2017 Ford F350 SRW Lariat (What Rear End Do I Have in this Truck)

[PeterTheWolf]

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Hello,

This my first post in hopes somebody can help me find out what Rear-End I have in my truck I just bought.

I purchased a Ford 2017 F350 SRW Lariat Supercab for pull my 5th wheel trail.

However, the first time I hook it up I realized I did not do enough research. The stock truck sits too high for the my 2017 Jayco_Eagle HT 27.5RLTS
trailer with 15" tires (Stock Tires: Rainier ST 225/75R15, 10 PR Load Range E (80psi Cold)).

So, the first this I did was moved the front & rear leaf spring to the lower shackle hole (2" lower).
Then I made the center shackle extension by 3.0" with a cross support bar (2" X 2" X .125" SQ. Tube Stock).

Here are some pictures of this:




Ok .... I figured I need to get the front end of the trailer down 5" to be level with the truck when pulling.
So, I figured I would drop the center shackle of the trailer 3.0" and the front and back leaf-spring connections 2.0" and then
drop the Truck's Rear-End 2.0". By the way, the truck has a stock 3.5" rack back to front.
Also, the truck will drop 1.5" when I connect the 5th wheel trailer to the truck (1500lb 5th wheel tongue weight).


So, this is where my issues is and why I am here to get advice from the seasons RVers.

I do not know what rear-end I have in this truck. To ensure I purchase the correct leveling blocks to replace the stock 4.0" rear-end blocks
I need to know if this rear-end is a Dana 70 or 80 or Sterling rear-end.

I want to replace the 4.0" stock blocks with 2.0" blocks to drop the rear-end of the truck 2.0". Which then give me a rack on the truck before I hook-up from back to front of 1.5"
with the stock front leveling blocks.

I have set-up a web page with the pictures of the Back differential cover (14 bolt), Rear-End Tag, Rear-Axle Sticker, Driver's Door Jam MFG. sticker, and the stock 4.0" existing
blocks.

These pictures can be view at this link:

Can I please get somebody that understands and/or knows a web-site where this FORD information is available?

Thanks,

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[powerscol]

Look on the truck axle by the center section. Attached to one of the bolts should be a metal tag that gives the differential ratio. There may also be a sticker, but they usually fall off. Also the dealer can possibly look it up with the vin number.

Hope this helps

[Joesgarage]

Being the ton truck you have the 80.
I have a 18 f350, rear axle is a 80 too.

[PeterTheWolf]

Look on the truck axle by the center section. Attached to one of the bolts should be a metal tag that gives the differential ratio. There may also be a sticker, but they usually fall off. Also the dealer can possibly look it up with the vin number.

Hope this helps

Yes ... I know it has a 3:55 ratio rear-end .... however, I am not sure what the numbers are telling on these tags/stickers......






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[PeterTheWolf]

Being the ton truck you have the 80.
I have a 18 f350, rear axle is a 80 too.

DANA 80 ... right?

I do know it has a Ø4.0" axle housing.
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[CoChris]

@PeterTheWolf Your axle code (from your DOT sticker) of "X 3J" for a 2017 F350 will be a Dana M275 axle with a 3.55:1 E-Locking rear end. This is the same as I have in my truck. The Dana M275 (SRW) and M300 (DRW) were new to the Super Duty line in 2017 (and on). All Diesel and some gas engine 2017+ Super Duties used the new Danas. Some gas engine 2017+ Super Duty still used the Sterling rear end.

Chris

[CoChris]

Being the ton truck you have the 80.
I have a 18 f350, rear axle is a 80 too.

Ford used the Dana 80 through 2016. In 2017+ Ford switched to the Dana M275 for SRW in the Diesel and some gas Super Duty. They still used the Sterling 10.5" in some gas engine trucks.

Chris

[Joesgarage]

Total brain cramp! Hit send before brain engaged.
Our trucks have the sterling
Got mixed up with my buds dodge that has the 80 in it.
Sorry for the fake news!

[PeterTheWolf]

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Thank you so much for all who replied.
Now I will look for the correct leveling blocks for my truck and know that it will fit my Rear-End.
We have plans for the first outing in two weeks.
Hope to get it all level before then.

Thanks again for all the knowledge shared!!!!!!
I really mean it!!!

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