Grinding noise in rear end

I have an 08 2.7L regular cab 4x4 tacoma with 38,000 miles on it. I bought the truck with 500 miles on it. I installed a 3 inch tough country lift with the add a leaf in the rear six months ago. Every since i installed the lift I here a grinding vibrating noise somewhere in the rear half of my truck when I let off the gas pedal or push in the clutch when im going over 55 mph. When im pushing on the gas pedal i don't get any noise and the truck sounds fine. I only get the noise when im coasting or off the gas. I thought it might be the driveline angle because of the lift so i installed 3 degree shims, but the shims did not solved the problem. The rear differental is stock and all i've done to it is change the oil 8 thousand miles ago to full synthetic, so i can not imagine that is the problem. Has anyone had a similar problem or does anyone have any ideas what is makeing the grinding vibrating noise? Thanks

 

I've had this exact same problem since my 2.5" lift. It is exactly as u explain. I have no idea what it is. I even had lower gears installed and it still does it. It seems to me like a vibration that is dampened once power is given to it. Anyone else have this problem or know what it is?

 

another thread said that flipping the driveshaft has often helped this problem. How would this make a difference? I'm slightly mechanically challenged

 

This is a common noise with the reg cabs, especially lifted ones, but stock guys have had the noise as well.. I got it after i installed my OME lift. It is definitely vibration in the drive shaft.
I did a ton of seaching on the subject when I got it and found people were getting rid of it by flipping there driveshafts, and some were having sucess with shims and going with a tom woods drive shaft. I decided to do the flip since it was free and it worked perfect.......for awhile, abut 10k miles or so later it started to come back. Ive got shims but havent installed them yet.

 

May have something to do with driveshaft balance.

When you rotate the shaft, your basically trying to find a better high/low spot to equal out the vibrations instead of having a high/high spot where you can feel the vibes.

 

Well i have the 3 degree shims installed like i mentioned above. I fliped the driveshaft tonight and took my truck for a drive, the vibration is gone. So for now the driveshaft flip has worked. I do not think with my add a leaf i really need the shims, but ill leave them in since im planning on upgrading to OME Dakar springs in the near future. Thanks for the everyones feedback.

 

Anyone ever find the best fix for this?

 

I am having the same problem. Put in OME bp-51 and medium Dakar packs. It might be important to note that this kit lifted the rear 5” not 2”, and has settled in at about 4”. Way more than I ever wanted. Now I have a grinding noise, mostly at highway speed, any time the drivetrain is unweighted (when I let off the gas).

Does anyone have more updates or ideas on this?

 

Whenever you get a lift kit for a regular cab, add another 1" to the advertised lift as our trucks are a lot lighter than the v6 Tacomas that the lifts are designed for. Your dakars will probably settle to 3.5" tho. Still pretty good rake tho lol

The grinding is going to be your driveshaft. Regular cab driveshafts have a slip joint that is notorious for that grinding sound when going +40mph and letting off the gas to coast. The permanent solution is getting a new driveshaft, usually Tom Woods, with a double cardan joint. The temporary solution is pulling the slip joint apart and heavily greasing the splines and then putting it back together.

 

Use this when you lube the driveshaft splines:

$17 Genuine Ford Fluid XG-8 PTFE Lubricant - 3 oz.

https://www.amazon.com/gp/product/B000NU77DA/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1

 

dakar pack, shims didnt work, flipping the driveshaft did, a year and a half later im getting serious axle wrap now since last week. anyone experience this? i get serious clunking

 

An update on my truck...

turns out the bp-51 kit is not compatible with my truck even thought shock surplus said it was.

My transfer case was destroyed. I ended up having to take the lift out and put a stock suspension back in.

before giving up I tried a tom woods drive shaft and leaf pack shims. Nothing made the noise any better.

what a s#%& show.

 

I just bought a 2012 with a 2" lift, I didnt realize it was making that noise until I bought it and got it on the highway. Its a reg cab, your situation sounds horrible, sorry to hear that. I was reading tom woods driveshaft should solve that problem.

 

I bought a Tom Woods and it didn’t help mine, but I still have mine if you want to give it a shot. Just pay shipping and it’s yours.

 

Ok guys I have an idea and I wanted to see what you thought. Two things.
When you lift the engine goes up and the angle of the drive shaft increases. This puts excessive wear on the U joint, under load no noise then not under load theres slop. That slop translates into vibration at high speeds. Thats why when people reverse the drive shaft noise goes away, the forward U joint doesnt have the slop (and why eventually this solution doesnt work as that U joint fails too). Second, now theres 1/2" of drive shaft missing and the slip joint doesnt allow the splines to seat properly. Basically you need a drive shaft that accommodates the new angle and makes up for the missing 1/2" of the drive shaft. You need a custom drive shaft, its sucks that is didnt work for some, and would mean Im wrong.

 

changing the angle of the differential canStarve the rear compnents

the angle is designed/engineered

ideally the angle at the diff & transfer case should be the same static level

when the diff is rotated m o r e vertical

less oil gets on the pinion

less oil gets to the outer axle bearings

 

Mine has done this since I bought it in 2011. I've put 152k miles on it since and nothing's changed. Early on I was trying to get rid of the sound and found that the splines of the slip joint are relatively loose, but tend to get tighter as the driveshaft is compressed, which is why the grind goes away with a load in the bed.

Annoying, but I don't think it causes any long term issues.

 

Sent you a PM about the driveshaft.

Edit: What helped with the grinding noise with my driveshaft was adding a spacer in between the rear diff and the rear most flange of the driveshaft (about 0.5 inches to 0.75 inches in width would be perfect). The noise is mostly gone, but I the spacer has screwed with the balance of the driveline.

 

So I spoke with the folks at Tom Woods and they said the only thing that will get damaged and you will go through is the driveshaft.
Some of these Tacomas I heard were like this strait from the dealership.