Zr2 front suspension

[Chuck FB]

49 minutes ago, kylant said:

the markings on the front ends of the cognito bars are identical to the factory markings. this leads me to believe they are indeed gm. i am convinced they are just a lighter rate factory bars

I had not said it in words but that was the location on the bars I was wondering about since its a tooling die stamped into the steel, what are the odds that some other company has the same dies. I assume its not stamped "GM" though or has any numbers, just the arrow and R or L ? . Now if it came packaged with the GM paper tag on it, now that would be hilarious. 

 

Do any of you even see a two wheel drive HD of the newer vintage around your areas ?. I know that is highly improbable to find up here anymore on a new lot and its not like the dealer would have a set of those in stock when they sell zero of a certain model truck.

[Chuck FB]

1 hour ago, GMCnewbie said:

I went with the new Fox 2.5 HTO shocks along with the Cognito torsion bars on my gasser.  The ride is so much better now when hitting speed bumps or anything else in the roads.  I've never used the Bilstein 5100's.  I've heard their fairly stiff which is why I didn't go with them this time around.  I had the 4600's on a pair of Rams from the factory and hated them on both trucks.  I wasn't a fan of the Fox 2.0 shocks, but they greatly improved ride quality over the 4600's on my old Power Wagon.

Is that correct that you have completed the swap and so the over all ride impression, is that with the new tire size ( which I forgot which size you were going with ) and a possible lower tire pressure being run that complements the capacity of the larger tire. Definitely a number of suspension related changes that you've done and no doubt its not easy to nail down which item had the most dramatic effect to the ride.

 

What were the 4600's doing on your Rams that you didn't like ( I had no idea what the stock shocks were on a Power Wagon ) and I've never had a ride in a friends power wagon but my brother had soon after he had bought it and he was raving about the ride and that was testing it on a horrible stretch of pavement with major frost heaves at that time and how well it was able to soak them up compared to any typical light vehicle that was considered to have a great ride.

[GMCnewbie]

19 minutes ago, Chuck FB said:

Is that correct that you have completed the swap

I completed the front swap (control arms, knuckles, differential carrier bars, torsion bars, and shocks).  I haven't completed the rear swap, yet, as I've been traveling so much for work over the last 2 months.  That combined with me being an idiot and failing to order enough LCA bolts and U-bolts to complete the jobs.  I was only able to complete one side of the rear last weekend as I mistakenly only order 2 U-bolts initially.  I've been in NYC all week for work.  I'm hoping to complete the rear-end on Sunday.

 

New wheels and tires are in my garage waiting for me to complete the full suspension swap.  I didn't want to swap wheels until I finished everything so I could get a sense of how ride felt versus stock.  I drove the truck for about a month with just the front suspension swapped and loved it.  The rear had the new shocks but nothing else.  The truck handled large dips and bumps with ease.  No more jarring rebounds or excessive bouncing.  I can now ride over decent sized speed bumps without coming to a stop first.  In short, I absolutely love the new ride.  I'm hoping the rear swap (including the Cognito leafs) will further enhance the ride quality. 

 

I will swap the wheels once I get the rear completed and ride height dialed in.  Fingers crossed that happens this Sunday.  I haven't checked the weather in Houston lately.

[Chuck FB]

59 minutes ago, GMCnewbie said:

I completed the front swap (control arms, knuckles, differential carrier bars, torsion bars, and shocks).  I haven't completed the rear swap, yet, as I've been traveling so much for work over the last 2 months.  That combined with me being an idiot and failing to order enough LCA bolts and U-bolts to complete the jobs.  I was only able to complete one side of the rear last weekend as I mistakenly only order 2 U-bolts initially.  I've been in NYC all week for work.  I'm hoping to complete the rear-end on Sunday.

 

New wheels and tires are in my garage waiting for me to complete the full suspension swap.  I didn't want to swap wheels until I finished everything so I could get a sense of how ride felt versus stock.  I drove the truck for about a month with just the front suspension swapped and loved it.  The rear had the new shocks but nothing else.  The truck handled large dips and bumps with ease.  No more jarring rebounds or excessive bouncing.  I can now ride over decent sized speed bumps without coming to a stop first.  In short, I absolutely love the new ride.  I'm hoping the rear swap (including the Cognito leafs) will further enhance the ride quality. 

 

I will swap the wheels once I get the rear completed and ride height dialed in.  Fingers crossed that happens this Sunday.  I haven't checked the weather in Houston lately.

Good to hear an update with the project as I know some were wondering what happened and as it turned out life happened, that's how things go sometimes and a project doesn't always get done in "a weekend".

 

I get the distinct feeling your factory shocks were already shot, thats pretty sad and yet that's probably been part of the issue with the ride. So far with my truck I will say its gone over speed bumps better than I had expected it would as there is some give ( 4800 bars ) and yet has not done the pogo stick reaction after going over the speed bumps. I've watched a video that a guy did with his truck with the factory shocks and then putting 5100's on I believe and he also showed the video in slow motion as he went over the exact same speed bump at the same speed and boy did that ever show how much after the bump reaction his truck had and that vastly changed after installing new shocks.

 

Isn't the weather pretty much the same most days in Houston during the summer, hot and humid

[GMCnewbie]

6 minutes ago, Chuck FB said:

Isn't the weather pretty much the same most days in Houston during the summer, hot and humid

That is correct.  But we haven't quite gotten to the always hot/humid days yet.  That usually kicks in around late May.  We're still in the rainy season right now.  

 

As for my stock Rancho shocks being blown, who knows.  They were crap from day one and replaced at only 5k miles with the Fox HTO shocks.  

 

I saw the same video you mentioned regarding the 5100 review.  It was an impressive change for sure.

[Chuck FB]

3 minutes ago, GMCnewbie said:

That is correct.  But we haven't quite gotten to the always hot/humid days yet.  That usually kicks in around late May.  We're still in the rainy season right now.  

 

As for my stock Rancho shocks being blown, who knows.  They were crap from day one and replaced at only 5k miles with the Fox HTO shocks.  

 

I saw the same video you mentioned regarding the 5100 review.  It was an impressive change for sure.

I am certainly a poor authority on weather in Houston, I drove around a ring road to bypass Houston and carry on south west and that was back in the beginning of Jan over 20 years ago. Seemed like nice weather at that moment at that time of the year. A few years later just touched on Texas by way of Guadalupe NP but was at night and Carlsbad Caverns above ground was certainly hot, thankfully NOT humid though as I would have died with the combination. I've just heard that Texas closer to the ocean can be horrible during the summer because of the humidity with the heat and desperately trying to stay under the shade of something to keep from overheating.

 

I'm sure for 2025 GM made sure to put on good Rancho shocks on my truck ( as I die laughing ! )

[Epsilon Plus]

The Fox HTO look like the ticket if they can hit a good sale. Dropping another 2k into the suspension with bars and shocks ain't in the cards until I ditch these crappy stock halogen headlights.

 

I don't haul/tow enough or have a sensitive enough arse to notice any difference with the 5100s over Rancho stock. Even on 37s on 18s @  40psi my truck still rides like a covered wagon. The wife hates riding in it. She will literally wear her drink if she tries to take a sip over anything but laser level flat pavement. One of my rear 5100s had a leak and when I sent it in for warranty I ran the spot empty, no shock for 3+ weeks and felt no difference. I chalk it up to the heavy springs not getting any compression without a significant load but who knows, maybe it is these garbage shocks 

Edited May 8, 2025 by Epsilon Plus

[GMCnewbie]

23 minutes ago, Epsilon Plus said:

The Fox HTO look like the ticket if they can hit a good sale.

They are pricey for sure.  I think i got them for $100 off from ShockSurplus.com a few months ago.  Not a great deal, but it covered the Texas sales tax.  I pulled the trigger simply because I was so fed up with how rough my ride was that I was willing to do just about anything to improve it.  My wife hated the ride as well and urged me many times to simply trade it in for something else.  I was very tempted to do it right up until I started taking the front end apart.  Carvana was offering me $70k for my truck in March which was $2k more than I paid for the truck a year ago.  The thing that kept me from selling was that Ford F250s are grossly overpriced and all of the local Ram stealerships around Houston have the worst service departments.  So I decided to tear into this truck in hopes of improving ride quality.  I'm very pleased with the initial results.  

 

Fortunately I don't have a need to max out my towing or payload capacities allowing me to run the Cognito torsion bars and leafs.  They still offer enough capacity for my needs.

[Chuck FB]

5 hours ago, Epsilon Plus said:

The Fox HTO look like the ticket if they can hit a good sale. Dropping another 2k into the suspension with bars and shocks ain't in the cards until I ditch these crappy stock halogen headlights.

 

I don't haul/tow enough or have a sensitive enough arse to notice any difference with the 5100s over Rancho stock. Even on 37s on 18s @  40psi my truck still rides like a covered wagon. The wife hates riding in it. She will literally wear her drink if she tries to take a sip over anything but laser level flat pavement. One of my rear 5100s had a leak and when I sent it in for warranty I ran the spot empty, no shock for 3+ weeks and felt no difference. I chalk it up to the heavy springs not getting any compression without a significant load but who knows, maybe it is these garbage shocks 

With those 37x12.5R18 flotation series tires and if you have little in the way of weight in the truck, while a scale would tell for sure what the axle weights are as I am guessing a bit off of my trucks weights and you would have more weight in tires. The pressures I come up with based on my axle weight guessing is that you may be able to run 30 in the front and 25 in the rear. While that may sound like a crazy low pressure it is amazing what a combination of a smaller diameter wheel along with a larger diameter and wider tire can carry at the same weight but with less pressure than the stock tires. Since you have the flotation tires your able to run them down to 25 psi on the highway as long as they are not overloaded at that pressure, if it was a metric LT tire then they stipulate 35 psi as the minimum to run at highway speed.  Something to experiment with at some point and see if it makes a noticeable difference.

[kylant]

update:
I can say the bars and the mini-packs do indeed make a significant improvement in the ride. I drove on a section of freeway yesterday where the expansion joints make for a bumpy/rough ride. the ride over this freeway is greatly improved. I can only guess it will get even better with bigger/more air volume tires as the new shocks.

 

all of my conversion parts are in, except for the 4 LCA bolts. Those are going on 3 weeks now. GM said they were in stock, the dealer says they have to source them through a 3rd party from GM ??? The dealer was going to check on them

[Chuck FB]

10 minutes ago, kylant said:

update:
I can say the bars and the mini-packs do indeed make a significant improvement in the ride. I drove on a section of freeway yesterday where the expansion joints make for a bumpy/rough ride. the ride over this freeway is greatly improved. I can only guess it will get even better with bigger/more air volume tires as the new shocks.

 

all of my conversion parts are in, except for the 4 LCA bolts. Those are going on 3 weeks now. GM said they were in stock, the dealer says they have to source them through a 3rd party from GM ??? The dealer was going to check on them

I am not surprised at your findings with those smaller bars, going from a 5600 rating for the standard duramax bars down to what certainly are smaller than 4800 bars ... "4400 yet to be determined !" rated units. That was a few months ago I saw a video from a guy in Texas who is always swapping vehicles and his also was the Duramax crew cab short box and he had already cranked up his keys to level the truck so that would not have helped the ride but then swapped in the cognito bars and set them up to the same level as he was running the same oversized tire before and after the bar swap as well. Of course this is him explaining this but he never told his wife anything about having done any changes to the truck and they went on a drive and she said what did you do to this pickup, it rides so much better !. He also mentioned that transitioning from the road into his driveway onto the cement ramp and how one front tire hits that ramp and then the other etc and how that would jar/pitch the truck, he noticed how much more compliant that was with these new bars. No doubt there is a downside and that would be some stability loss as it would not be able to track around hard turns without leaning a little, relative to the stiff stock bars.

[Epsilon Plus]

I get decent contact and tread wear with 45psi although they cup a bit from being on 18x8. A ZR2 9" with the proper offset would be much better and looks similar but I adore the Alaskans and the price was crazy right. 

 

I might go down to the 4400 bars but wonder if I'd have to run Cognito keys just to get back to stock ZR2 front height.

 

How are the mini pack leafs different from their Comfort Ride series leafs?

[GMCnewbie]

14 minutes ago, Epsilon Plus said:

 

I might go down to the 4400 bars but wonder if I'd have to run Cognito keys just to get back to stock ZR2 front height.

I initially installed the Cognito keys and reverted to stock keys as I thought the height was too much.  That was before I completed the rear swap.  Was hoping to do it tomorrow as I'm flying home right now, but I was reminded last night that tomorrow is Mother's Day.  Guess the job will have to wait until next weekend.

 

17 minutes ago, Epsilon Plus said:

How are the mini pack leafs different from their Comfort Ride series leafs?

I thought about the mini leafs but didn't want to disassemble the leafs.  So I went with the full comfort ride leafs.  Funny enough, they don't come with u-bolt mounts pre-installed.  So, I had to break apart the leafs anyway to transfer the mounts from the stock to the Cognitos.  So pick your poison I guess because you're gonna have to do some light assembly either way.

[Chuck FB]

4 hours ago, Epsilon Plus said:

I get decent contact and tread wear with 45psi although they cup a bit from being on 18x8. A ZR2 9" with the proper offset would be much better and looks similar but I adore the Alaskans and the price was crazy right. 

 

I might go down to the 4400 bars but wonder if I'd have to run Cognito keys just to get back to stock ZR2 front height.

 

How are the mini pack leafs different from their Comfort Ride series leafs?

I'd still encourage you to experiment with the tire pressures for the ride aspect, thankfully one is not married to a tire pressure and can easily be changed back and air is relatively cheap ( yet that is, if only the government could figure out how to charge us for breathing air ! ). Some tires are bad for having uneven wear on the tread blocks if its a more chunky tire tread, creating a high/low/high/low alternating messed up wear pattern on the shoulder lugs. Those types of tires need rotating often to keep that in check the best one can and my personal go to rotation pattern is the rear tires going straight to the front and the fronts get crossed when mounted to the rear ( rear wheel drive pickup that is ) 

 

A thought about swapping the bars and not sure if the current keys will work and not that I have any good answer for that either exactly but could you determine how many turns are left on the adjuster bolts. You would count the number of exposed threads and that should indicate the approximate number of turns you would additionally get out of each bolt.

[kylant]

The mini-pack replaces the thick overload on the bottom of the leaf pack. It's a multi leaf pack that is supposedly a much softer rate and eliminates the harshness. There are 2 1/2 inch blocks at the base of it that can be added or removed to adjust the right height. I left one of the blocks in and my truck netted 1.5 inches of rear lift.

 

I am pretty sure I'm going to have to run the Cognito keys with the torsion bars and the other lift components. I think the adjuster bolts are getting close to being maxed out. i'll see you when I get all put together. At least swapping keys is pretty easy, except for when the unloading tool falls off the crossmember, hits your head, and then you need to go get a few stitches. don't ask me how i know