Bush Hog 406 (drive shaft slipped off of Gear Box input shaft) Need advise (with pic

[pharmvet]

Well, I just posted 2 days ago about how proud of myself I was for shortening the drive shaft in my Bush Hog 406 and this afternoon I suffered a setback. I was shredding some pretty large brush/trees (approx. 2-1/2 to 3" diameter). I heard a different noise and looked back to find that my PTO shaft had come apart at the gear box. I immediately shut off the PTO and idled down the tractor for inspection. Upon closer examination I found that the drive shaft just rearward of the slip clutch had come off the gear box input shaft. As I mentioned in my post regarding shortening the shaft, I ran this shredder for about an hour last year. Other than that, this is the first time I have run it. It appears that there should be a bolt of some sort going through the male and female portion of the connection. Im not sure if this is a shear pin or a regular bolt. I suspect either one of 2 things happened"

1) The shredder came from the dealer without a bolt/shear pin.
2) My using it last year with the drive shaft being a tad too long put pressure parallel to the shaft and broke the pin/bolt, and using it just vibrated it apart.

Anyway, any and all suggestions and explanations on what I broke and how to fix it are welcomed.

[Bladehauler]

looks to me like the clamp bolts wernt tightened enough on the slip clutch, can you loosen them and slide the clutch back on the shaft and then tighten them down evenly.

[pharmvet]

looks to me like the clamp bolts wernt tightened enough on the slip clutch, can you loosen them and slide the clutch back on the shaft and then tighten them down evenly.

Yes, I think I can. Doesn't look like there was any damage done. What about the hole in the male and female portions of the coupling. Should there be a bolt through there to help prevent this in the future?

[Bladehauler]

since its a splined coupling,then yes , I would bolt it together through both.any bolt will do. grade 5 or 8 would be my preference with a nylock nut

[pharmvet]

Ok,just in case my dealer doesnt know, any idea what size bolt??

[banjodunn]

G'day you have a clutch on the pto shaft so you will not have a shear pin check your op manual for the correct adj of it. As for the bolts it looks to me like you will not have one that goes through the groove so take the clamp bolt into your local bolt place and get two new bolts grade 8 (or 10.9 if they are metric) and refit the shaft and tighten up ( your manual should give you a tension) and recheck the tension after about 10 - 15 min work. It pays to check their tension every time you back the clutch off and retension ( usually yearly )



Jon

[RickB]

looks to me like the clamp bolts wernt tightened enough on the slip clutch, can you loosen them and slide the clutch back on the shaft and then tighten them down evenly.

Looks to me like the OP simply loosened the pinch bolts then slipped the shaft on till the bolts butted up to the end of the shaft, then tightened the bolts.
Wrong approach.
The bolts must be completely removed so the clutch yoke can slip over the input shaft to the point where the bolts will engage the groove in the input shaft when installed. Then the bolts will clamp the yoke and sit in the groove completely preventing the shaft from coming off as long as the bolts are in place and tight.
No other parts are needed or used in this installation.

[pharmvet]

Rick, I think you are exactly correct. I don't think this could have come apart without doing damage had it been installed properly in the beginning. Several have mentioned that I should inspect the gear box and my tractor to make sure no damage was done when I ran it last year while the shaft was too long. Exactly where and what will I be looking for?

[Zebrafive]

If you do not have an owners manual, they can be viewed on Bush Hog's web site. You can also view the parts catalog.I think Bush Hog will even mail you an operators manual on request

[Zebrafive]

The hole in the gear box shaft is for non slip clutch applications, where a shear bolt would be used