Vibration when letting off the gas after lift...

[FiXXXerX]

So I know, 'Search' and all that, but I've been doing that for like 2hrs now and cannot find anything super helpful for my situation.

I have a 2001 2WD 4runner with 220,000mi on it and I replaced the old sagging springs and trashed rear shocks yesterday as well as replacing the rear endlinks with longer (From the front) options.

Part's wise : KYB Gas-A-Just Shocks, Moog 81041 springs and a 2.5inch spring spacer, and the longer endlinks.

So after doing all this everything seemed fine, but on my way into work this morning I noticed that when I'm at 20mph or over, when I let off the gas I get a weird vibration/noise. Nothing under acceleration, just when I let off the gas.

I saw a number of people saying to check u-joints, but I had those replaced last year and they still look good. The driveshaft has always been a bit of a wildcard as it IS the 2 piece (Sleeved with rubber insert) driveshaft that the 2wd's have. I also replaced the rear-diff fluid last year and while I know I have a small leak in drivers side rear axle, it hasn't been anything that I've really even noticed.

So, have I raised the truck too much? Is there a possible Pinion issue (I read that our vehicles use Cardan Joints, but I don't know if that's true for the 2WD)? What else should I look into at this point?

 

[STI_MECE]

Read my "Solved: Hard vacuum leak under deceleration " check the last few posts.

I haven't exactly pinpointed if it's my pinion angle or the fact that my slip yoke isn't 100% where it's supposed to be on the output shaft to get the same amount of engagement

A good test to see if you put too much lift on is by throwing a shit ton of weight in the back of the truck to make it squat.

If the noise goes away then you are in the same boat I am. The 2WD 4Runners are definitely at a major disadvantages compared to 4WD. We have a crappy driveshaft, and the adjustable endlinks that are made for the 4runner are made for the 4WD setups.

And by OEM standards, the 4WD upper rear links are longer than the 2WD links. Thus if you get adjustable end links for a 4WD 4runner the shortest length might put you over the amount you need to correct the angle

Ultimately I should have put the truck back to stock height on stock tires. But I bought mine used with a stock suspension, 2 inch Body lift, and 2.5" inch spacers on it with 35's...and had to buy new tires for it right off the bat because it was due for inspection. I went with 285s

I also have been driving around with the noise for 4k miles and it hasn't given me any problems. The only thing it has destroyed is my wallet because there really isn't enough information out there on lifting a 2WD setup. And I was blowing through parts trying to figure out what it really was.

Now that I figured it out. The only way to fix it is spend more money lol but I don't wanna do that because I spent all that money on the wrong parts. Such is life [emoji849]


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[FiXXXerX]

I appreciate the response!

I poured over the post in question, and what's funny is that I heard a loud open vacuum noise coming from under my hood last night and decided to check when I got home. Turned out that the rubber pipe that connects the 'resonator box' to the intake manifold looks like a wolverine (or maybe The Wolverine?) attacked it. The thing is just falling apart. I don't know if this has anything to do with anything, but I've got to get it fixed here before I know anything for sure.

Meanwhile, replacing the 3rd Member was something I bumped into while searching yesterday. I'm HOPING it's none of that and it's as simple as vacuum issues. But, I'll load it up to drop the height and see what happens, as you suggested.

I'll let you know what ends up happening here!

 

[STI_MECE]

Meanwhile, replacing the 3rd Member was something I bumped into while searching yesterday. I'm HOPING it's none of that and it's as simple as vacuum issues. But, I'll load it up to drop the height and see what happens, as you suggested.

I'll let you know what ends up happening here!

And just FYI it wasnt my 3rd member that was causing the noise. Do not ask me why it didnt make it whenever I first swapped it. But, do not go with that diagnosis at all lol

Check your pinion angle first and start from there. And also check if you can wiggle the slip yoke around on the output shaft.

I do not think the 2WD 4Runners should go beyond a 2inch lift. And based on all the information that is out there, its all based on the 4WD. If i had to make a rule of thumb for a lifting a 2WD drive 4Runner it would be to assume a 2WD 4runner will be lifted 1inch higher than what is advertised.

Its a big difference i know, maybe its not that big of difference in actuality. But the point is, I would never go up past a 2inch lift from what I know now. And If i were to buy a lift kit again, I would go with whatever is advertised as a "1inch lift"

Hope yyou can figure it out! Best advice i can give you, is if everything is functioning as it should crank up the music!

 

[FiXXXerX]

I'm gonna be going through to take care of a few engine related issues

1 - Replace Intake rubber hoses (Torn and disintegrating in multiple areas)
2 - Replace Rear Cam Seals (leaking, probably the worst issue on the truck at the moment aside from the intake hoses)
3 - Valve Cover Gaskets / Washers / Spark Plug Gaskets
4 - Transmission Mount (I'm pretty sure this is just done. It looks cracked and torn, and I feel things moving more than I should)
5 - Front endlinks (they are TRASHED)

Once I have that done, I'm going to invite friends over for dinner, then throw them all in the back of the truck and drive around a bit to see if the angle fixes the noise, lmao

So, I've got some work these next 2 weeks here!

I'll let ya know what I find.