at the moment i remove the Hogshead to change the low speed notch. I removed the starter and the bendix. There is about 0,08 inch play in the starter shaft.
What is the maximum horizontal clearance in the shaft what i should have?
In my opinion zero end float / zero preload
If it has endfloat, overtime it will only increase.
Alan in Western Australia
Markus ; you can put some gasket paper [round] behind the shaft at the Brush end , so there is less movement
The subject of Model T starter armature end play has been discussed.
Letís talk about what causes excessive armature end play and how to correct it.
Armature end play in an original starter is primarily caused by armature end axial loads wearing the Babbitt bushing in the brush cap. The Babbitt bushing used by Ford was easy to implement in production and had good radial load carrying capability, but in the long run the axial movement of the armature and the narrow wearing surface of the armature caused the Babbitt to wear excessively causing end play.
Wear on the main mounting bracket Z Bronze bushing thrust area was limited.
When I completely rebuild a starter I address the brush cap bearing AND the mounting bracket bushing oil seal issue. One can use the bronze bushing sold for the brush cap, but I have found this solution unsatisfactory for two reasons. First there is no provision for long term lubrication of this and installation requires some special tools to face the thrust surface. Ford used grease similar to Lubriplate at the time of manufacture. The low duty cycle of the starter allowed this lubrication method to work Ok, but you find many starters that have been modified over the years to add an alternate lubrication method. I found using a pre-lubricated sealed 6201 Ĺ ID ball bearing with a spacer for the armature shaft solution easier to install with no lubricated problems.
When you are inside correcting the end play you can also add the much needed oil seal in the mounting bracket. The lack of seal in this area is one of the built in oil leaks in the Model T. Here is a link to a description of the seal installation.
Model T Starter Oil Seal Installation
When installing the oil seal you will also have to adjust the width of the thrust washer or the brush cap bearing spacer to get the desired armature end play and position the armature in the correct place in the starter case assembly.