Hello, I have been trying to diagnose a growl or low grind noise that I hear when I take off from a stop, and is especially noticeably when making a turn and when trying to do this quickly. It sounds like it is coming from the rear end and possibly the wheels. After much googling here and on youtube, I am making a guess that it is coming from my differential.
First question I have is if I'm correct in assuming I have a limited slip differential? I have a 1998 2WD XJ with Dana 35 rear differential according to specs (since I have ABS), and since it's 2WD, no transfer case or front differential. I am attaching a picture of the tag that is in my glove compartment. Sorry for the poor pic, I had to take this last night in the dark with a flashlight. I understood a locking differential to be different from limited slip? My theory (after watching a video which seemed to point to my symptoms, is that the noise is "caused by the limited slip clutch pack locking and unlocking repeatedly at a fast rate" and that either the rear clutch packs are worn or damaged or the differential fluid is low and/or lacking the friction modifier additive. Anyone else ever have this problem and can tell me if I might be on the right track? I think this noise problem is commonly referred to as "chatter".

 

Go look at the differential. It should have a tag on it like this...



You can also get the Bill of Materials off the tube and then look it up.

Go here and read how to find your Bill of Materials (BOM). Then follow the link in the page to the Data Aftermarket Media library.

https://www.differentials.com/techni...dentification/

Here's my D35 with Trac loc (in orange rectangle) The other numbers are the build date (6/28/88).



Mine still has the ID tag on it as well. It also shows the gear ration and BOM on the lower line.

 

Limited Slip Differentials typically came as part of the tow package.. You could also use a VIN decoder to see what your XJ has. Since it's a 1998, I think they cover your year beyond just the basics.

 

With what you said I would think the noise could be a axle bearing or maybe a carrier bearing . If you have a bad bearing in a rear axle I would change all the bearings in the rear end . I had a bad carrier bearing and when I was changing them I found I had a bad pinon bearing also , that's why I would change them all .

 

Thank you Saudade!
I crawled under the rear and had to scrape away some crud to read anything. I cleaned up the tags and some of the markings on the pumpkin but found nothing on the axle. It may be under the lines that are attached but I looked on both axles and front and rear and below and found nothing.
Here's some photos.

 

From what I could read with a small flashlight, here's what they say.
Tag 1:
099457AB LS
3 55-6032-2

Tag 2:
USE LIMITED
SLIP DIFF
LUBE ONLY

Photo 3 from bottom left of Pumpkin:
8021 (but in the pic the 8 looks like a 5)
Photo 4 from bottom right of Pumpkin:
SHF-2
Photo 5:
pic of axle, no numbers

 

I did a VIN search when I bought it but didn't see anything about a tow package and I concluded it didn't have one. Maybe I'm wrong. Here's what I copied from that search. Do you know of a good website with a better VIN search?

Drive Type

4x2

Style/Body

Compact Utility (Utility Vehicle Categories "Small" and "Midsize")

Engine

4L

Manufactured in

TOLEDO, OHIO, UNITED STATES (USA)

Age

24 years

Manufactured By

FCA US LLC

Plant Company Name

Toledo Assembly # 1

Vehicle Type

MULTIPURPOSE PASSENGER VEHICLE (MPV)

Series

-

Body Class

Sport Utility Vehicle (SUV)/Multi-Purpose Vehicle (MPV)

Doors

4

Front Airbag Location

1st Row (Driver and Passenger)

Seat Belts Type

Manual

Engine Displacement (CI)

244.0949763789

Engine Displacement (CC)

4000



Fuel Type

Gasoline 20.2 gal

warning when 2.5 gal left

Engine Number of Cylinders

6

Additional Vehicle Info

Gross Vehicle Weight Rating From

Class 1C: 4,001 - 5,000 lb (1,814 - 2,268 kg)

Steering Location

Left-Hand Drive (LHD)

Trim

SE

Brake System Type

Hydraulic

Engine Configuration

In-Line

Fuel Delivery / Fuel Injection Type

Multipoint Fuel Injection (MPFI)

NCSA Make

Jeep / Kaiser-Jeep / ******- Jeep

NCSA Model

Cherokee (1984-on) (For Grand Cherokee for 2014 on use 02-422.)

Trailer Type Connection

Not Applicable

Trailer Body Type

Not Applicable

Bus Floor Configuration Type

Not Applicable

Bus Type

Not Applicable

Custom Motorcycle Type

Not Applicable

Motorcycle Suspension Type

Not Applicable

Motorcycle Chassis Type

Not Applicable

Error Text

0 - VIN decoded clean. Check Digit (9th position) is correct

 

You could well be right that it's the bearings or carrier! I'm a newbie at this. How would you describe the difference in symptoms between the bearings, carrier or worn clutch packs?
Good advice, if I have to take it apart anyway, I would def. do it all. I am hoping there's a way to do a diff fluid change and solve my problem. That case hasn't been opened since I had it, and I have no idea if it was ever serviced. There's plenty of crud on it. but I can see what looks like a gasket hanging out around the edges even tho it is awfully thin and very plastic-like so maybe somebody has been in there.

 

With worn clutch packs there should not be any noise , the Limited Slip will just not work very good if it will work at all .

 

Ok. I guess the bearings would be cheaper/easier to fix than bad clutch packs? or am I wrong about that?
How do you tell if Limited slip is working? I've never had a vehicle with this. What I did notice alot but could never find out why, is that when I have to make an extreme turn at a parking garage that I go to often, that there is an almost unbearable screech that sounds like the wheels are rubbing against the wheel well. Would that sound have anything to do with Limited Slip perhaps? Or can you tell me what that noise is from? I believe my tires are within spec. My vehicle has not been lifted. Thanks for any help and advice! Much appreciated!

 

To see if the Limited Slip works just get on some dirt and do a burn out to see if both tires are spinning or if only one spins .

 

So I got the build sheet. It does have the Dana 35 and "TRAC-LOK DIFFERENTIAL REAR AXLE"
According to another jeep site, "The Trac-Lok is a mechanical limited slip that shifts power from the wheel that is spinning to the other wheel. It works well in the snow and mud but it does not help if one wheel is lifted or has no traction resistance. In other words, it is not a locker. But it will give you more traction than an open differential. One trick in slippery conditions is to use a little brake with one foot while you step on the gas pedal. This helps the limited slip to engage."

This was a state government fleet jeep (Alabama), not sure if that is the same thing as "Police Package" though. I can say there are/were tons of electric lines stuffed into the hole by the fuses on the passenger side, from equipment they removed presumably, and holes left on the console etc where they mounted them. I started to try to sort it out when I got the jeep but it was too overwhelming and that will have to be dealt with later. The console under the radio has some buttons that I do not believe are stock, and they also do not work. Probably also went to equipment.
I got the build sheet from a site online. Posting it here. Not sure if there is anything there that constitutes a real upgrade, maybe someone here would know. I was hoping to see a transmission cooler and upgraded front suspension on there like someone else with a police package got. Also the upper speed limit removed. The articles I've read about police package jeeps said they were stripped bare to the essentials, and that is how this one feels.
https://www.allpar.com/threads/jeep-...e-cars.229153/

 

hmm..that is easier said than done. I would have to go out into the country for that, and I can only do that on the weekends.

 

Pull the cover. See what the fluid looks like.

 

yup was thinking that... gonna try to get the bolts loose. might need some new tools if I'm going to start doing maintenance myself, would a breaker bar work?
Cruiser, what fluid would you put in this? OEM for dana35c lsd says 80w90. Any brand you recommend? I better get some before I try to open it. I think I prefer a gasket to pure rtv in case the innards are bad and I need to go back in there. Is Felpro ok or should I get the expensive one?