Don't always think the worst

[2414.ginger]

My old 801.4 has always left a little patch behind it where ever it stands parked up, bit like myself really.
Anyway about 10 days ago I noticed patch was a little bigger than normal, 3/4 days not moved and the patch was begining to creep out to the back of the machine. 3/4 more days and patch now is about a yard out from the back of the machine.
Thinking it must be the rotary coupling that is going to need to come out I took up the floor plates to see what I could find, only to discover that the top of the slew motor was very wet with oil, on the top is a round plate with 7 studs, anyway by this time I'm really struggling to see in the twilight so make do with just a quick wipe down and get everything dried up. come out next morning to find its just as wet with oil again, go for another wipe down and think to my self one of the studs seemed a bit loose, as in, can turn almost 360 degrees without a spanner, check the rest, and 3 more are moveable by hand, now thinking this may be a cheap fix. Tighten everything up and leave overnight to observe, next morning 1 stud is still weeping so take out clean and turn the washer and put back, watch again, got it this time. And it only cost me time, but I gained much more in experience.

Anyway now I have access to the slew motor shall I have a play with the crossline relief valves?
Ever since I've had the machine its been poor on slew, full grading bucket on an incline and I begin to wonder if it can make it round to the top side, plus whenever I try to push soil into a trench it doesn't really do it, you can also push the boom around by hand without much effort, I thought there was supposed to be a brake when not slewing!
Now I have a gauge, but not the right fitting to check out what pressure I have, so can I tweak it little to see if it makes any difference? I was thinking 1/4 of a turn and try. Advice from anyone who has adjusted their machine, how much to screw in etc would be most appreciated. I know I really need to do it by the gauge, and am taking a risk, but any thoughts please.
TIA Pete

[Muz]

Well you can always tinker....slews mostly brake by their own lack of motion/feed due to the type of lobe pump they use for drive. Can't vouch for all of course . But at least it sounds like you nailed the fault


just be careful if you want to pull the drive apart because lobe pump/drives are timed, and if you don't know what you are looking at chances are you will not get it back together the same way and it won't work ... Don't ask me how I know

[v8druid]

yet more application of a little thought and a bit of common wins the day again eh
good to hear that was such a cheap fix Boyo ....... now't more annoying than an ever growing slick

[2414.ginger]

Update.
Went ahead and made some tiny adjustments, 1/4 of a turn on the cross line relief valves.
HELLS T**TS, what a difference that has made, it's like I have a whole new machine, now I have much more power on slewing and I have very noticeable slew braking.
I am also able to push things sideways with just the slew.
When I get the chance I will put the gauge on and make sure I have not given it too much ummph!!!
I have not yet been up onto sloping ground to see if it works better there, but will post more when I have.
Another weird thing is when tracking the upper body keeps in line with the tracks, where before it used to slew around to the right, and you had to keep slewing left to keep it in line.
Happy day's

[Muz]

Another weird thing is when tracking the upper body keeps in line with the tracks, where before it used to slew around to the right, and you had to keep slewing left to keep it in line.
Happy day's

So you had a leak there which was a different issue .. anyways .. I'm gonna pick you up on your operator skills from points you mentioned in your earlier posts , as you know , we are a premier forum for the furtherment of skill and technology .. and the rule is ... no side swiping its not what your slew motor was designed for .. every body does it .. but they shouldnt

[2414.ginger]

Yes, sorry about that Muz
The difference in power means that now I can, before I couldn't.
Doesn't mean I will.
The point I was trying to make was that sometimes some plonker has messed with things (not always for the better), and then things don't work quite how the manufacturer had intended. But then it doesn't take much to put things right, bearing in mind I have had this problem for the 3, yes 3 years that I have had this digger for.
My original problem was lack of slew power, particularly if swinging uphill, now with a tiny bit of tinkering I hope that things will be much improved.
PS I'm guessing you are including your good self in the every body does it part.

[v8druid]

So you had a leak there which was a different issue .. anyways .. I'm gonna pick you up on your operator skills from points you mentioned in your earlier posts , as you know , we are a premier forum for the furtherment of skill and technology .. and the rule is ... no side swiping its not what your slew motor was designed for .. every body does it .. but they shouldnt

Bluecol - Bull shit repellant.jpg

Can smell it from here Muz

[JBASport]

Slew Problem JCB 801

Hi, I am having the same problems slewing my old JCB 801. I am interested in your comment about 1/4 turn on the cross line relief valves, Where are the valves and do you tighten them (clockwise)?
Any help would be much appreciated. Thanks, Terry

Update.
Went ahead and made some tiny adjustments, 1/4 of a turn on the cross line relief valves.
HELLS T**TS, what a difference that has made, it's like I have a whole new machine, now I have much more power on slewing and I have very noticeable slew braking.
I am also able to push things sideways with just the slew.
When I get the chance I will put the gauge on and make sure I have not given it too much ummph!!!
I have not yet been up onto sloping ground to see if it works better there, but will post more when I have.
Another weird thing is when tracking the upper body keeps in line with the tracks, where before it used to slew around to the right, and you had to keep slewing left to keep it in line.
Happy day's

[Bradders8014]

Hi, I am having the same problems slewing my old JCB 801. I am interested in your comment about 1/4 turn on the cross line relief valves, Where are the valves and do you tighten them (clockwise)?
Any help would be much appreciated. Thanks, Terry

I would also be keen to know about the cross line relief valves as I have the exact same problem!