maybe the arm is set on the spindle such that inertia is carrying it too far for the rod to recover it...

Fri Jul 10, 2015 12:41 pm

The only other thing I could think of... is if the wiper rod bracket was attached upside down on the shaft, at at the wiper motor... and that would only make sense if the arms are different lengths. I don't know if they are. But, if they are... the other wiper might be having an odd travel issue too (maybe short throw).

Fri Jul 10, 2015 1:00 pm

Quote:
The wiper spindle goes past horizontal when the connecting rod is reaches its furthest left hand position, so the rod tries to push it over the top on the way back. The spindle jams and the rod pops off the ball joint.

I can't quite picture this.
What length is the right hand linkage?
FWIW, the right one is the one that pops onto ball joints at both ends, the left one that just pops onto the socket on the pivot, but is attached at the motor.
no, there is no stop.

The arm attached goes to the left side of the bus. Is that how yours is?

Sat Jul 11, 2015 1:09 am

Thanks Clara, yes, it's the rod that pops on at both ends that keeps popping off.

Easy e - I tried adjusting the wiper arm position to see if I could stop it doing so, but that didn't work either.

There is a fair bit of 'slop' in the right hand linkage (I can move the arm and spindle some distance by had before the left hand wiper starts to move). I don't understand how that can occur though, because both arms connect to the same bracket.

I'll post a photo of the crank position when it's gone past horizontal, then I'll pull the wiper motor out and check what's going on behind and measure the linkage.

Sat Jul 11, 2015 7:03 am

FWIW, it is not unusual for the 6V motor to pop the rod off under 12V power. So a voltage drop or 12V armature can be the solution for that.

Sat Jul 11, 2015 10:20 am

Who.Me? wrote:
There is a fair bit of 'slop' in the right hand linkage (I can move the arm and spindle some distance by had before the left hand wiper starts to move). I don't understand how that can occur though, because both arms connect to the same bracket.

The linkage ends can have the steel spring clip part inside that can be loose after all these years. Have retightened those up with small punch, hammer and a good hard surface as an anvil.

Check that the linkage connection to the wiper motor is bolted down tight.

The rubber mounts should keep the motor tight and at same time insulated from the body to cut down on wiper noise to the interior. In your image the right one is not installed correctly.

If you have not done so it is a good time to regrease the wiper motor gear box for faster wipers and much quieter operation.

Sat Jul 11, 2015 6:27 pm

Who.Me? wrote:
There is a fair bit of 'slop' in the right hand linkage (I can move the arm and spindle some distance by had before the left hand wiper starts to move). I don't understand how that can occur though, because both arms connect to the same bracket.

If you hold the linkage end of the pivot with one hand and wiggle the wiper arm with you other hand, does it feel like there is slop on the pivot?

Sun Jul 12, 2015 6:14 am

Didn't have a chance to do much investigation today, but did take the rod out to check its length.

It's 290mm without the fittings on the end and 325mm with the fittings.

Clara, do you mean is there any slop as the spindle passes through the body?

Thanks

Andy

Sun Jul 12, 2015 7:15 am

Who.Me? wrote:
Clara, do you mean is there any slop as the spindle passes through the body?

Thanks

Andy

Exactly.
I have a pair of new safari wiper shafts I just installed and both are sloppy. The one is so sloppy that the actual area the wipers wipe is maybe half the size it should be.

The new non Safari shafts from WW I put on my dads 63 truck were nice. I was very happy with those and would buy them again.

Sun Jul 12, 2015 7:25 am

The ball end of the wiper rod has a threaded connection. Have you tried reducing the travel length? Loosen the set screw and you can shorten the total rod throw. To Clara's point, check the condition of all the moving parts, pivots, and motor connection.

Tue Jul 14, 2015 10:07 am

Well, I think I might have located the problem :? ...

The motor shaft is bent. Quite a bit...

On the 'push' stroke, it looks like it must be pushing the connecting rod up to 5mm further than it should and on the 'pull' stroke, it will be pulling it by the same distance in the opposite direction.

Looks like I need a new armature anyhow.

Reading the Bentley manual, it mentions that the wipers should 'park'. Mine don't at the moment. Should this motor park the wipers when the switch is turned off?

Tue Jul 14, 2015 10:09 am

Clara wrote:

Exactly.
I have a pair of new safari wiper shafts I just installed and both are sloppy. The one is so sloppy that the actual area the wipers wipe is maybe half the size it should be.

The new non Safari shafts from WW I put on my dads 63 truck were nice. I was very happy with those and would buy them again.

I checked the shafts while I was out removing the motor. There is some movement, but I think that's the rubber washers compressing. They don't seem overly sloppy.

I think the motor shaft is the main cause of the problem.

Tue Jul 14, 2015 10:23 am

Who.Me? wrote:
Reading the Bentley manual, it mentions that the wipers should 'park'. Mine don't at the moment. Should this motor park the wipers when the switch is turned off?

Only if you have 1965 and later wiper motor in there.

How tight are the steel snap in cages in each linkage female end??

Tue Jul 14, 2015 11:22 am

Eric&Barb wrote: Only if you have 1965 and later wiper motor in there.

How tight are the steel snap in cages in each linkage female end??

Thanks.

The snap in cages are very tight. I have to twist a screwdriver to pop the ball joints out and it's painfully (literally) difficult getting them back in using my fingers.

Tue Jul 14, 2015 12:17 pm

Who.Me? wrote: Clara wrote:

Exactly.
I have a pair of new safari wiper shafts I just installed and both are sloppy. The one is so sloppy that the actual area the wipers wipe is maybe half the size it should be.

The new non Safari shafts from WW I put on my dads 63 truck were nice. I was very happy with those and would buy them again.

I checked the shafts while I was out removing the motor. There is some movement, but I think that's the rubber washers compressing. They don't seem overly sloppy.

I think the motor shaft is the main cause of the problem.
There should be *no* slop. maybe very little. how much is 'some'?

Have you tried the voltage drop yet?

The motor just spins the shaft coming out of it round and round.