Fishbait

Hello,

My 2000 4x4 has been making slight vibrations and grinding noise when starting out and turning slowly. I have 198,000 miles on it and use Amsoil synthetic 75/140 since the first oil change. It is due to be changed again and when I pulled the filler plug to inspect there was an inch of super super fine shavings on it. I was intentionally on a slight incline to drain some oil to inspect and the honey colored oil is saturated with enough glitter it couldn't be probably couldn't be reproduced by Zoom plastics in their plastic worms!
I have never seen this much in any tractor or vehicle.

Not familiar with rear end functioning and diagnosis....don't want to put 125.00 of oil back in if there are other serious problems going on!

Any ideas please advise!

2500Ram

Like you, I don't have experience with the D 80 rear but I have rebuilt some Ford 8.8's and 9's and you have BIG problem going on. Best case would be wheel bearings are toast but if you seriously have 1" of metal dust on the fill plug your ring and pinion have to be just about gone. If I'm not mistaken (again no experience on the d 80)the filler plug is above the full line so that is just what metal has been flung on to the magnet = much more on the bottom.

Start shopping for the best rebuilder

Bill.

crobtex

When my rear bearing went out, there was a lot of little shiney speck around the bearing and the end of the shaft, but not noticable in the pumpkin.
Take the cover off and check it out........

jefe4x4

Does the D-80 have a limited slip rear end? If so, probably a trac-loc. It uses wet clutches that go bad after a while. I would suspect this first, if it does indeed have the trash loc. There should be a metal tab on one of the cover bolts that would have the ratio and "LS" if it has same, and a caution to use special limited slip lube.
Pull the cover and take a look.
I've heard of very few woes with the D-80 besides being under filled from the factory.
regards,always, jefe

Fishbait

Yes I have the limited slip, w/5 speed and it has been 50,000 since I have changed the dif oil. Are you refering to the wheel bearings? or is there another bearing in the axle before the "main gears" behind the cover?

I didn't want to take the cover off yet and lose my oil until I had a better idea of what I am looking at....other than the obvious gear which I assume is the pinion gear...? This wouldn't be related to my vibration problem, would it?

I am still clueless with this issue. Which manuel is a good one to buy for the dodge 24 valve CTD? Is there one better than Haynes?

From experience is the rear end so complicated that it may be not be obvious unless torn apart? Can an average joe (me) take down and repair?

Thanks for all input.

turbo thom

My wifes trucks rear end went out and it was the carrier bearing. To replace those you have to remove the chunk and there they are on each end. Sort of a trick to replace.

..Preston..

mcctho21

Not sure of the reliability of this info, but I have been told that synthetics sometimes should not be used in limited slip rear ends. Too slippery if there is such a thing. Lets the clutches in there slip too much causing wear.

Rattlerattle

I killed a D80. Pretty sure that one of the carrier bearings went and I didn't notice it. That could been the first signs that you have seen with the metal on the fill plug. Mine chewed the pinion and took a couple of teeth of the ring gear, that got a bit expensive.

If you are replacing the bearings you may as well rebuilt the trac lock at the same time.

2500Ram

I was completely new when I did my first 8.8, would I suggest you try it with a Hayes manual, ablsoutly not. Do some research on the internet or here for a guide with pictures. You are dealing with pinion preload, backlash of .008 to .012 many tools involved, dial indicator, press, digital or mechanical calipers way too many to list and if you do anything you void your warrantee but unless you bough used recently with an '00 it's out anyway. The average joe can replace the ring and pinion, carrier berings and everything but it's not like an oil change you have to understand everything that's in there first and then have tools and time, yes the first time for me was 2 days to redo my 8.8 in the Bronco from stock 3:55 to 4:56 after that first time I didn't have it just right and had to start over that only took about 5 hours. After the 500 mile break in I took it to a well know gear shop for the fluid change and had everything checked again, it was ok.

Good luck.

Bill.

robert chilton

Drop the cover and put dino oil in it if you need to. The cheaper gear oil is better than all that gunk getting up and into the bearings. Grab the pinion (where the drive shaft is bolted on) and shake up and down really hard. Does it move? If not the pinion bearings are probably fine. If the pinion seal has a leak that is a good indicator of a bearing going bad. Next disconnect the drive shaft. Rock the pinion back in forth as if the driveshaft were turning it. How much slack is there? A little is normal but alot is bad news for the gears. If everything checks out this far its probably the trac lock or a wheel bearing. Due you get a loud bang or feel clunk/lurch when shifting from reverse to drive? If not I bet the repair isnt as bad as you are thinking.

jefe4x4

If it's a wheel bearing, you usually get seal failure with it. Does it leak oil out at the end of the housing? Again, pull the cover, drain your pig, clean it up with brake cleaner and inspect. I still think it's the trac lock. You said it clunks while turning? Do you mean as you are turning a corner. If that's the case, your trash lock clutches are suspect. I see 60-80K miles on a set of Trac Lock wet clutches. If you get more miles than that, you're driving in a straight line! A clutch type LS diff uses some kind of animal oil emollient that's just the right friction for the clutches. (you can tell by the smell that something died in there) If it chatters, soemtimes you can revive it by using more additive.

If your axle is terminal, or very expensive to repair, I would suggest getting a used complete axle from a junk yard with the same ratio. A used D-80's is not that expensive, just very heavy.
I'm a pretty good mechanic, (engines, fuel injection, electrics, transmissions, transfer cases) but it takes special know-how to work on setting a RG&P ( as mentioned above). I've swapped broken axle shafts on the trail in my Jeep, but I wouldn't set up a RG&P.
regards, as always, jefe

MKELLY

I've got a howling issue when the truck is coasting between 20 and 30 mph, the sound is not as evident under
power, but we know how that goes. The howling is slowly
getting louder. I replaced the inner and outer wheel bearings this past summer so something else is going south, any ideas?

Fishbait

I have taken the rear wheels off and spun the hubs and had no odd feel or noise. With the wheels on I moved hard side to side and top to bottom with no play. This led me to believe no problem with the wheel bearings.

I have no leaking on the rear axle at the pig or hubs either.

The pinion (if it is the "yoke" coming out of the differential that attachs to the rear driveshaft) has some play about 1/4" if I rotate it back and forth, but this is no different than when it was new.

I will get under it tonight to see if I can push the pinion left/right and up down as ya'll suggested. If I have any play am I to understand the pinion bearing may be bad?

I do not understand the working mechanics of the limited slip rear end. Is the above mentioned Trac-Loc the same?

I am not sure if the noise and vibration I feel when turning in a parking lot left/right is considered a chatter or clunk. If I idle through a hard left turn and right turn it has the same feel as a tire rubbing a control arm and when I straighten out it goes away. Had a "mechanic tell me this is normal with all these trucks as they get wear on them. I put some more friction modifier in the diff last year thinking that would make a difference but it hasn't.

What is dino oil?

Thanks so far for the good info....and your time!

MKELLY

I was told to add 2 bottles of the modifier and that it would take up to 250 miles before a difference would be noticed. Dino oil is conventional oil, fossil fuel. Some oils are a mixture of syn and dino and some are pure syn.
Hope that helps.

P Kennedy

The turn chatter is normal over time and the build up of material on the magnet is normal as long as it is only on the magnet. If the entire diff oil contents are contaminated with metal filings there is a problem but filings are not wear particles. Particles will form in the oil on the magnet like a sludge, filings are visible pieces and shiny like that from using a file on a chunk of metal. Dino oil- what people use when they are cheap- sorry could not let that pass, Dino is non-synthetic lubricants which is not recommended in your differential. The D80 is relatively easy to work on but has it's problems like you need a proper bearing puller to get them off without scarring up the carrier. I have a spare if you need one you pay the shipping, replaced mine at 120,000 miles this year with a modified Detroit Locker problem solved-both wheels go the way the driveshaft does now all the time. If you have any doubt pull the cover and inspect the ring gear for abnormal wear pattern, put a bar under the ring gear against the bottom of the case and there should be little or no movement up and down. Gently with the bar check for side play if you have up and down movement-bearing preload. Oil-synthetic is cheap and it is recommended to be changed 70-90,000 miles compared to a new ring and pinion installed. Your labor is cheap to inspect compared to a apprentice doing it at shop rates, your experience will increase while you save $$$$$$. The pinion seal will usually leak if there is a problem on the front bearings, the pinion seals are pricy for this brute. There is lots of help here if you use it and a manual helps but hands on is experience.PK