The forklift when moving straight forward or backwards or when turning only slightly moves extremely slowly and jerks a little, almost as if the battery is nearly dead or perhaps the brake is not releasing fully. It takes about 8-10 seconds to go a foot even when fresh off the charger and there is a faint buzzing noise that I don't recall it making when it was working normally. However when making a sharp turn in either direction the forklift quickly accelerates to its normal full speed both forwards and backwards and continues to go at that speed until you start to straighten out. When you're turning and going normal speed and start to straighten out it slows down immediately like you slammed on the brakes and goes back to the jerky barely moving thing it does. Anyone have any ideas on what might be causing this?