antony1103

Alot of previous discussion on the E-locker but nothing really answered my question. I have a 2013 FX4 with an L9 axle code (3.55 e-locker). When the E-locker is disengaged, does the differential act as a limited slip or open diff? I'm asking because I will be changing the gear oil soon and need to know if friction modifier is required (with an LSD).

doctorschlachter

No friction modifier required unless it is a LSD.

It acts as an open diff.

antony1103

That's what I thought, but its hard to tell when the traction control takes over. Now that I've looked into it, all the gear oil I'm seeing already has friction modifier in it. The Ford manuals even specifies friction modifier without differentiating between the different axles. I assume its okay with use gear oil with friction modifier on an open diff. The only downside I see from my research is a slight increase in oil oxidation, but I'll probably change it out so often for it to be a non-issue.

cbr600rx7

Why not get the OEM product if you are worried about it.

I have also noticed the rear acts almost like a LSD especially in the snow. I assumed this was just from the traction control but there may be more to it.

antony1103

Unfortunately the local ford dealer wants $24 a qt...

cbr600rx7

How many miles are on your truck for you to want to change it.

antony1103

Around 80k. I plan to change the fluid with better weather this spring so I'll probably have closer to 90k on it. I do a decent amount of towing and hauling and don't quite trust "lifetime" fluids. I figure the cost of the fluid is a small price to pay for some peace of mind. Thanks for the help all.

cbr600rx7

I agree with you on the lifetime fluid thing. I will probably change my doffs and transmission fluid around 100K my self.

I have run synthetic 75-140 in a lot of heavy ford rears and never had a issue. I have also used the 75-90 synthetic in a few LSD vehicles and never had a issue. Sorry I know it's not ford locking diff specific.

Great white

iTrader: (1)

Seems to be this guys opinion:



I was completely prepared to call BS until he did a takeoff on the second video with one on dirt, one on pavement and it left rubber. Don't think it was e-locker as there was a delay between the spinning wheel and the non spinning wheel grabbing.

I've never tried it myself but I can see how braking the spinning wheel can turn an open differential into (essentially) a locker....if it's implemented right that is.

Makes me almost wonder why my truck would have an e-locker if trac control works this way all the time.

I did get the truck sideways today with trac control on on snow covered roads...

cbr600rx7

The TRD tundras have used brake based traction control for years with open rear diffs. It basicly applies a little bit of braking force to the spinning tire (one with least traction) and in effect transfers some energy to the other in the toyotas case this can happen dozens of times in a second and sort of act like a LSD. I have no idea if the ford is set up similar or not but I have definitely noticed decent traction in only 2WD with ELD unlocked.

I really notice it when I'm in really slick conditions like heavy snow. We are talking 6 plus inches on the roads. When stoped or at slow speeds going up a hill it will fight for traction. If it was just a normal open diff I don't think it would manage so easy. Also it does this with ABS off and under very light throttle so I don't think it's the ABS kicking in but some form of traction control.

Now the kicker is the power wagons rear axle and aftermarket ECTED electronic locking diffs act as LSDs when they are unlocked. I was under the impression that fords locking rear was just a open diff when unlocked..... maybe there is more to it? Some one out there knows the truth. That's right ford engineer who is lurking around here some where, I am talking to you.