2gm/km2a

[steveinusa]

KM2A transmission isn't engaging in forward unless I raise RPM's up quite a bit (Tach Not working). Reverse is fine. From what I've read, it is probably the clutch-cones are slipping (old, 1981). Some say dismantle and ruff up the cones and re-assemble. I was thinking of just replacing. I have the shop manual and a gear puller is the only "special" tool needed.
Where does one get internal transmission parts like clutch-cones etc?

Also does the prop shaft simply slide in and out once disconnected from the transmission?
Or I could just enter and leave port in reverse all the time, Hehehe.

 

[kloudie1]

Steve, make sure first that you don't have a linkage issue.. Disconnect the linkage from the shift lever on the transmission. with the motor off, click the lever from neutral to forward detent to make sure you are getting a good engagement position. Next, Put the lever on the pedestal to forward.. Now see if the linkage can be engaged to the lever without moving the lever out of the detent.. If you have to move the shift lever much, the linkage may have slipped and require the cable to be reset. Before doing anything else, start the engine and by hand, shift to the forward detent. If it immediately engages, you probably have a linkage adjustment problem that requires adjusting the outer cover position down by the transmission... BE very careful to not get anything loose, like sleeves or jewelry near the moving coupling.. If it still slips, then consider removing the gearbox and replacing the cone clutches.. The drive clutch cone is part # 177088-03071 (about $320) .. While you are working in there, remember to change the oil seals and inspect the bearings.. Good luck !

EDIT: the shaft will slip forward but probably not enough to get the gearbox out. The motor mounts probably have to be loosened and the back of the engine jacked a little to get the gearbox clear of the coupling.

 

[Nelsonhow]

You could rough up the cones but...

Check the linkage carefully including the indents on the transmission. Try disconnecting the cables and shifting by hand while you're down there with the motor. If you find the problem is the adjustment of the linkage or indents you're in luck.

If the problem is not the linkage or the indents you'll have to pull the engine to remove the transmission. Given the difficulty of pulling engine and removing the transmission and the time it takes it would probably be more efficient to pull have Mack Boring or another reputable shop rebuild/replace the clutch plates and cones once you've got the transmission out. As long as you have it apart check all the parts.....

If you just rough up the cones, put it all back to together you might still have the same problem.

IMHO unless you're a contortionist and love busting your knuckles this is a job NOT TO BE RELISHED and redone more than once a decade. Don't ask me how I know..... I've been there with my 1 GM with the same problem......

 

[steveinusa]

Re: You could rough up the cones but...

Yep. If it comes to engine pulling, I'll have the whole kit n kaboodle done. Thanks for all tbe great replies everyone!