I recently bought a cat 2004 D5 GXL at an auction. It will go forward and backwards and it will turn once but there is grinding sounds. When I try to turn again, a transmission error light will come on in the parking brake will be engaged sn:CAT00D5GCWGB01039
Welcome to the Forums! Glad to have you. First thought was check the speed sensors or maybe a calibration but when I read "grinding noise" you're going to need Nige.
Someone told me it could be a valve not opening all the way or it could have been sitting for so long that it’s just seized up
In reverse, it will turn to the right, but that is the only way it will turn
@Nige could you help me it turns really good in reverse to the right and when I’m driving forward, it pulls to the left but going forward it will not turn right. It will kind of turn to the left going forward, but it will not turn to the left going backwards or to the riot going forwards at all
The noise is worrying. The first thing I would suggest is to remove the transmission filter (arrowed on the attachment) and cut it open to inspect the filter media for debris. It will cost you a new 1G-8878 filter element but the first thing you have to establish is whether or not something is coming apart inside the hystat power system. See this VIDEO for details on how to cut and inspect a filter. Post photos of whatever material you find inside it. Yes I know it shows an engine oil filter but the priciniple is the same for all types of filter.
My D3G did a similar thing. Turned out to be the front hydraulic pump. Nige was valuable in posting the test port locations on the machine. We had zero pressure at the one that drove the left side. We ended up pulling the engine to replace the front hydraulic pump and plastic flywheel on the engine. Right around $10K to fix in our own shop. I hope it is something else for you.