Dakota Durango Forum banner

rear end whine

12K views 17 replies 10 participants last post by  bigpav7 
#1 ·
Got the rear end on my Durango rebult a few months ago, the pinion bearing wAS going. Just now I started noticing a different whine, which sounds like its coming from the rear. Unlike when the pinion bearing was going out and it whined when I pressed the accelerator, this time it only whines when I get off the gas at around 56 mph. THe whine goes away immediately. I also cant hear it any other speeds. Does this sound like normal gear whine (being that the gears have 70K on them and the bearings are relatively new with only about 3K) or is this indicative of yet another issue with the rear of the truck? thanks in advance.

03 Durango 9.25 rear, 8.55s
 
#5 ·
Are you setting this up yourself or having a shop do it? If you had a shop do it, I'd get back to them to let them know it still isn't right.

Make sure the shop who does it really IS experienced with your particular diff and isn't just saying they can do it, btw.
 
#6 ·
talked to the guy who rebuilt mine. He basically said that if the whine starts getting louder, he'll open it up and start looking for the problem. But if it doesnt change, I may just have to live with it. I guess I dont really mind the noise too much, as long as I know it's not due to a problem that's going to take out my rear end down the line.
 
#7 ·
talked to the guy who rebuilt mine. He basically said that if the whine starts getting louder, he'll open it up and start looking for the problem. But if it doesnt change, I may just have to live with it.
What brand gears do you have? (Don't say Yukon....)
 
#8 ·
I have the same whine as well. I just had the pinion bearing and seals changed, lucky the stock gears didn't get damaged and were reinstalled again. The noise isn't loud at all but it's there. I also noticed my boss's 2006 E-250 does the same thing and the gears are still original.

If it does get louder I will contact my mechanic about the whine.
 
#11 ·
basically what has happened is that the backlash was not set correctly on your rear, Ive been in several dakota rears mostly 9.25 and if the pinion depth and backlash were not set correctly then it will cause this whine, I recently had my rear rebuilt with Motive gear 3:55s(kept breaking the stock pinion) with all aftermarket bearings, seals, etc, and mine has the same whine at 45 to 50 mph, far as reusing stock gears, the mechanic should have taken the current backlash setting in 3 different locations on the ring gear and should have set it back to the specs, it may have been set to manufacturers specs instead by accident
 
#12 ·
I actually remember him mentioning backlash. If I recall correctly, the backlash has to be set somewhere in between 2 values - that's what he said he did - dont believe that was based on any measurements. He basically said, "it has to be between this and this so I set is at this"
 
#13 ·
that is correct, but here's an example, me and a friend of mine thats really good at rebuilding rears did a carrier swap in my 9.25 and reused the stock ring gear, we checked what the gears were already set at in three different locations, that way we knew what range to set it back to, alot of time when you have new gears they require a different setting that should be included in the instruction book, another way to basically explain is that say your rear has 60K miles on it, alot of wear and tear on those gears and where they contact each other at, whenever you change that setting of where the gears contact, that will cause the differential whine, thats where alot of mechanics can make their mistake at
 
#14 ·
When I was a line mechanic at Chevy we would always install a new gear set if we had the rebuild the diff. Just changing the bearings would always change how the gear set pattern ( coast and drive) was mated while its was in service during all those miles.
It was better to start with a new gear set and bearings.
Doing the lead paste on the old gear set was tricky at best as it would give out some weird patterns on coast and drive.
Now using the original gear set and have a little whine did no harm, just its was annoying to listen to it.
Hope that helps to why that happens.
 
#16 · (Edited)
Having same issue.

Ok, i am going to start from the beginning. Ill start by saying I am fairly average on my knowledge of vehicles, but fairly dont know a lot on rear diffs, except for the general parts used etc.

My 2000 durango was in the shop for rear breaks, mechanical told me the rear diff fluid was really low, so he topped it off, he said that the leak should be fixed, with parts and labor, about $60. So i brought it in a few days later to him to have it fixed, he gets back to us a few days later and says the rear end has some problems needed to be fixed, we told him to go ahead, (he said things about the pinion bearing and something about the wear pattern on the teeth of the gears). I had noticed the whining sound maybe people have described prior to it going in, it whines when you accelerate, but if you are coasting, its almost nonexistent.

I get it back a week later (parts took awhile he said), and charge us $711. He showed me a box of parts he replaced, i saw the pinion bearing for sure, and a bunch of spacers and other small parts? No gears tho. I drive away and already its whining, and whining loud, louder than before. Way louder than before, 2 or 3 times louder, but still goes away when coasting.

I only put about 50 miles on it since i got it back, and it sat in my driveway, and its still leaking from the rear diff, he couldn't even fix that!

Also, when driving it, it starts to smell a burning smell from the rear end(this also started happening the day before it went in, but i had to drive a lot further for it to start making the smell), like i said i only put 50 miles on it so far, and always only 10 or so miles at a time; im trying not to drive it when possible. I dont know if that would help with a diagnosis.

Basically i just dont know what to do. Ive been reading all different forums all day. I dont know if i have a LSD? I read somewhere that they didnt put in the friction modifier in the rear diff and it made it whine, they added it and it dramatically decreased? could this be all it is? any thoughts?


what should i do besides go to a different mechanic????
is it just a spacing issue??
I just dont want to get screwed again




Lastly, the only reason i went to this guy is its a friend of my dads and usually gives us a good deal on labor costs. Im starting to think he might be incompetent when it comes to rear diffs?? This $711 seems really high from what ive seen elsewhere online. I kind of go through my dad, my dad tells me what he says, and how much it is, etc. We havent paid the mechanic yet, if he cant fix it, shouldnt he have told us he was over his head?? i mean, he couldnt even get the rear diff to stop leaking??? Im just torn, i dont want to pay him. All he did was replace parts, that if left as is, will just get warn and break like the last ones, except faster? and maybe even ruin other parts of my rear end.



I really appreciate you sticking around to read it all. thank you for any help you might be able to give.
 
#18 ·
I did a lot of reading when my rear end went out and learned that you can't just go to any mechanic to get the rear rebuilt. They need special tools and especially knowledge to set it correctly, so the work should only be done by people who specialize in this. Many transmission shops do rear end work as well, so that's where I would have tried first.
Sounds like this guy doesnt know how to set a rear end properly, so I wouldnt have him work on your truck's axle any further. Since he's your dad's friend, I would ask him to see his invoice for the parts and just pay him for that. Then, find a place that has done rear end rebuilds. Ask around, chances are you'll end up with a reputable transmission shop. Ask them to set up your rear. I would throw in a set of new gears as well, as previously mentioned.
 
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top