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MG TD TF 1500 - Smith's RD 141 Tach Reduction Gearbox

Good day all:

A few queries will be raised from my following epistle so please bear with me.

Firstly; this information quest applies to a TC Dynamo situation, but the set up for securing the TD reduction gearbox is the same.

Right then. I have a period Dynamo from a Morris vehicle that was not suited for tachometer use. That is, it was sans the split segment at the CE Bracket end designed to accommodate the reduction gearbox keyed portion. The CE Bracket was also without the threaded boss needed to affix the reduction gearbox in its entirety.

These problems have since been remedied by: 1) the addition of a threaded extension, supplied by Mr. Joe Curto, and machinist fitted to the CE end of the Armature shaft: 2) a press fit, threaded piece, supplied by ASL (Part # 35-052 B) installed in the end of the CE Bracket boss. The armature is now identical to an original unit and the CE Bracket is also functional.

The CE Bracket fitting, was pressed in and instead of Loctite 90 or such, it was fixed with a set screw.

The primary question arises with respect to the latter.

In the case of original equipment, the Armature tip is just below or flush with the outer face of the fixing boss. With respect to the above, the end of the Armature protrudes about 3/16 of an inch past but does not seem to affect the securing of the gearbox.

Is it necessary for the tip of the Armature to be flush or enclosed within the boss? And, does anyone foresee any dangers arising from the exposed 3/16 of an inch noted above ?

And lastly; I seem to be missing the keyed portion from a spare reduction gear box. I notice a small set screw, through the shaft of the existing portion extending from the gearbox, and I ask, is the keyed portion a separate part ? If so, are they available from some known source ?

I reckon I have tired you all and to avoid plugging up the forum, if anyone wishes I can be notified directly at: carminowe@eastlink.ca

Cheers then; respectfully:
Jack Emdall, TC6768/TD3191, Halfmoon Bay, British Columbia, Canada
kernow

Jack I'm working on repairing one (reduction box) right now. I'd be concerned that the protrusion will be spinning against the bronze bushing inside the gear box and you will have failure in short order.

As to the parts...I just placed an order yesterday for a repair kit from Abingdon Spares after I phoned them and they confirmed that the "keyed" portion was included in the kit.
L E D LaVerne

Cheers Mr. LaVerne:

The ware factor also crossed my mind so I reckon I had best the shaft before using.

Thank you for the ASL heads up, I'll order as soon as I post this.

Respectfully:
Jack Emdall
kernow

Jack - You will need to get the coupling kit (Moss P/N 360-040) which contains the adapter that fits the shaft from the gearbox to the end of the armature. Cheers - Dave
David DuBois

Are the Abingdon & Moss "coupling kits" the same?

Both include new input shaft, set screw and "keyed portion" to be specific.

JIM
JIM NORTHRUP SR

Jack, search around in the archives. There has been a lot of stuff about tach drive mounting over the years that would be helpful. You can't have any front to rear pressure on the tach drive coupler, so you may well have to shorten the armature. George
George Butz

This thread was discussed between 20/11/2013 and 21/11/2013

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