Diff drop, ever a reason not to install?

So I have a 2/1.5" lift on my 2020 OR, I installed the sway bar relocate brackets that came with it. I have a diff drop that I didn't install at the time, as it required cutting the skid plate bracket and I didn't have the right tools at home to do it at that time.

I've read a lot about diff drops, most people say to put them in.
My CV angles are pretty good from what I can tell. The fins aren't touching. I can slide a credit card between them with no contact.
I have had some vibration but only in the gas pedal and it's pretty much all the time at any speed. The dealer said that's normal for these trucks, as well as quite a few threads on here.
I really don't want to cut into a new truck if I don't have to haha.

Is a diff drop always needed?

 

Don't bother, a waste of money.

 

Not sure if it's "always needed", but I installed on mine when I did the lift.

 

Doesn't help anything, it doesn't prevent the diff vibe and it barely does anything to CV axle angle.

It does put the diff lower and rest very close to the skid plate.

I've stopped installing them as of 2016. I only put them on Tundras now.

 

Differential drop does more harm than good. If your inboard CV boot fins touch, do the boot slide mod: https://www.tacomaworld.com/threads/my-cv-boot-mod.190669/ It'll cost you two #16 hose clamps (nominally 1.5" dia.) from the hardware store.

 

@crazyfingers

 

Why does the diff drop do more harm than good on a lifted vehicle?

 

It potentially can make your diff (really your forward diff mount legs) more vulnerable, induce vibes by changing the U joint angle between the t case and diff flanges and I've heard from someone that it can effect oil circulation but I frankly don't buy that last one.

You can only drop the front about 1 inch but the pivot point is from the rear mount and the axles are closer to it so the adjusted angle is only about 3° or approximately a 1/4" drop for the CV's position which effectively net's you nothing.

Having a good steel skid plate mitigates the diff vulnerability, I am running a 5/8th drop more so because I just had the stuff to do it myself for free on hand and figured why not?

It doesn't really hurt anything either if you have a skid and don't get vibes.

 

If the diff drop causes the diff mount to protrude below the belly of the vehicle, it tends to catch on obstacles off-road, at which point the diff gets shoved into the engine oil pan: https://www.tacomaworld.com/threads/remove-the-differential-drop-on-your-05-tacoma.118545/

 

Yeah, it's not needed on 2nd and 3rd gens.

 

This ^

 

Alright guys, I am glad this thread was started, because everything I have read so far says to do a diff drop on 2.5" and greater lift. Now, there is a different story and reason not to do it. A diff drop kit is cheap, so money is not the issue here. It's about keeping angles near stock, which is what I thought a diff drop did. In fact in recent threads, I have seen people recommend the diff drop for those having a vibration.

So assuming a 2.5- 3 inch suspension lift, is a diff drop worth it or not? Also assuming proper skids in place.

 

No it's not worth it, because even if theoretically you could do a 12 in lift as long as you have the independent front suspension and don't use a drop bracket (which would actually lower the front differential, but in my opinion you should never go drop bracket) your differential in the front will never be moved so there's no way your driveline angles would be changed regardless of how much lift you have in the front, however in the back since you have a live axle that differential is not hard mounted in the frame the differential moves with the actual axle housing meaning when you lift the rear you're actually spacing that differential down and away from the frame which is why you would need axle shims or angle degree shims under the rear leafs to return the pinion input flange on the rear differential to the correct angles but the front stay stationary, installing a quote unquote diff drop only lowers the front of the front differential which does change the pinion flange input angle.

A lot of people I believe accidentally read the first gen posts on diff drops without realizing it and see the information and get it in their heads that it's necessary for their second or third gens: it is not.

The first gens have shorter CV axles and different spacing between the front and rear mounts of the front differential where it is somewhat beneficial to drop the front end of the front differential on the first gen.