A couple of weeks ago, my 98 disco started making a grinding sound when i turn left. So after some research, I had it in my head that it was a CV joint so I spent a good part of the day inspecting the bearing on that wheel and swapping the cv joint. Noise is still there. Where should I start looking next...

 

Where does the noise sound like it's coming from? Could be the other side, could be the diff, could be transfer output bearing, front driveshaft, etc. Have you checked fluids and swivel preload?

The only way to find the answer is to pinpoint the location the noise comes from. Might not be a bad idea to drop the gear oil in the front diff and check for chunks.

 

Diff spider gears is my first bet

 

Yup, mine too. Which is why I suggested dropping the gear lube.

Never know, sound can travel in funny ways.

 

True noises, vibrations all can be a pain to find. I need a undercarriage camera some times

If I were you I'd just drop the whole diff. Chances are if a big chunk came off and you don't have magnetic plugs it's just gonna sit in the bottom of diff housing since it probably isn't floating in oil..

Did you change both cvs or only one?

 

I only changed the driver's side- the side that makes noise when i turn in that direction. There is also a couple of inches of forward and back rotational play on both front wheels. Does that mean anything?

How hard is it to drop- and possibly replace the diff? The biggest job i've done so far is changing this cv joint, which i found fairly easy...

 

Easier than a CV. Unbolt the 6 bolts that connect swivel ball to axle. They are the 12 point bolts. Then the axle will pull out. Have a milk crate or something to rest the hub on. Don't let it hang by brake lines. Do the other side so both axles are out. Unbolt diff. Get bottle jack to break the sealant and a small pry bar helps too. Then just pull it the rest of the way off the stud. Be careful it's pretty heavy if you're not expecting it.


With that said I'd check the other cv first

 

Yup, if it makes noise when you turn in one direction it's usually something on the other side, by turning left you transfer the weight to the right side.

Take the FILL plug out first, use a 1/2" ratchet(so you know you can refill the diff) and then take the bottom plug out and drain the gear oil out. If you have a small magnet you can fish around through the drain plug hole and see if you get any chunks. Crawl under the front bumper and you will see the FILL plug plain as day on the front of the housing, the drain is at the bottom to one side.

 

Watching to rule this out on my own vehicle. Looking at my steering gearbox. Good luck.

 

my turning left grind is the front bearings. had it checked and the rotors wiggle back and forth.