swapping pto shaft on a 7610s

Soundguy · Jun 11, 2005

I've got a 2002 NH 7610s. it apparently has the 2 speed pto, as the 540/ 6 spline pto shaft is held in with a retaining ring, and according to the manual.. tht indicates it can be swapped out for a 1000 rpm shaft

I currently use a 10' mower setup for the 6 spline shaft on 540rpm.. I plan on getting a 15' batwing I've found for a great price.. but it's 21? spline / 1000rpm .

My question is: Is it really as simple as the manual states? remove the snap ring.. pull the 6spline shaft insert the 21? spline shaft, reinstall the snap ring?

Is there standing oil in this sump that I will lose and need to have a bucket ready for.. any tips / tricks... hidden problems?

This manual was for the 5610s, 6610s, and 7610s, so is vauge in some sections.

thanks

Soundguy

Soundguy · Jun 11, 2005

One more thing.. what should I expect to pay or that 21 spline pto shaft from CNH?

And is there any reason I shouldn't do this.. or should just wait for a 6 spline mower.. etc. ??

Soundguy

RickB · Jun 11, 2005

You should jump on the 1000 RPM mower immediately. The majority of driveline problems on Batwings are related to over-torquing 540 RPM drivelines, IMHO. Have seen 540 tractor output shafts and mower primary PTO shafts OF ALL COLORS twisted off from shock loads running big cutters. Changing the shafts will not be a problem once you figure it out. You have to line up two sets of splines. You can easily engage one, but sometimes it is necessary to rotate the seal collar a little by getting after the roll pin that protrudes near the snap ring. Or hold the collar and rotate the shaft. 9" needle nose ViseGrips work well for me. The shaft is well below the static oil level in the rear end, but the gears, thrust washers and bearings are stacked up in such a fashion that you may lose a cup of oil or less at each swap. Pull the shaft out with one hand, have the other in the opposite hand and stuff it in immediately. If you bought the tractor new, it should have come with the 1 3/8" 21 shaft as an accessory. Expect to pay in the neighborhood of $200 from NH, but that is off the top of my head. I strongly suggest you go this route for a 15' cutter.

Soundguy · Jun 11, 2005

I bought the tractor used .. but from the dealer who originaly sold it the year before. The guy owned an orange grove and kept banging into trees with it.. he brought it back for a tc48. It may or may not have had the 1000rpm shaft withit when new.. I just know I didn't get it. Explain a little more about that roll pin and snap ring issue, and the 2 splines to line up. I understand that the 540 and 1000 rpm shafts engage a different set of drive gears, and that's why they spin at different speeds.

Am I going to have to pull those 4 bolts that holed the pto seal/bearing in? or just the snap ring?

thanks for the info. I'm calling the dealer back on mondy and and will go back and look the mower over again.. If I like it I'll leave my credit card info and head to get my trailer.

Soundguy

RickB · Jun 11, 2005

No bolts, just the snap ring. Once you get proficient at it, it should be a one minute job. Really. The output shaft rides on an inner and outer bearing with the two driven gears and thrust bearings and washers between the bearings. The shaft seals against a sleeve with an o-ring. The sleeve is splined to and rotates with either shaft to reduce wear on the o-ring. The sleeve runs against a cassette seal fitted into the 4 bolt cover. Each shaft's splines engages the appropriate driven gear's spline and the outer collar. One shaft uses the same splines to engage the collar as it engages the gear with. This one is easier to install as it can be twisted slightly to engage each set of splines as you insert it. The other shaft engages the opposite gear first with one set of splines, then the collar just before full insertion with another set of splines. It may be difficult to turn the shaft and geartrain at this point, so it is possible to turn the collar to line up its splines using the short roll pin. The gears, collar, thrust washers and bearings are stacked and trapped in a way that keeps a lot of oil from coming out and also keeps the parts in alignment. maybe one of the guys at the dealership can give you a show & tell on this. All Fords and New Hollands built for North America with two speed non-shiftable PTO are very, very similar. Fiat- based New Hollands are a litle different, but not much.