Rear differential issues. Advice needed. - Page 2

carringb · 01-23-2019, 04:21 PM

Is there a chance you're axle was filled with conventional oil?

The symptoms sure sound like LSD chatter. However, a fresh oil change with synthetic (as spec'd by Ford) should take care of it. You should only need friction modifier if the oil has gotten really hot.

Since there was no improvement, I'd suspect they either used regular gear oil (which probably needs a couple bottles of friction modifier at least) or there is something worn out in there.

FWIW - if your rear axle was filled with conventional, Ford says that's only good for 3,000 miles in the E-series.

SteveInLA · 01-23-2019, 04:32 PM

The fluid change was done at Galpin Ford, usually considered to know what they are doing. I think the current plan is to take the van to Agile Offroad and have them install an ARB locker in the rear. There is a suspension issue and a few other things that they are well qualified to take care of also at the same time. Gearing will stay the same as the only issue I have is the inaccurate speedometer which I solved long ago by using a Garmin navigator that shows my speed based on the GPS.

deserteagle56 · 01-23-2019, 05:03 PM

Don't know if your 2010 model would work the same as my 2007 - but when I had my gearing changed I went to the local Ford dealer and they were able to electronically change the calibration of the speedo/odometer to correct for the new gearing.

SteveInLA · 01-23-2019, 05:14 PM

Quote:

Originally Posted by deserteagle56

Don't know if your 2010 model would work the same as my 2007 - but when I had my gearing changed I went to the local Ford dealer and they were able to electronically change the calibration of the speedo/odometer to correct for the new gearing.

After 2008, electronically changing the speedometer became more difficult. Where you could once enter any gear ratio you wanted to compensate, one now only had standard gear ratios to choose from. At least that's how it was explained to me in 2010. Agile has a wizard that can do the change but it adds to the expense. I may or may not have it done.

JoeH · 01-23-2019, 05:19 PM

Quote:

Originally Posted by carringb

FWIW - if your rear axle was filled with conventional, Ford says that's only good for 3,000 miles in the E-series.

Wah? Did you forget a 0 or is that really the spec? I've been running good ole Lucas dino 85W-140 oil in my FF D60 with no issues. That's also what ARB recommended. The caveat being that I have an open diff with an ARB locker so no L/S.

MadScience · 01-23-2019, 06:48 PM

I have a full float Sterling 10.5 with an LSD that I know is working. It has never made any such noises. So I don't think this is a matter that they are all like that, or have to be like that.

I'm using Mobil 1 75W-140 gear oil, and it claims that "in most applications" additional friction modifiers are not required. This statement seems to be working out for me so far. I think I have around 30k miles on that fill now.

However, I am not inherently trying to make these gears last forever. If/when they go, I'll re-gear lower. I'm on 33 1/2" tires with a 3.73 ratio. I may do so regardless.

carringb · 01-23-2019, 07:54 PM

Quote:

Originally Posted by JoeH

Wah? Did you forget a 0 or is that really the spec? I've been running good ole Lucas dino 85W-140 oil in my FF D60 with no issues. That's also what ARB recommended. The caveat being that I have an open diff with an ARB locker so no L/S.

Nope. Not a typo. Full synthetic is good for 150,000 miles. Dino gear oil is supposed to be changed frequently under severe duty:

Non-synthetic rear axle lubricants should be replaced every 3,000 miles or 3 months, whichever occurs first, during extended trailer tow operation above 21 Celsius (70 degrees Fahrenheit) ambient and wide open throttle for extended periods above 45 mph. The 3,000 mile lube change interval may be waived if the axle was filled with 75W140 synthetic gear lubricant meeting Ford specification

Note: Factory fill is synthetic... Lots of folks got duped into a fluid downgrade by their neighborhood quickie-lube.

geoffff · 01-23-2019, 09:02 PM

Quote:

Originally Posted by TomsBeast

It sounds like classic 'locker' or 'limited slip differential' behavior to me. Most have this 'stick-slip-stick-slip-stick-slip' feel and groan sound when turning. Mine does this more after it gets warm going down the highway, then I make a sharp turn into a gas station.

Oh, good to know. Glad to hear I'm not the only one who hears/feels that. It's a bit disconcerting.

-- Geoff

JoeH · 01-23-2019, 10:23 PM

Quote:

Originally Posted by carringb

Nope. Not a typo. Full synthetic is good for 150,000 miles. Dino gear oil is supposed to be changed frequently under severe duty:

Non-synthetic rear axle lubricants should be replaced every 3,000 miles or 3 months, whichever occurs first, during extended trailer tow operation above 21 Celsius (70 degrees Fahrenheit) ambient and wide open throttle for extended periods above 45 mph. The 3,000 mile lube change interval may be waived if the axle was filled with 75W140 synthetic gear lubricant meeting Ford specification

Note: Factory fill is synthetic... Lots of folks got duped into a fluid downgrade by their neighborhood quickie-lube.

Well, they also recommended a 100,000 mile service interval for Ford Gold coolant and we all know how well that turned out. But good info! I checked my notes and it was Dynatrac that recommended regular gear oil in my dynatrac front axle.

When I did my rear axle swap I just did conventional oil there as well, the thinking partly being I would rather change the oil every 20,000 miles and see how it looks and the wear on the gears than hope for 50,000 or 100,000 mile with a synthetic.

TomsBeast · 01-24-2019, 08:20 AM

Quote:

Originally Posted by geoffff

Oh, good to know. Glad to hear I'm not the only one who hears/feels that. It's a bit disconcerting.

-- Geoff

When I first bought my van used, 7 years ago, the guy told me he 'was pretty sure' it had a limited slip rear diff. I jacked it up to confirm.

Just to be clear, there's no linkage between a little moaning and growning while in a turn from a limited slip differential, and ring and pinion wear. They are two different mechanisms that happen to reside in the same package. LSD's do wear out over time, but Fords have a pretty robust design, I think both plates sets are steel, vs 1 set steel and the other clutch plates with friction pads (think motorcycle wet clutch). In either case, "worn out" just reverts back to an open differential, and you continue on your merry way... until one tire is stuck in the mud.

One way to view the chatter, moaning, what ever you want to call it, is when going around a corner, the LSD is talking to you, letting you know it doesn't want to slip, by design "but if I must, I will, with some protest" LOL.

Add an additive to reduce the friction in the LSD if you want, it quiets it down, folk lore used to say that modifier contain Spearm whale oil. I dunno. But this only works in what they call 'the clutch plate type' LSD, my Lock-right locker in my Samurai works by a different method.

Tails from the shop: I'm at a friend Charlie's garage, he and his son are working on their racecar, I'm enjoying a cold beer. A neighborhood car guy stops by, the banter and conversation turns to his son's street car with a Chevy posi-traction differential (Chevy's LSD, a desirable option in old muscle cars). The neighbor quips "You need to add whale spearm!" Charlie and my eyes meet, I'm giggling. "I think you mean whale oil, from a spearm whale, it's a kind of... nevermind" responds Charlie, rollin ghis eyes. I add "Hey Charlie, just how do they harvest whale spearm, anyway" we all laugh

I grab another beer