We just picked up a hoe at a sale and damn near the whole way home the hydraulic filter warning lamp would go on if you went above 1/2 throttle. Changed the filter, no difference. Tranny fluid isnt burnt looking or stinking, has a hard time starting in 3rd gear, 4th gear is impossible unless already moving. Had tranny fluid temp start to skyrocket when climbing a rather large hill in 4th gear and smelt a burning smell even. Seems worse now and the hydraulic filter restriction lamp is on at maybe 1/4 throttle. What is going on with this thing?
So it's your first backhoe right ?. 1st gear heavy work, 2nd general work, 3rd roading and light site work after your moving from 2nd, 4th road only and slight hills. If you run it much in 4th on a hill you are doing almost what is a converter stall, 4th gear wide open with the brakes on, this will cause the trans temp to go up up and away. You will run faster in 3rd when 4th falls on it's nose and ground speed slows and the temp will stay at a better temp. You may have a issue with the bypass/switch/wire going to it. They will sometimes come on when cold and go out after a bit. These machines are not speed demons, tire pressure/4WD Engaged/front end toe in/brake drag/ options on the machine, 4x1 bucket/extenda hoe/cab/AC/4WD/counter weights all rob power when roading.
I just have a gut feeling there is more wrong, the light seems to follow the throttle and it seems a little too coincidental to have a bad switch. Im a total newbie when it comes to backhoes, I run alot of case farm equipment but never a torque converter style unit. So you never start in 2nd gear? Im not sure what the proper shifting technique is with them, just press the disconnect switch and shift at a low rpm? Is there some kind of suction screen that could be plugged also that I dont know about?
Saskboy, Welcome to HEF Yes there is a suction screen, reference Case parts web site link below and part number 40. http://partstore.casece.com/us/parts-search.html#epc::mr54946ar1044446bi2575749-40 I have a 580SK and would assume your transaxle maintenance schedule is similar. The screen is supposed to be cleaned every 1000 hours with the oil and filter replacement. While the filter restriction lamp will certainly come on with cold oil, I would not expect it to be on with hot oil as you describe unless there truly is a restriction somewhere. Unless you know for sure what specific oil is in the machine, you should consider a complete oil and filter change with Case oil (I believe Case hy-trans is recommended but check your manual or dealer). Yes you can generally start in 2nd gear. In fact that is fairly common on flat ground.
Have you tried replacing the hydraulic filter? Located behind fuel filters. :drinkup
I was going to ask that same question, are you sure it's not the hyd filter light and not the trans filter light. Would have been nice to cut that trans filter open also do to the early charge pump issues. You could also unhook the wire to the switch on the main hyd filter base and try it, no light change the hyd filter. Still have a light on and your back to the trans filter.
Yea it lights up as hyd filter if i remeber right. I bet tha suction screen that somone pointed out a few posts back is the culprit. I did change the filters and cut them open, no debris at all, no metal particles. Good advice on swapping around the wiring for the filter restrictions also. Im heading to case after work to grab a few things and hopefully fly out to the farm to work on this thing tonight. I appreciate the help here. I have worked on and rebuilt a few crab steer case 90 series powershifts and transmissions but this whole backhoe thing is all new to me as far as how the thing is supposed to work. No owners manual came with it and im just fumbling along. You should of saw my first attempt at using the hoe..... lol.
So I drained the oil, suction screen was full of **** and filings, cleaned it out and put on new filter. A few of the bigger chunks look like what would be the washer behind the spider gear. This hoe apparently had a bunch of work done to it 80 hours ago and i'm skeptical that they cleaned the housing out. My main problem now is that the unit wont move at all now. It did this a few times before and had to shut it off and restart before it would take off. I checked the disconnect solenoid and it's fine, same with the regulator valve in the shuttle. The shaft out of the torque converter is always spinning no matter if you are in forward or reverse. It's like the tranny isn't turning at all inside because I can just slip it in and out of gear without the disconnect switch period, no grinding. Is this a pressure problem or valve problem in the tranny? Hey at least that restriction light is out now....... lol.
Was there much metal lying in the bottom of the transmission? Fine grey muck? If so, I have seen it get into the control valve & gum up the workings of the transmission cut-out operation. The metal filings could have got into the charge pump as well, causing it to have a problem building pressure. The early s/n transaxles used a pressed steel thrust washer at the spider gears, these never did last very long. There is an updated part that uses an extended tang to locate the washer - these came into use over 20yrs ago!
Oil was full of silver particles, some good sized flakes of metal also. Shows a recent spider gear part receipt in the manual.
So I got it moving again, the charge pump has trouble priming itself. I worked it all day, it works fine except for when your in loose dirt it has a hell of a time going much more than a walking speed in 2nd gear. Hard road its fine, can push dirt in 1st but still slow moving compared to what it should. Trans is maybe slipping with low charge pressure? I havent gotten a gauge yet so i cant be sure. Anyone ever have a pooched torque converter cause low ground speed/ power?
They had a time with those charge pumps going out and any crude that made it to threw the strainer went to the charge pump first and then back to the spin on filter. So you could have lost a pump or loosing a pump. Like said need to check your pressure at the valve, there was a change to a different trans control valve also for better service.
Slow is slow on the backhoe's, it drives me nuts to have to run in 1st on them. Loose, sandy, soft ground can pull them down also in 2nd.
Is the charge pump the same thing as the transmission front pump, like you see on car or truck automatics? Or is it some kind of transfer pump out of the sump and then over to the real pump?