Axel Wrap and Drop bracket lift repercussions

DISCLAIMER: I am not a mechanic, just mechanically inclined.


To start this: I bought this truck in TN from a tall (6' sumthin) kid who slapped on a hodge podge Drop bracket lift. It used BDS and tuff country parts. (knock off rough country) It has 4" spacers blocks for the front and rear. Tuff country UCAs and BDS rear shocks. (Stock shocks on IFS) On top of mix matched 285/70/17s with Rockstar rims with a negative offset. (1-2" maybe) [ODM @ 170,000 miles]


Appearance: Tall, Aggressive, Barcelona Red, dirty girl, been a few places. (from what I saw, a Diamond in the rough)


Ride quality: It was a rough ride from the get-go. Not that I knew what good Tacoma suspension felt like but it def was very stiff and bumpy. It handled, "ok" on turns but it would squeal and moan on the tires. The drive shaft only vibrated once while the test drive and thought I hit something, so it went under the radar.


After getting it home: The main issue it was having at the time was drive shaft vibrations. (While coasting at high speeds, right when acceleration was applied) [60-80 MPH] When first diagnosed it was just the U-joint gone bad. Easy fix, slapped in a new u-joint and boom smoother driving. Fast forward a couple of weeks, it starts vibrating again but not as much as it used to, (Now at much lower speeds, off and on, still only when accelerating, especially up an incline) [25-35 MPH] So I let it slide and kept greasing it. At that time, I did start to notice on the tires that the outer edge of the tread of the tire was having much more wear than the rear tires. Went and got it aligned. Instantly was driving better. (I was at the time kind of wheeling her a bit with the off roading due to my hobbies and added more wight with a camper shell) [ODM @ 190,000 miles] {Around this time I did hit a pothole hard and bent a tie rod. I got both sides replaced and realigned. As well as ditching the rims and moved to the stock rims and tire size} [265/70/17] Did some long +300-mile trips and replaced the U joint two more times and I am still dealing with the vibration issue. I apparently let it slide too long and after an intensive off roading trip, on the way home, the drive shaft said, "I'm tired grand pa" and snapped at the knuckle. (Had to put it in 4WD hi and limp her home. Now repaired) I did some digging on here and learned about the axel wrap issue. (Will add this story to the threads about the drive shave vibrations and axel wrap) I took it to a couple of shops, and they all pointed to the carrier bearing and the leaf springs. I got a new carrier bearing and has been playing with the spacers and shims just to get those angles right.[ODM @ 200,000 miles] (Will follow up with the maths of all this on a later post) After plenty of trial and error to help the angles it calmed the vibrating drive shaft issue. (still minor vibrations) [35-45 MPH especially while applying acceleration] Sure enough of them rear leaf springs were also not happy. They were stressed and frowning. Surely, they are now the root to my affliction I am thinking. [Current ODM @ 224,000 miles] (EDIT) I also added 1.25" spacers back on to the stock size wheels and tires and now it is wearing away at the Inner lip of the tire.

NOW: I finally scrapped up the cash and bought a 2.5" lift OME leaf spring pair and some Bilstein 5100s for front and rear. My game plan is to remove the spacers and run the new lift as intended. Play with the carrier bearing a bit for adjustment of the angles. Hoping the new leaf springs completely stops that dang vibration due to axel wrap. Slap some new shocks in and call it a day. Smoother rides off into the sun set and many life fulfilling adventures to come.


MY questions/concerns moving forward: Due to the lowering of the LCA mounting point, I am wondering how it will affect the scrub radius. What should I consider adjusting to getting it closer to "factory" or "most efficient" geometry without having to remove the drop bracket. Bigger tires? Return to negative offset, adjust the caster and toe? I don’t know. (most will agree, RIP THE MF OFF/GET RID OF THAT HERESY, but I say naynay, I am too poor) (Actually I'm just in love with the truck and just trying to help her the way I can)


Will follow up with pics, math, and measurements.


Feel free to lay that science on me if you are smart noodle or share your similar experience with either axel wrap or DB lifts.

 

Axle wrap is the result of using the tall lift blocks that most drop bracket kits come with (so not directly related to the DBs themselves, but rather with the rear lift method employed).

You mentioned getting 2.5" lift OME leaf springs, combining those with shorter lift blocks (or no blocks at all) will certainly help reduce the axle wrap.

The lowering of the LCAs causes little change in scrub radius (wheel offset has a far larger effect on this).

I have ¾" drop on my driveshaft carrier bearing (actual rear lift ~3.5"). Between that and raising the pinion up another 2° or so, I was able to get the vibration to about 80-90% better than before I did anything to it (it's only very slightly more noticeable than the stock vibration these trucks are known to have). The proper fix is a one-piece shaft though.