Differential Questions - Page 4

Drizzt · 03-11-2018, 06:48 AM

Well, after another $2000 to replace bearings, shims and the ring and pinion which they said was bad (note that they did not say it was causing the issue), still have the problem. It actually appears worse, with much more oil seeming to be pouring out over a short time. So still on the hunt.

Dumb question, does the location of the vent tube outlet matter as long as it's above the axle? Originally it was attached to a crossmember at the body, now it's on the frame. I can't see that as an issue, but it's the only obvious thing that is different from before they ever worked on it.

Drizzt · 03-11-2018, 06:52 AM

They also used 75W140, but the Ford shop manual I have says that's for the Dana 80, the Dana 60 should take 80W90.

Drizzt · 03-11-2018, 07:06 AM

Another dumb question: what is the proper fill level of the diff? I’ve read it should be up to the threads of the fill plug and that it should be 1/4-3/8 below. The manual only gives a quantity of oil, which is useless as the locker is larger than the stock diff so it’ll need less oil.

REF · 03-11-2018, 08:44 AM

When you say you still have the problem, which are you referring to? Seeping oil from the vent tube or the noises?
It is perfectly normal to see some diff fluid come out of the vent tube on a fresh oil change, at least that’s what I’ve been told. I just noticed some coming from my vent tube on my newly installed FF with a Truetrac, as the fluid heats it will push out until it’s at the proper level. The vent tube was zip tied above the diff with one of those “Y” connectors on the open end to help keep debris and water from getting in. I’ve thought about bringing it up to the fuel fill area for even better protection.

'03 Ford E350 7.3L Diesel
SMB RB50 w/CCV top
Quigley 4X4 w/Deavers & Agile RIP kit

Drizzt · 03-11-2018, 10:16 AM

The problem of it blowing oil out the vent tube. It isn’t a little, enough comes out that it’s coated the frame rail, splattered all over the underside of the bed and covered the hitch, and will drip off when parked. I’ve driven it four times about 20 miles each and it’s done it each time. I can’t imagine that’s normal level equalization, is it?

But part of my reason for questioning correct level is that when I checked it after the problem revealed itself again, it’s already down to the point that if I put my pinky finger into the plug hole to the first knuckle and point down it barely touches the tip of my finger. However I don’t know how far they filled it, either. I should have checked it before I left their shop...

REF · 03-11-2018, 10:31 AM

I think maybe confirm the fluid, I believe they put 80/90 in mine but not positive, that certainly could be your issue

arctictraveller · 03-11-2018, 10:50 AM

I'd for sure start with the factory recomended oil. A thicker oil will get hotter than a thinner oil, which then will expand more than the lighter oil. Then, I'd keep a close eye on the level to see if it settles down. You could put the vent hose in a little bottle of some sort to minimize the mess and keep track of the quantity. Someone once overfilled a PTO gearbox on a ship I worked on and it got so hot it was smoking. I've had plenty of diesel engines that were filled with coolant to the normal level, but that would then puke out coolant until it reached it's desired level which looked to be too low, but was stabilized. Apples and oranges for sure, but so long as it eventually stops barfing oil, you might be ok. My guess is 1 wrong oil, 2 too full.

ShuttlePilot · 03-11-2018, 10:55 AM

Quote:

Originally Posted by REF

I think maybe confirm the fluid, I believe they put 80/90 in mine but not positive, that certainly could be your issue

I second this idea before moving forward. Not just the weight of the oil but brand and which product of that brand. Oils have a resistance to foaming index. Many times venting fluid is caused by foaming. An example is the atlas transfer case which will puke oil if a high foaming oil is used. Manufactures use additives or modifiers to increase a fluids resistance to foam. Some brands have a reputation for this as Mobile 1 full synthetic products are known to foam horribly and puke out the vent. Amsoil is known for good anti foaming. Amsoil actually posts their test data on their web site others do not. I'm not partial to Amsoil as I try to use whatever the manufacturer specifies.

- Eric

Vanimal · 03-23-2018, 12:09 PM

No doubt Dynatrac is reputable I cannot see spending 5-6 G's on one when there are excellent replacements out there. I for one have a FF NEVER had issues. I have been running it with 4.30's the front was a dually with spacers removed the rear is stock. my plan is to remove the rear at some point and go with a F series only because of larger tube housing, bearings, 10,000 rating and availability. The sterling would work but I prefer Dana. I forgot to mention I built my own 4x4, conversion and all, so that is why I would not pay the money mentioned.