Read diff aditive
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From: Bellevue Ne
Read diff aditive
I have a 2000 Excursion 6.8 4x4 and she had a 2001 5.4 4x4 expedition im gonna be changing all the gear boxes and transfer cases. When do I add
Genuine Ford Fluid XL-3 Friction Modifier Additive - 4 oz.
to the rear diff because Iv'e read that some rear diffs need them and some dont another question is its calling for a specific ford transmission fluid in the transfer case and ford no longer makes I have read. Can I get some recommendations on what other fluids to use thanks.
Fleet Mechanic
Joined: Mar 2017
Posts: 1,365
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From: Phenix City, AL
Depends if you have a limited slip differential whether you need the additive. Mine is LS and I when I changed the fluid I used Mobil 1 synthetic gear lube which has some LS additive already in it. I didn’t have to add any additional additive.
I used Mobil 1 ATF in the transfer case.
I used Mobil 1 ATF in the transfer case.
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From: N. IL
Fleet Mechanic
Joined: Mar 2017
Posts: 1,365
Likes: 179
From: Phenix City, AL
There should be a metal tag under one of the bolts holding your rear diff cover on. It should have your gear ratio. Mine had an “L” in amongst the numbers, telling me it was LS.
If you use one of the quality synthetic gear oils many already have the additive. That way it doesn’t matter if it is LS or not.
If you use one of the quality synthetic gear oils many already have the additive. That way it doesn’t matter if it is LS or not.
FTE Chapter Leader
Joined: Nov 2010
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From: N. IL
thx Chris.
The best way is check your axle code on the sticker in your driver door jamb and locate on this chart:
Axle Type
31 — 3.73 non-limited slip, F-250/Excursion
C1 — 3.73 limited slip, F-250/Excursion
32 — 4.10 non-limited slip, F-250
C2 — 4.10 limited slip, F-250/Excursion
33 — 4.30 non-limited slip, F-250
C3 — 4.30 limited slip, F-250/Excursion
36 — 4.56 non-limited slip, F-250
C6 — 4.56 limited slip, F-250
41 — 3.73 non-limited slip, F-350 (single rear wheels)
D1 — 3.73 limited slip, F-350 (single rear wheels)
42 — 4.10 non-limited slip, F-350 (single rear wheels)
D2 — 4.10 limited slip, F-350 (single rear wheels)
43 — 4.30 non-limited slip, F-350 (single rear wheels)
D3 — 4.30 limited slip, F-350 (single rear wheels)
46 — 4.56 non-limited slip, F-350 (single rear wheels)
D6 — 4.56 limited slip, F-350 (single rear wheels)
61 — 3.73 non-limited slip, F-350 (dual rear wheels)
F1 — 3.73 limited slip, F-350 (dual rear wheels)
62 — 4.10 non-limited slip, F-350 (dual rear wheels)
F2 — 4.10 limited slip, F-350 (dual rear wheels)
63 — 4.30 non-limited slip, F-350 (dual rear wheels)
66 — 4.56 non-limited slip, F-350 (dual rear wheels)
F6 — 4.56 limited slip, F-350 (dual rear wheels)
81 — 3.73 non-limited slip, F-350 Chassis Cab, narrow frame (dual rear wheels)
E1 — 3.73 limited slip, F-350 Chassis Cab, narrow frame (dual rear wheels)
82 — 4.10 non-limited slip, F-350 Chassis Cab, narrow frame (dual rear wheels)
E2 — 4.10 limited slip, F-350 Chassis Cab, narrow frame (dual rear wheels)
83 — 4.30 non-limited slip, F-350 Chassis Cab, narrow frame (dual rear wheels)
E3 — 4.30 limited slip, F-350 Chassis Cab, narrow frame (dual rear wheels)
86 — 4.56 non-limited slip, F-350 Chassis Cab, narrow frame (dual rear wheels)
E6 — 4.56 limited slip, F-350 Chassis Cab, narrow frame (dual rear wheels)
88 — 4.88 non-limited slip, F-350 Chassis Cab, narrow frame (dual rear wheels)
EW — 4.88 limited slip, F-350 Chassis Cab, narrow frame (dual rear wheels)
G3 — 4.30 limited slip, F-450 Chassis Cab
73 — 4.30 non-limited slip, F-450 Chassis Cab
78 — 4.88 non-limited slip, F-450 Chassis Cab
G8 — 4.88 limited slip, F-450 Chassis Cab
75 — 5.38 non-limited slip, F-450 Chassis Cab
G5 — 5.38 limited slip, F-450 Chassis Cab
GW — 4.10 limited slip, F-450 Chassis Cab
98 — 4.88 non-limited slip, F-550 Chassis Cab
K8 — 4.88 limited slip, F-550 Chassis Cab
95 — 5.38 non-limited slip, F-550 Chassis Cab
K5 — 5.38 limited slip, F-550 Chassis Cab
KW — 4.10 limited slip, F-550 Chassis Cab
Axle Type
31 — 3.73 non-limited slip, F-250/Excursion
C1 — 3.73 limited slip, F-250/Excursion
32 — 4.10 non-limited slip, F-250
C2 — 4.10 limited slip, F-250/Excursion
33 — 4.30 non-limited slip, F-250
C3 — 4.30 limited slip, F-250/Excursion
36 — 4.56 non-limited slip, F-250
C6 — 4.56 limited slip, F-250
41 — 3.73 non-limited slip, F-350 (single rear wheels)
D1 — 3.73 limited slip, F-350 (single rear wheels)
42 — 4.10 non-limited slip, F-350 (single rear wheels)
D2 — 4.10 limited slip, F-350 (single rear wheels)
43 — 4.30 non-limited slip, F-350 (single rear wheels)
D3 — 4.30 limited slip, F-350 (single rear wheels)
46 — 4.56 non-limited slip, F-350 (single rear wheels)
D6 — 4.56 limited slip, F-350 (single rear wheels)
61 — 3.73 non-limited slip, F-350 (dual rear wheels)
F1 — 3.73 limited slip, F-350 (dual rear wheels)
62 — 4.10 non-limited slip, F-350 (dual rear wheels)
F2 — 4.10 limited slip, F-350 (dual rear wheels)
63 — 4.30 non-limited slip, F-350 (dual rear wheels)
66 — 4.56 non-limited slip, F-350 (dual rear wheels)
F6 — 4.56 limited slip, F-350 (dual rear wheels)
81 — 3.73 non-limited slip, F-350 Chassis Cab, narrow frame (dual rear wheels)
E1 — 3.73 limited slip, F-350 Chassis Cab, narrow frame (dual rear wheels)
82 — 4.10 non-limited slip, F-350 Chassis Cab, narrow frame (dual rear wheels)
E2 — 4.10 limited slip, F-350 Chassis Cab, narrow frame (dual rear wheels)
83 — 4.30 non-limited slip, F-350 Chassis Cab, narrow frame (dual rear wheels)
E3 — 4.30 limited slip, F-350 Chassis Cab, narrow frame (dual rear wheels)
86 — 4.56 non-limited slip, F-350 Chassis Cab, narrow frame (dual rear wheels)
E6 — 4.56 limited slip, F-350 Chassis Cab, narrow frame (dual rear wheels)
88 — 4.88 non-limited slip, F-350 Chassis Cab, narrow frame (dual rear wheels)
EW — 4.88 limited slip, F-350 Chassis Cab, narrow frame (dual rear wheels)
G3 — 4.30 limited slip, F-450 Chassis Cab
73 — 4.30 non-limited slip, F-450 Chassis Cab
78 — 4.88 non-limited slip, F-450 Chassis Cab
G8 — 4.88 limited slip, F-450 Chassis Cab
75 — 5.38 non-limited slip, F-450 Chassis Cab
G5 — 5.38 limited slip, F-450 Chassis Cab
GW — 4.10 limited slip, F-450 Chassis Cab
98 — 4.88 non-limited slip, F-550 Chassis Cab
K8 — 4.88 limited slip, F-550 Chassis Cab
95 — 5.38 non-limited slip, F-550 Chassis Cab
K5 — 5.38 limited slip, F-550 Chassis Cab
KW — 4.10 limited slip, F-550 Chassis Cab
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From: Media PA
I have a 2000 Excursion 6.8 4x4 and she had a 2001 5.4 4x4 expedition im gonna be changing all the gear boxes and transfer cases. When do I add
Genuine Ford Fluid XL-3 Friction Modifier Additive - 4 oz.
to the rear diff because Iv'e read that some rear diffs need them and some dont another question is its calling for a specific ford transmission fluid in the transfer case and ford no longer makes I have read. Can I get some recommendations on what other fluids to use thanks.And as said, use a high quality synthetic gear lube in your axle that already had the friction modifier in it, that way if it is a LS diff, its covered and if a non-LS diff then no harm will come from having the modifier in it. I use Mobil 1 also.
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Fleet Mechanic
Joined: Jul 2010
Posts: 1,753
Likes: 34
From: Los Angeles, Ca.
You can use Dex/Merc from anyone, it's what used to be called Dexron3. Do not use Merc V in the t-case, but it is the stuff to use in the transmission.
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Fleet Mechanic
Joined: Feb 2011
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From: Thousand Oaks, CA
A half of a tube of Sta-Lube SL2411 Equa -Torque Differential Friction Modifier did the trick.
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