Air shift problem

[jpekarek]

OK, I am sure there is a tech manual that speaks to this, but I have been pouring over them and the posts and cannot find a topic pertaining to this exactly. On my M54, there is a slight air hissing noise when shifting into 1st gear or reverse. I know this is normal from researching the forums. My problem is that every so often, after backing out of the driveway and shifting into 1st gear, something under the truck sticks and air hisses out and does not stop. Is there a sticking valve or something causing this? I can’t seem to find one.

 

[jwaller]

yes, there is a ball valve that is bolted to the side of the transmission that needs to be repaired or replaced. mine was doing the same thing.

 

[BKubu]

There is a valve on the passenger side of the transmission and also on the transfer case that works to shift the sprag from forward to reverse. I have had the valve on the side of the transmission stick. Usually shifting back and forth a few times from first to reverse will cause it to "unstick" itself. You might either consider replacing the valve or pulling it out and cleaning it out.

 

[BKubu]

I was typing my response as John sent his. I see that John told you the same thing. Sorry for the duplicate info.

 

[kastein]

OK, I am sure there is a tech manual that speaks to this, but I have been pouring over them and the posts and cannot find a topic pertaining to this exactly.

that is your problem, if you pour over them the pages stick together and you frequently can't find the one you are looking for!

good to know what this is, I always wondered about the hissing noise when shifting. Mine doesn't like to go into 1st till I let it slide a little forward or back sometimes, my bet is that the teeth on the gears just aren't quite lined up or my synchros have seen better days.

 

[jpekarek]

Sweet! I will get up in there and check it out myself. I will post some pictures of the repair.

 

[wdbtchr]

I got a kit from Memphis to rebuild mine a couple of years ago, fixed it right upl. right now I have air leakage through the exhaust port on the valve all the time, I understand the cause is the "piston" in the xfer case needs rebuilding. I have a kit for that but haven't had time to install it yet.

 

[area52]

Good thread here:

http://www.steelsoldiers.com/5-ton-up/18459-frustrating-809-series-sprag.html