# Removing a yoke from motor shaft



## electro wrks (Mar 5, 2012)

Have you tried removing the last bolt and driving a knife edge into the apparent parting line?


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## Duncan (Dec 8, 2008)

Take the last bolt out - the yoke driveshaft interface will have a recess and mating protrusion to ensure that they are aligned - this may have stuck together


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## GeorgeChapman (Aug 10, 2019)

Thanks for the suggestions, as advised i got the final bolt out and with a bit of brute force got the yoke decoupled.

This has reviled another conundrum; the flange that was holding the yoke seems to be attached to the shaft with a M29 hex nut (see attached picture).

My 2 options now appear to be :

try and remove the nut exposing the shaft
leave the flange in place and use to attach to the transmission coupling

I value any suggestions

Thanks


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## kennybobby (Aug 10, 2012)

Howdy George,
Post up a picture of the transmission coupling so we can see what you are working with. 

How are you mounting the motor and how are you mounting the transmission? The reason being the amount of error in alignment of the shaft centerlines will affect balancing and vibration levels.

A very rigid or stiff direct coupling will require high precision in the mounting alignment to avoid vibration and bearing issues.

The yoke coupling was likely used to allow some radial misalignment, and a sliding drive shaft would allow axial compliance without excessive load on the bearings.


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## Duncan (Dec 8, 2008)

GeorgeChapman said:


> [*]try and remove the nut exposing the shaft
> [*]leave the flange in place and use to attach to the transmission coupling
> [/LIST]


Use the coupling! - It will be designed to be well located and withstand any "swirl" forces from the driveshaft

What are you filling this to?

If it's an old longitudinal engine with RWD and you have a big enough motor then you need to keep that coupling and the yoke and simply drive the driveshaft directly


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## brian_ (Feb 7, 2017)

GeorgeChapman said:


> ... the flange that was holding the yoke seems to be attached to the shaft with a M29 hex nut (see attached picture).
> 
> My 2 options now appear to be :
> 
> ...


That's a great discovery. I see no reason to remove that strong and concentric drive flange; if you are using a flywheel you could bolt it to that flange, and if not using a clutch you could fabricate a splined coupler to suit the transmission input shaft with a matching flange.


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## brian_ (Feb 7, 2017)

The yoke was for a U-joint, so the motor would not have been mounted directly to a gearbox. That's perfect (just use the yoke with a new shaft) if not using a conventional transmission, but not useful if mounting directly to an automotive transmission.


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## brian_ (Feb 7, 2017)

GeorgeChapman said:


> ... the 4 M15 bolts...


Just a minor detail: bolt sizes are designated by the shaft diameter, not the hex size. Are those really M15 bolts (through 15 mm holes), or something like M8 bolts with 15 mm hex heads?


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## GeorgeChapman (Aug 10, 2019)

Thanks for the replies, some great advice.

Now just looking for a donor car which is big enough to fit it (11" diameter, 15" length & 110kg) but light enough to be propelled efficiently. 

It looks like i'm also facing the question whether to connect directly to the diff or retain the transmission (of whichever donor car i choose) but i'm still reading about the pros and cons of each.

Cheers


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## electro wrks (Mar 5, 2012)

Is this motor a shunt, series, or compound motor?


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## GeorgeChapman (Aug 10, 2019)

It's a series motor.


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