Is diff drop necessary?

Took my 22 SRD to the dealership. I have 17inch KMC rims and 33 inch Toyo tires, with a 2” rough county leveling kit. The dealership is recommending a diff drop (quoted at $2k). I took it to my tire guys afterwards and asked for a second opinion, because the tires are making a “woomp” sound. I’ve put maybe 6k miles on them and they’ve never made the sound. Tire guys recommend a cross rotation, they said the diff drop isn’t necessary. What’s everyone’s thoughts on this?

 

2000 dollars? Sounds like they are trying to take advantage of you!

If there is a 4 wheel parts shop anywhere near you, give them a call. They are very knowledgeable in modified vehicles.

Approximate location?

 

I’m in Tucson, AZ. The paperwork says “$1998.04 diff drop due to changing the geometry of the axel. $219 for alignment following instal.” And then another $119 after that for something else. My tire guy did recommend a shop that can do it. I’ll probably swing by there tomorrow too.

 

It's never needed. Also stay away from Junk Country.

 

It’s dark out now, I’ll grab some pics in the morning and post them.

 

I'm sure there are other members here from your area that will chime in with a good shop close to you. I would get second and third opinions before letting the dealer steal your money.

 

If you can turn a wrench buy a Diff drop kit and install it yourself I think the kits are around $100. There are several youtube videos on the process. Looks like an easy job. Although from what I have read a diff drop is not necessary with a true 2" lift. Apparently suspension lifts vary from truck to truck with actual lift height. The main reason for a diff drop seems to be to improve the CV angle and save your bearing especially the drivers side which has needle bearings that get damaged with the angle increase.

 

That’s what I’m hoping for, someone with a similar setup that can tell me what they did with theirs or someone in the area that can recommend a shop.

 

Not sure if any of these help lol

 

I don't think that is enough to require a diff drop - in fact, it rather looks like mine.

 

Whew that’s a relief haha. Any idea why the front passenger tire would randomly be making a “whomp whomp” noise intermittently while at very low speeds? Usually when coming to a complete stop.

 

That's just the normal Toyota fail diff noise. They all seem to make it now and would require a ECGS bushing or a trip to the dealer. My stock 19 makes the same noise.

If it goes away in 4wd it is most definitely the side bearing.

 

I tried that before I took it in, I still get the same noise even in 4wd. My tire guy said he thinks the tires need to be cross rotated to even out some of the tread wear, so we’re gonna try that tomorrow. It was making a weird buzzing noise at 33mph under the dash on the driver side, that’s why I originally took it on. It does it intermittently too. I thought the needle bearing but it still does it in 4Wd. The rubber flap behind the tire was loose and when I pushed on it, it would rattle. I had them tighten that up so hopefully the buzzing dash noise was due to that. If we do all this stuff with the tire rotation and it still makes noise, I’ll have to take it to a 4x4 shop. Fingers crossed

 

I have a diff drop I’d give you if you were local. Just had my Readylift spacer lift removed.

I think a diff drop is a good idea. No way it should cost $2000.

You’ll need spacers for the rear skid plate too.

 

I’d recommend doing your research on diff drops on 4runners. They are definitely not a universally agreed upon as a “need” for lifts.

They come with their own potential problems, like somewhat improving CV angles, but changing front driveshaft angle into the transfer case.

And 2000 bucks is nuts for a couple of spacers anyway.

 

@McSpazatron thank you! Definitely good info to have. I don’t think it’s needed after reading through some threads.. now just have to figure out this slight whomp sound. Pretty bummed because it only has 10k miles on it. Send good vibes haha she’s my baby

 

@Nano909 thank you! Appreciate you!

 

If you want an opinion about a reputable shop in Tucson head over to Trail Boss 4X4. Good guys.
In my experience both Desert Toyota and Precision Toyota suck. They epitomize the term "stealerships". Bought mine from Auto Nation in Tempe due their shenanigans.
With my Dobinsons IMS 2.5 F, 1.5 R lift a DD was not needed nor recommended.

 

Just adding another vote to skip the diff drop.

CV angles look good to me.

 

@runnerjimmy They did a quick look and noticed some uneven tread wear, I’m taking it tomorrow morning so they can do a full inspection.

 

@Burnt Taco i was just reading reviews on them! Glad you posted. I’ll run it by them tomorrow morning. Thank you!

 

Jack the front corner up from the frame and see how much droop you have and note the CV angle at full droop. That will tell the tale.

 

@tessakoz, who installed the lift for you? And, did the tires just start making this new sound recently, with no recent changes made?

 

@glwood54 it isn’t even technically a lift, it’s just the puck spacers. We’ve been going to our friend at Big O for like 8 years, he’s awesome. He’s taken care of our overland Chevy for a long time. He installed the spacers and tires in May, and it’s been great up until the sound about a week ago. The dealership did do the oil change and rotated the tires about 3 weeks ago.

 

There are many videos on youtube on this. Just spacers as noted by other members, but no way in h#$% that it would cost 2K. The kit alone is like 60 bucks if that so not sure how they are coming up with the 2K. I have it on my 4R and don't think I can tell a difference either way.

 

Took it by an off road place that was recommended, they said the same thing that the drop isn’t necessary and the 2k price was outrageous. Thank you all for the input!

I’ll keep everyone posted about the rattle and the tire noise, so if anyone else finds this thread they have some answers.

 

Well, 'lift' was used just to ask about the leveling kit. I was curious as to whether the installer had an opinion as to a diff drop being needed. I guess if they didn't tell you they thought it was, there's the answer, at least from their viewpoint.

 

@glwood54 Oh for sure! I did ask them about it yesterday when I showed them the paperwork from the dealer and they said they didn’t think it was necessary. They said with a 5” lift for sure, but not for something like what I have. I think the dealer just couldn’t find the source of the rattle, so they tried to get me to buy something else. I even asked, ok so if I pay you guys 2k and I still have the rattle, then what? And they didn’t really have an answer lol

 

I am in Tucson as well. Please DM me for information if you have more questions.

 

Updates:

Got her back after having the tires rotated by my tire guy. Still making a slight “whooomp whooomp” noise when I slow down almost to a complete stop, but not as loud. Haven’t heard the dash rattle again, so I’m hoping them putting the bigger bolt in the rubber flap behind the drivers side tire took care of that.

Thanks again to everyone for your input! Appreciate you all.