Grumpy Bears 2015 Silverado 2WD

Grumpy Bear · October 23, 2017

Both fronts done. Rear in progress. Have to lower the gas tank to do the drivers side spring.

Grumpy Bear · October 24, 2017

Deaver spring, Sulastic shackles and King shock in place. Now for the tough one. That's allot of leaves.

Edited November 11, 2017 by Grumpy Bear

Grumpy Bear · October 24, 2017

I edited two previous post on this install concerning the knuckles and wheel bearings. I’m not going into the who or how but the information ball got dropped hard. It doesn’t matter why. It matters that all is good and the worst of it was some lost time and a bit of frustration. Most of it mine.

We reused the OEM bearings and spindles and the install was for the most part butter and bread. There were no disassembly issues, period. Fact is the bearings fell out once unbolted.

There is a small interference issue with the reservoir hoses which is nothing more than a matter of some fine adjustments of brackets. Let’s move on to the back.

Passenger side went in pretty straight forward. The reservoir may need some tweaking to clear the bump stop pad at full compression but that is still unknown and yet on the list of “watch out for that’ things. Like the front hoses and like the lower ball joint stud vs tape weights and a few other minor things that could be a problem if not caught.

That’s the thing with projects like this. Owner wants what he wants. Wrench needs what he needs. Three vendors across the country customizing parts for a truck not in their hands nor in sight and blind to each-others work WILL produce some issues of impingement. It’s why we have a punch list and why there will be a moan list.

Grumpy Bear · October 25, 2017

Installation of parts is done. Now we tweak. Pinion angle, wheel alignment and bump stops.

I took some photos and measurements and sent to Ben for review. He will tell me what's what.

It did not produce a perfect 2" drop. A very solid 1.5" was realized which gave a very pleasing 1" forward rake. It will settle some over then next few thousand miles so this is great. I can always shim it taller. Just not shorter. I think it made a huge visual impact. Lost that 'ducks eating in the pond' butt to the sky stance.

I have over an inch more front travel and half that gain in rear travel. All four corners are perfectly centered in their respective travel. It doesn't get better than that to tune from.

Edited October 26, 2017 by Grumpy Bear

Grumpy Bear · October 27, 2017

And we have two new issues to deal with. First is camber adjustment. Extended camber bolts are ordered and arrived late yesterday. Too late to finish up last tonight. I actually kind of saw this coming mixing and matching parts like this.

This second one is just common sense but I didn’t foresee the fall out. When you lower your truck with the spring by taking out arch or shackles you close the distance between the axle and frame mounted bump stop. So you gain rebound range and loose compression range. The truck now sits as it would with about 1000 pounds in the bed. And there’s the part you don’t think about. Load puts energy into the springs. Sitting static at that same height it’s under no such load. That changes the amount of force the bump stop sees when first contacted. The bumper ‘acts’ as a softer secondary spring. Bump stops, urethane ones, are highly progressive. Each half inch or so it’s compressed takes about 5X more force…until it won’t compress anymore or the load is balanced to the load of deformation. So while the shorter distance limits up compression travel the bumper, receiving more energy defects further, more rapidly and abruptly.

So could you shorten it? Many do. It’s even in the instructions for some cheap tuner kits. But doing so runs two risks. First the part you are cutting off is the soft end (normally) so while it takes more travel to reach it it’s very harsh once it hits. That can totally upset the balance.

So let’s say the mount allows you to shorten the big end. Yep you get to keep the progressive nature of the bumper but now you run the risk of bottoming the shock or in the case of piggy backs, crashing the reservoir into the axle housing. It’s case specific and in this case applicable.

Thank goodness and the unforeseen only part of this lower was by the arch reduction method. The other part was in a lower spring rate which allow the truck to settle lower before spring force equals truck weight. Leaving the bumper then uncut puts rate back in once the bumper is in play and being highly progressive it will prevent the reservoir crashing the bump stop pad.

Look King did not intend on the OEM shocks to be installed in lowered trucks so this is all on me and I will get if fretted out.

The delay in receiving the camber kits put my truck off the lift and at the back of the days list. These boys need to make money and that doesn’t happen if I’m tying up the lifts for days on end. Patients…….

Edited November 11, 2017 by Grumpy Bear

Grumpy Bear · October 29, 2017

OMG!!

Well the initial work is done and I have it back. Picked the truck up last night and by this evening have logged my requisite 500 miles. Back Monday for re-torques and moans.

So…every scrap of harshness is gone. Railroad tracks. Bridge expansion joints. Awful pockmarked Illinois roads and I went out of my way to drive the worst in my area then headed into Iowa to visit dad and ride some roads I grew up on that I’ve been avoiding since the first time I ran them in this truck. No need to dodge them anymore. Don’t kid yourself, 1960 Cadillac it is not. More like a modern higher trim level pony car. Firm. Very firm. Almost hard but not harsh. Always in control and very responsive. There’s a double set of esses not far from here that are marked 40 mph and that number has been generous until now. 55 mph was a breeze. Can I do it faster? Who cares but I don’t have to slow anymore. There is only a front sway bar on the WT1 and I’m not sure I’m going to need one. The turn in is on cue and precise. Holds the line as pointed. Very confident feeling. Makes the tires feel like I just traded in my LT’s for Gumballs. Okay, not quite but very inspiring.

So all four corners were different heights. 500 miles settled everything in nicely and now that it has, it is dead level standing 37.25” +/- .0625” at the tops of the arches. That’s not a lift and not a lower. It’s a level done from both ends. Level enough that on level pavement an angle gauge on the bed sill is about as dead zero as it gets. I can literally move it either side of zero with two pounds of air from either ends tires.

Down over two in the rear and a bit over an inch up in front. I stopped at four dealerships today and found about a half dozen of my model that measured roughly 36” up front and 40” out back.

Moans (for Deegan’s):

Headlights were aimed but still a bit high.

A mild groan/rattle from the suspension at low speeds at turn in. (At highway speeds it is dead silent). Loose sway bar link maybe?

Steering wheel is about 4 degrees left.

Moans (for Filthy Motor Sports)

A bit softer would be good. N2 pressure? Stack? Viscosity? I’m only using about 1-1/2” of compression my zip ties say. Well away from the bump stops. It’s more of tuning request than a moan I guess.

Things that made me smile:

Everything settled in perfectly.

I have a working day/night mirror now. Before it ran out of adjustment before I could see a full picture that didn’t include half the bed cover. Less dash glare reflecting from rear glass at night.

I get an extra gallon of gas in her and the gas gauge is actually pretty accurate at three quarter and half now. That puts me squarely over 500 miles of range even if I’m not getting peak mileage.

The rear axle that was out of square by .2 degrees from factory which is now dead square has drastically increased coast down distances. Like over 600 additional feet drastic. I can let off the gas at 55 mph and still be over 45 mph if I lift a half mile from the sign. That’s nuts. That is Buick like. My Buick anyway. Any questions?

Edited October 29, 2017 by Grumpy Bear

Grumpy Bear · October 30, 2017

$4543.09 That's this suspension projects current cost. Parts, shipping, taxes and installation. Given the result I'm good with that.

I added a few X-Gauges today.

When I added the oil pressure ECM diagnostic output it floored me. I now know the meaning of 'dummy gauges'. Warmed up idle by the dash reads 38-40 psig. By the ECM it reads 19-22 psig. At a 55 mph cruse the dash gauge read 38-40 the ECM read 23-27 . Tip in just hard enough to turn off the AFM the dash reads 42-45 the ECM reads 30-32. Pin her ears back the dash gauge reads 80 PSI PLUS PLUS pegged to the wall. ECM reads 48-50 psig. Not for the faint of heart.

Only got a look at two tanks of E-10 fuel both read 8-9% alcohol.

Engine Oil Pressure

TXD: 07E0222345(01)

RXF: 046205230645

RXD: 3008

MTH: 001400320000

NAM: User Defined

Engine Fuel Alcohol Composition

TXD: 07E0220052(01)

RXF: 046205000652

RXD: 3008

MTH: 006401000000

NAM: User Defined

Edited October 30, 2017 by Grumpy Bear

Grumpy Bear · November 3, 2017

Today we finally got the re-torque on the suspension done. Now at 48,000 miles having logged 1,000 on the King setup (Installed at 47,000 miles) I am pleased to report that the “hard” is now “firm” and very comfortable. Not even overly firm.

We installed some zip ties to measure wheel motion and find limits of travel for the future tuning phase.

Cylinder Deactivation Commanded (On/Off)
TXD: 07E0221133
RXF: 046225110633
RXD: 3001
MTH: 000100010000
NAME: CDC

Thank you Linear Logic for retrieving this code from my ECM.

Would you be surprised to learn the AFM is triggered by the TPS?

The system is armed by satisfying a list of conditions. Some temperatures and time limits. A few others. And/Or gates we refer to them as in process control systems. But once satisfied you get more or less ‘on’ time by moving the TPS trigger point.

BTW, that point is 30% with a 2% dead band. 29% shuts off cylinders and 31% turns them back on. Literally if you had a Live Tune you would change this set point like moving a timing value. Just punch in a different value. That tells me that OBD-II plug in modules costing $180 or more are a device that moves this set point in a temporary fashion. Like holding your finger on a momentary contact switch. Wow! Thing is with a programmer you get a bunch more capability for a few dollars more.

Grumpy Bear · November 8, 2017

Another thousand miles logged. She’s fully settled and still 37 inches and change. Had it on the rack looking for the squeak/rattle and found it. Front leaf eye bushings are in the slip/stick mode. Not enough grease or perhaps not the right grease and washed out, so out they come again to get cleaned, inspected and repacked. That means a gas tank drop again.

Collecting information on shock travel still. Rear shocks are sitting at 4-1/4” of 8-3/4” of stroke and using 2-1/4” in compression. Bump is set at 2-3/4” and N2 pressure is 200 psi. Ditto on the N2 up front. Front droop (rebound) is 2” and bump stop limited. Looks to be about 2” and change up front as well in compression. Hard to get a direct measurement inside the coil. In essence then we are using about 4” of nearly 9” in available travel. Bottom line, it is firmer than the stroke needs to be for the roads and speeds I travel.

That said, I don’t have enough information to start making wholesale changes in that direction. Still need a few numbers from King. Maybe some equipment/tools as well.

Measurements of bump stop stiffness and some questions answered about the N2 preload. Ideally I would like to see at least two more inches of travel employed. That means some limits would have to be removed or moved.

Deaver delivered. I have a spring that puts the shock at mid-travel and gave the drop I was looking to get. The ride quality in in the right zip code now and not just on the right planet.

Ben has been at the SEMA show and unavailable. Email stack up and I’m not a huge priority all things considered. Time and patients will crack this nut.

Different subject. Cold temperatures and high winds are wreaking havoc on fuel mileage. I talked about preheat last winter and that needs a revisit.

Edited November 8, 2017 by Grumpy Bear

Grumpy Bear · November 10, 2017

We put Pepper on the rack before we started to assure we were still on the marks I set earlier and we were. (That alignment is posted several pages back).Then the suspension got her face lift. The readout on the left the result. It moved it quite a bit. The photo John took after the alignment when the printer went wheels up at the worse time possible. Deegan's is a first rate shop.

As you can see the camber is actually inside the GM spec and in perfect proportion. But there was not enough in the factory camber eccentrics to reach the negative camber numbers I prefer.

Edited November 13, 2017 by Grumpy Bear

Grumpy Bear · November 18, 2017

50,000 mile Service Record:

Tread depth is seven and a half thirty seconds (.234”). Projected tire life remains 70,000 miles. Rotate and balance. Adjust pressures to 35 psig.

Motor: 6 quart Red Line 5W20 & Mobil 1 filter.

Trans: 6 quart Red Line D6 service fill. New GM filter.

Diff: 2.5 quart Red Line 75W90, new gasket.

I’m in the process of converting the fleet to WIX filtration.

The initial impression of the suspension conversion was…it was rock hard. Ben called it ‘firm but in control’ and that it would settle in over about a thousand miles. I was skeptical. In fact two post ago I was ready to start making some drastic changes and a bit disappointed. Today…not so much.

I consider myself patient. Evidently not patient enough. Now having logged 3,000 miles it has done as he said it would. Calmed down. I’m not sure I’d even call it real firm. Perhaps moderately firm and very much in control. As much as I liked the way it took a corner early on I’m just giddy about it now. The truck rises and falls with the swales in a pleasant manor absent the boat like feel but not welded to the road giving the impression you in a roll-a-coaster car. You hear the tar snakes but don’t feel them now. Broken pavement is where you start to appreciate how well these shocks work. Rough tracks are just that, rough. But my fillings stay in place and the truck stays planted. Washboard sections it eats like jam on toast. This is the forth vehicle I’ve totally redone and the best of the bunch to date.

The Deer Slayer II

Today, King/Deaver/Sulastic paid for itself and sealed its place in my all-time favorite personally modified rides. How so? A buck large enough I could see his full back above the hood stepped into my path while I was traveling 55 MPH in a drizzling rain on one of the worst sections of Illinois 72 left only a few miles from my home. A road that before these modification made me believe that 45 mph was way too fast to travel it.

It’s just after dark. There is an oncoming car with his high beams on. It lit this deer up like a Christmas tree at about 100 feet from me out of a road side thicket. Curb side service of deer roast looked unavoidable. If you could have frozen time and discussed it I would have bet a month’s wages this truck was toast and that dear the meat in the sandwich. 55 mph in a 100 feet?

I hit those brakes like the floor board was on the highway in an attempt to scrub off enough speed to limit the damage. He barely gave me a notice. Rack held high and turning his head toward me I could count the hairs of his eyelashes.

That truck came down like it caught the wire on an aircraft carrier. Dead flat and straight as an arrow in flight. The ABS kicked in at about 10 feet from target for a blip and then…Can’t tell you how I missed him but I did cleanly. I’ve ridden bikes for decades and made many a front tire only panic stop and I’ve never felt anything like it. On rough pavement? In the rain? On a dime with nine cents in change. Smooth as a kitten.

With the GM suspension I can guarantee you there would have been blood in the street. That was freaky.

Edited November 18, 2017 by Grumpy Bear

Wish I kept my 2000 Z71 · November 22, 2017

Hi Marty, I appreciate all the information on the suspension re-work you did on your 2015 Silverado 2wd, and I'll run the article by the 4wheel drive shop I visited earlier who said there was really nothing he could think of that would remedy the issues on newer 4x4's, mine is a 2017 with a max towing package ( I ordered after getting bad information on it's ride characteristics) and he hadn't heard of anyone who has tackled the issue, and I don't know how similar my 2017 4x4 suspension is to the suspension on your 2015 two wheel drive Silverado. But it's worth looking into, so thanks again.

Grumpy Bear · November 22, 2017

1 hour ago, Wish I kept my 2000 Z71 said:

Hi Marty, I appreciate all the information on the suspension re-work you did on your 2015 Silverado 2wd, and I'll run the article by the 4wheel drive shop I visited earlier who said there was really nothing he could think of that would remedy the issues on newer 4x4's, mine is a 2017 with a max towing package ( I ordered after getting bad information on it's ride characteristics) and he hadn't heard of anyone who has tackled the issue, and I don't know how similar my 2017 4x4 suspension is to the suspension on your 2015 two wheel drive Silverado. But it's worth looking into, so thanks again.

Who will know is Ben Brazda at Filthy Motorsports. Give he a jingle and tell him I sent you. and your welcome. If you need part numbers or something give a shout.