Hi. I just bought a Cat D3B. I knew it only worked in 1st & sometimes 3rd. I was not scared of that because the filter was perfectly clean and they have used it this way for 2 years, so I knew it was more of a valve issue rather than internal explosion. I was going to run it this way till spring. When we started using it 3rd started to work regularly along with 1st. Never any slippage like bad discs etc. Well then we lost 1st all together. Won't even try. Now we have two 3rd's. 2nd gear position is also 3rd, as well as 3rd being 3rd. I know this sounds goofy, but it's true. We pulled the top of the trans off and visually looked at the spools and valve body. All is moving fine into their detents and so on. The inside of the trans is perfect. No metal, disc fibers etc. I have seen when transmissions are on the way out. Crap everywhere. Not here. When we had just 1rst when we got it, and would try another gear just to try, it would lock the tractor in it's shoes. No free rolling even an inch. The same happened when we would throw into neutral position. Stopped dead. Well now it will free roll like it should when the shifter is moved. Before 2nd gear position turned into our second 3rd gear, It would engage and draw the engine right down. It was trying hard, but it was as if the parking brake was locked on. Noise but no movement at all. Does anybody know of these crazy symptoms? Thank you
sound like the plantery gears are locked in 2nd speed clutch pack
Hi. Thank you. I guess I need to suck it up and pull it apart. Thought I may for once get an easy fix. Oh well, that's owning equipment. Thanks again
Let us know what you find when it comes apart. Thanks
Sounds like you might have smoked a clutch and that perhaps the frictions are warped and cannot disengage. What’s puzzling is the clean system….have you checked the suction screen and magnet for debris?
Oh yea, thie first thing I did was pull the filter. Not a crumb in it. I am puzzled too. We have had D6 and D7 transmissions go to heck, so I have learned that. Those screens were packed with junk. It's crazy.
It sounds like you have a trans clutch locked together. Try removing the shift valve from the trans and useing a rubber tipped blow gun apply air PSI to each trans clutch pack. You should hear them apply and release. If you dont hear them"clunk" on applying air its locked. If you hear a rush of air in the trans case then the clutch pack is blown out. I been testing trans in machines and rebuilds on the bench like this for 32 years. In my days with Cat a D3 was smaller than anything I was allow to touch so a question....... it this trans shifted with electric solenoids? If so check that you dont have electrical problems causing the WRONG solenoids to engage. I have seen and chased these same problems on machines that shift the trans electricaly.
Hi. No it does not work with solenoids. Are you speaking of the control valve body under the plate on the tranny top? The big valve with 20 or so bolts? We haven't had time to monkey with it just yet but plan to shortly. Thanks again to everyone for the help. I will post what we find once it is all over. Maybe we can all learn something from it.
Like Mortrak said I'd air check clutches ..I like to test not guess ...
As stated a D3 was smaller than the product line I serviced so cant tell you the exact location of the valve body but if the shift linkage is attached to it your on the right track.
Yes, it is the control valve, this I know. I can see the spools moving and all detents feel fine, and the spools are moving to their fullest. So your saying I leave that valve body in place and apply air? Where are the ports to do so? There are plugs on the top of it labled P1, P2 and such. I assumed these were for trans pressure testing, but would this be the location to be applying the air?
I have done quite a few of these and I tend to think she has broken a planetary, but air testing the clutches is a good Idea and fairly easy