Topic Sponsor
2015 - 2020 Ford F150 General discussion on the 13th generation Ford F150 truck.
Sponsored by:
Sponsored by:

Some 5.0 diff info

Thread Tools
 
Search this Thread
 
Old 05-28-2018, 08:20 PM
  #1  
Senior Member
Thread Starter
 
mikeinatlanta's Avatar
 
Join Date: Dec 2017
Posts: 3,269
Received 1,329 Likes on 797 Posts
Default Some 5.0 diff info

Found two near identical equipped trucks on the lot and spent some time comparing. Both fresh builds. 145" wheelbase, 4x4, 5.0, tow package, 36 gal tank, 7,000lb GVWR package. One had the 3.55 elock an one had the 3.73 elock. The 3.55 had an 8.8" and the 3.73 had the 9.75" diff. Odd thing is both trucks had identical 3,800lb RAWR. Anyone who knows these two diffs knows the 9.75 is much more substantial, but they had the same spring stack and same weight rating on these two trucks. The 3.55 equipped truck tow rating was 9,100 and the 3.73 was 10,900. Both had the same 11,600 sticker on the hitch.

Just and FYI. Get the 3.73 and without a doubt you get a stouter diff, but it will have the same RAWR on a 5.0 equipped 145" truck. No matter to me because I'll be adding air bags and exceeding RAWR, so I'll be doing it with the 9.75".
Old 05-28-2018, 09:04 PM
  #2  
Senior Member
 
RL1990's Avatar
 
Join Date: Nov 2016
Posts: 3,249
Received 1,139 Likes on 713 Posts
Default

Adding air bags doesn't allow you to exceed the RAWR. If you need increased payload capacity you may want to look at a Super Duty.
Old 05-28-2018, 09:07 PM
  #3  
Senior Member
Thread Starter
 
mikeinatlanta's Avatar
 
Join Date: Dec 2017
Posts: 3,269
Received 1,329 Likes on 797 Posts
Default

Originally Posted by RL1990
Adding air bags doesn't allow you to exceed the RAWR. If you need increased payload capacity you may want to look at a Super Duty.
Didn't ask permission, said what I intend to do. Feel free to write me a ticket when you see me on the highway.
The following 2 users liked this post by mikeinatlanta:
UNBROKEN (05-28-2018), UncleG (05-29-2018)
Old 05-28-2018, 09:09 PM
  #4  
Senior Member
 
ZeroTX's Avatar
 
Join Date: Sep 2017
Posts: 1,593
Received 373 Likes on 248 Posts

Default

Originally Posted by mikeinatlanta
Found two near identical equipped trucks on the lot and spent some time comparing. Both fresh builds. 145" wheelbase, 4x4, 5.0, tow package, 36 gal tank, 7,000lb GVWR package. One had the 3.55 elock an one had the 3.73 elock. The 3.55 had an 8.8" and the 3.73 had the 9.75" diff. Odd thing is both trucks had identical 3,800lb RAWR. Anyone who knows these two diffs knows the 9.75 is much more substantial, but they had the same spring stack and same weight rating on these two trucks. The 3.55 equipped truck tow rating was 9,100 and the 3.73 was 10,900. Both had the same 11,600 sticker on the hitch.

Just and FYI. Get the 3.73 and without a doubt you get a stouter diff, but it will have the same RAWR on a 5.0 equipped 145" truck. No matter to me because I'll be adding air bags and exceeding RAWR, so I'll be doing it with the 9.75".
The reason is pretty simple... higher numerical gears = SMALLER teeth on the gears. So if you go 3.73 in an 8" diff, your gears are going to be a lot smaller than 3.73's in a 9.75. I assume that to maintain the ratings, they needed to go to a 9.75, else have gears that are too weak.
Old 05-28-2018, 09:14 PM
  #5  
Senior Member
Thread Starter
 
mikeinatlanta's Avatar
 
Join Date: Dec 2017
Posts: 3,269
Received 1,329 Likes on 797 Posts
Default

Originally Posted by ZeroTX
The reason is pretty simple... higher numerical gears = SMALLER teeth on the gears. So if you go 3.73 in an 8" diff, your gears are going to be a lot smaller than 3.73's in a 9.75. I assume that to maintain the ratings, they needed to go to a 9.75, else have gears that are too weak.
My Ford Motorsport race 8.8 diff came with 3.73. The 8.8s I have seen fail fractured the housing. Not on a truck though.
Old 05-28-2018, 11:48 PM
  #6  
Senior Member
 
MagneticScrew's Avatar
 
Join Date: Jun 2017
Posts: 410
Likes: 0
Received 97 Likes on 65 Posts
Default

Originally Posted by mikeinatlanta
didn't ask permission, said what i intend to do. Feel free to write me a ticket when you see me on the highway.
🤣

👍🏼
Old 05-29-2018, 05:36 AM
  #7  
Member
 
UncleG's Avatar
 
Join Date: Sep 2017
Posts: 2,124
Received 357 Likes on 262 Posts
Default

Originally Posted by mikeinatlanta
Didn't ask permission, said what I intend to do. Feel free to write me a ticket when you see me on the highway.
Same.



Quick Reply: Some 5.0 diff info



All times are GMT -4. The time now is 06:56 PM.