Axle Code 37 Fluid Question?
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Lead Driver
Joined: Mar 2004
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From: Northern Indiana
Axle Code 37 Fluid Question?
I always thought the all the 3.73 Ford axles were limited slip. Guess I was wrong. Bought my new to me 2016 and going to change the rear fluid and it has axle code 37 which upon research is a non limited slip axle. So it would take 75W-140 with out the limited slip additive. Having a hard time finding an aftermarket fluid that doesn’t already have it in it. Am I correct about not needing additive and will have to reluctantly go pay the $28/qt that Ford wants for the fluid?
Logistics Pro
Joined: Oct 2006
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From: East Central Ia
I know what you mean, had a lightning rear axel from a new totalled truck for my f150. Axel had 2 tags on it, 1 tag gave warning and Ford part number for lube and othe tag had 800 number to call Ford if there was any trouble with axel. I bought the $85 lube over the parts counter so I could have peace of mind.
Tuned
Joined: Jan 2021
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1. check if u have a green plug on top left of axel that would be electronic rear axel, also only one tire spins when jacked off the ground no friction modifier
2. spin one rear wheel if other wheel spins in opposite direction no friction modifier open or conventional rear end
3. Limited slip both tires spin in same direction, locked together, then u need friction modifier
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Lead Driver
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From: Northern Indiana
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Fleet Mechanic
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very easy to tell jack rear end up off the ground.
1. check if u have a green plug on top left of axel that would be electronic rear axel, also only one tire spins when jacked off the ground no friction modifier
2. spin one rear wheel if other wheel spins in opposite direction no friction modifier open or conventional rear end
3. Limited slip both tires spin in same direction, locked together, then u need friction modifier
1. check if u have a green plug on top left of axel that would be electronic rear axel, also only one tire spins when jacked off the ground no friction modifier
2. spin one rear wheel if other wheel spins in opposite direction no friction modifier open or conventional rear end
3. Limited slip both tires spin in same direction, locked together, then u need friction modifier
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Lead Driver
Joined: Mar 2004
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From: Northern Indiana
So the additive in the fluid doesn’t hurt anything if I have a standard rear axle? I am sorry for the triple checking, just want to get it done right the first time and move on.
Funny twist to this is I looked back through the stack of maintenance records I got with the truck. At 102,000 the previous owner had the Ford dealer service the trans, coolant, rear and front axles and transfer case. That sure was nice of him. I bought the truck at 111,000 miles so I am thinking of waiting until 150,000 to change everything. On the invoice for the service it says “light service of the rear axle” , front axle, trans etc. Anybody know what that means? I am assuming it means they sucked the old out and didn’t drop the pans?? They also on the invoice show they added the friction modifier?
Funny twist to this is I looked back through the stack of maintenance records I got with the truck. At 102,000 the previous owner had the Ford dealer service the trans, coolant, rear and front axles and transfer case. That sure was nice of him. I bought the truck at 111,000 miles so I am thinking of waiting until 150,000 to change everything. On the invoice for the service it says “light service of the rear axle” , front axle, trans etc. Anybody know what that means? I am assuming it means they sucked the old out and didn’t drop the pans?? They also on the invoice show they added the friction modifier?
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