4H grinds, vacuumn or transfer case?
Hi guys, new jeep owner here in need of 4wd information. I have a '90 YJ 4-cyl manual shift with no mods. 4H grinds when I try to engage it but goes into 4L fine. 4L seems to work but the 4x4 light does not come on. Should I look towards the vacuumn lines/system or the transfer case? Thanks in advance of all responses.