8n eating bendix gears

[Anonymous-0]

After my bendix shattered (in bottom of bell housing in little pieces) I replaced the ring gear and installed new style starter drive. Old tractor cranked like a new one about 10 times. Then made horrible clunking noise (same as it did when last bendix disintegrated) then locked up. I pulled the starter and found that the new bendix is now cracked between almost every tooth. Any ideas would be appreciated.

 

[Ramon]

Was the starter mounted properly, i.e. square with the case? Did you double check the ring gear on the flywheel before you installed it? Starter armature shaft OK, possible burrs?

 

[Den N Ms]

Chris,Question,was the starter ring gear put on the flywheel the right direction?Bevel on the teeth on the same side of the flywheel as the clutch.

 

[Dean]

Chris:

Has your tractor been converted to 12V?

If so, are you using a 6V starter?

Dean

 

[Bob]

Dean,

If a 6-Volt starter on 12-Volts is his problem, there's gonna be LOTS of broken starter drives out there!

 

[Anonymous-0]

Chris; Sometimes the ignition timing running too far advanced can be the cause by a kickback effect of sorts? Causing those newer style of bendix to disintergrate? You might check that out if nothing else seems to be the cause. Jim.

 

[Anonymous-0]

tractor was converted to 12V several years before I got it. No problems with it until now (and none reported by previous owner). I've been using it pretty hard for about 4 months. Ring gear professionally installed at machine shop, bevels appear to be facing corretly (toward rear of tractor). Visually verified that it is seated all the way around before I installed Flywheel. Starter was mounted correctly (flush all around). Can't SEE any deviation (bend) in shaft and little play in shaft. Couldn't say whether the starter is 6 or 12V.

Remember that whole issue began when first bendix shattered. If it's kicking back, I haven't noticed it. I'm an old hot rodder and have played with timing (on chevys) quite a lot, but this tractor doesn't share a lot of behaviour with a big block chevy.

I was thinking bent shaft or excessive end play.

 

[Anonymous-0]

Incidentally, the first one to break was the old style... the second was a new style.

 

[jim(SE-Mich)]

My best guess (after 50 years owning and using 9,2,8N's) would be to retard the spark slightly.
I am convinced that (from your description) it was kick-back from the ignition firing too soon.
Did you reset the timing recently or change the points?

Be sure to let us know for everyones benefit what solves the problem.

 

[Bill2]

Check to see that the shaft on your starter is not bent. That happened to mine when a ring gear was torn up.

 

[Anonymous-0]

Haven't touched the ignition (points) since I first got it home. I hadda clean them to get fire, but didn't even check the gap (front distributor... my first). If someone will give me a hint, I'll retard the timing a bit to see if that has any impact. I believe that I'll replace the entire starter instead of just the drive, since it's only a few dollars more. That way I'll also eliminate any other problems the starter might have.

 

[Tom N MS]

I agree. Of course you know lots more about these old machines than I ever will but, the 6 Volt starter is not an issue at all.

 

[Bob Harvey]

Silly question, shouldn't the 'beveled' part of the ring gear face forward (towards the engine) seems to me that with the starter drive engaging from the 'block' side to the tranny side, it should be "intuitively obvious" that the beveled side eases engagement. Pls. correct if wrong.

 

[JOHN HUNT]

so now you have to rebuild the starter, it bent, it took out the ring gear too.. so you have to replace both of them... before you brake the case of transmission like i did ... there not cheap too...

 

[Anonymous-0]

starter drive engages from back to front. That is, the starter drive rests behind the flywheel (tranny side) and engages by being "pulled" into the flywheel (toward the starter motor).

 

[Dell (WA)]

Chris........the 4-nipple frontmount distributor is "different". 1st REMOVE the distributor to TIME the ignition at 1/4" per picture. Thats right 1/4" gap. It is also 0degTDC, butt'cha can't time the squarecan with timing light. Ain't NO TIMING MARKS. Werse'zan Chebbys.

Ittza 2-bolt, 15-min job to remove yer frontmount distibutor and work it on the kitchen table. Points gap is 0.015" and timing is 1/4" gap. The distributor is driven by an "off-set" tang scheme and you can NOT install outta time. Just gently finger start the 2-bolts and then twirl the rotor roundy-round till the off-set mates and drops in. Then tighten yer 2-bolts 12-ft/lbs and snapple yer danglin' 4-nipple cap back on. Simple, eh?

So you think replacing a $150 starter motor is money saved over replacing a $40 starter Bendix? ........my math computes differently, Dell

 

[Dunk]

(quoted from post at 17:25:18 03/18/08) Dean,

If a 6-Volt starter on 12-Volts is his problem, there's gonna be LOTS of broken starter drives out there!

Reckon it would help to change the starter switch???

{sarcasm dripping}

(This has nothing to do with you, Bob)

(But I bet you know why I posted it.)

 

[Dell (WA)]

Bob.........I can't believe you posted that (grin). The "camfered" edge of the flywheel ring gear FACES the INCOMING starter bendix gear. Which is being "sucked-up" into the flywheel ring gear from the tranny side. So it should be "intuitively obvious" that the beveled teeth edge should face the tranny.

This is un-like modern starter motor drives where the drive extends into the flywheel ring gear from OUTSIDE the engine block. And the ring teeth are beveled facing the incoming starter drive.........respectfully, Dell

 

[Anonymous-0]

Dell, I was hoping you'd get involved. I paid $67 locally for that drive (Oil City Tractor) and I can get a whole starter (with drive) on Ebay for $104. Since I'm half convinced that the starter itself is the cause of the issue (bent shaft or excessive endplay) I'm thinking that the starter needs to be replaced, and the whole unit is cheaper than replacing the drive again THEN finding out that the starter motor is the prob. I will retard the timing at any rate, since I've about convinced myself that I did (ater all) MAYBE feel a little kick back when the bendix let go. The new ring gear wasn't unharmed by this latest failure, but it's still a lot better than the original.
I appreciate all the help. I'm an old gear head (rodder) that's swimming in new waters.

 

[Dell (WA)]

Chris.........$67 for the improved "clutch" style starter drive. Hiway Robbery. Our Host, Yesterdays tractor only wants $36.75 (cheap)

As fer retarding the squarecan ignition timing, most complaints are they can't gitt-itt to advance fer enuff. The side-slide timing screw stops'em.

Remember, 6:1 flathead was designed for clear NO-LEAD 70-octane gas, not modern 88-octane no-lead gasoline. I really don't think over advancing yer frontmount ignition was yer original problem........Dell, yer self-appointed sparkie-meister

 

[Steve IA]

When my NAA showed similar symptoms, I found after close examination and a couple of bendii, that the bushing that supported the starter shaft was worn enough so the shaft and bendix were no longer square with the ring gear causeing binding/breakage.
Got a rebuilt started and that fixed that.
HTH.
Steve 8N 169302

 

[Anonymous-0]

Well, just re-checked the starter and the shaft is definately bent. Probably was after the first drive let go. Wish I'd checked it closer then. Then I'd know for sure.

New starter will be ordered today.

Once it's in, I'll update this.

Thanks All!

 

[Bob Harvey]

Oops, musta had my mirrored glasses on !!