mp3mike05

So I had a 92 cherokee 2x4 for about a month and sold it to buy a 98 cherokee 4x4 (first mistake?)

Anyways, there is a pretty loud howl coming from what sounds like the rear diff when going 40-45 mph. If I let off the gas it is quiet, and the second i touch the gas (not even accelerating really) you can hear the howl again. Doesn't do it in neutral so I assume it is driveline related.

Changed out the rear diff fluid and no major metal in the fluid, and the gears looked fine to me. Is this a pinion bearing going / gone bad? What do you think the best course of action is. I don't think I will have the jeep more than a year, and it's main use is to beat around in, some small trails, and to tow my boat to the lake.

wapozzi

i get a howling sound, but i think its my trans, only happens when im in 5th

bfisher42

im having almost the same problem right now and i cant figure it out. i have a hack 'n tap with a cv driveshaft. same about 40-50 mph i get a slight howl but when i let off the accelerator i get a clunk in the from what sounds like under my seat. when i just barely press the accelerator at 40-50 mph it sounds like a grinding/binding noise. when i press it in a little more it goes away. im frusterated to say the least.

xjoffroad

could be the pinion bearing. i have had axle bearings howl and carrier bearing to. you need to take it to a differential shop and they can usually tell you by listening to it.

mp3mike05

Any way I can test this on my own? Would there be something like horizontal or vertical slop in the driveshaft?

Think it will last 6 months Haha? Reallly not wanting to pay to have this rebuilt

4.3L XJ

Yes it will last. I had one howl for a couple of years before I changed it out. Two things I would suggest here. First, get some stuff called Power Punch. There are two types, honey colored and black. Get the black stuff and pout the whole bottle in. It has molybdenum in it (looks like metal filings) and it gets pressed into the pits on the gear teeth that are causing this noise and will quiet it a little. Second, if you end up needing repair, just replace the whole thing with a 97 and up Chrysler rear or a D44 out of an 87-89. That is far cheaper than hiring a shop to rebuild.

CAEMI

Howling rear end when you hit the throttle and stops when you release...that's pinion bearing, if my memory serves. Pinion angle changes under load, causes howl, release the load, howl stops. (Please...no comments on that one.)

No doubt that one or more bearings are going bad. Speed effect is just arriving at the right harmonic so that it resonates enough for you to hear it over all the other noise. IMHO, it won't go away until you replace the parts. Look at the axle bearnings in the diff housing, too...maybe do all of them just to be safe. Labor costs more than bearings.

Make sure you CLEAN everything to the nth degree or your brand new bearings will meet the same fate. Quickly. AMHIK...

xjoffroad

how can you honestly say this? I have seen pinion and carrier bearings seize up after a day or two after making noise. some have had it howl for months and never a problem. I would get it fix ASAP. Hate to be stuck on a road somewhere and need a tow to a shop. just extra $$ to spend.

never heard of molybdenum but his issue is not with the gear teeth. its with the bearings themselves.

cjmass47

i am getting the exact same thing as you except at almost an speed but is worst at the ones you stated. i cant figure it out either i thought it was the rear axle bearings but now im starting to think its the transfer case it doesnt really matter because im doing an axle swap and hopefully running a doubler with new transfer cases if i can scrap up a little more money but i would still like to figure out whats wrong.

Loganfwx

I've got the howl too. How difficult is it gonna be to replace the pinion bearing? Also, am I gonna be screwing anything up by not replacing it tomorrow?

caged

to replace the pinion bearing, you have to gut the whole inside of the diff. therefore, needing to reset the gears.

that's why it's cheaper and easier to just grab a junkyard axle and replace the whole thing.

CAEMI

BTW, if my memory is correct I believe if you are hearing constant growl it is wear on the pinion and ring gears - usually caused by getting water in there or some grime of some sort.

Usually, neither situation results in disaster-on-side-of-road type of end but neither will it ever get better on it's own.

TrekkerJmm

I HAD the "Roar" also and it turned out to be the right axle bearing (seems to be a common problem on Chryco 8.25's) , so I replaced both sides and the roar went away JMO...Tj

nickjc13

dirt probably got in one of the bearings making it howl.