Diff drop recommendation

[Victorsen]

I know there is few threads on diff drops. Wanted to get some feedback on whether it is necessary. I have a 2 inch lift after a OME suspension install, planing on putting 35s, which will probably give me another 1 inch or so. So is anything greater than 3 inches a diff drop is recommended.? I have a badlands non Sas. Also will need to check CV angles after the wheels are installed, if CV angle is greater than 30 ?

Sponsored

 

[orion]

I know there is few threads on diff drops. Wanted to get some feedback on whether it is necessary. I have a 2 inch lift after a OME suspension install, planing on putting 35s, which will probably give me another 1 inch or so. So is anything greater than 3 inches a diff drop is recommended.? I have a badlands non Sas. Also will need to check CV angles after the wheels are installed, if CV angle is greater than 30 ?

I would jack the front up off the ground and turn your wheel all the way left/right and spin the tire. If the tire moves freely at all extremes your good.

 

[V1Rotate]

Changing tire size does not change any of your driveline angles. In your scenario above no matter how big you go on tires you're still at 2" of lift in the eyes of the diff/CV's

 

[Victorsen]

Thank you

 

[87-Z28]

Take a look at your front lower control arm (LCA) sometime. It is attached to the wheel/knuckle at one end and the frame at the inboard side. The frame attachment pivots about a for-aft axis causing the wheel/knuckle end to move in an arc as the LCA sweeps through various angles.

all the front end geometry that is tied to wheel motion (tierods and CV shaft) is thus controlled by the motion of the LCA. The struts are attached to the LCA and the frame, so shock travel induces LCA motion. As the shock undergoes rebound (extension) the LCA pivots down increasing its angle wrt horizontal. The tierods and CV angles also increase during rebound, since they are tied to LCA motion through wheel knuckle.

increasing tire diameter does not theoretically change LCA geometry which is controlled by the strut. Practical problem is larger tires can cause interference with vehicle body during jounce (shock compression). A solution for this is to add lift via the struts which necessarily increases LCA angles to gain said lift.

 

[murphtron]

I know there is few threads on diff drops. Wanted to get some feedback on whether it is necessary. I have a 2 inch lift after a OME suspension install, planing on putting 35s, which will probably give me another 1 inch or so. So is anything greater than 3 inches a diff drop is recommended.? I have a badlands non Sas. Also will need to check CV angles after the wheels are installed, if CV angle is greater than 30 ?

Hey @Victorsen what’s the link to the post with the charts in your screenshot? I remember seeing those awhile ago.

 

[Victorsen]

https://www.bronco6g.com/forum/threads/differential-drop-options.81041/

 

[GI_Jo_Nathan]

But for future reference, Broken Innovation is the best answer for the diff drop if someone needs one.

 

[RP80]

After struggling for a year with a diff-dropped M210 front end, I finally pulled it when upgrading to the Dana UFDU. Broken axles, broken diff mounts, broken diff—had 'em all. We worked a lot to get the diff drop to a place where the mounting made sense, and was secure. Ultimately with all these issues we're not able to directly trace it to the diff drop, but history with IFS vehcicles suggests that they frequently cause more problems than solve. IMO it's not worth the trouble.

 

[GI_Jo_Nathan]

After struggling for a year with a diff-dropped M210 front end, I finally pulled it when upgrading to the Dana UFDU. Broken axles, broken diff mounts, broken diff—had 'em all. We worked a lot to get the diff drop to a place where the mounting made sense, and was secure. Ultimately with all these issues we're not able to directly trace it to the diff drop, but history with IFS vehcicles suggests that they frequently cause more problems than solve. IMO it's not worth the trouble.

Interesting. What drop were you running? Did it relocate all of the mounts?

 

[RP80]

The drop is a combination of spacers/bushings, and a bracket to replace the stock mount that drops the diff ~3/4".

The stock diff mounts in a way that has a slight amount of movement. The diff drop keeps this slight movement. Assumedly this is introduced by Ford to allow some play to minimize NVH. This also allows for increased force on parts as torque winds up.

When upgrading to the UFDU, the diff mounts solidly with zero play. For wheeling, this is optimal.

Edit for another thought:
The real fix for the concern with CV angle is upgraded half-shafts. The stock shafts are notoriously weak anyway, so upgrading addresses two issues—overall strength and CV angle. I believe a diff drop is a stop-gap "solution."

 

[RedHotLava]

Hey GI Jo, did you meant Broken Innovation?
I'm considering some drop diff setups and I didn't see a Broken Industries. Thanks.

 

[RedHotLava]

But for future reference, Broken Industries is the best answer for the diff drop if someone needs one.

Hey GI Jo, did you meant Broken Innovation?
I'm considering some drop diff setups and I didn't see a Broken Industries. Thanks.

 

[GI_Jo_Nathan]

Hey GI Jo, did you meant Broken Innovation?
I'm considering some drop diff setups and I didn't see a Broken Industries. Thanks.

Yep you're right!

 

[Goods7506]

I know there is few threads on diff drops. Wanted to get some feedback on whether it is necessary. I have a 2 inch lift after a OME suspension install, planing on putting 35s, which will probably give me another 1 inch or so. So is anything greater than 3 inches a diff drop is recommended.? I have a badlands non Sas. Also will need to check CV angles after the wheels are installed, if CV angle is greater than 30 ?

I have spent a few hours a day on installing the dobinsons front differential lowering kit on my 2024 ford bronco badlands and its been a complete bitch to get it in and aligned and I still don't know if its correct ! the video instructions I have found suck and then I tried to install the dobinson front sway bar disconnect lowering kit that that damn thing isn't correct !

Sponsored