What's new
By:
Ram Heavy Duty Forum

Register a free account today to become a member! Once signed in, you'll be able to participate on this site by adding your own topics and posts, as well as connect with other members through your own private inbox!

Thuren Leveling Kit - Worse than stock what could be the issue?

ClawSS said:
My hemi rides rough...rougher than any diesel I have ridden in. I'm Thuren 2" with softrides in the back on thick 37's running just 35lbs in the back. Thing will bounce you off the back seat after a bridge approach and then proceed to bounce 3 times as it settles down. I have new Fox 2.5 adjustibles in the back to soften it but they didn't help. Rear trackbar solved the rear from wandering, but no help on the bump and bounce.
Everything on the road is felt in your torso. I have a thread somewhere on here. I've given up (FYI).
Click to expand...
That sucks…. I have a 3500 diesel with Carli 3.25 off road lift, track bar, sway bar, rear add a pack, 37s on 20” wheels, 65r psi and it rides smooth. I can hit bridge expansion joint at 75 and it still is smooth. Is it possible that 35lbs is too low making the truck bounce?
 
phatboy64 said:
That sucks…. I have a 3500 diesel with Carli 3.25 off road lift, track bar, sway bar, rear add a pack, 37s on 20” wheels, 65r psi and it rides smooth. I can hit bridge expansion joint at 75 and it still is smooth. Is it possible that 35lbs is too low making the truck bounce?
Click to expand...

Probably the difference in the 2500 vs 3500 rear suspension.

His 37’s can hold a RAW of 4,190 lbs at 35 psi.. so unless he’s got a bit of payload that’s plenty of pressure.
 
You need to do the rear also, that’s the biggest culprit on our trucks. I have a hemi also with the same level but have also done front sway, rear springs (mid rate), rear shocks and front and rear track bars. Wasn’t cheap but am quite happy. Actually enjoy my truck. Probably would have traded it had I not gone this route.

And lastly yes tire pressure. Get the OBD2 tool to reset your tpms thresh holds.
 
I'll mention a few things having a lot of stuff on my truck, but also mix and matched if you look at my signature line.

1st off some of what you describe sounds like blown shocks or badly mismatched shocks. Did you do all 4 corners with IFP 2.0s or just the fronts ? Are any of your shocks leaking oil or showing other signs of a seal blowout/failure ? Unfortunately I've heard of more and more 2.0 IFP's not lasting very long and folks swapping them out for 5100's if they don't want bigger badder shocks. I've run both and the 5100s have a more "sporty" feel being digressively valved, but they seem to hold up quite well if you don't abuse them. I wonder if this was some of the driver behind Carli ditching Fox for their own in-house shocks on anything that isn't a Pintop/Dominator (Kings).

2nd, IMO, the springs and shocks are not the end all be all of making these HD trucks ride well. Admittedly I'm far more focused on the Diesel's, but being that its the same platform the only real difference is engine weight which can be accounted for with Spring/Shock tuning. I'm going to list below the modifications, in my opinion, in the order of importance for improving the street ride of these trucks (Excluding Tires/Air Pressure) :

  1. Front Swaybar - Doesn't matter if its a Thuren or Carli get which ever you can find the best deal on. The stock front sway bars are far too stiff unless you're running an in-bed camper or some sort of tall service body with a high center of gravity.
  2. Thuren Rear Trackbar - The factory rear trackbar geometry is garbage IMO. The 3500 guys don't have this problem being on leafs instead of a 5 link with coils, but us 2500 guys do. CJC has a good video on this, but doing a Thuren rear trackbar makes a notable difference in the ass end of these trucks for stability.
  3. Front Trackbar (If worn out) - If the front trackbar is starting to wear out you'll notice slop in the steering along with the front axle being able to shimmy around. Imo the front trackbar is ok until you lift a bit or your stocker is worn out. Since you've already got Thuren front springs, I would go with Thuren's bar.
  4. Springs/Shocks - Having the right spring rate for your needs/application is very important as is having the right sort of shock/shock valving/tuning for the application. I do like how my Thuren fronts ride with my Fox 2.0 w/Reservoirs for the most part, however, I know I'll be going to King's with Stage 2 Valving for what I really like/want out of the ride. In the rear you'll notice that I have the Carli R2 springs instead of the Thuren softies or the stock springs and I actually got the matching set of Carli Fox 2.0s with Resi's so that I have shocks that are valved for the springs. The Carli R2 springs help considering I wanted to keep rake empty, but I also have weight back there with my diamondback HD, tools, etc. They're softer than the stock springs, have better travel characteristics for off the pavement, and still let me tow/haul the things one would sanely tow given the 2500 CTD configurations lower payload.
  5. Control Arms/Radius Arms/etc. - For the street I think the Carli radius arms are the best option given they have a tight joint instead of a rubber bushing like stock. They'll allow the axle movement while staying tight and not binding up like a stock rubber bushing can. Running my metalcloak 2 piece arms I actually get some movements that some might not like for the street given the axle is allowed to more easily flex/move, however, I love them on poorly maintained back dirt roads or going out into the field. For the rear control arms I really don't think you need to replace them unless you want more flex offroad and the metal cloak units look good for that. I'll either add them to my setup later on or go with the yet to be released Thuren rear control arm setup w/King 3.0 shocks (Assuming I go with King 3.0's upfront).
 
I also have the Thuren 2” leveling on my 2500 Hemi thinking it would soften the ride. My wife has scoliosis and it still rides rough feeling every bump and she suffers almost wanting to follow me with her own car. Would the Thuren front sway bar soften the jarring bumps? I don’t expect the 2500 to ride like my previous 1500 but would spend the money if it made a noticeable difference. I have my continental stock size tires at 55 psi. I would get a 1500 but I tow and love this 2500. Thanks
 
HEMIDUTY said:
I also have the Thuren 2” leveling on my 2500 Hemi thinking it would soften the ride. My wife has scoliosis and it still rides rough feeling every bump and she suffers almost wanting to follow me with her own car. Would the Thuren front sway bar soften the jarring bumps? I don’t expect the 2500 to ride like my previous 1500 but would spend the money if it made a noticeable difference. I have my continental stock size tires at 55 psi. I would get a 1500 but I tow and love this 2500. Thanks
Click to expand...

If you want to "see" how it would feel with a softer swaybar disconnect the end links and take it for a drive around the block.
 
HEMIDUTY said:
I also have the Thuren 2” leveling on my 2500 Hemi thinking it would soften the ride. My wife has scoliosis and it still rides rough feeling every bump and she suffers almost wanting to follow me with her own car. Would the Thuren front sway bar soften the jarring bumps? I don’t expect the 2500 to ride like my previous 1500 but would spend the money if it made a noticeable difference. I have my continental stock size tires at 55 psi. I would get a 1500 but I tow and love this 2500. Thanks
Click to expand...

Is it the larger bumps or the small bumps ? Small bump compliance is going to be mostly down to tire selection/size/pressure as articulated by Carli in this article.

www.carlisuspension.com

Tires and Wheels: How Do They Affect My Ride?

If you're looking for the cliff notes: 17"/18" wheels, 35"-37" tires and inflate them in accordance to THEIR load curve (40-45PSI Front, 35-40PSI Rear), not the factory tire's load curve to which most factory TPMS Systems are set. If you're going to run 20" wheels, stick to 37" MT tires as...
www.carlisuspension.com www.carlisuspension.com

That said just like @werard mentioned you can disconnect the front sway bar to get an idea of how much the sway bar is influencing your ride quality. The Thuren swaybar was the 1st thing I installed on my truck 100% stock and it did make a notable difference to overall ride, but it wasn't until I swapped the stock 20s for 18s and went to 315/70R18's at much lower pressures that I got the small bump compliance I was looking for.
 
I’ll disconnect the sway bar and give it a try. Certainly an easy option before dropping some coin, appreciate the feedback!
 
Also you could have the wrong psi in the suspension. Have you checked what it's set at? I had to add to my Kings and take away from my fox shocks. Just a thought. I know on my 2500 diesel it was a dramatic improvement.

I do run my tires at 47psi
 
waveslayer said:
Also you could have the wrong psi in the suspension. Have you checked what it's set at? I had to add to my Kings and take away from my fox shocks. Just a thought. I know on my 2500 diesel it was a dramatic improvement.

I do run my tires at 47psi
Click to expand...
His 2.0 shocks are sealed with correct pressure from factory. Different from your King Shocks.
 
waveslayer said:
Also you could have the wrong psi in the suspension. Have you checked what it's set at? I had to add to my Kings and take away from my fox shocks. Just a thought. I know on my 2500 diesel it was a dramatic improvement.

I do run my tires at 47psi
Click to expand...
Changing the nitrogen pressure in the shocks is not the correct way to stiffen/soften the shocks.
 
Where is the physical 2500 Ram Hemi suspension support group located and how do I sign-up? I'd love to get together with those with Mega Hemis and see if we just are forced to suffer the ride.
I cannot debate that it could be Load Range E Falkens and no weight (but a 37" spare) in the bed. Ramboxes weight more too which is why my "soft ride" Thuren rear springs only gave me .5" of lift instead of the advertised 1".

Maybe I can find a 1000 lb slab of plate steel to drop in the back and spacer up the rear springs (Thuren spacers) to get back non-squat. I'd just need a 6x4 x1" thick sheet in the bed.
 
ClawSS said:
Where is the physical 2500 Ram Hemi suspension support group located and how do I sign-up? I'd love to get together with those with Mega Hemis and see if we just are forced to suffer the ride.
I cannot debate that it could be Load Range E Falkens and no weight (but a 37" spare) in the bed. Ramboxes weight more too which is why my "soft ride" Thuren rear springs only gave me .5" of lift instead of the advertised 1".

Maybe I can find a 1000 lb slab of plate steel to drop in the back and spacer up the rear springs (Thuren spacers) to get back non-squat. I'd just need a 6x4 x1" thick sheet in the bed.
Click to expand...
Without knowing what air pressure you're running in those tires it could be tire related for sure. The .5" lift with the Thuren softies is likely going to be down to the fact that megas are heavier and the extra weight of the Ramboxes - That's why I went with Carli R2's for my truck/usage. I was tempted to try the Thuren's with spacers and airbags, but eh I think the Carli springs ride just fine for me compared to the stockers.

The best place to start for tires is going to be looking at tire inflation load tables and then adjust from there doing a chalk test :

www.4wheelparts.com

How To Find The Right Tire Pressure For Your 4x4 Using Chalk - The Dirt by 4WP

Improve Fuel Economy, Tire Life, Traction And Vehicle Ride With Proper Tire Pressure
www.4wheelparts.com

I'll give you a good example. Typically I run 40/35 F/R empty on my 315/70R18 Toyos (36x13) and 45/45 when I'm towing or hauling something that's got some heft to it. Last time I had an alignment the guys inflated them to their side wall pressure of 65PSI (E2) and you could feel every last bump in the road and the truck just rode like horrid garbage as if I had flintsone rocks for tires. Stopped at a gas station and dropped my pressures ... back to riding great. Now being that I have a CTD I'll need higher pressures upfront than you Hemi guys, but there is a lot of ride quality in the tire pressure.

For comparison I had a 1500/5.7 that was setup for offroad fun stuff at one point with Kings, control arms, the works - ridding on 315/70R17 Load Range C2 Toyos. That truck was running something like 28F/25R most of the time empty to get a good ride. Most folks would say those pressures are far too low, but looking at the load tables and doing a chalk test it was 100% on point for that lighter truck and what it was used for.

Lastly you really want to ensure your nitrogen charge is at the right value and check it fairly regularly - Shock Surplus suggests every 10K miles for 100% street use on Foxes. I've also had Kings in good health leak a little PSI if I was beating on them so it's just one of those things.
www.shocksurplus.com

FOX Won't Warranty Your Shocks? Here's the Solution.

You spent a good deal of money on some high performance Fox shock absorbers, expecting them to last a good amount of time. Even if they don't last 5-6 years, you expect them to at least make it 1 or 2 years without problems. Unfortunately that’s not the case sometimes, and we frequently have...
www.shocksurplus.com www.shocksurplus.com
 
ClawSS said:
Where is the physical 2500 Ram Hemi suspension support group located and how do I sign-up? I'd love to get together with those with Mega Hemis and see if we just are forced to suffer the ride.
I cannot debate that it could be Load Range E Falkens and no weight (but a 37" spare) in the bed. Ramboxes weight more too which is why my "soft ride" Thuren rear springs only gave me .5" of lift instead of the advertised 1".

Maybe I can find a 1000 lb slab of plate steel to drop in the back and spacer up the rear springs (Thuren spacers) to get back non-squat. I'd just need a 6x4 x1" thick sheet in the bed.
Click to expand...
I know mine is a little different because I have a 3500 but I also am running the FalKen Wildpeek 37” on 20”s and run 65 psi all around.
 
I don’t tow or haul anything and run 35/40 front rear. Avg about 30k miles per year. Just a daily driver that runs empty all the time.
And I am running adj. Fox 2.5's in the back that I thought would help, but barely a difference....although I can make it ride harder.

Thanks @KLSU for confirming that I'm not the only one that is less comfortable than expected. I would have thought I could have glided over road pebbles with low pressure 6"+ sidewalls even if Load Range E....
 
Last edited:
This Thuren's response to me after them requesting pictures of my install and questions about the Sway bar:

I would recommend letting more air out of the tires. Go 40psi in front and 35psi in the rear. Hemi truck is much lighter and thus doesn't need as much air.

Sway bar would also improve ride quality and would be worth doing next. Install photos look great and I'm not sure why specifically your ride quality hasn't improved. I suppose ride quality is a bit subjective so it's hard to translate the difference in feel via text.

Let me know if you have further install questions regarding the sway bar. Indeed it is very straight forward.
Click to expand...

Pretty much what everyone on this board is saying.. I'll buy the Sway bar later this year and after looking at install videos seems pretty easy to install myself.
 
Last edited:
You must log in or register to reply here.
Back
Top