I have a 444C wheel loader that is having transmission issues. It feels somewhat slow accelerating, and when you get to even a small hill it slows way down, almost doesn't move on a steep hill with engine wide open. While it's doing this the transmission whines, sort of like a cross between a whine and a whistle, it gets higher as you accelerate. It still operates somewhat normally on the flat, I use it daily. I've put new transmission fluid in, JD Low Viscosity, which is what it's rated for. It does have a trans fluid leak, but I make sure to keep it topped up. I've replaced the two filters behind the steps to the cab, are there any other filters affecting the trans fluid? Also, the trans fluid pressure goes into the red slightly when you accelerate, then drops down when you let off. Any ideas?
what kind of transmission is it? If its a twin disc/ allison there is a suction strainer in the bottom of the sump. if that is clogged it will cavitate the trans pump and will cause your condition. there is a round 6 bolt plate on either side of the transmission one is for inspection, one is actually the strainer.
It is a twin disc Allison. How do you get the strainer out? It appears by looking that you have to remove or lower the transmission to access those covers, there's only 1/2" gap to the main frame on each side. Sent from my iPhone using Tapatalk
Holy Moly. every machine that i have this transmission in has a good ten inches between the frame and the sump of the transmission. 1/2 inch wont cut it...hmm can you post a picture?
Yes-- the suction screen covers are approximately 1/2" from the main frame--- can't be removed without transmission being removed, although if they are plugged up, it's usually a sign that the transmission has to come out anyway-- Does oil look like it's aerated after you use it a bit ? I had 1 instance where internal suction tube cracked and the loader lost power-- if overfilled a bit to cover the crack, it worked OK..We removed and replaced it , but it ran like that for awhile previous to the repair-- Also those Deere loaders with Allisons can be very doggy if the engine RPM drops even 100 rpm below max. especially when shifted into high range. Hold the foot throttle down and have someone check that the throttle linkage at the injection pump is reaching the stop on the pump-- worn foot pedal hinges etc can lead to a gradual drop in RPM that isnt immediately noticed if the same operator is in it all the time. Engine speed should be checked with an external tach but if you don't have one , the injection pump stops should be reliable enough.