Noticable delay in duration of gear change from 3 to 2 driving up incline in auto or manual and also when changing direction in 2nd. Had assumed it took longer to fill the clutch pack to take up 26K hours of wear put went to check pressures and this is where I am at. 3rd and 4th have 14bar . 2nd has 9bar in forward and reverse. Checked from cold (10 Celcius) with all . Left guage on 2nd and worked temperature up to 70C with no change in pressure . All rise approx a bar when at full throttle ,hot or cold. I swapped coil and valve between 2 and 4 and my pressure is still down on 2. Checked voltage to coil and both 13.5 V . Any kind of internal leak should see pressure reduce with temp rise and increase alot more with increasing engine speed.
A sod off you miserable skinflint and buy a new one.
We got a new L90H, and she's a beauty, and with the optishift transmission, she up shifts going up hill
Sounds real nice but i dont have enough secure work at the moment for a big spend. Is the optishift a big improvement? Does it have torque lockup?
I think that is part of how it works is the lockup torque. Direct drive makes for lower RPMs. Our first H was an L110, then an L180, and then the L90 was this summer. We still run a bunch of F series. Some 90s and a 70. We had terrible luck with the Gs, an L45 and a 70. At the end of it, they had to get rid of the burner on the 70. The H went with the DEF, and as long as you use clean DEF fluid, no problems. Only E we have left is a 150. Kind of surprised no one has been around this problem you're having before.
In my experience on Cat wheel loaders a lockup torque converter is only of any use if the loader is being used almost exclusively on a load & carry operation, say more than 50m travel from loading face to discharge point. In truck loading operations it never even engages. The downside of the lockup is the one-way stator clutch mechanism that is prone to failure.
Is the lock up available in 1st gear for steep stockpiling?
Not sure about Volvo but Cat loaders lockup is only active in 2nd speed or higher. I would've thought you needed the converter slip in a stockpiling (pushing I assume?) situation.
Not sure something about a free wheeling stator, I just drive them. Probably should read the manual. It works like any other machine, but it accelerates like a car, even going up a hill.
At times the loader would haul material up the heap at a 1in 3 to 4 slope. With a well heaped bucket 2nd is too high.
Under those circumstances you need the converter to have the capability to slip. if the converter was locked up then the only thing that could slip would be the tyres, and that's not good for the powertrain.........
I have no idea how it works Nige. If you switch it off, it works like a regular loader. Turn it on, I can go 46KM per hour up a hill on the road, that a loader without it might do 15.
That's the reason they have a lockup clutch, to make the drive train more efficient at relatively high ground speeds. If the lockup clutch engaged in 1st speed forward, then either the loader would spin the tyres or break something in the driveline. That would be the only option because there would be no slip in the torque converter. Let's have a bit of a tutorial on lockup clutches shall we..? Here is the power flow in converter drive. Engine is on the left, output drive shaft to the transmission on the right, so the red housing on the left is connected to the flywheel/flex plate, or however it is driven. The power flow goes through the red housing and turns the impeller (also red) that is bolted to it. The impeller forces the oil through the stator (multiplying it's power as it does it) and turns the turbine, and because the turbine is bolted to the output shaft the shaft turns. Simples..... Now engage the lockup clutch on the left. The red input housing on the engine flywheel side and the turbine (that was previously being turned by oil from the impeller via tha stator) is now locked to the output shaft and the drive goes direct from the engine flywheel to the output shaft. Downside is that in this state there is no "fluid clutch" between the engine flywheel and the drive train. Also the oil passing through the torque converter, although it is doing nothing drive-wise, would heat up rapidly because of its convoluted path through the converter. The stator (green) is mounted on a one-way sprag clutch comprising a set of rollers & springs a bit like a ratchet mechanism. The sprag clutch allows it to rotate in one direction but not the other. In lockup the stator is turning, in converter drive the oil pressure on it causes it to back up against the ratchet which holds it in one position. In my experience on wheel loaders the sprag clutch mechanism is the Achilles' Heel of torque converters that are equipped with a lockup clutch.
Nice explanation. I know what you are saying about first gear and it is normally used for bucket filling or pushing where a lock up cuold more harm than good but on a steep stock pile of fine grade stone or grass silage clamp gear 1.5 would be a nice option when it is the gradient and weight are the issue and not traction.
No convertor lock-up in E-series loaders. 13.5 volts to a shift solenoid is inadequate. Should be between 22 and 26. Check wiring from Connector TA on back panel circuit board to shift solenoid manifold on RS of upper trans.
Well that's got that question cleared up.........
It's only in the H, but at least he got a start on his OP, and We got to see how the system works.
Thanks funwithfuel . Will pull back panel tomorrow and check it out.
I will see if I can find the diagram when I get home
Didnt get time to go at it and wont for a few days but a wiring diagram would be great if you have one.
these are the inputs from the gear selector And these are output to shift solenoids. You should see 24 volts when energized. Coils should show approximately 20-24ohm resistance. Hope this helps. Good luck
Great stuff . Thanks. That will help loads . Just need to make time now . Any ideas?
To make time? ........ Not a clue. Once it's gone, its gone.
The Irish equivalent of "When I get a round tuit"..?
Between drinking tae in the morning and stout in devening, there aint much time in the middle
Back at it again. Never got any further since as the machine was going 6 days a week since and has clocked 1600 hundred hours of hard work. The problem remains exactly the same. Pressure for 2nd gear is 10 bar. Every other clutch gets 15. It takes half a second longer for 2nd clutch to enguage than any other. Put a 2nd gauge on forward clutch and it runs at 14 bar in gear 2 and 15 bar in 1 3 4. I swapped coil from gear 4 and put it on valve 2 no change. Swapped complete valve between 2 and 4. No change. The coils are rated for 26 volts but all are running on 14.5. Connected the 24v battery charger to coil on gear 2. No change. If it is a clutch pack seal i would expect some deterioration in pressure or time delay. If it was just time delay i would put it down to clutch taking longer to fill due to wear. My next plan is to remove the valve block and inspect the gaskets supplying the feeds. Then pull out the whole lot if i find nothing but that is no small job. Any more input or suggestions would be great.
I would start by removing the stem of shift solenoid SC. Make sure you don't have any damage to the o-rings. Then I would swap that stem with that of SE . So you're switching 2nd with 4th. Also, keep in mind, the loader will almost always start in second gear, unless the load or incline dictate otherwise. Make sure the gear you are feeling is the gear you are in. Verify by observing the instrument panel. You can be preselected in F4 but start out in F2 or F1. If your clutch pressure is low but hasn't gotten worse, I'd say the clutch pack and seal rings are ok. I'd be looking hard at the stems vs the magnets. I attached a little light reading for the meantime
BTW is 2nd gear cluch pressure weak in fwd and reverse?
Same pressure in both directions and when I powered it on its own via the battery charger when no direction clutch was engaged. I did swap valve stems between 2 and 4 and looked in the valveblock ports and inspected the O rings but no change and nothing obvious a miss. A tear in the gasket would likely deteriorate over time but a pack seal would be even more likely to worsen over time. I will read what you sent on. Thanks. .
Nice read but nothing jumping out at me as regards my problem. I pulled the 2 layers of the gear selector control valve to find an O ring missing without a trace off 1 of the oil lines going into the valve so I am waiting for parts and crossing my fingers.
Fitted new gaskets and O rings on pair of steel pipes leading off into transmission. Pressure for 2 is up to 15 bar and delay gone.
Glad you got it sorted. **** like that will give you grey hairs.
Grey and bald went to war on my head a few years ago.
Who won?
Its not over yet but i miss the organic spark protection
The baldness won early for me .