Help! my rear end rides like a trampoline.

[Aarons72]

So I have owned this 71 GMC burb for 2 days...I have never had a ride with rear coils, I have always had leafs...so anyway, the back of my burb just bounces all over the place...up and down...side to side a little...it feels like the springs are crazy soft and the shocks are practically sideways...so on a tight budget what do you suggest I do to make it ride better? By looking at the picture what do I need to do to make things ride right? I know there are some products out there to correct lowered rear suspension like this but I dont know what they are called or where to get them. I can only spend a few hundred max.


Thanks! Aaron

[502ms]

I have not seen the stock suspension for a suburban, but are those stock coils, cut to that height? Because there is no way that has enough of a spring rate to even support a BMX bike, let alone a 2 ton behemoth like a Burban. I definitely think proper lowering springs are needed. Some of the forum vendors can get you setup on something hot for your rig without breaking the bank....
Posted via Mobile Device

[bk2life]

From the one pic you have a couple of things going on. the stock spring is cut in half, not a biggy, but will make it ride bouncy. Next your shock is almost horizontal. You know this, it is not moving much more than an inch, meaning no shock absorption to them bouncy coils.
Then I can’t see it to well in that pic but it looks like there is an inch maybe 2 of clearance between the axle tube and frame. I don’t see a c-notch, so I am going to guess there is a bump stop back there holding the truck up, not really the coil spring. And with it being on the bump stops your shocks aren’t working at all.
What to do?
Personally id pull the springs out and put airbags in their place. You are on a budget, run some ¼ airline to the license plate frame and put a Schrader there to fill it with air.
What will this do?
It will lift the truck up while driving, allowing your shocks to work, and get the truck off the bump stops.
Or..
Put factory springs back in it, and if you want it lowered, put lowering blocks in it to bring it back down.
--more pics of the rear end will allow more comments

[N2TRUX]

Originally Posted by bk2life

What to do?
Personally id pull the springs out and put airbags in their place. You are on a budget, run some ¼ airline to the license plate frame and put a Schrader there to fill it with air.

I agree, but would run separate lines with two fill valves. This prevents air transfer from side to side, and keeps air in one side in the event of a slow leak.

[Aarons72]

anything option with bags seems expensive and out of my reach...I want to keep it really low. Who do you guys recommend for shock relocator kits and that sort of thing?

[lolife99]

I posted in your burb thread.
http://67-72chevytrucks.com/vboard/s...d.php?t=549065

[69gmcc10]

I think making your rear functional for around $100-$150 and a little labor is very doable! I see 2 problems in your set up right now, the first is that I dont think that spring is safe being cut like that, It has little spring to it if any and it brings the trailing arm too close to the frame making the shock lay down. The second issue is yor spring is not effective if it is leaned over more than 30 degrees, so you need to find a way to pick it back up. If it were me, like everyone else stated, I would replace those springs, but I would get 3" lowering shocks (CPP $95), have a local shop bend some long ubolts ($35) and fab a lowring block from some scrap (1.5" or 2"), then I would modify the exsisting shock mounts to get them mor vertical.

lowering block 101 thread- http://67-72chevytrucks.com/vboard/s...d.php?t=196457 (make your u-boults from 3/4" thread 24" rod and 3 1/2" gap, trust me)

shock mount mod- http://67-72chevytrucks.com/vboard/s...d.php?t=437582

[71swb4x4]

I agree with the post above. That was my recommendation too.
New springs, I think that's a must.
1.5" to 2" lowering blocks.
Shock relocator brackets.
Then take a look at your shocks, it could be possible they will work, or you may have to buy shorter shocks. I wouldn't buy shocks until you know what you are doing with the rest.

[69gmcc10]

I wouldn't buy new shocks either, the ones you have look new.

[71swb4x4]

Originally Posted by 69gmcc10

I wouldn't buy new shocks either, the ones you have look new.

I konw you mean well, but the shocks need to be made for the amount of travel that the burb will do. New or not, if they are made to travel from 10" to 16", and the burb needs 6" to 11" to work effectively, the new looking shocks will not work. In fact they will likely be bottomed out and will make for a very harsh ride.
It is possible those shocks will work, but that will have to be verified once the suspension has been configured.

[69gmcc10]

Originally Posted by 71swb4x4

I konw you mean well, but the shocks need to be made for the amount of travel that the burb will do. New or not, if they are made to travel from 10" to 16", and the burb needs 6" to 11" to work effectively, the new looking shocks will not work. In fact they will likely be bottomed out and will make for a very harsh ride.
It is possible those shocks will work, but that will have to be verified once the suspension has been configured.

-that was more the point I was trying to imply, you dont need another pair of new shocks until after you fix the problems and discover if they will work or not.

[Aarons72]

thanks guys, love the info. I am going to keep doing some research and get some work done this week hopefully. Any ideas for what brand lowering coils?

[Aarons72]

So here is how much clearance i have from the axel to bump stops...and then I noticed that the rearend is bottoming out on the bed of the suburban floor..so the wood is getting dented under there. If i do lowering blocks wont that make my axel even closer to the floor of the burb? Sorry these are horrible pictures.

[lolife99]

Yes lowering blocks will get you closer to the floor,... but your should be installing a taller 6" spring to bring you back to where you are now.
You need the taller spring to help with your shock angle also.
(shock relocators)

[69gmcc10]

Just for an example, Think of it this way, if you have a truck that sits at stock ride height and you want to lower it 6" you have 2 options.

Option 1) 6" lowering springs, they bring the bed of the truck 6 inches down and the training arms get 6" closer to the bed of the truck, this changes the angle of the shock allot (more parallel) and massively changes the efficiency of the shock.

Option 2) 4" spring and 2" block bed of the truck gets 6" closer to ground , but the trailing arms only got 4" closer to the frame and not the full 6", this wont change the angle of the shock as much (less parallel) and decrease the loss of efficiency in the shock. If you match the blocks with the shock relocators, you can move the shocks even more vertical and get more efficiency out of them and make that bounce in the rear much less.

Hitting the bed of the burb gives you a decision you need to make before you make any suspension mods. Are you going to raise the bed (at least the section over the pumpkin), lengthen your bump stops (decrease travel) or are you going to increase the ride height of the burb by an inch or 2.

Good luck and keep us informed!

[Aarons72]

Originally Posted by 69gmcc10

Just for an example, Think of it this way, if you have a truck that sits at stock ride height and you want to lower it 6" you have 2 options.

Option 1) 6" lowering springs, they bring the bed of the truck 6 inches down and the training arms get 6" closer to the bed of the truck, this changes the angle of the shock allot (more parallel) and massively changes the efficiency of the shock.

Option 2) 4" spring and 2" block bed of the truck gets 6" closer to ground , but the trailing arms only got 4" closer to the frame and not the full 6", this wont change the angle of the shock as much (less parallel) and decrease the loss of efficiency in the shock. If you match the blocks with the shock relocators, you can move the shocks even more vertical and get more efficiency out of them and make that bounce in the rear much less.

Hitting the bed of the burb gives you a decision you need to make before you make any suspension mods. Are you going to raise the bed (at least the section over the pumpkin), lengthen your bump stops (decrease travel) or are you going to increase the ride height of the burb by an inch or 2.

Good luck and keep us informed!

Got it! Makes perfect sense.

[bk2life]

Originally Posted by Aarons72

anything option with bags seems expensive and out of my reach...I want to keep it really low?

airbags are about 69 dollars each.

about 10-20 dollars in steel to make the mounts.

done.

no lowering block, no u-bolts, everything you have stays the same.

air it up to drive, air it out to be where you are at now.

[lolife99]

Originally Posted by bk2life

airbags are about 69 dollars each.

about 10-20 dollars in steel to make the mounts.

done.

no lowering block, no u-bolts, everything you have stays the same.

air it up to drive, air it out to be where you are at now.

Plus the price of fittings, line, switches, tank, compressor, moisture trap, etc.
You still have to address the shock issue, with shock relocators.
Plus a lowering block allows you to drive a lower ride height with the correct amount of air in the bag.

[bk2life]

Originally Posted by lolife99

Plus the price of fittings, line, switches, tank, compressor, moisture trap, etc.
You still have to address the shock issue, with shock relocators.
Plus a lowering block allows you to drive a lower ride height with the correct amount of air in the bag.

you must have not read the above posts. he wants to do it cheap, no switches, no tank, no compressor, etc..

the shock issue would be mute. yes the shocks are at an angle, raise it 2 or 3 inches they would work as intended..
and it is as low as its going to go, the rear end is hitting the floor, you can add as big as a lowering block as you want, it wont go lower--meaning aired out or very low air pressure he will be at this height, add air it will raise, thus eliminating the bad ride all together.

thanks..

[lolife99]

I did read that.
But you wrote,... "air it up to drive, air it out to be where you are at now."

Kinda hard to do that unless you have an air supply.
Not trying to get into a pissing match.

His static drop was done incorrectly.
Just trying to help him fix it.

There are a tone of trucks that ride low on the cheap.
But they also ride like crap.

[bk2life]

true, and sorry if i came off rude. wasnt intended.

*his truck is an "easy" fix, there are several routes he can go

[4shongo]

Give Jeff at CPP a call. Order some new 6" springs, new lowered shocks to match the drop, and the rear shock relocation brackets. Easy fix and will only cost around $300. Problem solved. I used these parts to lower my 72 Suburban ( I used 4" springs). It rides great.
Posted via Mobile Device

[CC69Rat]

Keith- Training arm bracket flip? +.75 on the height of the truck overall, eliminates (or helps ) with the chunk on the bed wood, then some new 6" springs and relocators. Yes?

[lolife99]

Originally Posted by CC69Rat

Keith- Training arm bracket flip? +.75 on the height of the truck overall, eliminates (or helps ) with the chunk on the bed wood, then some new 6" springs and relocators. Yes?

Before I would do a bracket flip,... I would just run a 5" drop spring.
To me it's not worth the effort.
I would add a set of shims at the rearend if you are worried about pinion angle.

[Aarons72]

Relocted my upper mounts this weekend and flipped and changed sides of my lower mounts so my shocks didnt bottom out. Rides way better...In the future Im gonna upgrade my rear shocks and probably do a different spring or I dont mind the idea of the cheap bag option (manually filling etc) ...Anyway this weekend was awesome...changed all my rotten fuel lines, got my gas guage working and got new exhaust...but I am officially out of money. Anyway, thanks for all the tips. Im happy with how it rides for now.