• Welcome Visitor! Please take a few seconds and Register for our forum. Even if you don't want to post, you can still 'Like' and react to posts.

Mileage and limited slip differentials

Lefty

Well-Known Member
Joined
Feb 8, 2022
Messages
442
Reaction score
450
Points
63
Location
Saint Paul, MN
Vehicle Year
2003
Make / Model
Ranger Edge
Transmission
Automatic
I'm thinking about installing a limited slip in my 2WD 3.0 liter 8.8 4/10 Edge. I would imagine that I will have reduced mileage. Does anyone out there know what differences I can expect?

Also, I do not intend to buy an old junkyard axle or even a new differential. It just seems like overkill. I'm hoping to crack open my own differential and simply install a new OEM limited slip assembly. Does anyone know of a reliable source for the parts?
 

Attachments



Uncle Gump

Forum Staff Member
Forum Moderator
Supporting Member
TRS Event Participant
Joined
Sep 17, 2018
Messages
10,799
Reaction score
8,600
Points
113
Location
Ottawa IL
Vehicle Year
2006/1986
Make / Model
Ranger/BroncoII
Engine Size
4.0L SOHC/2.9L
2WD / 4WD
4WD
My credo
Lead, Follow or get out of my way
Changing the carrier is doable.

Ever set up a rear end before? They require some special tools.
 

Lefty

Well-Known Member
Joined
Feb 8, 2022
Messages
442
Reaction score
450
Points
63
Location
Saint Paul, MN
Vehicle Year
2003
Make / Model
Ranger Edge
Transmission
Automatic
My friend put a limited slip in his Mustang. We think that he has the know how and the tools.
 

gw33gp

Well-Known Member
U.S. Military - Veteran
TRS Banner 2010-2011
Ham Radio Operator
Joined
Aug 7, 2007
Messages
1,496
Reaction score
256
Points
83
Location
Costa Mesa, CA
Vehicle Year
2002
Make / Model
Ford
Engine Type
4.0 V6
Engine Size
4.0 SOHC
Transmission
Manual
2WD / 4WD
4WD
Tire Size
33"
I have never heard of a LSD causing reduced gas mileage, if that is what you are talking about. The only time it has any affect is when going around corners and the drag at that point is very minimal. The scrub of the tires while going around the corner should have more drag than the LSD.
 

RonD

Well-Known Member
Joined
Jun 2, 2012
Messages
22,336
Reaction score
5,544
Points
113
Location
canada
Vehicle Year
1994
Make / Model
Ford
Transmission
Manual
+1 ^^^

No change in MPG unless differential was setup wrong, i.e. a howling noise when driving, indicating too much friction
Since you have to pull the axles plan on new bearings and seals

Differential cover didn't have a gasket from factory, they just used RTV, but you can get a gasket if you want
Check the Vent tube/hose, make sure its clear, you can get small filter for the end of the hose under the bed, should have one on it now
Clear vent helps to prevent leaks as it allows pressure in the axle housing to equalize as the oil heats up and expands
 

don4331

Well-Known Member
V8 Engine Swap
Joined
Sep 6, 2013
Messages
1,606
Reaction score
786
Points
113
Location
Calgary, AB
Vehicle Year
1999
Make / Model
Ford
Engine Type
V8
Engine Size
5.3
Transmission
Automatic
I'm thinking about installing a limited slip in my 2WD 3.0 liter 8.8 4/10 Edge. I would imagine that I will have reduced mileage. Does anyone out there know what differences I can expect?

Also, I do not intend to buy an old junkyard axle or even a new differential. It just seems like overkill. I'm hoping to crack open my own differential and simply install a new OEM limited slip assembly. Does anyone know of a reliable source for the parts?
@Lefty : Just to be clear here - the limited slip carrier and side gears are different from the non-limited slip ones. So, you will need limited slip carrier, matching side gears, limited slip clutches and "Z" spring. I usually get everything but the clutches from another axle (i.e wreckers) as they're not really wear items; clutches come from Rockauto or similar.

Procedure:
Undo the cover and drain oil, remove cross pin (5/16" extra long box end wrench - its locktite in), remove c-clips, pull axles. Then undo the carrier caps (make sure you keep drivers on drivers side, passengers on its side) and remove.
Transfer your ring gear to the limited slip carrier (ring & pinion are a matched set, a little heat is often handy here - propane torch not hotter), install the carrier, setting it up correctly. 90% of time, the shims used at factory are what you need, but there is the other 10%....
If you decide on new bearings for your limited slip carrier, you need a bearing puller and press. (and it just about guarantees shims are off...)​
Then you install clutch pack (having soaked them in friction modifier) and limited slip side gears.
Slip axles in, install c clips, spider gears and cross pin.
Compress the "Z" spring and insert it into carrier to set the preload on the clutch packs. I think there is colourful language required here when spring slips out of clamp before it is quite in, and goes into low orbit)
Button it up with the rear cover and add oil and friction modifier.

Optional: axle end bearing and seals, rear brake hardware (pads, cylinders, etc anything that needs doing while you are there).
 
Last edited:

Lefty

Well-Known Member
Joined
Feb 8, 2022
Messages
442
Reaction score
450
Points
63
Location
Saint Paul, MN
Vehicle Year
2003
Make / Model
Ranger Edge
Transmission
Automatic
Thank you for adding clarity to this job, especially because I'm a rookie!
 

dvdswan

Well-Known Member
U.S. Military - Veteran
Joined
Feb 11, 2021
Messages
2,040
Reaction score
1,596
Points
113
Location
Seattle, WA
Vehicle Year
1991
Make / Model
Ranger XLT 2WD
Engine Type
3.0 V6
Transmission
Automatic
2WD / 4WD
2WD
My credo
Keep your mind like an umbrella, it only works if its open... Continually learning.
Thank you for adding clarity to this job, especially because I'm a rookie!
hmm, I thought you were a lefty...
 

don4331

Well-Known Member
V8 Engine Swap
Joined
Sep 6, 2013
Messages
1,606
Reaction score
786
Points
113
Location
Calgary, AB
Vehicle Year
1999
Make / Model
Ford
Engine Type
V8
Engine Size
5.3
Transmission
Automatic
Thank you for adding clarity to this job, especially because I'm a rookie!
Wasn't sure if you're a rookie or not, but others ghost the site for information. I wanted to make sure they got all the information they would need.
 

Lefty

Well-Known Member
Joined
Feb 8, 2022
Messages
442
Reaction score
450
Points
63
Location
Saint Paul, MN
Vehicle Year
2003
Make / Model
Ranger Edge
Transmission
Automatic
Wasn't sure if you're a rookie or not, but others ghost the site for information. I wanted to make sure they got all the information they would need.
I gotta say that I came to this site because I soon found out that much of the wisdom here is solid. This is a very good group.
 

lil_Blue_Ford

Well-Known Member
Forum Moderator
V8 Engine Swap
TRS 20th Anniversary
TRS Event Participant
Joined
Aug 6, 2007
Messages
6,245
Reaction score
2,424
Points
113
Location
Butler, PA, USSA
Vehicle Year
95
Make / Model
Ford
Engine Size
4.9L
Transmission
Manual
There is another option too, the Detroit TruTrac. It replaces your differential with a geared limited slip, no clutch packs to wear out.

My F-150 has a Lock-Right locker in it. Not the best street manners, but it goes.

My first Ranger got a junkyard limited slip, just used the tech library to figure out what gears I had and what the axle codes were for the limited slip version. Worked well.

My choptop has a limited slip from a donor I bought that had extra clutches installed as per the tech library. Makes it work more like a locker but a little nicer on the street. The Tru-Trac works like that, but without clutches.

I’m currently working towards getting a limited slip out of a donor I bought ready and under my green Ranger. That will get extra clutch packs.
 

ekrampitzjr

Well-Known Member
Joined
May 28, 2021
Messages
263
Reaction score
260
Points
63
Location
Virginia
Vehicle Year
2011
Make / Model
Ford Ranger
Engine Type
4.0 V6
Transmission
Automatic
2WD / 4WD
2WD
Absolutely change all bearings and seals while it's apart. That includes the axle bearings and seals at each end by the wheels.

The cost of those parts is minimal compared with the hassle of pulling out the axles again later.

Remember you will need to add limited-slip additive to the fresh diff lube after the conversion.

When you were asking about mileage, were you actually asking how many miles the limited-slip will last compared with an open diff? I understand limited-slip clutches are a wear item, so that is a potential issue over many miles.
 

lil_Blue_Ford

Well-Known Member
Forum Moderator
V8 Engine Swap
TRS 20th Anniversary
TRS Event Participant
Joined
Aug 6, 2007
Messages
6,245
Reaction score
2,424
Points
113
Location
Butler, PA, USSA
Vehicle Year
95
Make / Model
Ford
Engine Size
4.9L
Transmission
Manual
Absolutely change all bearings and seals while it's apart. That includes the axle bearings and seals at each end by the wheels.

The cost of those parts is minimal compared with the hassle of pulling out the axles again later.

Remember you will need to add limited-slip additive to the fresh diff lube after the conversion.

When you were asking about mileage, were you actually asking how many miles the limited-slip will last compared with an open diff? I understand limited-slip clutches are a wear item, so that is a potential issue over many miles.
Some synthetic lubes and stuff come with the additive in it, so you kinda have to pay attention when you buy the gear oil if it will need the additive or not. I have synthetic gear oil going in mine that says on the bag (yes, it’s in bags not bottles) that no additional additive is needed
 

Lefty

Well-Known Member
Joined
Feb 8, 2022
Messages
442
Reaction score
450
Points
63
Location
Saint Paul, MN
Vehicle Year
2003
Make / Model
Ranger Edge
Transmission
Automatic
Some synthetic lubes and stuff come with the additive in it, so you kinda have to pay attention when you buy the gear oil if it will need the additive or not. I have synthetic gear oil going in mine that says on the bag (yes, it’s in bags not bottles) that no additional additive is needed
I've had my share of problems with vendors. I've often got the wrong parts. I wonder is you could recommend someone who might have the right parts for sale. I've got a 410 8.8 differential now.
 

lil_Blue_Ford

Well-Known Member
Forum Moderator
V8 Engine Swap
TRS 20th Anniversary
TRS Event Participant
Joined
Aug 6, 2007
Messages
6,245
Reaction score
2,424
Points
113
Location
Butler, PA, USSA
Vehicle Year
95
Make / Model
Ford
Engine Size
4.9L
Transmission
Manual
I've had my share of problems with vendors. I've often got the wrong parts. I wonder is you could recommend someone who might have the right parts for sale. I've got a 410 8.8 differential now.
Ok, so IMHO, your easiest solution for upgrading to a limited slip is to get a junkyard axle and swap the whole thing. A K6 or R7 axle code on a Ranger door sticker is 8.8” limited slip 4.10. (I have the axle codes section of the tech archives saved on my phone for junkyard searches). Little more difficult swap would be an Explorer 8.8 which would give you disk brakes in the rear. That would be a D2 axle code for 4.10 LS.

Unless it was impossible to find the ratio I wanted or I was going to go with something like the TruTrac, I would likely just swap the entire axle and skip messing with setting up gears. If you’re just going to use the differential, you can use any LS diff from an 8.8 Ranger since you will re-use your gear set. An Explorer 8.8 uses 31 spline shafts so you have to use the entire axle. Your gear set could be swapped to one though. The TruTrac and ones like it would have to come from a place like Summit Racing or Jegs or JC Whitney or something.

I got my gear oil from Autozone. Think what I got for my green Ranger was Pennzoil synthetic stuff. Since I’m re-doing the axles and it’s going to be a bit of a go fast toy, I went synthetic. For most of my axles I just use regular gear oil though and buy it by the 5 gallon bucket…
 

Sponsored Ad


Sponsored Ad

Top