UPDATE Removed Overloads

lucas287 · May 23, 2020

Just wanted to report on some work I did today on my truck. It's a high country so I think that comes packaged with the Z60 smooth ride suspension. I noticed that the overloads come into play far too often and make the rear end a bit jarring. Its not too difficult to conceptualize actually. The leafs are doing their job oscillating but then they strike the rubber pads on the overload and the party is over. Those overloads are so stiff.

I see two benefits to those things:

1) high payload (not me - 99% of the time)

2) axle wrap (especially with a torquey 6.2)

So, I pulled em. Left the blocks though. Netted .75" of drop. Also replaced the stock blown shocks with Bilstein 5100s. The result:

Fantastic ride quality! The edge of all the little bumps is gone. The big bumps...pshh...what big bumps. Soaks em right up now. Weight transfer during slow speed transitions like in parking lots or neighborhoods is more flat. It's a bit less eager to oversteer too.

The bad: axle wrap/slight vibes. Might be pinion angle but I doubt .75" would really cause that. Plus I did this to my QC Ram 5.7 that had a long a** driveshaft and it didn't get any vibes.

I was already planning on getting Roadmaster Active Suspension and now I'm committed. They basically act as a three in one sway bar, overload spring, and a traction bar. Tons of F150 ecoboost guys use em to combat the torque rich axle wrap from a dig.

Anyways, terrible at documenting things so this isn't a write up, just wanted to share my results.

Edited May 28, 2020 by lucas287

lucas287 · May 28, 2020

UPDATE: I've driven around for a few days now and I've introduced vibrations that we're never there before! Right off idle, less than 1500 RPM, I now have some vibes. on the highway - you guessed it - it vibrates. In town - yep - it vibrates. I double-checked the torque on my u-bolts (100 ft lbs) and I'm running 30 PSI air pressure in the back.

I think a combination of lowering the ride height with decreased spring rate is causing significant axle wrap which amplifies operating angle issues with u-joints. I was inspecting my overloads and it seems like they were called into action A LOT and I think they were acting a quasi-traction bar limiting how much the leafs twist under torque.

I watched a few videos showing just how much axle wrap exists even with the overloads and it's pretty crazy. And those videos were with the 5.3. The 6.2 makes so much more low end torque it's ridiculous, making the problem worse. F150 ecoboost guys really struggle with axle wrap too - because of all that torque! I also firmly believe that's why placing leaf spring clamps forward of the axle helps with vibes. It increases spring rate by engaging the overload limiting the pinion from creeping up.

Going against my better judgement, I'm going to change more than one variable tonight.

1) I will put the overloads back...

2) remove the lift blocks

3) place leaf spring clamps forward of the axle

4) tighten the SHI* out of my u-bolts. Probably need new ones anyway they're arguably too long and they're TTY.

I'll report back if anything has changed.

lucas287 · May 28, 2020

Oh yeah - if time permits, I will take some readings of my static pinion and t-case angle. Ideally, they should be equal but opposite. For example, (-3) on the t-case and (+3) on the pinion. That's in a perfect world though, maybe on a 4 link setup where the pinion doesn't climb under load. I'll aim for the pinion being point down 1 degree lower than the t-case. Maybe (-3) and (+2) which will allow for 2 degrees of pinion creep without getting too out of hand.

flyingfool · May 29, 2020

pictures???

lucas287 · May 29, 2020

12 hours ago, flyingfool said:

pictures???

I suck at documenting work. I'm also a member on thelawnforum and I always forgot to update my journal over there! I'll snap some pics before I put them back in and then after removing the blocks.

I only dropped about .75". The blocks should drop 1.25".

lucas287 · May 29, 2020

Here's an update. Last night I just focused on measuring and correcting angles.

It took forever to get the yoke and pinion flanges at just the right angle to get accurate readings, but I got it pretty darn close.

1) Zero'd out my angle finder on the yoke off the t-case.

2) Then I squared it up on my driveshaft. 2.5 degree difference. (For your visualization, imagine the t-case pointed downwards 5 degrees. The driveshaft was half that at 2.5 degrees.)

3) using a deep socket on the cup of the u-joint in the pinion flange, I measured the pinion angle. 2.7 degrees.

This means my operating angles of the u-joints themselves are within spec, but they are not equal. On a one-piece driveshaft, the pinion angle should be parallel to the t-case/transmission yoke angle.

Rummaged around in my garage and found some 2 degree axle shims. With my impact I loosened the u-bolts and put my floor jack under the leaf pack with the help of a scrap 4x4 wood block. Created just enough separation to slide them inline with the pin. Dropped it down, tightened it back up, and torqued to 100 lb ft. Repeat the other side.

Results?

Zero'd the gauge on the t-case, measured the pinion angle - BOOM - only .7 degrees difference. This is actually ideal as the pinion will climb under torque.

Took her for a drive and the majority of the low speed vibes are gone! Highway is still there though. My shi* Goodyear LS2 tires aren't helping though even though I had them shaved.

Next I will put the overloads back in and remove the block and drive it for a few days to evaluate before using some leaf spring clamps.

lucas287 · June 3, 2020

Put my overloads back in last night. Was going to put the 2 degree pinion shims back in but realized the alignment bolt that both clamps the leafs together and centers on the axle doesn't protrude enough through the shims to actually engage with the hole in the axle.

For now, it's quite a bit better. The axle doesn't wrap NEARLY as bad, but still feel it when I'm aggressive on accel and it's still there on decel too.

Hoepfully these bad boys are the solution. They should be hear Friday and I'll report back. Probably start a new thread actually.

https://www.amazon.com/Hellwig-2002-Traction-Control-Spring/dp/B0119G0E5O

Eddie 70 · June 13, 2020

Get them installed yet?

cpaul55 · June 20, 2020

Are you still considering getting the Roadmaster Active Suspension?

lucas287 · June 20, 2020

On 6/12/2020 at 9:54 PM, Eddie 70 said:

Get them installed yet?

I did. And I did a write up on them. I was pumped about them at first! Thought they worked really well but I'm thinking that was just a placebo effect after all. I drove on them for two weeks fiddling with the preload and there wasnt any way to install them without negatively impacting ride quality. Do they control wrap? Yes. But that's because they work by increasing spring rate.

lucas287 · June 20, 2020

1 hour ago, cpaul55 said:

Are you still considering getting the Roadmaster Active Suspension?

Maybe?? Idk. The direction I'm leaning is to get legit traction/long/ladder bars. Specifically the rough country ones.

flyingfool · June 20, 2020

there has been one forum user who installed them, and loved it.. but your 6.2 power might be more than they can handle. I think you need drag racing style set up

cpaul55 · June 21, 2020

I've had them for awhile but I wanted to see if someone elese was experiencing some of the things that I was.

lucas287 · June 22, 2020

On 6/20/2020 at 7:54 PM, cpaul55 said:

I've had them for awhile but I wanted to see if someone elese was experiencing some of the things that I was.

Just out of curiosity, what are you experiencing??

lucas287 · June 22, 2020

On 6/20/2020 at 11:02 AM, flyingfool said:

there has been one forum user who installed them, and loved it.. but your 6.2 power might be more than they can handle. I think you need drag racing style set up

Yeah I think so too. I'm not doing anything crazy to this engine (famous last words) except E85 conversion, full custom tune, and maybe a muffler delete. But even with that I'm looking at 500 ft lb of torque. That's big block level torque for the same puny leaf springs that go on a 4.3 model.

I'm pretty dead set on Rough Country's traction bars. I've done lots of research comparing them to caltracs and the likes and I think they'll be best for my goals, which is really just zero axle wrap. I don't care if I always blow the tires off since it's kinda fun I can always put it in 4wd if I want to hook up.