Command Front Drive Adapter Bolt Hole Slop

[PhanDad]

Is there supposed to be a spacer in the bolt holes of the Kohler Command front drive adapter? I don't see any spacers in the parts schematic for the 62513 spec CH18S that's OEM for the Sovereign. Just hex flange M8x1.25x25 bolts are listed. Sure looks like a lot of slop to me:

Has anyone who installed one of these found this much slop to be normal? I would have figured on a tight tolerance since these holes/bolts carry all the engine torque to the driveshaft. If the slop is normal, I plan on tightening the bolts with their edges on the "push" side of the adapter bolt holes. My first Command came with the front adapter already installed so I don't know if this is normal.And I can't find anything specific in the service manual about the torque spec for the adapter bolts. So based on the "General Torque Values" table, I'll use 24.4 N-m for the bolts which are property class 8.8. Is that a reasonable torque? Thanks in advance for your thoughts.

[Ronald Hribar]

Maybe you could use a shoulder bolt

[Bruker]

I know I wouldn't feel comfortable torqueing it down with that much clearance in the holes. I think I'd try to come up with some spacer to take up as much as possible.

[BLT]

Doesn't that adaptor have a pilot bore or lip?

[PhanDad]

Bob,

Yes the adapter has a pilot bore that keeps it centered. So the slop is only "rotational". I should have noted that since it makes a big difference to the "slop" issue.

But I'm still surprised at the amount of slop. The pilot bore is obviously machined to a very tight tolerance, so the bolt holes could be as well. Maybe the bolts are heavier on higher HP engines and Kohler only wanted to make 1 adapter for all engines.

[BLT]

24.4 NM is the equiv to 5/16 gr 5 which is 17 Ft lbs or roughly cyl hd torque on Briggs CI engine. Being that those are flange hd bolts, they could have enough clamping force but I don't think going to 20 ft pounds would hurt anything just to be safe.

[stevenj]

The clearance is of no concern. Since the adapter is pilot located, the slop/clearance is in the rotational direction only. The bolts are not shear pins. When the bolts are tightened, the clamp load holds it from rotating. If you are concerned, then rotate the adapter relative to the crankshaft in the opposite direction of crankshaft rotation so that the edge of the holes are touching the bolts, tighten the bolts, and forget about it.

If the holes in the adapter were smaller, then the dimensional control on the true position of the holes would need to be much tigher to ensure that the adapter holes would align with the crankshaft holes when the adapter is located on the crankshaft pilot. No need to have tighter tolerances than are necessary as all they do is add cost.

[Burntime]

Yeah, what he said! LOL. I do agree though, the bolts just hold it in place. Once in your locked and loaded!

[PhanDad]

Thanks for the opinions.

I'll install it with the bolt edge "pushing" the adapter.