Ford 7710 PTO Gears Noisey

Last week bearing went down on upper PTO shaft while rolling hay. Chewed up all the rear pto gears. Replaced the upper and lower gears. Installed the proper shims(according to manual) and checked the endplay and torque required to turn shaft, but get lots of noise from pto at idle. Smoothes out at higher rpms.

At teardown we did not have the shim in front of the bearing on the upper shaft, but manual says to be sure to install those. Thought that might be the difference in noise.

No noise at idle prior to the bearing going down.

Any ideas?

I would say that if you installed everything according to the book down to and including checking the rolling torque... it's probably OK. 10 series PTO's always make a racket at idle. Quite a loud clackety clack type of noise.... If it goes away above idle I'd think it's fine.

Rod

Agree with Rod. If it's not making noise above idle, I would ignore it. The shim on the upper PTO shaft would have no effect on the rattle noise, it's simply 4-cylinder engine harmonics that you hear. Try bumping up the idle speed just a tad, that might help also.

Something just hit me...what rolling torque? If the upper 2-gear shaft assy is supposed to have end play, why are we checking rolling torque? Rolling torque is usually only required for shafts that have preload, and that one definitely is not supposed to have preload. As I recall, it's more like .003" end play.

Please clarify exactly what you did with regards to rolling torque.

(quoted from post at 13:09:57 07/29/13) Something just hit me...what rolling torque? If the upper 2-gear shaft assy is supposed to have end play, why are we checking rolling torque? Rolling torque is usually only required for shafts that have preload, and that one definitely is not supposed to have preload. As I recall, it's more like .003" end play.

Please clarify exactly what you did with regards to rolling torque.

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The manufacturer service manual said that the output shaft should turn with 0-5ft/lb torque. The endplay specification was .001-.029in for the upper shaft and .003-.005in for output shaft. Checking the torque to turn output shaft was the very last step for installation in the service manual.

Thanks for the input.

Hmmm...I don't have a 10 series repair manual in front of me, however you may have mis-read something.

First, you don't check the output shaft (the 540 or 1000 RPM shaft) end play. Even if you did, you can't change it. I suspect that the .003-.005" end play spec is for tractors with single speed PTO, which you do not have.

Next, the .001-.029" end play spec is for the upper long PTO shaft that splines into the PTO clutch. This can only be checked with the top 3-point cover removed, or through the LH side cover.

Finally, the upper PTO cluster gear end play is going to be around .005", and not much more than that. If you have upwards of .030" end-play in that thing, that could well be the reason for your rattle.

I would STRONGLY suggest that you take another look at the manual to make sure you didn't make a big mistake. If everything is setup properly, there should be NO rolling torque of the final PTO assy (other than seal drag), assuming the upper drive shaft is not installed. If the upper shaft is installed, you'll be reading PTO brake band drag, which is going to differ depending on which output shaft you have installed.

this same exact thing happened to me on my 9700 i have to have my housing bored and have to get a sleeve machined so the bearing will fit in there corectly. luckly i had a parts tractor and it had brand new gears and bearings in who knew.

(quoted from post at 19:45:30 08/03/13) this same exact thing happened to me on my 9700 i have to have my housing bored and have to get a sleeve machined so the bearing will fit in there corectly. luckly i had a parts tractor and it had brand new gears and bearings in who knew.

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Good Luck I hope you get it going again.

Thanks for the input from everybody! We got it going and used it to pull a 15' bushhog this weekend with no problems.