Expert: Robert Summers - 10/10/2008

Question
I have a 1988 Chevy Cheyenne and I accidentally left it in 4 hi for a while and drove on it. I know it sounds stupid but I did. I feel like an idiot. But none the less, I found out when I started hearing a grinding noise coming from the front end. I then found that my differential was engaged. I am worried that I did major damage to the gears up there. After I took it out of 4 hi and put it in 2 hi the noise stopped of course because the gears are no longer turning the front tires. But is it possible that I fried my front end? And if so where can I find a reasonably priced replacement?

Answer
Hi RJ... well leaving it in 4 hi shouldn't have hurt it unless you had some problems in the first place...first check the fluid level in the front end...if ok check the lash in the front drive shaft to the front end...if it has excessive lash you may have a bad pinion bearing. try engauging the front end and turn the drive shaft by hand and see if you can feel anything. if that doesn't tell you anything then pull the cover off and have a look inside...if front end was low on fluid you may have bearing problems inside....also check that the front end is engauging all the way...sometimes the cable that pulls it into gear gets frayed and it only engauges halfway and causes a grinding noise...hope this helps