Shuttering front end on potholes

[HappyPrtagee]

I just have about 1000 miles on new Konis and first thought they were just breaking in but potholes have my front tires (100 pounds) shuttering. My airbags are properly adjusted and it feels more like a side to side slight shudder. Rig feels great over gradual dips but goes “ bam” on potholes. I have 90K on it and not a ton of service information. Looks like I have original front end components. Airbags are Firestones so I assume at least changed once.

[R.Wold]

New tie rod ends improved this condition on mine and I did them at 50k. So even with good consistent maintenance yours may be ready. With that milage several front end components may need attention. My front end now feels tighter and is less noisy when hitting pots holes, etc.

Also when I put Konis on my Bay Star it made the front suspension too stiff. They improved handling a bit but the cost was a more harsh ride and if I’d kept that rig I would have put the Bilsteins back on the front.

With softer (or well worn) shocks your front end was probably more forgiving of hard jolts, but with it stiffer now, the jolts are harder and this may be what’s setting off the shuddering.

[wolfe10]

Originally Posted by HappyPrtagee

My airbags are properly adjusted and it feels more like a side to side slight shudder. Rig feels great over gradual dips but goes “ bam” on potholes. I have 90K on it and not a ton of service information. Looks like I have original front end components. Airbags are Firestones so I assume at least changed once.

Assume you have an Alpine coach, but you might want to list your coach info in your signature or in your posts.

You mention "airbags are properly inflated". But airbag pressure is controlled by the RIDE HEIGHT VALVES and pressure itself is not adjusted on an air suspension diesel pusher.


Have you check for play in the front end. Easy to start-- with engine off, just have someone turn the steering wheel back and forth while you check each connection for play between steering column and the right front wheel.


Also, check that the new shocks are properly torqued.

[HappyPrtagee]

Thanks Brett and yes it’s Alpine 38. I did mean ride height versus pressure on adjustment. I have to admit I didn’t take torque specs seriously when I installed shocks. Can it make a big difference? I just tightened them without much regard to the rubber bushings. This started when I installed Konis. What is my other brand choice in front if I determine that the shocks are too harsh? I will torque them properly and check for play. Easiest place to find torque numbers?

[wolfe10]

What Koni shocks did you install?

[HappyPrtagee]

I installed Koni 99B 3209 shocks on front. The rig had Monroe’s that I pulled off. I live in my rig so it’s worth it for me to spend a few hundred on more forgiving option but cannot find a part number for comparable Bilstein, Monroe or Rancho shock that will work. My tie rod ends feel tight. Just feel that these shocks are too strong. Preferred feel of Monroe’s but just tossed them when I installed Konis. Previous owner had dementia so got very limited information on rig history. The Koni 8805-1021 is no longer available and Bilstein is telling me they have no aftermarket shock. Monroe’s would be fine. Most of my miles are local, it’s my house.

[wolfe10]

Those 99 series Konis were just right for our 2003 Alpine 38'FDDS. Controlled over the large bumps without adding harshness over the small ones.


And, don't believe that shocks will affect: "...feels more like a side to side slight shudder"