2018 RAM 3500 with factory rear air suspension VOILENT REAR AXLE HOP

[GrantP]

They do thread in true however Fox corrected that issue , we saw that issue alot about 2 years ago but once they fixed it we have not seen a single issue with them and thats over a year ago.

I personally have King 2.5s, there great shocks but majority of people wont spend $2200+ on a set of shocks. A 2.5" shock has alot more surface area and tuning ability so ya it will ride better then a 2.0 but for people that only drive on road / light off road the IFP's do work very well for the cost and still ride much better then stock.

I'm glad to hear that Fox did something about it, and I agree King 2.5 shocks are overkill for most people. For my usage, there's no way I'll run anything less now...it all depends on how you use the truck. I wasn't real happy with the Fox 2.0's but they were definitely an improvement over stock when they remained attached.

I had Fox 2.5's on my 2nd Gen and had to rebuild them twice. I think I'm just burned out on Fox.

 

[AEdelheit]

I'm glad to hear that Fox did something about it, and I agree King 2.5 shocks are overkill for most people. For my usage, there's no way I'll run anything less now...it all depends on how you use the truck. I wasn't real happy with the Fox 2.0's but they were definitely an improvement over stock when they remained attached.

I had Fox 2.5's on my 2nd Gen and had to rebuild them twice. I think I'm just burned out on Fox.

Oh I understand and a few years back was not a fan of Fox either but they have come a long way recently. Unfortunately Kings are not bulletproof either but overall great shocks. I rebuilt my Kings last year after about 7 years of use as the reservoir was dented to nitrogen was getting in the oil but they do typically hold up well. I keep talking my self out of stepping up to short body 12" travel 3.0s, only money right.......

 

[JR]

I'm assuming the 2.5 and up is only for lifted rigs? I can't afford to go any higher than stock, these gen 4 trucks are already too tall as it is for towing 5th wheels and gooseneck. And getting things in and out of the bed.
Thank you for the info on the 2.0. I'll definitely look into them.

 

[AEdelheit]

You can do 2.5's for a stock truck, if you dont mind spending the extra money the larger piston surface are offers alot more control.

 

[BIG HIPS 3500]

UPDATE.... I called FCA they said un able to help unless you can duplicate. Nobody was concerned with the terms, violent, hazardous, loss of control. sooooo I hooked 3 GOPRO cameras and tried and tried and yes!! I caught something today, as suspected starts in the rear works it's way up to the front and ends with a death wobble. I will be calling the service manager tomorrow. I'm 50 years old and not tech oriented, but I will find someone at some point to edit the videos and help with posting them here, give me some time.

 

[SnoKing]

You most likely have had the dealer looking at the wrong end of the truck. Have them replace the "crappy NEXON" OEM tires with Michelin Defenders.

 

[sag2]

UPDATE.... I called FCA they said un able to help unless you can duplicate. Nobody was concerned with the terms, violent, hazardous, loss of control. sooooo I hooked 3 GOPRO cameras and tried and tried and yes!! I caught something today, as suspected starts in the rear works it's way up to the front and ends with a death wobble. I will be calling the service manager tomorrow. I'm 50 years old and not tech oriented, but I will find someone at some point to edit the videos and help with posting them here, give me some time.

So did you note where exactly it did it? What lane, speed, tire pressures, load, etc. You will have to be able to duplicate it several times at the same spot in order to confirm it is repaired.
And if it is death wobble you can steer them just fine when it is doing it. Have done it on several trucks trying to fix them to prove it out.

 

[AH64ID]

Both pics in ALT, both bed heights the same. Pin weight is 5,700# and RAW is 9,750#. Yes even in standard ride mode mine rides lower than regular sprung trucks.

With 4200lb of truck camper in bed the Alt mode is 1-1.5 lower than the normal mode. Unloaded I don't see any difference. The one time I tried to go to Alt mode when unloaded I got a message about not enough weight to go to Alt mode. When I have been in ALT mode and then unloaded the camper I didn't get any messages.

I had to move my folks 5er yesterday and took some measurements. I'm guessing there was about 2K in pin weight, maybe a hair more.

Empty in Normal ride height: ~40.75" to the fender
Loaded in Normal ride height: ~40.25" to the fender
Loaded in ALT ride height: ~39.4 to the fender
Empty in ALT ride height: ~40.75" to the fender

So it appears that the empty height will be the same regardless, assuming a low payload. The only thing in the bed was the RVK3600.

The other day I had about 500lbs of cargo in the bed, behind the axle, and it was still too light for ALT ride height.

What I was surprised at was that even in Normal mode it drops a little for the weight, which is probably a good thing.

 

[Cummins12V98]

I am 55" to top back corner of the bed with full RAWR.

 

[DonFitzwater]

UPDATE.... I called FCA they said un able to help unless you can duplicate. Nobody was concerned with the terms, violent, hazardous, loss of control. sooooo I hooked 3 GOPRO cameras and tried and tried and yes!! I caught something today, as suspected starts in the rear works it's way up to the front and ends with a death wobble. I will be calling the service manager tomorrow. I'm 50 years old and not tech oriented, but I will find someone at some point to edit the videos and help with posting them here, give me some time.

Did you get this made into a YouTube video yet?

 

[Mike Ellis]

Had this happen in my 2nd Gen dually years ago, but just a few times. What is happening is the truck is being put into mechanical resonance by exactly the right (wrong?) set of energy inputs from the regularly spaced bumps on the road. It is generally caused by a combination of the suspension spring damping ratio, tire pressure, and the speed of the truck passing over regularly spaced bumps. The easiest way to avoid the problem is to simply change the speed on the section you encounter that has the bumps - a few miles an hour difference will solve the problem.

In my '97 I was driving on a stretch of Interstate where there were a lot of harsh expansion joints. Thump...thump...thump.... you dually drivers know the routine. It was very late at night and I was trucking along nicely when I encountered an area they had been working on. The rate of thumps changed and INSTANTLY my truck went into hysterics. It was porpoising back and forth (front-to-back bucking motion, like being on a bronc) so violently I thought my neck would snap. Launched my drink out of the cup holder, threw crap all over the cab of the truck, glove box door slammed open, all of this in literally a couple of seconds. I hit the brakes and as soon as I started slowing down the bucking died out quick. Had to stop in the next town to buy some fresh drawers and clean up my truck. It was an incredibly violent episode, you would not believe the amount of dust and dirt that got into the air from carpets in my very clean truck.

When it happens, it definitely gets your attention. For me, the few times it happened was at highway speeds and always on expansion joints -- regularly spaced thumps. I learned to pay attention to the rate of the the thumps and would slow down. The resonance is at a pretty narrow range of speeds, so you only have to slow down a few mph to prevent it.

 

[Bob4x4]

The freeway expansion joints can get bad on an empty truck with stock suspension but if the op is not exaggerating.. Expansion joints aren’t bad enough to cause a total loss of control and unable to steer

 

[smittyd174]

This is why I chose to stay leaf springs, they're simple and no guess work. Dump a load on and go and it is what it is. I thought about the air for ride quality but figured it was one less thing to break.

 

[Cummins12V98]

This is why I chose to stay leaf springs, they're simple and no guess work. Dump a load on and go and it is what it is. I thought about the air for ride quality but figured it was one less thing to break.

This is the first issue I have heard of other than sub zero ice build up on level sensors. Still I see ZERO proof it’s the rear suspension.

Mine has been 100% reliable. I give it a workout with FULL RAWR loads all the time.

 

[AH64ID]

Any updates?

The more I drive my auto-level the more I'm 110% happy I didn't get regular springs.

 

[APay18]

Any updates on aftermarket shocks for rear factory air ride? I’ve got 125k on the odo and that’s 90% towing so I think it’s time for replacements. I would really like some aftermarkets but don’t know what to purchase and I looked at the sticker on my OE shocks part# 68188465AE but can’t seem to find any?

 

[Cummins12V98]

Factory is what's available. IMHO they are a good shock. May not be the BEST but that's the way it is.

Front shocks are much more important IMHO. I put the 4600 Bilstein's on mine they helped a bit. I have ZERO ride complaints with my DRW. I fun ALT all the time.

 

[Minnow101]

And....the OP goes MIA. Gotta love it.

 

[APay18]

Cummins12V98 where did you find the rear shocks and what’s the Part #?

 

[Cummins12V98]

Cummins12V98 where did you find the rear shocks and what’s the Part #?

I did not replace mine but they should be available thru MOPAR.