Starter bendix, drive?

My 1950 Farmall Super A has a 6V Delco Remy starter.
This is the gear in the "not engaged" position:
<a href="http://s723.photobucket.com/albums/ww237/farmallholder/?action=view&current=Starter1.jpg" target="_blank"> </a>

and in the "engaged" position:

<a href="http://s723.photobucket.com/albums/ww237/farmallholder/?action=view&current=Starter2.jpg" target="_blank"></a>

My question is: what type of drive do I have?
I know that Hugh was a strong advocate of the newer type "starter drive". If mine is NOT the favoured type, should I change it? If yes, can I just order a starter drive with Bermuda Ken or any other CIH dealer?
I appreciate your comments. Hendrik.

That's a Bendix drive alright!

The newer clutch drives are nice. But the Bendix drives have been reliably starting Farmall (and most other brand) tractors for 75+ years. With all respect to our late friend Hugh, I see no compelling reason to change over.

Incidentally a replacement Bendix drive can be purchased at your local starter/alternator shop for $40 or so.

whats wrong with that bendix, it looks to be in good shape.is the drive just sitting in the engaged by it self? the spring should push it back to disengage position.other than that if its working dont need one.its usually the drive teeth that get worn and the bushings.

I wouldn't change it if it still cranks the engine ok. The gear doesn't look worn. If you're still using a 6 volt battery. I would use 00 battery cables. Hal

Yo Robert, When "dudes" change from 6 to 12 volt I warn them it can be a bit tough on starter drives due to high kick in engage torque and, therefore, I recommend use of a light duty lower CCA 12 volt battery. You or someone else mention "clutch type" drives as an alternative in that situation, can you elaborate on that and/or the differences ???

On the pictured (what I describe as) centrigugal Bendix brand type inertia drives, once they spin out on the worm theres no slippage right, as they cant go out any further???

Is there some sort of "clutch type" starter drive that works such that the faster flywheel turning (like right after she starts) dont turn the starter real, fast which is tough on its bushings/bearings???

The other type of drive (like the old GM cars and a ton of other cars) is where magnetic solenoid action (NOT inertia as the one in picture) engages the starter gear into the flywheel teeth

Talk to me enlighten meeeeeeeee, youre the mechanic remember, I"m just an electrical dude lol

Ol John T and all in Indiana (Hoosier)

Hey John - as far as I know a "clutch type" starter is what's known as a solenoid-shifted starter; ie. the GM style you mention.

As the name suggests the solenoid shift starters use a solenoid to drive the starter pinion into engagement with the flywheel ring gear rather than depending on a fast-spinning bendix screw and inertia to drive it into engagement. Once the pinion is fully engaged the solenoid closes the power circuit to the starter winding and the starter begins to spin.

The advantage is the pinion is not turning when it engages the ring gear. This reduces wear (teeth chipping) on both gears. It also holds the pinion in engagement - and the engine cranking - should the engine hit once but not immediately start. (With a bendix drive a single cylinder hitting can drive the pinion out of engagement and the starter to spin free. The operator must release the starter switch then wait until the starter coasts to a stop before beginning another crank sequence).

Clutch style starters also always incorporate an overrunning clutch. This is so the starter armature cannot not be overspun if the operator is slow to release the starter switch once the engine starts.

----

As for reducing the shock on the bendix caused by a 6 to 12 volt conversion, rather than swapping in an undersized (smaller CCA) battery I prefer to keep full-size battery and use undersized ungrounded battery cable instead. This limits the inrush current and softens bendix engagement forces yet still provides a good, fast spin. Also retaining he bigger CCA battery helps cold weather starting – an issue for us poor souls in rural western NY where winter seems to last about 7 or 8 months(!) It also provides longer reserve capacity for powering lights with the engine stopped, to get the tractor back to the shed with after busted alternator belt, etc.

For a Super M I’ve found a #2 battery cable is right – it noticeably lessens the “bang” when the bendix engages, but does not significantly slow the starter nor cause the cable to heat up much. A smaller, easier cranking tractor (H, A/B/C, etc) could probably get by with a #4 battery cable.

Make sense? ...Bob

Okay, so I didnt before, but nowwwwwwwwwww take when you say "clutch type" you mean the solenoid type of starter VERSUS a starter motor that uses the inertia Bendix starter drive as shown in the picture. I.E. you cant just change the "drive", you need a solenoid operated starter (like most all old GM with the bottle lookin solenoid) where the solenoid engages the teeth instead of inertia making it screw out..

I thought before there was ONLY some sort of different type of "starter drive" you used on the SAME starters that had some type of over running clutch, but now take it you mean the whole system is different i.e. change the entire starter out to a solenoid operated drive engaging one versus the one shown RIGHT????

Interesting about using smaller cables verus a smaller battery HMMMMMMM I dont have any calculations but for sure a wimpy cable may drop guessing 1 or 2??? volts which has the same affect as my idea of using a wimpy battery !!!!!!Plus you have the advanatge you noted of more stored energy if you go with the big honkmin battery !!!!!!!!!!!! BY JOVE YOU MAY HAVE SOMETHING

John T

The new style starter drive refered to is not actually a clutch type. It still is inertia engaged and does not have a overunning cluth. It does have a reselient type of shock absorbing mechanism and works very well usually. Over the years I have had two of them that did not, they were very sticky and would not engage on the 6 volt system, one of them was mine just last winter. No amount of tweaking it would get it to be reliable every time, however, they gave me another new one . Should have, at $75 at CaseIH.
One more thing, to look at them you would say, this isn't going to work and also, you can leave out the two spacer washers that were used with origninal bendix style. Must of course keep the small ID one to control end play of armature. Far as undercutting an armature, if it was I do, if it wasn't I do not. Auto lite as used on Chrysler products way back in the 40's did not undercut, Delco quit doing it somewhere in the 60's or so. You don't smear the copper in between the bars nearly as bad when it is not undercut. My op.

Have never seen "clutch" type starter drive in person but what I have heard is the spring and screw are replaced by some sort of rubbery device. The drive for M pictured on Messicks site looks like it may be the "clutch" type.

John T - That's how I understand it! At least I've never seen a non-bendix, non-solenoid shifted clutch-type starter - unless you count the old GM "stomp on" (foot pedal-engaged) starters from the 40's and early 50's.

Another thing: When swapping a bendix starter for a clutch-type starter you also must provide a separate, low current starter switch (key or push button switch) to supply the starter solenoid. The OEM saddle-mount and light bar mounted high current switches are a bit cumbersome to adapt otherwise.

----

As for the voltage drop thru the undersized #2 battery cable, 2 volts end to end is what I seem to recall. I'll check next time I fire up my Super M and will post back! ...Bob M

Quote from John T above:
"I thought before there was ONLY some sort of different type of "starter drive" you used on the SAME starters that had some type of over running clutch, but now take it you mean the whole system is different i.e. change the entire starter out to a solenoid operated drive engaging one versus the one shown RIGHT????
"
John,
This is exactly what I always thought of when Hugh was talking about a "starter drive". So I envisaged changing from a Bendix to a "starter drive" being a simple job. I am not looking forward to modifying the whole starter and switch.

Rustred,
I manually placed the drive in the engaged position for the second pic and it stayed in that position. Just touching the drive was sufficient to send it back to the disengaged position. Is that correct or is my spring weakened?

Just an FYI. Those "replacement" drives are actually trying to solve the torque spring problem. The Bendix drive has that hefty flat wire coil spring that connects the motor to the drive pinion, and it tends to break. All the gas over diesels guys can tell you about it in detail. Leave it in diesel and try to crank it and it may be your last attempt at tractor driving for the day. Nothing a $100 and a couple of hours can't fix, if you can get the replacement spring. The heavy engagement of a 12V on a gasser may do the same thing over time. The spring takes a beating and eventually cracks.

PS: The later Bendix style drives got rid of the coupling spring.

I think you are correct, the drive in the picture above has not got the flat wire spring. I spent 15 minutes looking at sources for IH new style bendix drives, and the old style. The new have the thin wimpy spring, and no provision for the flat wire spring. The Clutch nomenclature is probably Bogus (if someone has different pictures let us see the real clutch drive!) JimN

You have the original Bendix drive. Ive feen using them for like 50 pluss yrs and no problems on all the 6v tractors. It sure helps to have good ring gear on the flywheel.

(quoted from post at 00:15:39 11/07/09) I think you are correct, the drive in the picture above has not got the flat wire spring. I spent 15 minutes looking at sources for IH new style bendix drives, and the old style. The new have the thin wimpy spring, and no provision for the flat wire spring. The Clutch nomenclature is probably Bogus (if someone has different pictures let us see the real clutch drive!) JimN

Click to expand...

The newer style drive does have a clutch built into it but it still operates the same as the old spring style. There is a ratchet style clutch on the back face designed to reduce the chance of overspeeding the armature in case the driver does not return to the disengaged position soon enough.

Thank you all! I appreciate all the effort you put into my question. What I understand is that if all major components like starter, Bendix, ring gear, cables, starter switch, battery and connections are in good shape there should be no problem starting a well tuned engine.
I'll keep my Bendix while my ring gear is in good shape.
Hendrik

The ratchet style drive replaces the roller style over running clutch used on solenoid operated starters. I just replaced three drives on H tractors in last year and have been using them since their introduction over 20 years ago and there is no ratchet or overruning clutch. Stricly enertia engagement and disengagement. I have not had the need to tear apart the shock absorbing driving member to examine just how it is put together as I have not seen a failure that wasn't warranty .