Rear Axle Howling at 89,800 miles

[Snowman269]

My truck must be trying to tell me something. I've never had a rear axle failure before. This seems too low of miles to be having trouble. I had the fluid changed around 45,000 miles & was ready to do it again. The manual says to change it every 100,000 due to synthetic from the factory. Is this early? Some just drive their rigs and never change rear end fluid, yet they go for much longer. What do you guys think?

Dennis

 

[RenoF250]

My truck must be trying to tell me something. I've never had a rear axle failure before. This seems too low of miles to be having trouble. I had the fluid changed around 45,000 miles & was ready to do it again. The manual says to change it every 100,000 due to synthetic from the factory. Is this early? Some just drive their rigs and never change rear end fluid, yet they go for much longer. What do you guys think?

Dennis

I change my diff. fluid every 25k or so and it was very dirty the first time. Are you sure it is the rearend and not a u-joint or carrier bearing? Did you pop the cover and look in there?

 

[Snowman269]

No, I haven't yet. I'll be hopefully tearing into it this week.

 

[CPUNeck]

My truck must be trying to tell me something. I've never had a rear axle failure before. This seems too low of miles to be having trouble. I had the fluid changed around 45,000 miles & was ready to do it again. The manual says to change it every 100,000 due to synthetic from the factory. Is this early? Some just drive their rigs and never change rear end fluid, yet they go for much longer. What do you guys think?

Dennis

Dennis, do you tow heavy? Does the sound change on accel and deccel? Really stupid, but must know, is it leaking? (pinion, rear cover damp etc.) Haven't looked, but perhaps if you have really torqued it, if there's a crush sleeve, it could have deformed a little messing up the preload on the pinion. That certainly is one cause of roar. Keep us informed.

FYI, my truck has over 170k with the OEM pinion and seal , but I canned the OEM open diff for an Auburn!

 

[Snowman269]

Dennis, do you tow heavy? Does the sound change on accel and deccel? Really stupid, but must know, is it leaking? (pinion, rear cover damp etc.) Haven't looked, but perhaps if you have really torqued it, if there's a crush sleeve, it could have deformed a little messing up the preload on the pinion. That certainly is one cause of roar. Keep us informed.

FYI, my truck has over 170k with the OEM pinion and seal , but I canned the OEM open diff for an Auburn!

Tow Heavy = 12,500lb 5th wheel about 700 miles a year.
Medium = 6,500lb enclosed trailer about 4,000 miles a year.

I'm replacing the enclosed trailer for a Car Hauler. Occasionally I need to load up to 10,000lbs in the trailer. This will allow me to make less trips, I hope. So I'll be heavier more often now.

I have really torqued it before, once I made the T/C slip for 1 or 2 seconds when it was already locked, ooops! I try to be easier on the trans since the lockup clutch on the T/C won't tolerate much of that. I need to start saving $$$ for BTS before I get.

No leaks. The whirring changes with speed, the tone changes ever so slightly with decell from accell. I had a (friend) tech from the Ford garage climb all over the truck while driving to locate the sound. He agreed, it's in the rear end. Couldn't be 100% if it was pinion or axle bearing. We are going to use the dealership hoist after hours (Wed or Thurs evening).

I have heard of an Auburn only, what your thoughts on one.

Also, does anyone have recommendations to strengthen a rear axle to ensure long service life? I'd hate to have to baby this truck, I bought it to work. It's been a good truck. I plan on getting 300,000 to 500,000 miles out of her, if reasonably possible.

 

[CPUNeck]

Dennis I would say the Sterling axle has proven itself over many many years of service. I certainly don't baby mine (use wise), but change the fluid every 30-40k miles regardless of what Ford thinks. On a side note and I have no flame suit guys so this is just MY opinion... From the factory I believe the fill hole is low. If you fill the axle to that level and drive on fairly new roads, the crown of the road leaves the drivers side axle outer seal dry. I have always over filled the axle (like at least a quart) and let my vent do its thing.

I like my Auburn Gear a lot. If your mostly on road, boat ramps, etc. it will be great. Next I'm going with the Detroit Locker. I was scared off by all the comments on how loud and stuff these unit were, but I'm a builder and a posi will serve me better. This summer I'll probably replace it. This carrier was at least 40% more beefy than the OEM unit that came out. No complaints on the rear end at all. I haven't replaced a single seal, OEM ring-pinion, etc.

 

[Snowman269]

No flame suit needed. The crown of the road is a fact and your theory into the drivers side bearing going dry is certainly a possibility. My first thought is, it is likely! Second thought is how much oil IS too much? At what point would you increase heat & drag. One quart over may be the right answer.

I wonder what the average crown is to roads? I know different parts of the country have different specifications.

I have had Detroit Lockers in GM trucks & Detroit Lockers are in many over the road trucks. Yes, they are loud, but they last for many years in heavy duty service applications. If I change the rear diff, it will be a Detroit Locker. Unless I find something better.

 

[Snowman269]

Rear axle update: I have friends at Ford garage with afterhours access.

Put truck on hoist and run axle in drive, it was BAD! Sounded like marbles. Disassembled and inner pinion bearing was trashed/pitted. carrier bearings were the same. The inside of the housing & components were covered in metal particles.

So they cleaned up inside of pig, replaced the pinion and carrier bearings. Should I replace the outer axle bearings too? My thoughts are yes.

We didn't pull the drive axles and wipe out the axle tubes, so I'm thinking whatever is in there will hopefully end up in magnet. Am I being too anal?

Should I just not worry about outer wheel bearings until they need attention? If i do that, any metal fragments from them going bad would ruin the new bearings that were just installed.

I did ask about the crown of the road theory & the axle tech said the taper of the axles carries oil the the outer bearings, no need to overfill. He said you can see this in action in a tool shop where a spinning bit will carry the lubricating oil across the whole bit from the spinning action.

So what do you guys think about all of this?

 

[CPUNeck]

Rear axle update: ...

So what do you guys think about all of this?

Well anal is NOT the first word that comes to mind, more like systematic is more appropriate I couldn't even drive the truck with new carrier and pinion bearings knowing the axel tubes could be full of metal chunks Anyway hope you decide to pull the axels, at least I'll sleep better

 

[Snowman269]

Yeah, that's what I thought.