My DIY Diff Drop

[tobyw]

Taking cues from all of those that have already paved this path, I dove in and booger welded a diff drop bracket that drops the front mounting location 1-1/2":

The lowering bracket itself was relatively easy, but as has been clearly noted before, the upper frame bracket has a welded nut and welded stud from the factory that need to be removed in order to relocate it. This took some creative work with a long-reach rotary file, but with some time I was able to chew away all of the factory welded stuff and was left with two holes ready to accept normal hardware:

It's really difficult to get pictures up there, but here you can see the differential hanger is now below the frame bracket:

And for the passenger side bracket, a simple 1" spacer puck:

Eventually I will come back to this bracket and make it a double shear setup, but I'm short on time this weekend so it's going to have to wait.

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[Apollo]

My favorite type of post is seeing someones fabrication solutions. Looks great. I’m not sure how much movement the trans has relative to the top mounting brackets but maybe just a spacer with a larger mating surface would be sufficient.

 

[Oldhippie]

That seems like a good amount of drop…how much lift are you doing?…I plan on under an inch with 3” lift over Sasquatch…but good work!

 

[TeocaliMG]

Very cool to see someone else take a crack at it! Very satisfying to make your own parts!

 

[Mudlight]

Curious to see the pinion angle/ CV angle now. Any tips on grinding the frame brackets?

 

[tobyw]

That seems like a good amount of drop…how much lift are you doing?…I plan on under an inch with 3” lift over Sasquatch…but good work!

Well... I had intended to shoot for approximately 2-1/2" via combination of SVC perch collars and the upper portion of the typical Amazon spacer lift (2" from the SVC perch collar and 1/2" from using half of the spacer kit). The intent behind the diff drop was to compensate for the spacer lift, since the perch collars don't change the droop limit from my understanding...

However, after installation, I'm sitting at 3-3/4" lift up front??? I have NO idea how that could possibly happen, and I'm pretty frustrated with the current situation...

Curious to see the pinion angle/ CV angle now. Any tips on grinding the frame brackets?

Pinion angle has changed slightly but I have no good pictures before/after. I want to say there was another guy that did a ton of measurements and CAD work when he built his drop and noted a 4* change in pinon angle, but he didn't drop the rear mount below the frame bracket if memory serves? If that's the case, mine should have something less than that...

As for CV's, I can take some pics but as I mentioned above something is massively jacked up (no pun intended) with my perch collar installation so I'm going to try and work through that before I can really see how the dust has settled here.

Grinding the frame bracket sucks, plain and simple. There are a couple of options depending on the tools you have available, and I ended up using a cutoff wheel on a die grinder to get the nut removed, leaving just the flat washer that was glued in place. To remove that I just ground it away with a rotary file. The other hole uses a welded stud, and the bottom side looks like a flat washer, so again I just used the rotary file to eat that away. Probably took me about 10 minutes of actual work time, but I honestly cannot imagine trying to do this on your back... I'm fortunate enough to have a hoist so it was, relatively, easy work since I could stand directly below it.

 

[Oldhippie]

Well... I had intended to shoot for approximately 2-1/2" via combination of SVC perch collars and the upper portion of the typical Amazon spacer lift (2" from the SVC perch collar and 1/2" from using half of the spacer kit). The intent behind the diff drop was to compensate for the spacer lift, since the perch collars don't change the droop limit from my understanding...

However, after installation, I'm sitting at 3-3/4" lift up front??? I have NO idea how that could possibly happen, and I'm pretty frustrated with the current situation...



Pinion angle has changed slightly but I have no good pictures before/after. I want to say there was another guy that did a ton of measurements and CAD work when he built his drop and noted a 4* change in pinon angle, but he didn't drop the rear mount below the frame bracket if memory serves? If that's the case, mine should have something less than that...

As for CV's, I can take some pics but as I mentioned above something is massively jacked up (no pun intended) with my perch collar installation so I'm going to try and work through that before I can really see how the dust settled here.

My understanding is that “spring perches“ don’t change droop so no diff drop is needed (the CVs and tie rods do have more angle at ride height) any droop increase over 2” (spacer or shocks) puts the CVs into the “danger zone” and a diff drop becomes necessary. I would think you are “safe” even at 3 3/4” (with 2” being perch) without the diff drop but it is still good idea with the change in ride height CV angle (as long as it does not cause CV “plunge” problems).
As for the excessive lift, how tall is the spacer? Ya would only need about 1/4” to get a 1/2” lift…
good luck!

 

[tobyw]

My understanding is that “spring perches“ don’t change droop so no diff drop is needed (the CVs and tie rods do have more angle at ride height) any droop increase over 2” (spacer or shocks) puts the CVs into the “danger zone” and a diff drop becomes necessary. I would think you are “safe” even at 3 3/4” (with 2” being perch) without the diff drop but it is still good idea with the change in ride height CV angle (as long as it does not cause CV “plunge” problems).
As for the excessive lift, how tall is the spacer? Ya would only need about 1/4” to get a 1/2” lift…
good luck!

I think I understand the same thing, in that the perches don't allow any additional droop so in theory my CV's are safe with the perch lift. However, I was also under the impression (perhaps incorrectly) that the Sasquatch package already had the droop limit to the razors edge? So when I added the spacer up top, I was putting my droop into the red zone for sure, thus my desire to lower the diff... Sooooooooo much information to comb through out there, and I'm probably wrong on about 98.736% of my comprehension of it

The top hat spacer I installed was approximately 3/8" thick, so at the 1.5:1 ratio (again, this could be a misunderstanding on my part) I should only be seeing around 9/16" of lift from it, which means I've got 3-3/16" from what are supposed to be 2" perch collars????

 

[Oldhippie]

Yeah, my understanding is Sasquatch has about 2” droop margin and non Sasquatch have about 1/2 less because of the “smaller” CVs, but I am no expert for sure…I have a zone 3” lift (2”spacer & 1” perch) and plan to do about 3/4” diff drop for “peace of mind”…

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