ECGS Clamshell bushing; impact on gas mileage

TLDR: Does anyone know if the ECGS clamshell bushing (replaces needle bearing) has a noticeably negative impact on gas mileage (it seems like it might have more friction than the needle bearing)? I might have a bad needle bearing but I'm not certain, and might not want to replace with the ECGS clamshell bushing if it's going to reduce my gas mileage on my daily driver.

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My situation:

2016 Trail with 40k miles and a 2-inch lift (installed when fairly new).

I started to hear a pulsing grinding noise at around 15-20mph a couple months ago; typically after first starting the engine after it's been sitting cold (60 deg F air temp) -- it seems to go away after a few mins. I also haven't noticed it anymore for the last month or so.

A mechanic initially suspected wheel bearings in front left and right, but then ruled that out and isolated the sound to the front diff, which that mechanic didn't want to work on.

With some googling, I discovered the common needle bearing issue (sounds like it happens on almost any lifted 4runners and tacomas?) that people fix with the ECGS clamshell bushing.

This hypothesis seems to fit in some ways, but not others:
- typical symptoms are to experience the vibration at higher speeds than I do
- my CV axle does not seem loose

I tried listening for the noise in 4WD, but it's very hard to tell since it takes a few mins to drive anywhere it's safe to engage 4WD, and by then the noise is usually much less noticeable anyway.

I was going to take it to a new mechanic to diagnose/fix. Since it was also time for a diff oil change and work on front shocks anyway, I figured it's a good time to get it fixed, so I purchased the ECGS bushing for replacement.

However, I'm unsure if I should actually be replacing it at this point.

Arguments against:
- needle bearing might not actually be bad
- impact on gas mileage?

Arguments for:
- with a 2 inch lift, needle bearing is likely broken/strained or otherwise likely to go bad eventually anyway, so it makes sense to upgrade to the bushing pre-emptively if my mechanic is already going to removing shocks, changing the diff oil, and likely inspecting the needle bearing.

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Does anyone know if the bushing will harm gas mileage, and/or do you have any other opinions on whether it's worth the replacement even if needle bearing seems fine?

 

Why are you making this so complicated? If you need to replace the bearing, do it with the bushing. If not, don't. No you're not going to notice a decrease in fuel efficiency lol

 

If you’re worried about mpg, then why did you lift?

 

It will not have any noticeable effect on fuel efficiency.

But a grenaded front diff will probably set you back a few mpg...

Also engine temp or length of time the truck has been running will have zero impact on the sensation you get from a bad needle bearing. It's strictly related to axle rotation and felt based on speed.

 

Nothing wrong with finding a straight stretch of pavement and run it in 4Hi. And since you say your mechanic is going to do the front shocks, now is a good time to have the bushing installed. I have had my ECGS bushing in for about 50K now, and would say it did not affect gas mileage. (I'm 15-17mpg on 285's). Tell your mechanic there's some really good You tube videos on this subject. I did my own after watching some installs. Good luck!

 

Welcome from Wisconsin! We replaced our needle bearing with the bushing 40,000 miles ago, only had 2,000 miles on and when it was taken out it looked as good as new, no strange wear, nothing. It's usually not a case of the bearing failing... they do, but the machining tolerance of the axle, the bearing has an incredible amount (in most cases) of 'slop' surrounding the axle. We are getting a decent mileage with our 4Runner, 17.6 interstate, 16 daily, 3 in. lift on 275's. If you bought a 4Runner for mileage.. you chose poorly. The lift you want will also NOT help mileage. Mileage cannot be a concern when buying a 4Runner! It's a consideration, but not a primary reason. However, dependable, fairly tough and convenient are some reasons to own one. As long as you have your 4Runner tore down, change out the bearing with the bushing, and enjoy that 4Runner... for thousands and thousands of miles! Good luck.

 

As noted above, the true test of a needle bearing going bad is on a straight highway run of about 35-40 mph. If you can hear the noise in 2wd, shift into 4Hi while driving straight. If the noise goes away, replace the bearing with the ECGS bearing. I've never heard of anyone being concerned whether mpg is affected by this bearing, as so many other things affect it more significantly, like the lift as also noted above.