Transmission Issues?

I own a Craftsman Riding Mower, model #917.252502. It has a 6 speed transmission.

When the mower is not running I can freely move the gear shift lever through all the gears (including reverse) with no issues or resistance.

When I sit on the mower, start it and put it in either 1st gear or reverse, the gear shift lever becomes 'locked' and I can't take it out of that gear.

To make it more interesting I jacked up the rear end of the mower and started it without sitting on it (I was pushing down on the seat so the kill switch wouldn't engage and kill the engine). I could freely put it in any forward gear or reverse and move the gear shift around. However, the rear tires would barely spin, or spin and then stop. It took no resistance to stop the tires with my hand in any gear.

I lowered the mower again, sat on it and started it up. Put it in 1st gear and it started going forward. Tried to take it out of gear and the gear shift lever wouldn't budge. Turned off the mower, the gear shift lever moves effortlessly!

What the heck is going on?

Is this a bad transmission problem? A linkage adjustment problem? I would love to be able to use the mower again, but this has got me stymied as to what the root problem is and how to fix it. Don't understand the behavior with the mower off, me sitting on it, and jacked up rear wheels.

Help!!!

Remove deck & check clutch rods items 41 & 43 as well as clutch return spring items 55 & 72 & all associated hardware for being worn out or out of place by entering your model number at Sears Parts Direct.

https://www.searspartsdirect.com/mo...st=&q=917252502&searchTerm=917252502&shdPart=

Thanks!

Would a mis-adjustment or wearing in those parts cause the behavior I described? In other words, the gear shift moves in and out of gear freely while the engine is off or rear wheels jacked up. Locked gear shift with motor running and me sitting in the seat?

Wouldn't a worn or mis-adjusted part exhibit the same behavior in all those conditions?

Absolutely! Also adjust brake page 21 in manual per specs. using figure 22.

mekelly said:

Thanks!

Would a mis-adjustment or wearing in those parts cause the behavior I described? In other words, the gear shift moves in and out of gear freely while the engine is off or rear wheels jacked up. Locked gear shift with motor running and me sitting in the seat?

Wouldn't a worn or mis-adjusted part exhibit the same behavior in all those conditions?

Click to expand...

Just wanted to close the loop on this issue. I didn't notice any parts that were bent or missing although the brake definitely needed to be tightened. So, I went to Sears and purchased a replacement ground drive belt. I knew I was paying twice what I could find one for on Amazon but wanted a Sears belt to eliminate one more variable.

Well, the new belt solved the problem! Transmission now shifts fine when the engine is running. Very strange because although the other belt was an off brand, it worked for a long time.

Anyway, glad to be back in business and although I hate to pay that much for a belt, sometimes OEM is best I guess!

No
If there is no load on the gears thetransmission will happily turn the wheels
When you put a load on the gears then the gears will try to dissengage as they are in reality all little wedges.
Being wedge shaped means it will try to push the gear in front of it foreward while simultaneously trying to push the shaft away which dissengages the gears

He who offers the least amount of resistance wins.

The input gear is a bevel (45 deg cone shape ) so when it engages it tryes to push the gear backwards along their shaft axsis.
That force is resisted by a thrust washer which bears against the case and when the case wears the output shaft will either rotate or move backwards dissengaging the gears again depending upon which is the easiest.
SO when you get wear, the drive works perfectly with the wheels in free air but sits there going click click click wheels on the ground.

With a non-geared transaxel as you have with a foreward-neutral-reverse lever. It moves a pair of gears against the bevel drive gear,
Contacts on one side it goes foreward, driven gears sit either side of the drive gear- neutral, contacts on the other side goes backwards
This movement is done using a shaft with 3 slots and a ball bearing on a spring which locks the shaft into the correct position.
Because of this posative stop detent system, you feel what you think is the gears clicking into mesh but it is really just the selector shaft clicking into the correct position.

Great explanation!

Thanks for all your help (you helped me with the B&S oil leak on that forum as well.

I went from thinking I was going to have to part out the mower (couldn't get out of gear with engine running, leaking oil like crazy, small gas leak between carburetor and air filter housing, bent blades, star pattern worn off one of the mandrel shafts, both rear tires not holding air, etc.) to a great rider again!

All for about $100 worth of parts and 6-7 hours time.

Just in time for the hot weather here in Atlanta! No more push mower, I am riding now!!!