So my boss just got a 2008 Ford F450 Lariat 4x4 and wants me to change all the fluids on it. So when it comes to differentials I know I can can use 75w140 in the rear and 75w90 in the front but I'm not sure if it is limited slip or not. He has another f450 the same year thats RWD i know is limited slip but on this 4x4 version not sure? Im assuming the rear might be the same but dont know if the front is limited slip or not?. So what im really asking instead of stressing over this just put a limited slip additive in both differentials and call it a day? Could it hurt/benefit if its not required?
Can I add limited slip additive to a regular diff?
- Thread starter jbotelho15
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Check your door sticker or axle tag for whether its lsd or not. FM will have no effect on an open diff other than lightening your wallet.
So just look for the letters LSD on the door jamb sticker?
JHZR2
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Is 140wt the right viscosity for a light duty rear axle? Just asking. Even if it is, I might try a 110 wt to free up a little bit.
My observation, though not necessarily the rule, is that better syn diff lubes already contain some LS additive. Companies like redline offer ester base additive too.
I prefer Amsoil svg best for diffs. Actually best was specialty formulations. Redline starts good but shears or degrades faster, I've observed in diffs and MTs.
My observation, though not necessarily the rule, is that better syn diff lubes already contain some LS additive. Companies like redline offer ester base additive too.
I prefer Amsoil svg best for diffs. Actually best was specialty formulations. Redline starts good but shears or degrades faster, I've observed in diffs and MTs.
Dana S110 axle I assume. You can call a local Ford dealer with the Vin and find out for sure. My buddies '09 is LS.
Originally Posted By: JHZR2
Is 140wt the right viscosity for a light duty rear axle? Just asking. Even if it is, I might try a 110 wt to free up a little bit.
The Dana S110 is a big boy for a pickup. 14,700 or so pounds GAWR, often derated in a pickup application. It calls for 75w-140. I know because I just priced some Amsoil SVG for my buddy with an '09 F450. He cringed a little even with my discount. $91 plus shipping for the fluid change.
Is 140wt the right viscosity for a light duty rear axle? Just asking. Even if it is, I might try a 110 wt to free up a little bit.
The Dana S110 is a big boy for a pickup. 14,700 or so pounds GAWR, often derated in a pickup application. It calls for 75w-140. I know because I just priced some Amsoil SVG for my buddy with an '09 F450. He cringed a little even with my discount. $91 plus shipping for the fluid change.
It's a utility truck not a pick up GVWR is 16k and I'm sure he'll be close to that the way he loads the thing. Plus he tows a bobcat every once in a while
Originally Posted By: jbotelho15
So just look for the letters LSD on the door jamb sticker?
I am afraid not. There are extra codes on the door sticker, and I remember using some code reader web-based application years ago. Didn't need it after that and can't recall now.
They also put an aluminium tag on the diff with a designation. The best is, probably, as some suggested consult with the dealer
So just look for the letters LSD on the door jamb sticker?
I am afraid not. There are extra codes on the door sticker, and I remember using some code reader web-based application years ago. Didn't need it after that and can't recall now.
They also put an aluminium tag on the diff with a designation. The best is, probably, as some suggested consult with the dealer
Wow guys...
Make it easy on yourself. Chock front wheels. Jack up the rear end and put in neutral. Turn one rear wheel. If the other side turns in the opposite direction, it's an open differential. If it turns same direction, it's limited slip.
Putting in the friction modifier when not needed....will not hurt an open diff.
Make it easy on yourself. Chock front wheels. Jack up the rear end and put in neutral. Turn one rear wheel. If the other side turns in the opposite direction, it's an open differential. If it turns same direction, it's limited slip.
Putting in the friction modifier when not needed....will not hurt an open diff.
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Just add the LSD additive or go with a syn that doesn't require the additive. The vin number wouldn't tell you if someone added a LSD aftermarket. I had an LSD thrown in my Ranger along with a rehear and the vin number would lead anyone that read it to believe it was an open diff. They'd think it had a 3.73 open diff when it was changed to a 4.56 with a trak lock.
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Yeah no tags and nothing on the door saying LSD or anything I guess I'll have to jack her up and do the wheel spinning thing.
No, the door tag will have the axle code which you can reference to determine which rear end, gear ratio and whether its open or locker or what-have-you.
If it's a S110 Eaton Dana axle with "limited slip" it's an Eaton TrueTrac helical differential (Torsen type). Eaton does not recommend friction modifiers nor synthetic lubes for optimal limited slip operation. But it won't hurt anything if you have the stuff in there.
Originally Posted By: Kuato
Wow guys...
Make it easy on yourself. Chock front wheels. Jack up the rear end and put in neutral. Turn one rear wheel. If the other side turns in the opposite direction, it's an open differential. If it turns same direction, it's limited slip.
Putting in the friction modifier when not needed....will not hurt an open diff.
This^. And I would stick with the 75 (or 80 or 85)-140 gear lube.
Wow guys...
Make it easy on yourself. Chock front wheels. Jack up the rear end and put in neutral. Turn one rear wheel. If the other side turns in the opposite direction, it's an open differential. If it turns same direction, it's limited slip.
Putting in the friction modifier when not needed....will not hurt an open diff.
This^. And I would stick with the 75 (or 80 or 85)-140 gear lube.
Ford puts a tag under one of the diff cover bolts which lists all the axle's information. There is an "L" interpolated into the gear ratio on limited-slip vehicles. So, an open diff truck with 3.73 gears will say (in part) "3 73". A limited slip truck would say "3L73".
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