Got a strange issue with this '98 D4C 7SL Dozer The machine doesn't want to run in 2nd or 3rd. I've pretty much issolated it to the trans. in that at first I thought there might be steering brakes out of adjustment. I backed off the brakes, drove up an incline, stepped on bothe clutch pedals and it wouldn't roll back down. I put it in nuetral and it would'nt roll back down. I shut off the engine and then it rolled down. When it's on flat ground and I go from 1st to nuetral it's a very firm stop, like there's a brake on. I've checked all the pressures and I've got about 400psi at all check points. Changed trans oil/filter/screen and same results. It seems when the engine is on that somehow the transmission is in a bind. Any help would be appreciated.
I will be the first to ask, post a picture of the data plate please so knowledgeable people can reply.
Ok Here it is
Have you checked torque converter pressures.? See attached. Try going right through this procedure (don't worry about steering clutches for now) and post your results. Note that converter inlet pressure spec is a maximum with cold oil. The procedure doesn't mention the cold part....
Thank you very much for the reply I think the transmission is needing a rebuild
Seems odd it wouldn't free wheel even in neutral. I don't know if a torque converter issue would cause that yet still work in 1st gear. Wonder if somehow one or both brakes are somehow binding and 1st gear has enough power to overcome it. Is the middle brake pedal and linkage all free?
I think it would probably pay you to put some time in to do the testing that would confirm the state of the transmission before taking the plunge and pulling it. It may confirm your suspicions but at least then you will know one way or the other.
I went a head and pulled the trans and put in a pull-out from a unit that had a hole in the engine. I believe the transmission is ok but I'm having trouble with it. I put 10W-30 engine oil in and it's foaming really bad. My confussion is that the bleed plug at the oil filter is clean(no bubbles in the oil) but after I run the unit a couple minutes then I'm getting so much foam that the foamy oil is coming out of the filler tube. The foaming oil would make sense if I was sucking air from the bottom side of the pump but based on the oil looking ok at the filter bleed, I think there's probably another issue. Any ideas? Thanks
You should use TO-4 transmission oil not engine oil and how did you check the oil level?
I've never used that before, I've always been told to use engine oil. I'll give TO-4 a try. What wt.? I checked it with the engine stopped the first time just to be able to move the machine around the yard. I figured we would check it when we got it running after a few minutes. I've swapped these transmissions out several times over the years but never had this foaming issue like this.
1. You were told wrong. 2. SAE 30. You could also possibly have an air leak in the suction side of the transmission pump.
my first thought was an air leak in the suction line but then when I pulled the plug on the filter housing it was not foamy...hence my confussion. Do you suggest SAE 30 with detergent or without?
Cat or an equivalent oil meeting Cat TO-4 spec. is all you need to worry about. Is it possible the filter wasn't installed or seated properly? A tiny leak or fluid bypassing could cause foaming.
you need an SAE 30 that meets TO-4 spec. It’s not an engine oil so it will be non-detergent.