7610 PTO Brake quit working suddenly

Hurst

Member
My '86 7610 PTO brake has suddenly stopped
working. It is letting the PTO drag along
slowly when it is disengaged. It was working
flawlessly up until a couple of days ago. From
what I have read, it sounds like the brand has
probably broken? The PTO still engages just
fine and disengages like it did minus the
braking action. It has load monitor, so I am
just wondering if there is anything to
adjust/look at before I split it at the rear
end? Does anyone happen to have these pages of
the repair manual scanned that they could e-
mail me a PDF?

Best,

Hurst
 
The first thing you do is pressure test the low pressure hydraulic system and make sure it's got 160-180 psi... or at least 150 psi baseline.. and if it doesn't... find out why not. Just because the PTO engages doesn't mean there's enough pressure there to drive a load.
It's certainly not impossible that the band is broken but on the scale of probabilities I'd rate that a lot lower than a hydraulic supply issue.
If it's just a broken band you should be able to see that from the left side access cover... and you could probably change it through the top cover without a split... although if you've got an open station tractor it's probably just as easy to split it and be done of it.

Rod
 
Rod,

Is there an easy way of describing where the lower pressure test port is on this tractor? It has deluxe remotes if that changes anything. (I imagine it is going to be a port down by the hydraulic pump or up by the main valve under the seat) I checked the fluid and it is up to the full mark. The tractor doesn't have Dual Power, it's pretty basic. About the only option it has is the side saddle tank under your left foot on the operator's platform.

Hurst
 
Where is this adjusting bolt? Can you tell it is broken from the outside or would it be broken internally?

Hurst
 
Rod,

Given that it happened suddenly, I'd be leaning towards a broken band. I've actually seen more broken bands in my time than pressure issues.
 
Yeah, everything was working just fine last week, then the guy that has been driving it came to me today to tell me it was spinning slowly (not a good thing when hauling a manure spreader down the road...). I can go back and hold the beater by a rooster comb and it stops spinning without a whole lot of force. It won't hurt to check the pressure though, just to make sure nothing else is wrong. Does anyone have a picture of the test plug for the low pressure port? Would it be the port that the Dual Power on my 6610 feeds from but would be a blank plug on this 7610 since it doesn't have Dual Power?

Hurst
 
One other question...

If I do end up splitting this thing, it would probably be cost-effective to go ahead and replace the PTO clutch pack since it has been about 15-17 years since the last PTO clutch job on this tractor. Are the aftermarket kits that come pre-assembled any good? Like this one:
Ebay PTO clutch pack replacement
 
I wouldn't waste my money on that entire clutch pack. Why buy a housing when you don't need one?

Myself, I'd replace all the seals in the assembly, and maybe even reuse the clutch plates if they look OK. Sounds like you'll need a brake band for sure, but certainly not a housing, unless the bushing in the middle is torn out.
 
I have found the same clutch pack for less than $200, which would just leave me needing a brake band if that is the cause. It looks like the discs are about $150 from NH, so I thought if the quality was pretty decent on these aftermarket parts (I believe they are A&I) it might be cost-effective to do it while I have it apart given the tractor has quite a few hours on the current clutch pack and gets used on some heavy PTO equipment (20ft batwing and round baler). I imagine the 20ft batwing is what is doing most of the damage to the PTO clutch. I wish there was a neutral position that could be chosen to let everything spin down before the brake engaged (and allow for easier hookup).

Hurst
 
If it pressure checks OK I don't think I'd bother getting into anything other than the band if the band is the problem.
You could buy a load of A&I crap parts that are worse than what you have in there now..

Rod
 
There should be a 1/8" NPT pipe plug where I placed the blue "x" in the picture. This is where you would test the low pressure system for the PTO.

Remove screen #7 and clean it while you're there.
a177246.jpg
 
If the batwing mower doesn't have an overrunning clutch in the driveline, that's what likely tore out the brake band.

I agree with Rod. Don't put in inferior aftermarket parts if your factory parts look good. I don't care what the clutch pack costs, if the old one is good, leave it alone. Maybe pull the piston out and reseal it.
 
Rod,

It seems to me that the earlier 10-series tractors had more issues with broken brake bands. I do recall a service bulletin coming out talking about a beefed up brake band, along with stronger attaching parts. I'm fairly certain that this beefed up band came out after the 10 series was introduced.

So, if it had the older, weaker band, and the owner is frequently stopping a high-inertia implement without an overrunning clutch, then yeah, the brake band is most likely busted.

In my career working at FNH, I have replaced at least a couple dozen broken bands, easily. Most of those were on 6-cylinder, 8000-9700 tractors, usually pulling forage harvesters.
 
Thanks for the advice Rod and Bern! I was reading some older posts about the brake band and apparently it is a little finicky about the adjustment when you install it? Is there a specified procedure for installing it, or do you tighten it up tight one time to form it to the housing, then back it off just until the housing is able to spin by hand? It seems like even if it is just the brake band, it is worthwhile splitting it at the rear on an open station tractor vs doing the brake through the top and side so you can pull the assembly out and adjust the brake on the bench.

Hurst
 
I don't remember the setting procedure for the band so I'd suggest you reference the service manual while you're working on it. I'd also warn you that if you disturb the clutch that you observe the clutch support locator screw settings VERY carefully. IIRC, those only take a couple of foot pounds of torque and if set incorrectly they'll cause a side draft on the sealing rings and they're wear the housing or leak... or both.

In terms of splitting vs going through the top... I would say if you have an open station tractor without the lower fuel tank and NO LOADER, split it. If it has a loader or a cab or a side fuel tank or any combination of the three I think I'd pull the top cover and worm my way around installing the band that way. Just keep in mind that you will not be able to service the clutch drum that way if the tractor has a load monitor. So again... just a band can be done through the top. Plates can also be done with some screwing around but it's more work than splitting it.
If you do split it... MAKE SURE the plates all reseat on the output shaft when you're pushing it back together. You might be well advised to pull the top link rocker and let the rear bearing retainer and upper shaft slide rearwards while you push the tractor back together.

Rod
 
Like Rod, I don't recall the exact setting procedure on that band either. Also like Rod says, exercise caution when adjusting the locating screws on the side of the rear axle housing. Best bet is to find a manual and follow the directions to the T.

As for splitting versus going through the top, if the tractor does NOT have Load Monitor (it was optional on the 10 series), and does NOT have a cab, I'd go through the top. If it does have Load Monitor, it is my opinion that it's more trouble trying to fish around replacing parts than it is to split it. I think Rod has more patience than I do in that regard.

The biggest problem with splitting the tractor is putting it back together without damaging anything. I've seen more than one person really trash things inside forcing it back together. Be careful and have patience when joining the rear axle back up to the trans.
 
I have a few virtues.... but patience is NOT among them LOL

I just didn't find the band and clutch plates to be bad to deal with when the rear shaft and top cover is removed. Keep in mind that the time I went through that quest was due to hydraulic leaks and the cover was off anyhow... and IIRC, I had to change the PTO control valve. For a simple open station a split would have been easier but at that point it would have been extra for me to do that.. and then have to deal with a cab and fuel tank in my situation. There were moments when I was just about mad enough to burn the damn thing. That's how patient I am..


Rod
 
I was taught to set the band so that a well lubed band and drum will allow the valve assembly to rotate from 3 or 9 o'clock to 6 o'clock when the assembly is held by the drum. i't shouldn't drop like a rock, but smoothly rotate with a hint of drag. Done more thna a few that way, and nevewr had to go back into one.
 

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