9TC Got the call on Monday that the dozer wouldn't go into first gear forward. I went to check it out and found that it would go into first, it just had no power. It seemed like first reverse was working but that was only because that direction was just very slightly down hill. Once I put the blade on the ground, no reverse first either. Second engages strong in both directions. I can't really tell what is happening in third, pretty low torque gear. I suspected the worst, that clutch pack #5 is toast. I was going to do some pressure testing but I had left my gauge sets on the other truck. I went to get them and when I came back the operator had moved it and magically gotten first back. I don't have a lot of patience when it comes to troubleshooting a problem when it isn't currently happening, but I watched him operate for about a half hour with no hickups. Found out this afternoon that it stopped working late yesterday. This machine used to be a one operator unit (other than me, the company and I share the same yard and they stockpile aggregates and over burden there. Whenever the machine hits my yard I use it to keep the piles out of my work area) but the company lost him and now I see operators that I don't think should be in the seat. Not Monday's operator, he is pretty new to the company. From what I have seen he is a really good get for this company. Before I left the mainland I used to be an operator trainer, I can spot a bad one from a mile away. Anyway, I talked to the old operator a few minutes ago and he said that the machine would occasionally lose power in first for him. Usually before the trans got up to operating temp. Why he never told me that I don't understand. This unit lost the trans pump a few months ago on a job and the conditions for that repair were far from ideal. So I have been changing the trans filter and looking for trouble at an accelerated rate (one a month after the failure and again last week before they moved it to this job site) I haven't found any metal or clutch material. So tomorrow I will go do some pressure testing. Probably pull the filter again. But clutch packs don't heal themselves so I am looking for other ideas. Thanks, guys.
Have you pulled the suction screen yet.?
No, I haven't touched it yet. Gathering up oil and filters so I can drain it and check all the screens
When you remove it take lots of photos
Well, took me some time to get back to it. They were supposed to get it to my yard while it was still moving, but they dragged their feet. Every time I passed the jobsite it was in a different place. I don't know if they were moving it because it was in the way or if they were using it. Kind of suspect the latter. So, of course it stopped moving one day. I found the transmission pump shaft had sheared bolts again. Seized pump. Finally got to drain the oil to check the screens.
That's clutch material on the screen, but not a lot of it, or so it appears. all depends what was on the inside of the screen rather than the outside. How much metal was on the magnets.? Got any photos.?
Lots of beat up metal. Lot of white plastic. Some of what might be friction material in the screen itself. Nothing in the other two screens. A bit of glitter on the filter. The way the banding has come loose on the filter makes me wonder if the filter had collapsed a little. So I pulled the trans pump to look at the damage. There wasn't very much. I'll post pics of that if I have them. But I will describe it anyway. One of the impellors had two slivers of metal embedded in the face and there was some minor scoring in the corresponding area of the case. The dozer was parked in a terrible spot (15% grade, nose up hill) and in the way of the job so we decided to see if we could get the pump to turn and pray it would get the machine off the jobsite. It cleaned up pretty easy. 2" scotch-brite surface disc and and about 15 minutes. You could hardly tell that it was ever even damaged. Reinstalled the pump and drove it off the site.
To be continued............
Not a great picture but you can see one of the slivers. So now it's in my yard and started doing a little pressure testing. This is all cold oil. Pump pressure is 435 psi at low idle and 541 psi at wot. Speed clutch pressure is (low/high idle) 1st forward 90/150. 1st reverse 90/145 2nd forward 370/380. 2nd reverse 370/380 3rd forward 110/125 3rd reverse 110/120. Haven't checked the directional clutch yet because I either need a longer hose for the Guage or a body in the cab doing the shifting. Is there even any point? Those numbers are screaming at me that clutches 3 and 5 are in bad order. About ready to put money on piston seals. What else should I check before I start pulling the trans? Also, just so I have it... who has drawings of the axle removal tool (ft1952) and the adaptor (ft1897) or anything else that I haven't thought of yet.
I do. I’ll send them to you tomorrow. Scratch that. Check your message inbox.
With that much metal ide plan on pulling it. Its not going to get better and your pressures are low anyway
If I remember correctly, almost all of the debris was on the outside of the screen. There was a tiny amount of black flakes inside. What magnets? Where are they? It has been a really long time since I have been in one of these transmissions. So long, that I think I was still a little baby mechanic and my partner did most of the mental heavy lifting. So I apologize to everyone if my magnet question is dumb. All the metal I found is in the picture. I kind of half hope that all of that was from the previous pump failure. But I can't imagine where it could have been hiding from the last time I checked the screens. Last question is, what is all the chewed up white plastic?
I vaguely remember air testing the clutch packs (20 years ago). Is that possible to do with the trans still installed? Or better yet is there any way to run the transmission through its gears with the rear cover removed? I know the transmission is coming out of the machine, but I would really hate to pull it and then reinstall it just to find out that I missed something dumb, like magnets.
My 2 cents the stuff you call white plastic sure looks like a Teflon piston seal to me