Front Suspension Travel

Randal365 · July 9, 2016

I have a 2015 GMC Sierra, with stock suspension. My issue is with the front suspension. Has anyone noticed, that when the front suspension goes into heavier than normal compression, ie; maybe driving slowly off a 3-4" curb onto the pavement. The struts absorb the compression OK, but the front of the truck seems to jump or lift off the gound on the rebound, with very little shock absorber action and you can feel/hear the suspension hit the end of it's travel. I take it, it's the struts hitting the end of their travel.

Also, there is a bridge that I go over once in a while, that has a slightly higher surface than the approaching highway on both sides. It's a new bridge and is properly ramped up on each side, just a little steeper than it should be, because the highway needs asphalt , but if you don't slow to at least 40 - 50 kph, the suspension will hit it's limit and really hammer the front on rebound and it feels as though the front is actually airborne, for a bit. Yet with my 1993 (4" lift) and 2005 GMC Z71's (stock suspension), I can travel at 100 k with no issues.

Is this normal for these new trucks?

Is there struts with more travel or better rebound suppression?

What have you done to correct this?

I have been planning a 2" front lift, is this going to make it worse?

southern_sierra · July 10, 2016

I have a 2015 GMC Sierra, with stock suspension. My issue is with the front suspension. Has anyone noticed, that when the front suspension goes into heavier than normal compression, ie; maybe driving slowly off a 3-4" curb onto the pavement. The struts absorb the compression OK, but the front of the truck seems to jump or lift off the gound on the rebound, with very little shock absorber action and you can feel/hear the suspension hit the end of it's travel. I take it, it's the struts hitting the end of their travel.

Also, there is a bridge that I go over once in a while, that has a slightly higher surface than the approaching highway on both sides. It's a new bridge and is properly ramped up on each side, just a little steeper than it should be, because the highway needs asphalt , but if you don't slow to at least 40 - 50 kph, the suspension will hit it's limit and really hammer the front on rebound and it feels as though the front is actually airborne, for a bit. Yet with my 1993 (4" lift) and 2005 GMC Z71's (stock suspension), I can travel at 100 k with no issues.

Is this normal for these new trucks?

Is there struts with more travel or better rebound suppression?

What have you done to correct this?

I have been planning a 2" front lift, is this going to make it worse?

I have a 14 GMC Sierra z71 cc and its the same way. I replaced the stock ranchos with the black shocks that come on a regular 4x4. They helped the ride just alittle, took some jarring away but not much.I can hit a small pothole at about 20 mph and it sounds like it knocked the front end out from under it. I cross a bridge everyday with approaches just like your talking about and I always brace for it. It feels like the shocks top out. I can cross the same bridge in my daughters 2014 4 runner and you almost feel nothing when you cross it, the same with my wifes expedition. I have never had a truck that rides like this one does. It rides as good as you could ask for on the highway can be alittle bouncy at speed but put it in town with bad streets or off road and its rough as hell. I have 275/55/20 tires which I think helps to feel every little thing on the road but the front springs are just to stiff. I have never had this problem with other trucks I have had including f-150's and a Tundra. This is the first GM truck I have had since 1995 and will probably be the last. I like the truck alot but I curse the ride everyday. I have been waiting on bilstein to come out with the 6112 front shock and spring package but its been about 2 years and their still not out. I guess I will just ride it out until I decide to trade it.

ridethedesert · July 10, 2016

I have a 2014 Sierra Crew Cab Standard Bed 4x4 Z71 that exhibited the same front suspension problems. Smooth as could be on the highway but driveways, bumps etc would send the front end bouncing up and down uncontrollably. My 2004 Sierra never did anything close to it. I also blew a rear shock at 14,000 miles. It failed completely. I took it out and you could compress it and it wouldn't come back out.All the fluid was missing, I cut it open. The other side would slowly spring out like normal so just one side blew. I called Rancho and they said the shocks GM specs for the trucks are a little under their lowest shock, the Ranch 5000 shocks. Well those retail for $50 with free shipping so you can imagine GM probably paid $10 or less for these "shocks".

I ended up going with the Fox 2.0 Perfomance series front shocks and the 2.0 rear shocks. They're a little pricey for the fronts but they completely fixed everything I felt was wrong with the suspension. It leveled the front 2 inches the correct way. The level kits for $150 just throw a spacer in the mix and from what I've read it messes the geometry up and actually reduces your travel by 2 inches. The only way to maintain the geometry and gain the travel is the Bilstein 5100 shocks or the Fox shocks.or King shocks but that was out of my price range. By the time you factor in the labor to have someone modify your stock shocks to fit the 5100 kit in, you might as well just buy the Fox shocks that come assembled and ready to go. At least that was my reasoning.

You can't even compare the truck before and after. Bumps are no problem, off road I go through sand washes, whoop sections, you name it. The truck has been solid. Before I felt the rear was way better than the front in stock form and now the front is so good it makes the rear feel terrible. I did add the Air Lift ultimate bags to the back because after the front was leveled, I didn't want the rear to sag when the boat or bike trailer was hooked up. That did add a little stiffness to the rear but not bad. I run the bags at 0 psi because they have an internal jounce bumper.

For a Z71, GM should have worked a deal with Fox to get some decent shocks on the trucks. The Ford Raptor comes with 3.0 Fox shocks and aluminum control arms. GM could at least be somewhat competitive and offer more than what the Z71 currently offers.

Randal365 · July 11, 2016

Thanks for the reply, to both you guys. I'm not too sure what I am going to do, yet. I thought maybe I was the only one that has noticed the front end bounce or extreme rebound. I was wondering if maybe this was a warranty issue. You would think that a Z71 package would have top level shocks.

I also have air bags in the rear of my truck, as I am a contractor and pull a 16 ft cargo trailer. So get that tied to the back and hit a bump in the front. The rebound is unreal. I don't have the internal jounce bumper, so the bags are supposed to have at least 5 lbs in them.

So, are you saying, with the Fox 2.0 Performance shocks, they automatically gave you your 2" front lift and with no modifications for the installations, other than the shock/strut install. Also I imagine you got a wheel alignment after. I may have to check them out.

Randal365 · July 11, 2016

I'm thinking these new trucks are for the city boys, who barely ever drive off asphalt. Nice pretty trucks but not for tough work or rough roads. They sure aren't built like they used to be.

HondaHawkGT · July 11, 2016

Thanks for the reply, to both you guys. I'm not too sure what I am going to do, yet. I thought maybe I was the only one that has noticed the front end bounce or extreme rebound. I was wondering if maybe this was a warranty issue. You would think that a Z71 package would have top level shocks.

I also have air bags in the rear of my truck, as I am a contractor and pull a 16 ft cargo trailer. So get that tied to the back and hit a bump in the front. The rebound is unreal. I don't have the internal jounce bumper, so the bags are supposed to have at least 5 lbs in them.

So, are you saying, with the Fox 2.0 Performance shocks, they automatically gave you your 2" front lift and with no modifications for the installations, other than the shock/strut install. Also I imagine you got a wheel alignment after. I may have to check them out.

The Z71 package is nothing more than a sticker package with cheap Ranchos. Complete waste of money these days unless you like the interior trim. Like ridethedesert mentioned, the GM factory Ranchos are cheap, made to a pricepoint and are really just labeled as Ranchos to make guys think they're buying the "off-road" version. The black shocks are not much of an improvement. Cheap monotube shocks that give a sloppy ride. I swapped my black factory shocks out at 12k miles and one of the rear shocks was on its way out.

If these trucks were made for city boys, they'd ride like a Ram 1500. These trucks ride rough because they're sprung stiffer to handle more load, they're just not equipped with good shocks that dampen correctly. Ford weakened the 2015 front suspension to save weight/money and put a bed in back that can't handle work. Unless you order the HD payload package, the rear suspension sags so bad the bumper drags on the ground. Their 4WD setup is still junk after all these years, with hubs made out of plastic and lock with vacuum, which really sucks when you develop a vac leak a few years down the road. Even the factory bed liner peels off waaay too easy. Ram gave up on "tough" half-tons when they put coil springs in the back. Overly bouncy, soft cadillac ride with horrible rear sag that makes towing miserable unless you add air bags. The interiors disintegrate if you use your truck for work. The paint makes the GM paint look high-end.

ridethedesert · July 11, 2016

Yes the Fox 2.0 Shocks come with the preload ring set for a 2" lift/level out of the box. All I did was lift the truck off the ground, unbolt the stock shocks and bolt in the new shocks. Ya alignment is needed after. And I aligned it again a couple months later because the front shocks/springs settled down a bit.

southern_sierra · July 14, 2016

I ordered a set of 5100's today, should get them Saturday. I will install them either Sunday or Monday. I will report back with a ride update.

ChevyRoofer · July 14, 2016

I ordered a set of 5100's today, should get them Saturday. I will install them either Sunday or Monday. I will report back with a ride update.

Just the front set or did you get the rear set as well?

southern_sierra · July 14, 2016

Just the front set or did you get the rear set as well?

Just the front for now going to see how it rides.

southern_sierra · July 18, 2016

I installed the 5100's front only on the third setting. The overall ride is stiffer than the stock black shocks. I cross a bride with a high approach that caused the stock shocks to top out. With the 5100's its smooth as glass on the approach. In town driving on patched streets it rides stiffer. Before I though i felt every little bump, now I really do. On a wash boarded gravel rode the ride is better much more controlled. Overall I'm not as happy as I though I would be with the ride. Its a little stiffer than I would have liked but its what it is. I do have 20 inch tires and I know that is contributing to the feeling ever little bump. I my go to 18's later. It will be interesting to see the reviews on the 6112 vs the 5100 if they ever let them out.

thearizonacowboy · July 18, 2016

I installed the 5100's front only on the third setting. The overall ride is stiffer than the stock black shocks. I cross a bride with a high approach that caused the stock shocks to top out. With the 5100's its smooth as glass on the approach. In town driving on patched streets it rides stiffer. Before I though i felt every little bump, now I really do. On a wash boarded gravel rode the ride is better much more controlled. Overall I'm not as happy as I though I would be with the ride. Its a little stiffer than I would have liked but its what it is. I do have 20 inch tires and I know that is contributing to the feeling ever little bump. I my go to 18's later. It will be interesting to see the reviews on the 6112 vs the 5100 if they ever let them out.

Try airing down your tires a 2-3 PSI. It really does make a huge difference

southern_sierra · July 18, 2016

Try airing down your tires a 2-3 PSI. It really does make a huge difference

Yea, I have them at 31 cold now, they get up to 34 hot. I my let them down to 28 cold just to see. I still want 18's and wouldn't mind 17's.

HondaHawkGT · July 19, 2016

17's are great. I run approx 42 psi and they ride like pillows.

TJay74 · July 19, 2016

28psi is going to be really close to the trip point for the TPMS sensors. Door card is 35 for front and rear. I run 37 in the front and 34 in the rear. I don't base my air pressures off of the door card but more so how the tire is wearing.