John T - Starter motor question

I have the starter motor off a 55T baler, which is in as new condition, and am considering installing it on a W4, which doesn"t have one at the moment. I have changed the pinion and Bendix assembly with one from a Super A starter. Can you tell me how to reverse the direction of rotation please.
Also, this motor has four field poles compared with two on the other motor. The baler engine is a Super A engine so would have thought the starter motors would have been the same.

Your comments would be much appreciated. Sid.

Even if you rewired the starter to run in the opposite direction, the spiral on the armature shaft will be wrong. It will move the drive in away from the ring gear when it starts to turn.

Owen is correct, The armature will need to be swapped out. I am not sure how you got the drive to assemble with the spirals reversed. If the motor was on the baler pointing to the rear from the front of the FW, it will really not work. JimN

Cedric, I agree with my friends who have more specific IHC knowledgeable then myself, Im knee deep in theory on IHC or any brand, but Im more of a John Deere man when it comes to specific and detailed questions (like starter direction etc).

That DC starter motor is series wound so to reverse its direction you need to reverse the relationship (such as swap ends of field connections) of the armature versus the field windings HOWEVER as Owen first noted below if?? it has an inertia type centrifugal (Bendix) starter drive if its (motor) reversed it wont spin/engage outwards.

Based on starter work Ive done and buying parts etc... IN MY OPINION IT WOULD BE EASIER CHEAPER N BETTER to get the correct strater versus having to re wire to change direction and change out an armature etc to get the correct shaft. That assumes you indeed do need to reverse the direction, of course

best wishes

John T

Cedric - To reverse starter rotation, the brush connections must be rotated electrically 90 deg releative to the fields. 2 ways to do this:

1 - Rotate the commutator end plate 90 deg from its present position (Which direction doesn’t matter)

It’s not easy to accomplish. New holes for the thrubolts are required in the end plate, a new hole located/drilled for the commutator plate locating pin, and the field conductors (copper straps) repositioned/reconnected to the insulated brush holders. It also now puts the end plate bushing oiler in an odd position.

-or-

2 - The field shoes/coils can be removed and reinstalled inside the frame rotated 90 deg. Again this requires repositioning and reconnecting the copper field straps to the insulated brushes.

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Of course you need the a new bendix for the opposite rotation – which you’ve already done.

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Were the starter mine I’d take it to an old time starter/alternator shop tell them what you need, and let them rework it. Alternatively I'd sell the starter you’ve got and use the proceeds to help pay for a rebuilt “correct” starter for your W-4.

Do you want to buy a starter for that engine.

Cedric: The difference for different rotation is starter positioned ahead or behind the flywheel, and any I've run across the armature had to be changed to change rotation.

My own personal experience was rushing off to a auto electric shop with a non working 1066 starter. Having 7 tractors, 4 trucks, 2 skid loaders and combine this was a shop I visited quite regularly, and knew the owner well. He knew I was in a rush and from my discription, knew it needed brushes and armature. He had me out of there in 15 min. during which time I socialized with another customer.

Home I go, install the starter and 1066 wouldn't start. Standing beside the tractor, I told the operator to hit the starter, ah ha, the fan was turning backwards. Back to the rebuild shop. Bear in mind the shop operator knew I also had a IH truck with 466 engine. We both agreed we should have communicated better the first time, plus he should examined the starter a bit closer. That is the difference between a 400 engine in a 1066 and 400 engine in a truck. Same block and flywheel but tractor starter is behind flywheel, truck starter ahead of flywheel. Different armature and starter drive.

Thanks to you all for your response to my queries about the baler starter motor.

Hugh: The baler engine starter is in front of the flywheel which presents a similar problem to that which you experienced with the 1066 and the truck, and is why I want to reverse the direction of rotation.

To make things a bit clearer, I have three motors, one off the baler engine, one from a Super A and another of unknown origin but is similar to the S/A. The S/A motor does not have a threaded terminal post to attach a cable to, so cannot use it, whereas the baler motor does, and when mounted in position on the tractor the terminal is located near enough to where an original W4 starter would be. Also, the armature is as new with the varnish still on the rotor and barely a mark on the commutator. I have fitted the Bendix drive and pinion off the S/A so it is just a matter of changing the direction of rotation. I had hoped to do the conversion on the cheap by doing it myself, but if it comes to the crunch I guess I will have to take your advice and get an auto electrican to look at it.

An unanswered question in my last post: I am interested in as to why the baler engine starter has four field windings in it compared to the others which only have two. Any suggestions ?

Thanks, Sid.

The use of 4 field magnets produces more torque (and consumes a bit more amps) than a 2 pole.
My concern is that there may be armature differences between the two setups.
The armature pole to commutator segment offset. determines which winding gets what polarity when.
As does the location of the brushes around the commutator. I would check the commutator carefully to assure the same offset configuration, and number of segments etc.
One simple way to do this is to silver solder a copper stud to the top of the switch post on the starter body without the post.
Crossing the field connection wires where they attach to the brushes (to the opposite brush should make it reverse, but it might not be in ideal time. Thus will run, but not optimally.
Another option is to have a threaded stud put in to replace the switch post at a shop. No issue, broken stude are commonly replaced. JimN

The biggest problem still remains with the armature shaft. The splines in the shaft that the Bendix drive slides on are spiral cut. When the direction is reversed the the spiral must also be reversed or the drive will retract instead of extend when power is applied.

The Bendix spring, helical spline and the pinion are mounted on a separate sleeve which can be removed from the armature shaft. This enables different size pinions and different rotational splines to be fitted to the same armature. I had already made this swap. Reversing the direction of the armature is going to be too much of a hassle so have given up on the idea. Sid.