2012 5500 differential vibration/chattering

[MChrist]

Our 2012 5500 Cab/Chassis is making a horrible grumbling sensation. Come to a stop sign, turn either direction, apply throttle and you get a sensation just like running over rumble strips on the side of the road. It's not from the front end. You feel it through the seat, which implies rear end. Doesn't seem to be rear tires. Also only seems to be while accelerating. Do these rear ends have clutches that chatter? That's what this seems like. Truck only has 14,000 miles.

Any ideas? Thanks.

 

[JR]

Sure does sound like sticky or worn out clutch packs, although that's hard to believe on a 14k mile rear end. Warranty time?

 

[cerberusiam]

The AAM axles don't have clutches in the LS, it is a Torenson type LS that uses gears and brake disks. Try doing the turning with minimal accelration and see if that makes a difference, too much TQ and they will try to lockup and skid tires.

 

[MChrist]

The AAM axles don't have clutches in the LS, it is a Torenson type LS that uses gears and brake disks. Try doing the turning with minimal accelration and see if that makes a difference, too much TQ and they will try to lockup and skid tires.

It grumbles with even very light throttle. And it doesn't happen if I coast into a turn. Rear tires aren't very aggressive, nor are they cupped or wearing oddly. I would say they are wearing quickly, however. At this rate, I don't think I'll get 40,000 miles out of the rears. We typically get up to 80,000. I've even had to change out the fronts at 10,000 due to cupping and went to a highway rib style.

 

[cerberusiam]

You might try an LS additive to see if that does anything. The downside is the additive may make the brake disks too slippery and the LS will not function as well.

They are not supposed to need an additive if the correct fluid is used but not every single one is the same. If you ar enot sure what is in therw now might be worth a change.

 

[MChrist]

I'll crawl under it today and see what I can find out. I glimpsed at the back side of the diff and was shocked at how huge it was!!

 

[AH64ID]

The Ram 5500 does not use an AAM axle, it uses a Dana S111. More specifically if it has a limited slip it will be a S14-111L.

It does appear that the OE locker in the S111 is a TruTrac, which like the AAM is a helical gear style LSD and is clutch-less.

I would have it looked at under warranty.

 

[MChrist]

I only got a chance to look at the tag today. "Spicer" is cast into it, and the tag says "model S111L"

 

[Missouri Mule]

IIRC Spicer is a Dana brand.

 

[AH64ID]

Yes, a Spicer S111L is the same as a Dana S111L.

 

[MChrist]

Well, I have somewhat of an update. Earlier, I mentioned that this truck was really chewing up tires front and rear, but the driver was a very easygoing driver... turns out not so much.
I had data loggers installed into all our trucks to monitor speed, location, and something I wasn't even aware of... I can pull reports of hard acceleration and hard deceleration!!!
Lo and behold, our easygoing mellow driver turns into a wild, aggressive driver after he leaves our shop. While our other drivers may get a few "hard decel" per month, he pulled 44!!! I thought something might be wrong with his transponder, so I drove this truck last night. I have to slam on the brakes as in a full blown panic stop to get the alert. Driving aggressively doesn't even trip it. You have to slam on the brakes like an idiot (from 50 to a stop in about 100 ft). This truck weighs 13,000 empty, and near 19,000 full. AND IT'S LIQUID WEIGHT!!!
I've been monitoring his tire wear, and it's 3 times what the other trucks average. Now I know why.
I also found that he likes to drive well over 70 mph. Today is his last day...
So now, I wonder if his aggressive driving style may have damaged the rear, or maybe the carrier bearing? Son of a ... ... ... ... . !

 

[JR]

too bad you can't obtain tne keys to his personal truck while hes out, and fry the tires right off it. Then when he asks wtf, you can show him your results and tell him you've only begun.
It's a real shame the most you can do to people like that is terminate them.

 

[MChrist]

Another update. Took truck in question to a ram dealer that actually works on 5500s. Not all of them do...
They replaced both upper ball joints and said that took care of the growling, grumbling feeling. Does that make sense? Truck is 2WD. I haven't picked it up yet, it's an hour away.
This growling feeling was happening at around 10,000 miles and I figured it was the aggressive tires that were also wearing oddly. So I've had bad upper ball joints since 10,000 miles?? Either this is a wrong diagnosis, or I'm looking at replacing uppers every other oil change??
I'm calling them back today to see if they even opened the rear end. I have a feeling they didn't.

 

[DonFitzwater]

Sounds like an inexperienced tech diagnosis to me. I've never seen ball joints bad on anything at 10k.

 

[Bob4x4]

I had a 5500 come in at around 15k that had shot upper ball joints.Not sure why but the warranty had already been restricted

 

[sag2]

The shudder in sharp turns is fairly common on 4500-5500 especially when they are at or close to max GVW. The helical set up in the diff is very aggressive and when the truck is so heavy it can't slip the tires it shudders like you have a solid differential.

 

[JLandry]

...the warranty had already been restricted

Bob,

What does a restricted warranty mean?

John L.

 

[sag2]

It can be anything from total loss to customer modifications.

 

[Vinnie_z]

I may be late on this I just came across it but I purchased a 5500 2 years ago. and obviously the factory didn't put limit differential additives in .friction modifiers.every right or left hand turn you felt chatter like the wheels are coming off. I replaced the fluid at 12,000 miles with royal purple and a bottle of limited slip additive ms 10111. and it felt like I put a new rear in a truck.now with 26,000 miles after the 12 initially put on the vehicle I still have no chatter in the rear.