Farmall H4 Magneto Impulse coupling puller. I machined this puller to easily and safely remove the most stubborn H4 magneto impulse coupling without damage to the magneto permanent magnets or shaft threads. This puller is an improved version of the original International H4 magneto SE-912 service tool. Couplings should be removed to clean and lubricate the pawls and spring to insure proper impulse trip point timing.

To pull the tightest coupling without damage simply lock the inner and outer drive members together with a drift pin inserted through the hole in the outer member as pictured in the 4th and 5th illustrations. Apply a box or socket wrench to the retaining nut and an adjustable wrench to one of the coupling driving lugs and loosen and remove the retaining nut. Insert and bottom the puller body into the coupling and tighten the hardened puller bolt while holding the outer member with the adjustable wrench. Tighten the center puller bolt firmly and with a light tap on the bolt head the most stubborn impulse coupling will be easily and safely removed without any damage to the magneto shaft threads or permanent magnets.