Not Happy with 4.5/7 RQ, should I bag it?

[Bryantcm]

So I just finished a complete overhaul of the suspension on my 67 with a 4.5/7 drop with all the usual parts: spindles, KYB, c-notch, new wheels/tires, etc etc.

The end result is I'm really happy with the look, but the ride quality is just not acceptable. The rear is particularly harsh, I'm assuming due to the 5" drop springs.

So my question is this: Is air ride that much better for a quality and compliant ride? While I am budget minded, I'm not one to spend thousands and it not be "right." I'm considering making the change to a basic air ride kit with manual valves since I'm not really concerned about laying frame or playing with Air. Just set ride height and enjoy.

Any opinions on the difference in ride quality? Is it worth the effort?

[SCOTI]

Did you use shock relocation brackets w/those 5" drop springs?
What size are the tires?
How much gap between the bumpstop & the rear end?
How much room between the rear end & bed floor?

[Bryantcm]

Originally Posted by SCOTI

Did you use shock relocation brackets w/those 5" drop springs?
What size are the tires?
How much gap between the bumpstop & the rear end?
How much room between the rear end & bed floor?

There is more than enough room for suspension travel. It's c-notched with pancake shaped bump stops. Its not bottoming out, just stiff.

[SCOTI]

Originally Posted by Bryantcm

There is more than enough room for suspension travel. It's c-notched with pancake shaped bump stops. Its not bottoming out, just stiff.

Did you use shock relocation brackets w/those 5" drop springs?

And... How much is more than enough?

[Bryantcm]

Originally Posted by SCOTI

And... How much is more than enough?

I used both front and rear shock relocators. To give more detail, I started out with heated springs and worn out bilstiens from the previous owner. I installed:

Front:
Western Chassis front spindles and 2" drop springs from performance online and 344068 KYB shocks. All new control arm bushings, ball joints, tie rods, adjusting sleeves, pitman arm, idler arm, etc. Pretty much every wearable part and all hardware is new.

Rear:
CPP c-notch, rear shock relocators, performance online 5" drop spring, 2" lowering blocks and KYB 344055 shocks. New spring retainer cups, trailing arm bushings, 5-lug axles, etc.

I will have to measure the clearance when I get home for an exact measurement, but I'm guessing its in the neighborhood of 6-8".

My real issue with it is that even going over the smallest of bumps, such as a change from ashpalt to a brick paver crosswalk at the entrance to my community, it is really harsh, even at low speeds of 10 mph. I was expecting the truck to ride better than it did before I did all of this work and there is no change in ride quality.

[SCOTI]

Since it has shock relocation brackets the angle should be close to OE. Many times the shocks aren't effective because they're in such a severe angle from dropping. We can focus on other possibilities....

What size are the tires? The big diameter wheels using short sidewalls are not going to help ride quality so I'm betting that's part of the issue.

And.... Thanks for providing a thorough list of parts. It makes 'helping' (providing insight?) much easier.

[lolife99]

Originally Posted by Bryantcm

I used both front and rear shock relocators. To give more detail, I started out with heated springs and worn out bilstiens from the previous owner. I installed:

Front:
Western Chassis front spindles and 2" drop springs from performance online and 344068 KYB shocks. All new control arm bushings, ball joints, tie rods, adjusting sleeves, pitman arm, idler arm, etc. Pretty much every wearable part and all hardware is new.

Rear:
CPP c-notch, rear shock relocators, performance online 5" drop spring, 2" lowering blocks and KYB 344055 shocks. New spring retainer cups, trailing arm bushings, 5-lug axles, etc.

I will have to measure the clearance when I get home for an exact measurement, but I'm guessing its in the neighborhood of 6-8".

My real issue with it is that even going over the smallest of bumps, such as a change from ashpalt to a brick paver crosswalk at the entrance to my community, it is really harsh, even at low speeds of 10 mph. I was expecting the truck to ride better than it did before I did all of this work and there is no change in ride quality.

Great Post!
It would have been nice to have all this info in the first post.

I agree with SCOTI that the short sidewall tires will contribute to the rough ride.
IF you could swap on some 15" wheels with a 70 series tire,... you woud be amazed how much nicer it rides.
But that's the price of running big diameter wheels.

[71swb4x4]

The questions Scoti is asking will apply to bags and springs. So if there is a problem other than springs, adding bags will not solve your problem. Scoti's been around the block a few times, get him his answers and he will point you in the right direction.

[PGSigns]

First thing I would do is borrow a set of stock wheels and tires and see how it rides. That will tell you how much of the ride issue is tire related. That part wont improve with the air. The air is a better ride but the tires and shocks have a huge influence on the ride quality.
Jimmy

[PGSigns]

If you had a spring rate checker you could see what the springs are. A short stiff spring and a longer softer rate spring can give you the same ride height. So springs from one manufacturer to another can be much different. I like a air ride setup and the schrader valve test would not be that expensive.
Jimmy

[SCOTI]

Yes, properly spec'd & set-up air bags will offer better ride quality vs the 5" drop spring from CPP.

[CHRIS67GMC]

After reading it appears the harsh ride is do to spring rate. Real heavy spring rate to hold truck up with such a big drop.

Will a air bag ride better of coarse it will as long as it is used properly with in its range and psi. If you have a ton of air in them they will ride harsh also.

The fix would be to put lower blocks in it to the spring more space. Change spring or a air bag.

If you want ride quality buy good shocks and no kyb are ok not good. The most important part of ride is in the shock.

[SCOTI]

With the 2" blocks already in there, some 6" dbl convoluted bags in place of the coils would work well (Firestone 267c's or Slam Specialties RE-6's; 3" compressed height, approx 5" ride height, 7" max ext height).

And I agree w/CHRIS67GMC on the shocks.

[Bryantcm]

Originally Posted by SCOTI

With the 2" blocks already in there, some 6" dbl convoluted bags in place of the coils would work well (Firestone 267c's or Slam Specialties RE-6's; 3" compressed height, approx 5" ride height, 7" max ext height).

And I agree w/CHRIS67GMC on the shocks.

SCOTi. Just measured current ride height and it is 8". This seams to be quite a bit more than you mention in your post. What air spring would you recommend?

[SCOTI]

Originally Posted by Bryantcm

SCOTi. Just measured current ride height and it is 8". This seams to be quite a bit more than you mention in your post. What air spring would you recommend?

Same springs but use the adapter brackets on the install to make up the difference in height (they also make installation easier since no holes need to be drilled).

[Bryantcm]

Originally Posted by SCOTI

Same springs but use the adapter brackets on the install to make up the difference in height (they also make installation easier since no holes need to be drilled).

Ahhh, I see. I thought that might be the case. Any brackets better than others? They all seem to be pretty much the same between BC Fab, Pro Perform and Porterbuilt.

[Bryantcm]

So thanks to everyone's comments I came home and climbed under the truck to take a look. I had only seen it on the lift at the shop when I picked it up Saturday,
so that didn't give the whole picture.

Shocks look to be in a close to stock position, no bad angles. Space between axle and c-notch is good but there's less room between the pumpkin and the bed floor than I thought, maybe 5".

The real thing that concerns me is the driveshaft. There is maybe a half inch clearance between the driveshaft and the top of the crossmember. This seems
Like it would be a problem to me. Any thoughts? Here's the best pic I could get as it's pouring rain here rt now.

[SCOTI]

Look closely where it passes through the x-member for a contact line. If it's ever hit, it will scribe a distinctive line on the shaft.

One thing to remember is the movement @ the back of the shaft (rear suspension travel) will be less than toward the front of the shaft. My old 68 was dropped w/bags (bolted directly between the T/A & frame), blocks, & bolt-in c-sections w/no bump stops. The differential definitely hit the bed floor (wood/what was left of it) but I didn't have issue w/the OE 1pc shaft making contact @ the x-member. All trucks are different so the concern is very valid. The only way to see what point it might make contact is to remove the rear springs & drop the truck to the bumpstops & see if contact is made. If you feel it's too close for comfort, ECE sells a replacement unit that allows more clearance.

Pop some bags in place of those short coils & I bet the ride will improve. Set it up w/schrader valves (don't T them; keep each side independent) for a static/air bag drop. Beautiful thing is you can add air to them when needed to allow extra capacity & then just bleed them back down when done.

[Bryantcm]

Originally Posted by SCOTI

Look closely where it passes through the x-member for a contact line. If it's ever hit, it will scribe a distinctive line on the shaft.

One thing to remember is the movement @ the back of the shaft (rear suspension travel) will be less than toward the front of the shaft. My old 68 was dropped w/bags (bolted directly between the T/A & frame), blocks, & bolt-in c-sections w/no bump stops. The differential definitely hit the bed floor (wood/what was left of it) but I didn't have issue w/the OE 1pc shaft making contact @ the x-member. All trucks are different so the concern is very valid. The only way to see what point it might make contact is to remove the rear springs & drop the truck to the bumpstops & see if contact is made. If you feel it's too close for comfort, ECE sells a replacement unit that allows more clearance.

Pop some bags in place of those short coils & I bet the ride will improve. Set it up w/schrader valves (don't T them; keep each side independent) for a static/air bag drop. Beautiful thing is you can add air to them when needed to allow extra capacity & then just bleed them back down when done.

I appreciate all of your input SCOTI. I am definitely going to try the bags. Maybe Porter hilt will sell me just the bags and plates from the stage 1 rear kit since I already have the shocks and relocators

[SCOTI]

Originally Posted by Bryantcm

I appreciate all of your input SCOTI. I am definitely going to try the bags. Maybe Porter hilt will sell me just the bags and plates from the stage 1 rear kit since I already have the shocks and relocators

What's the 'ride height' spring dimension of the current springs (measure the distance between the bottom of the frame & top of the T/A)?

[Bryantcm]

Originally Posted by SCOTI

What's the 'ride height' spring dimension of the current springs (measure the distance between the bottom of the frame & top of the T/A)?

I will measure that tonight. That way I can get some good input on which bags are correct for my ride height as I have seen at least four different types of bags recommended.

[72MARIO]

Here is a good link on how to bolt bags in place of coils
http://67-72chevytrucks.com/vboard/s...d.php?t=129463

[STPrider]

I had a similar setup to you when I was running a static drop. Didn't have so much of a problem with bad ride quality, but I went to bags on all four corners with schrader valves. I was very impressed with the ride quality! Some people don't like it, because the valves have a tendency to leak. Invest in a tube of Loctite pneumatic sealer, and TAKE YOUR TIME being meticulously clean. I daily drove it, and loved it!

[knomadd]

Lots of good advice from the guys who have posted before. I've done this swap myself. I went from a 5" spring to a 3" spring and 2" block, which helped, but I wanted more out of the ride quality. I ended up doing a bag swap on all 4 corners, with schrader valves. I used the bag cups that Scoti had circled in the picture on the previous page too.

The one thing I want to tell you is the ride quality will not be the same as a stock height vehicle. Unless you do a lot of modifications like the guys do that race these trucks, you won't have a fantastic ride quality, but it will be an improvement over what you have now. Just make sure you're not hitting the bump stops, or the rear end and bed floor don't contact and you shouldn't have such a harsh ride.

As for buying the parts, try the vendors on the forum. There are a lot of them on here that can help you get what you want. I bought all my stuff from Travis (ProPerformance) on here. I too already had the shock relocators and drop shocks. He was very helpful and got me everything I needed to make my system work. Send him a PM and tell him what you're looking for.

[Bryantcm]

All the parts are ordered, RE-6 bags, PB brackets and Schrader fill kit. So hopefully it works out to be what I'm looking for. I really like the idea of being able to add air to the back for those trips to Home Depot on the weekends