Hi,

I'm trying to figure out what might be wrong with my '97 Discovery (126K miles).

A few days ago, after just leaving to go to work (not on the highway yet), I heard a grinding noise coming from the rear (seemed to be left-side, to me.) I was going low speed, in fact I was at a stop sign and had just started pulling forward and turning left.

At first, I thought maybe my mud flap was rubbing the tire (it was just the first thing that popped in my mind, based on the sound.)

Anyway, after a few seconds there was sort of a sound as if something 'broke', and then the deep grinding noise went away. In it's place was a 'quieter' grinding noise, that I couldn't hear very well without rolling down the window.

At this point, I was thinking that it might have something to do with my left rear brakes. I had noticed some braking issues for a while - the car seemed to pull a bit to the left when braking hard, for example. Thought maybe the caliper or something 'broke'.

Well. I was late for work. I drove on (about 30 miles...). And at the end of the day, I started driving back home.

About half-way, I heard a louder grinding noise again, and then the car jerked pretty hard to the left (I was on the highway) - I believe the left rear wheel seized up a bit. So I pulled off the highway, and after looking it over, ended up taking the back roads home (slower speeds).

Okay, I should have stopped when I first heard the noise, I know.

The 'quiet' grinding is pretty much constant, but one thing to note is that it gets briefly worse when hitting a pothole, for example.

Anyway, I'm just looking for comments on what the problem might be. I'm guessing it's either the rear differential or the left rear hub bearings. Or maybe even something going on with the left rear brake caliper. The noise sounds like it is coming from the left rear (which gives me hope that it's not the differential), but I haven't yet tried having someone else drive it while I sit on the passenger side.

The car has 126K miles on it, and so I don't want to spend a lot of money on it by taking it to a dealer/mechanic. But I love my Disco, and am willing to put in the hours to fix it if I can.

I do have the RAVE cd, btw. I know tools might be an issue.

Any advice would be appreciated...

Mike

 

yeah, you need to chock your front wheels and jack up your rear axle. Be aware that in park, it will roll if an axle is up, and your parking brake acts on your rear driveshaft. Check proper procedures for jacking, and then start looking at your hubs. Wobble the rims to see if there is excessive play. Could be a number of things, I would start with brakes and wheel bearings.

 

Yeh, quit driving it and go get your hands dirty. Right now all you are doing is causing whatever to get worse.
Pull the wheel and brakes, then tell us what you see.

 

Check all your fluid levels, and setting the parking brake WILL lock the front driveshaft too.
I know because I tried it and it WILL lock the front driveshaft.
But still chock the wheels.
Sounds like a stuck caliper to me though.

 

Ok, I've got the car jacked up and on a stand. I took the left rear wheel off, and removed the bolts from the axle, so I can turn the hub. It feels and sounds like something is dragging, but not real significantly - of course, that's just by hand-turning it, not sure how that translates on the road. I'm tempted to take the other wheel off to see what 'normal' feels like - maybe later.

Anyway - not much time to work on this tonight, so I figured I would get some tools tomorrow. Some questions:

1. This is a pretty stupid question - what do I need to remove the level plug on the rear diff? It has a square hole in it...what size? From the stains, there does appear to be some leakage around the plug, not sure how significant though (nothing dripping, but I guess it could be dry.)

2. I can't get the bolts off the calipers. I'm going to borrow a breaker bar this weekend and try that. Can anyone confirm the right socket to use? Definitely don't want to ruin the head..

3. From the RAVE cd, it sounds like the rear axles should just slide out, once unbolted from the hub. But I can only pull the left/rear one out about an inch or so...should I try to force it out, or do I have something wrong?

Thanks for the help...I've had my Disco for almost 12 years...it's my baby!

Mike

 

Wow, you have owned it almost 12 years and you have never removed the fill plug on the diffs?
Did you have it serviced for you, like at the dealer or a quick lube?
It will take a 1/2" drive ratchet or breaker bad, use a 3" extension, just stick the square end of the extension into the plug and lefty loosey and righty tightly.
Stick your finger into the hole, if your finger comes out dry then you are WAY low on gear lube.
I would wait to remove the axle until you check the gear lube level, you might want to remove the drain plug and see if chunks of metal come out.
You will need 2 quarts of gear lube to refill it.

 

So, you have trashed your wheel bearing or the spiders are about to fail.
With the lack of service this truck has had, you should consider doing a full service in addition to the rear diff repair.
Make sure you have a socket large enough to remove the axle bolt as well as a new bearing and race set and gaskets.

 

Yeah, I took it to the dealer when it was under warranty, then mostly quick lube places after that (except for scheduled maintenance up to around 75K, I think.)

Probably just a coincidence, but early last summer I had a 'complete' lube job on my truck - oil, transmission, differentials, etc. They said they couldn't figure out how to do the transfer case, though...Anyway, about two months later, my transmission oil cooler sprung a leak, and I replaced that myself. Now this...makes me wonder if they screwed some stuff up, but it does have 126K miles, so I guess I can't complain.

Thanks for everyone's help. I'm going to drain the diff tonight and look for metal.

Mike

 

Ok, the diff was full (oil dribbled out when I removed the fill plug.)

I then removed the the drain plug, and drained the oil into a bucket. I didn't see a single speck of metal! I even put a powerful (rare earth) magnet in the bucket and swirled it around - no metal.

So I reckon that's a good sign, right??

Next step - remove the caliper. Can't get the bolts off, though; I plan to either buy or borrow a breaker bar and try that.

Thanks,

Mike

 

Go to the Auto Parts place and get some good penetrating oil.. I like PB Blaster.. something that touts its abillity to creep into threads and free rusted parts.. Spray the bolts down with this... let it sit, spray more Tap on head of bolt with something weighty, small hammer or similar.. Tap.. DO NOT BEAT.. Do this up every 30 minutes for a few hours.. be patient, it will creep into the threads, it will work its way on its own but I like to believe the vibration of tapping helps it wick farther faster..

If its a 6 sided bolt use a 6 sided socket.. im not sure what type of bolts your rear calipers have.. My fronts had 12 point bolts.. (First Ive ever seen) so look at them carefully, dont just reach back there with a socket and feel around.. Stick your head back there.. remember righty tighty lefty loosy... (when looking at the bolt)

Good luck