PTO Hydraulics on 08+ rigs

[EngineerMike]

This involves only 08 & 09 rigs only so far as I know; maaaybe very late 07's (see below to check)? PTO, for those who haven't run into the expression, is Power Take-Off, meaning power taken off a drive "access" from a piece of machinery, usually a transmission.

Late in the WRV game they switched from engine mounted Saur-Danfoss hydraulic pumps (driven off the foward end of the shaft that drives the air compressor) for the hydraulic power steering, radiator fan drive & brake boost, and began using tranny mounted PTO-drive+hydraulic pump. The Allison trans has one PTO cover plate on each side of the forward part of the trans for older model coaches. The 08/09 rigs replace the PS PTO plate w/a red "Chelsea" brand PTO bolted to the trans w/6 twelve point (spline?) blue fasteners, and the hydraulic pump is bolted to the forward side of the PTO. To see if you have this config, crawl under the coach behind the rear wheel at the forward side of the battery compartment, and look up.

Country Coach has been installing Chelsea PTOs since 2003 or 4, but have seen a lot of catastrophic failures of the shafts connecting the PTO to the pump. When I heard that I started looking into it. The CC config had the PTO mated directly to one pump or two tandem inline pumps, also forward of the PTO. WRV added another red Chelsea case between the PTO & the pump. That case has a small diameter hydraulic line feeding trans fluid thru it to lubricate the spline shafts (female spline from PTO, male to pump) continuously. CC omitted this lube chamber, and that is where the failures occur unless the PTO/pump connection is undone every 5,000 miles to manually relube the spline connection. Worst case on CC rigs is the poorly lubed splines hammer themselves to Neverland, then the PTO shaft spins but pump doesn't sooo- no fan & no power steering (and on our rigs, no brakes if such should come to pass). Coach overheats blowing radiator, and you have to arm wrestle 35,000 lbs of stuff over to the shoulder w/out assisted steering, then call a tow. Then, break out a big sweaty wad of money and kiss it good bye

Those CC owners who benefitted from the early unpleasant experiences of others (who put on lots of miles & TKO'd their PTO) got wind of the problem, and started installing the middle case, called a "wet kit" to lube the splines. Apparently, WRV also benefitted from the early CC experiences, as my rig came from the factory w/the wet kit installed

For those w/an 08 or 09 rig, just to make sure, I'd recommend checking for the middle case w/the small diameter line feeding it (the small line comes from a tee in the small line feeding the PTO case). Probably there. If not, post here and I can give you instructions on getting parts, etc. to have the kit installed (~$800). If you have a late 07 you might also want to take a look. If you have no red Chelsea PTO, this does not involve your rig. PTO w/"wet kit" looks like this:

Brass fitting @ lower right is from the small hose feeding trans fluid to the spline lube case. Main PTO case is on left w/the name plate. Hydraulic pump is to the right, which is forward. Small hydraulic line @ bottom left corner is the feed line from trans that has a tee to feed the middle red case thru the brass fitting.

[TerryM]

E-Mike,

Mine looks just like your picture. Thanks for the post.