Suburban Suspension Upgrades

[merc_twister]

Hi, new member to the square body forum......looks like a great site. I'm looking for ideas on the best way to upgrade suspension on our 1991 3/4T Suburban, will mainly be used for cross country family trips and pulling boat to lake. We've taken the truck on a few trips, but its a rough ride compared to the 1/2T Suburban's my parents had owned growing up. I was thinking doing a 2.5" rear shackle flip with a thinner leaf pack in the back and maybe a new spring pack upfront. If needed I could always add air bags in the rear when pulling a trailer. I would like to run 285's, currently running 10ply 265's. Thanks in advance for any ideas or help!

 

[HotRodPC]

Running them 10 ply tires it probably the reason for the rough ride. Get some nice radials and you might be satisfied with the ride quality without suspension mods.

 

[Old77]

Yeah try the tires first then try a different shock. Generally speaking a 3/4 ton is going to be harder than a half ton burb. To improve more than what you'll get by changing tires and shocks you're going to have to get into significant and pricey mods

 

[bucket]

If your Burb has the 52 inch rear springs, a pair of the longer 56 inch springs (and moving the hangers to the other set of holes) will really help out. Tuff Country or BDS brand front springs would work well too.

I bought my '88 K10 Burb in stock form and put about 20K on it like that. It rode well I thought. Then I installed 3/4 ton axles, 4 inch lift BDS front springs, blocks in the rear with 8-leaf 56's (stock 52's were only 5-leaf) and a set of 305/70/16's that were load range E. It literally rode just as well as stock. It was our family rig for several years, including daily driver duties and long trips.

 

[merc_twister]

Best Tire

Seems like most of the tires available in LT265 or 285 are E rated, anyone have a recommendation for a smooth riding all-season tire. I currently have Cooper Discover ATP LT265 75R16E, would like to add a little lift to clear a 285.

 

[Craig 85]

You may just try lowering the tire pressures in the rear. My 2016 Ram 2500 came with the rear tires set at 80 PSI from the factory and it rode like crap!! I dropped the rear pressure down to 45 PSI when I'm unloaded and it rides 100% better as well as won't wear out the center of the rear tires. If I need to load the truck or tow something I air back up. I've done this on several other trucks I've owned (3/4 and 1 tons).

Make sure you air back with loads. I forgot to do this one time with my 2001 GMC 2500 CC when towing a 31' travel trailer. You could definiately feel the sway due to the rear tires flexing the sidewalls.

 

[HotRodPC]

Glad other are making suggestions about tires too. Honestly IMO, 3/4 ton trucks with 56in C6P rear spring pack ride firm but very comfy. I'd imagine it's the same for Burbs too especially since they are heavier. I'd hate to see you spend a **** ton of cash and making unnecessary mods to a rig that normally should ride fine. Of course it's not going to ride Lincoln on Air Bags, but hopefully you wouldn't want it to either.

 

[merc_twister]

Thanks for all the input. I dropped the rear tires down to around 50psi during last trip and it seemed to help a little. I was expecting it to be alitte rougher ride being a 3/4t, but it's jarring. I was also thinking about a different set of shocks, currently has yellow Monroe's. Sounds like the bilstein's work good, anyone have any other recommendations? I was also wondering if dual shocks upfront might be contributing to poor ride, are both necessary?

 

[bucket]

Mine has the dual shocks up front, it still rides nice.

 

[HotRodPC]

Thanks for all the input. I dropped the rear tires down to around 50psi during last trip and it seemed to help a little. I was expecting it to be alitte rougher ride being a 3/4t, but it's jarring. I was also thinking about a different set of shocks, currently has yellow Monroe's. Sounds like the bilstein's work good, anyone have any other recommendations? I was also wondering if dual shocks upfront might be contributing to poor ride, are both necessary?

If it's jarring, then something else is wrong or someone has modded the suspension. My 3/4 tons have always rode nice. They do have a firm stiff bounce if you hit a dip or something like that, but otherwise, they're smooth as glass going down the freeway at any speed, and in OK, this is Pothole capital of the US and I have no complaints. I'm running old ass Uniroyal Liberators Load Range D in OEM tire size 235 85R16 on OEM 16in wheels.

 

[HotRodPC]

Thanks for all the input. I dropped the rear tires down to around 50psi during last trip and it seemed to help a little. I was expecting it to be alitte rougher ride being a 3/4t, but it's jarring. I was also thinking about a different set of shocks, currently has yellow Monroe's. Sounds like the bilstein's work good, anyone have any other recommendations? I was also wondering if dual shocks upfront might be contributing to poor ride, are both necessary?

Just make sure your shocks are not seized and they do work. If they're seized, then they're not allowing the springs to absorb the bounce and it would be like riding on bricks.

Dual shocks should have nothing to do with rough ride. True a shock does control bounce but it's primary purpose is to hold the tire to the pavement and keep it from dribbling. Dual shocks are nice for oversize tires where if the tire is big and heavy enough it can overcome the single shock and still dribble. If you've ever seen a tire dribbling like a basketball as they were driving down the freeway, it's because that car needs shocks or stuts replaced. If you ever see cupping or lots of small flat spots all the way around a tire, it's because the shocks are bad and the tire is dribbling and pounding the pavement causing the cupping.

 

[75gmck25]

My 3/4 ton camper special has the 8200 GVW rear springs and 10 ply 245/75R16 tires. It rides really rough over bumps when unloaded, but the ride improves greatly if I have a load in the bed. With 300-400 lbs it smooths out, and with about a ton in the bed it feels like the ride of a light duty 1/2 ton.

Bruce

 

[theblindchicken]

I'd start with ensuring that all the bolts and bushings are nice and greased up. Binding suspension will be one of the biggest causes of a rough ride. Newer shocks should probably help out a lot.

If the front is what is mostly stiff, then your current shocks may be too stiff for your preference, especially with running dual shocks. You'd want to run a higher dampening shock with only single fronts, but a little bit of a softer one when running duals since you have twice as many shocks.

For the tires, you'll always have a stiffer ride with higher rated tires since there's typically less sidewall flex. Your tires actually absorb a fair amount of the small bumps in the road and the suspension absorbs the rest.

 

[yevgenievich]

I have exact same set up and so far seen most improvement with greasable spring mounting components in the front. Have not ventured in to the back yet(56" springs), but seen that rear springs from gmt400(64") is one way of improving the ride without compromising load capability(without air bags). Or just softer spring and add air bags.

 

[89GMCJimmy]

Mine rides pretty good off-road but getting to and from OHV roads on the freeway is pretty bad spongey boaty
with the lift how does it affect shock angle? I have the two options also would a Bilstein with different valving help? I'm looking for cheapest option till work picks up again, I'll be saving up for some ORD progressive custom springs. In the meantime I was hoping for a cheaper option?
My set up 2" Tuff Country EZ Ride Front 3" Tuff Country EZ Ride Rear ORD HD Front shackles and 4 1/2" ORD rear super shackles Both at 90* angles ORD Steering Brace ORD Sway Bar disconnect
Bilstein 5125 fronts in the rear stock position not the forward dual position and also Bilstein 5125 rear shocks.