Driveline noise, bad!

[Spidey]

Well, I'd thought this was the front CV axles to begin with, but have removed them, and the front driveshaft as well, and the noise remains.

This is a gear/bearing whining type noise, increases in pitch with wheel speed, and only occurs under load, if I let off the gas there is no noise at all. The best description I can give is that it sounds similar to a dogbox transmission, but not exactly, it starts at low speed as a growling/groaning type whine and with speed turns to a high pitch whine, very much like a power steering pump that is very low on fluid. If I'm light on the throttle, like just maintaining speed, it sounds worse and is a little louder and more 'metallic' sounding. Also when I let off it goes louder for a sec before disappearing. When coasting to a stop on the brakes, I can hear when the transmission downshifts into 2nd and then 1st with a 'rrrrrr, rrrrrrrrrrr' noise. I've checked the fluid and it is still fairly red and appears fine, I was planning to change it and the filters but I don't want to 'waste' my money if it isn't going to do any good. I've inspected the rear driveshaft and everything looks good, u-joints are good and theres no play, I did not remove the the boot at the t-case to inspect the yoke or anything though, but there are no signs of fluid leakage anywhere. The noise sounds like it is coming from the transmission and t-case area, but I'm not sure if it could be the rear end transmitting the noise forward in the driveline.

Thanks in advance for any ideas and help!

Shannon

 

[Spidey]

You know, the more and harder I listen, the more it sounds like the rear end. I'm going to change fluid in the morning, any way to 'flush' it, or is spraying everything with brake parts cleaner pretty much enough?

 

[Simpleman]

Could be rear wheel bearings or front hub assemblies.

 

[Spidey]

Definitely not a front hub as there are no front axles in and the noise happens under load/acceleration. After much searching on LOST I'm thinking my rear diff is pretty much toast. I don't want to speculate too much on what exactly it is because it could be anything, but my rear axle vent tube did get disconnected one night a few weeks ago while wheeling in some deep swampy grasslands. I'm fairly certain water got in and has destroyed something. I was planning to change the fluid tonight and inspect everything but we're getting tons of rain here so it's going to have to wait a day I guess.

Thank you for the input though!

 

[tjkj2002]

Definitely not a front hub as there are no front axles in and the noise happens under load/acceleration. After much searching on LOST I'm thinking my rear diff is pretty much toast. I don't want to speculate too much on what exactly it is because it could be anything, but my rear axle vent tube did get disconnected one night a few weeks ago while wheeling in some deep swampy grasslands. I'm fairly certain water got in and has destroyed something. I was planning to change the fluid tonight and inspect everything but we're getting tons of rain here so it's going to have to wait a day I guess.

Thank you for the input though!

Just because the front CV's are not in does not rule out bad hub bearings,but I'd be more incline to agree with the rear diff being the culprit.

 

[LibertyTC]

Differential

Do you have a Trac-Lok diff?
If so, it could be that the water downed gear lube has broken down, and is effecting the clutches. Best thing is to remove the diff cover, inspect/clean and refill of course with the gear lube and Chrysler friction modified additive.
Best of luck..hope it's nothing serious.
Let us know how what u find...(yeahthat)

 

[Spidey]

I don't know if I have a trac-lok diff or not, is there an easy way to find out aside from pulling the diff cover? I requested a build sheet from Chrysler last night, we'll see what it says in a few days I guess. I'd guess I don't have one though, as when I've been stuck in mud and such, only 1 wheel spins, that wouldn't happen with the trac-lok would it? I'm really tempted to get out there and just change the fluid in the rain but ugh, getting soaked and laying in water in the cold isn't very appealing right now lol.

Troy(I believe that is your name), I don't want to argue, but I know for a fact it is not a front hub bearing. The CV axles not being in, may not solely rule out it being a hub bearing, but all of the symptoms together do. I do have a bad front hub bearing though , totally different type of hum and vibration compared to this other noise. The hub bearing vibration and hum changes with steering input and going over dips and such in the road, this other noise does not, only changes with load and speed(in pitch) and disappears when letting off the gas.

Thank you guys, I'll be sure to post my findings and get some pictures of the diff with the cover off. I also want to add that before I reconnected the vent tube, the axle had spit out some goopy thick black 'grease' type fluid, very similar looking and feeling to general purpose grease you get in a tub. Boy I can't wait to change the fluid.

 

[JeepJeepster]

Uhh, if the vent tube came off and it was spitting stuff out did you not think it would be good to change the diff oil? How long was the vent off and did you go offroad while it was off? A couple ways to figure out if you have trac lock or not is to see if there is a tag on the right side of the axle. It will say OPEN or TRAC LOC on it. Another way is to jack up the back of the jeep and spin one of the back tires. If the tire on the other side spins in the oppisite direction then its open. If you cannot turn it then you have trac lock.

May want to check the rear ujoints too..

 

[Spidey]

I did think it would be a good idea actually, I just spent all weekend underneath the thing trying to fix and diagnose this problem. I first thought it was the front CV axles so I started there, no change, removed front DS, no change, I've been working my way back and had planned to change the fluid, I just didn't get a chance, but you're right, I probably should have done that first. I did change the front diff fluid through all of this, as that is where I thought the noise was coming from, but it seems it was being transmitted through the driveline from the rear the whole time. I have gotten under there several times and inspected everything like the u-joints and yokes, checked for play, etc, there is nothing visibly wrong, well, yet... I'm going to go jack up the rear now and give it the spin test. There is some type of yellow 'tag' wrapped around the outermost part of the axle tube on the passenger side but it is not able to be read after much wheeling.

The vent tube was off about a week, and yes, I mentioned in my previous post that it was ripped off while wheeling in some swampy areas, so most likely water did get in. I have not done any off-roading or wheeling since then though, the noise developed probably a week after that happened.

 

[JeepJeepster]

ohh man, well, if you were in a swampy area them its untelling what got in there. Surprised it lasted a week.. Usually when you are diagnosing something its best to start with the cheapest and easiest stuff. And with those u joints, its kinda hard to tell anything about them if they are seized up. Try to feel of them after driving and if they are crazy hot they are probably bad. Just dont burn yourself.. Get the fluid changed and see what it looks like then go from there..

Here you go.. even got disc brakes! nice upgrade, haha.

http://www.lostkjs.com/forum/phpBB2/viewtopic.php?t=47721

 

[Spidey]

Yeah pretty crappy circumstances, but live and learn I guess! Thanks for the link, certainly wouldn't mind getting rid of the drum brakes but we'll see what I find. I'm going to eat now and the rain has let up so I'm going to tackle this shortly in the driveway after picking up a gasket, I'll post my findings.

 

[Spidey]

Finally got around to draining the 'fluid' and pulling the cover off. A good 4qts of goop came out, not good This stuff was so thick it was barely coming out, as you'll see in the pictures. After as much goop came out on it's own as possible, I reached in and started feeling through for metal bits which there were some of, not a large amount but enough for concern. I scooped and scooped and scooped and the stuff just kept coming out, from the axle tubes, it took forever due to being so thick, at least an hour to get everything possible out. I then sprayed everything with brake parts cleaner to get a good look, and the ring gear seems pretty worn, along with the pinion. The edges of the ring gear are very flattened and sharp, and after looking at pictures elsewhere I see they shouldn't be this way, so I guess this is my problem. Also, feeling around in there, one of the spider gears was able to move slightly while the other was not, is this normal depending on how the diff is sitting, or no?

 

[tjkj2002]

Time for a complete rebuild,new ring&pinion,all new bearings,and all new seals.

 

[Spidey]

I meant to get pics of everything after cleaning but was freezing and forgot. Thinking of picking up a spare rear and going to 4.10s, are the Chrysler gears decent enough? And how about an affordable but good master rebuild kit, is there one preferred over another? I see Timken and National.

 

[tjkj2002]

I meant to get pics of everything after cleaning but was freezing and forgot. Thinking of picking up a spare rear and going to 4.10s, are the Chrysler gears decent enough? And how about an affordable but good master rebuild kit, is there one preferred over another? I see Timken and National.

You can get the gears anywhere for the 8.25,I'd highly recommend Yukon gears.Your looking at about $100-$125 for a master install kit(make sure it includes new ring gear bolts),$20-$50 for new axle bearings,$20-$40 for axle seals,and probably $50 for the new spider gears.

And I'd go with Timken for the bearings.

 

[Spidey]

I meant the gears made by Chrysler, or whoever makes them for them. The prices are a little better than say, Yukon, but I guess not by much. Thanks for the responses, man.

 

[ThunderbirdJunkie]

(pictures)

That's

Gross

Good luck with your new rearend.