Shaft is turning but it is not turning the teeth. bearings good,spline good.shaft good, gears good. the pto turns but doesn't dig and makes no noise. has no pins in housing are broken.

possible that the teeth of the pto dog are worn to a taper and not fully engaged
the lever for the engagement is moving the full travel to engage
the bearings on the pto shaft are failing and allowing misalignment of the shaft thereby walking the dog out of engagement

I am thinking that you have a broken/ stripped drive spline on a front axle. If you have reduction gears in the hubs , it may be stripped teeth on a gear. If you jack up one front wheel and turn the drive shaft that wheel should turn. IF so repeat the procedure for the other wheel and if it doesn't turn like the other side then that is the side with the problem

There is a gear that is in constant mesh in the PTO with a gear in the cluster shaft of the gear box. Fitting a PTO is a critical operation as there are shims between the PTO flange and the gear box housing to ensure correct teeth clearance . IF this clearance is not enough then the gears bottom out and jam prevention proper lubrication and rotation. Also it is vital that the teeth pitch of the PTO gear matches the pitch of the gear box gear as this will cause the PTO to be pushed of the side of the box.

Here's what Chilton has to say on assembling the main shaft.
1.assemble 2nd gear, from rear of main shaft, with hub toward rear.
2.Install 1-2 synchronizer ring , with clutch taper to rear, together with a blocker ring on each side so their keyways line up with the clutch keys. Some units will have a snap ring to go on now or some units will have a 1st gear spacer sleeve to go on.
3. Install 1st gear with hub toward front and 1st gear thrust washer.
4.Press rear main bearing onto shaft being sure to seat it firmly. The diagram shows a piece of 1 and 5/8 ID pipe used to do this.
5. Install correct snap ring in groove on mainshaft behind rear bearing. Max gap between snap ring and rear face of bearing is 0"-.005".
6.Install 3rd gear, hub to front, and synchronizing ring, notches to front.
7. Install 3-4 clutch assembly with taper and hub to front. Make sure keys in hub correspond to notches in 3rd gear synchronizer.
8.Install snap ring on mainshaft with ends of snap ring behind spline teeth.
9.Install rear bearing retainer. Spread snap ring in plate to allow plate to drop around main bearing and press on end of mainshaft until snap ring engages groove on bearing.
10. Install reverse gear with collar to rear.
11. Press speedometer gear drive on mainshaft. From the inside face of the speedometer drive to the inside face of the rear bearing retainer should be 4 and 5/16".

Cub Cadets have one of two types of PTOs. The most common is gear driven. The gear teeth of the PTO shaft are very small and thin. If the PTO is engaged without proper clutch action, the gear teeth grind together, trying to engage. A little wear on these gears will cause the surface of the gears to become beveled, and when the PTO comes under load, the beveled surfaces of the gear teeth force the gear lock to disengage. The only option is to replace the worn gears...

The second type of PTO drive is electric clutch. This is a disc type clutch that is engaged by energizing an electromagnet built into the clutch pack... any disruption of electrical power to the clutch pack while under load will cause the clutch to disengage and then possibly try to engage while under load and casues the clutch pack to slip and will overheat almost instantly...

There are two places at the shift leaver that could be the problem. there is a nut and lock-nut together on the shift rod. you can loosen the lock-nut, adgust the play in the rod and then tighten the lock nut (sometimes this is behind a cover plate). Also, the leaver can become loose where it is attached to the splined shaft comming out of the transmission case. This must be tight. It may have slippped. It must be possitioned in a spot that makes it centered so that when shifting either up or down... it feels right. When you get it just right tighten with locktight compound so it doesn't come loose easily. If this is loose for very long, the teeth on spline or the leaver will strip out. Hope this helps.

I don't know what has not been removed so pardon me if I suggest something already removed. Remove the cylinder, intake manifold, magneto, stator, sprocket and shift lever. A case splitter is highly recommended. They don't cost that much and it makes for a clean separation. The two positioning guides will tend to hamper separation as will the crankshaft and output shaft as they slide through the bearings. That's another reason for a case splitter. Now would be a good time for new crank and output shaft bearings and seals and a new shift shaft seal. I assume the reason for the teardown is either a bent shift fork or broken gear teeth. If replacing a gear with a broken tooth or two, also replace any gears the broken gear meshes with. If you don't, you will get to do the gear repair a second time very soon after the first ride. Whatever pressure broke the teeth on one gear was also present on the meshing gear. It may look good, but it isn't. Please take a moment to rate my answer. Thanks.

4R100 or 4R70W?

Geartrain
Power is transmitted from the torque converter to the geartrain components through the input shaft and forward clutch cylinder.

• By holding or driving certain members of the gearset, four forward ratios and one reverse ratio are obtained and transmitted to the output shaft. The ratios are as follows:

GEAR RATIO 1ST 2.71 to 1 2ND 1.54 to 1 3RD 1.00 to 1 4TH 0.71 to 1 REVERSE 2.18 to 1
Input Shaft
The input shaft is supported by two bushings in the stator support. End positioning of the input shaft is controlled by the splines in the converter turbine and the overdrive planet assembly.
Output Shaft
The output shaft is supported by two bushings in the case and by the slip-yoke and bushing in the extension housing. End positioning is controlled by the parking pawl gear and snap ring or shoulder and by the reverse ring gear hub and snap ring.
Overdrive System
The overdrive planetary system consists of the overdrive planet assembly, overdrive sun gear, overdrive ring gear, coast clutch cylinder, overdrive one-way clutch assembly and the center shaft, as shown in the following illustration. The overdrive planet assembly is splined to the input shaft. The overdrive sun gear is centered by a bushing on the input shaft and held in place laterally by needle bearings on the reactor support and the overdrive planet assembly. The overdrive sun gear is splined to the coast clutch cylinder, which in turn is splined to the overdrive one-way clutch inner race.
The outer race of the one-way clutch is splined to the overdrive ring gear, which is splined to the center shaft. The center shaft is centered by the forward planetary assembly and is laterally held by needle bearings on the center support and the overdrive planet assembly. The center shaft is splined into the forward clutch cylinder.
Two friction clutches are assembled in the overdrive planet assembly. The coast clutch is splined between the coast clutch cylinder and the overdrive ring gear. The coast clutch is activated to perform engine braking in MANUAL 1, MANUAL 2 and third gear with the transmission control switch engaged.
The overdrive clutch is splined between the case and the coast clutch cylinder. The overdrive clutch holds the coast clutch cylinder and, in turn, the overdrive sun gear, to permit the planet assembly to overdrive the ring gear.
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Forward Drive System
The forward drive system consists of the forward clutch cylinder, intermediate brake drum, intermediate one-way clutch, input shell, forward ring gear, forward ring gear hub, forward/reverse sun gear and the forward planetary carrier and forward planetary gears.
The forward clutch cylinder is splined on the center shaft. The forward ring gear is piloted on the forward ring gear hub. Thrust bearings on the forward planet assembly and forward clutch cylinder hold the forward ring gear hub in place.
The intermediate brake drum is radially supported by bushings on the center support and is laterally controlled by thrust washers on the forward clutch cylinder and center support. The intermediate brake drum has the inner race of the intermediate one-way clutch press-fitted on its pilot. The intermediate one-way clutch's outer race is splined to the intermediate friction clutch, which is splined to the case. The intermediate brake drum has lugs that are slotted into the input shell to form a mechanical connection. The input shell is splined into the forward/reverse sun gear. The forward/reverse sun gear is common to two planetary gearsets. The forward planet is splined to the output shaft and is laterally positioned by needle bearings on the sun gear and on the forward clutch cylinder, as shown in the following illustration.
Two friction clutch assemblies, the direct clutch and the forward clutch, are shown with the forward planetary assembly. The direct clutch assembly splines the forward clutch cylinder to the intermediate brake drum. The forward clutch assembly splines the forward clutch cylinder to the forward ring gear. The forward clutch is activated during all forward gears. While in third or fourth gear, both the direct and forward clutches are applied to hold the forward planetary assembly and enable it to act as a solid shaft.
In second gear, the intermediate clutch assembly holds the forward/reverse sun gears. It is applied, along with the intermediate one-way clutch, to hold the intermediate brake drum, input shell and forward/reverse sun gear. In higher gears, the one-way clutch overruns.
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Low and Reverse Drive System
The reverse planetary assembly consists of the reverse planetary carrier, reverse planet gears, the reverse ring gear, the reverse ring gear hub, the reverse clutch hub and the low-reverse one-way clutch assembly.
The reverse ring gear hub is splined to the output shaft and to the reverse ring gear. The reverse ring gear hub is laterally held by a needle bearing on the inner race of the low-reverse one-way clutch and a snap ring on the output shaft. The reverse planet assembly is splined to the low-reverse clutch hub. The low-reverse clutch hub is connected by the reverse clutch to the case. The inner race of the one-way clutch is bolted to the case.
The reverse clutch assembly is activated in REVERSE gear and in MANUAL 1. The reverse clutch bypasses the reverse one-way clutch during coast and MANUAL 1. The reverse clutch holds the reverse planet assembly in REVERSE gear to enable the sun gear to drive the reverse ring gear in the opposite direction.
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Apply Components
The following information describes the operation of the three 4R100 one-way clutches.
One-Way Clutch—Overdrive
The overdrive one-way clutch, shown in the following illustration, transmits engine torque from the overdrive sun gear to the overdrive ring gear in first, second and third gear range. The overdrive one-way clutch transmits power when the sprags are engaged between the inner and outer races. The inner race is splined to the coast clutch cylinder, which in turn is splined to the overdrive sun gear. The outer race is splined to the overdrive ring gear.
The overdrive one-way clutch engages whenever the overdrive planetary system attempts to drive the overdrive sun gear clockwise when the overdrive ring gear has a counterclockwise torque from the vehicle. When torqued counterclockwise, the overdrive one-way clutch engages and acts as a wedge to lock the sun gear and the ring gear together. During coast, the overdrive one-way clutch enables the ring gear to overrun or spin at a faster rate than the sun gear.
The overdrive one-way clutch overruns when in overdrive (fourth gear). In overdrive, the coast clutch cylinder is held by the overdrive one-way clutch, which in turn holds the overdrive sun gear. This causes the overdrive planet assembly to walk around the sun gear and overdrive the overdrive ring gear. The inner race of the overdrive one-way clutch is thus held stationary while the outer race is allowed to overrun clockwise.
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1. THE STEERING GEAR SHAFT ADJUSTMENT TOO LOOSE OR SHAFT AND OR BUSHING BADLY WORN 2 .EXCESSIVE GEAR WORM END PLAY DUE TO BEARING ADJUSTMENT 3.STEERING LINKAGE LOOSE OR WORN. 4.FRONT WHEEL BEARINGS IMPROPERLY ADJUSTED. 5 STEERING ARM LOOSE ON STEERING GEAR SHAFT. 6. STEERING GEAR HOUSING ATTACHING BOLTS LOOSE. 7.STEERING ARMS LOOSE AT STEERING KNUCKLES. 8.WORKING PINS OR BUSHINGS. 9.LOOSE SPRING SHACKLES.THIS IS 9 POSSIBLE CAUSES THAT WILL CAUSE STEERING TO BE TOO LOOSE.

need more of a discription but right off my head a couple things

if its big its the starter plate if its small its the starter gear

drive shaft
the other is called a spline connecting drive shaft to throw out bearing you need to send out whole drive shaft to get replaced cause these require balancing they connect by u-joint
if they dont know what a drive shaft components are then you will need specialist to do whole drive shaft correctly