At last working dynamo

[Tiger]

After spending a lot of time trying to get my original Dynamo to charge and possibly failing.
I purchased another unit and last night managed to get it working.
The one on the car is still not showing any charge but I can install the replacement unit.
The replacement unit has end float of about 1/16” I guess 
Is it necessary to reduce this before fitting??
I am reluctant to strip the working unit and wonder whether I could insert a packing washer near the large drive spiral??
Regards 
            Tim

[Stuart Giles]

The ball race bearing in the drive end controls the endfloat on A7 dynamos, so there should be none or a tiny amount if the bearing isn't totally knackered/loose on the armature spindle/loose in its housing. I would definitely want to sort this if it were mine. Even if the endfloat didn't get worse in use, the amount already there will cause ignition timing scatter.

[Bob Culver]

There is nothing complex, esp the last 35m type but keep an exact diag of what was where. However often spacers, washers etc missing and the Woodrow dwg despite caption is of the 35A model. Diags 35M have been published here, last by Dave Mann about 7 May. Beware the key does not damage the plain outer bearing.
If the main drive gear has to be held in a vice use soft wood clamps.

[Dave Mann]

  Photo 14 Dynamo drive end bearing.jpg (Size: 37.65 KB / Downloads: 397) That situation can arise if the washers each side of the bearing are missing or the spacer is worn down.

[Tiger]

After stripping my Dynamo .
It looks to have professionally built with a armature rewind.
However I can’t see why there is too much end float.
I am wondering whether the spacer fitted next to the large bevel is short.
Asking a lot here would anyone know the length ??
Tim

[Dave Mann]

As I've got a few spacers all of different lengths and all showing signs of being worn down I usually make them sized to suit the job.

[Tiger]

Thanks Dave
The spacer fitted is OD 18.3 mm
Length 13.5 mm

Shaft Dia 15mm

If you could help with a longer spacer that would be great.
I estimate a length of 21 mm would be needed
I am happy to shorten a spacer .
Regards
Tim

[Dave Mann]

Hi I have 6 old spacers ranging from 12.38 to 13.9 mm you are welcome to, 21 mm seems somewhat long is there something else missing.

[Tiger]

Thanks for your reply.
I can’t see anything missing after studying your diagram.
What do you think of adding an extra collar to the existing spacer ?

[Steve Bryant]

Hi all. I hope you are coping ok with your winter weather. 
Since this topic is about working Dynamos,  I would like to ask those of you in the know about the best way to repair  the rear end frame damage where the bearing  is normally pressed in. The casting looks like cast iron.                    

If I can't find a way to repair the damage, I'll need to find a good serviceable replacement for the end frame. I'm not sure but according to the Woodrow I am missing the large thin steel  washer which appears to go under the brush holders. I'm also missing the oil slinger at the front.  All part of the legacy of  the previous owner's servicing I'm guessing.

Cheers,
Stephen