Help to get Smoother Ride for 03 Crew Cab - Chevy and GMC Duramax Diesel Forum
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post #1 of 23 (permalink) Old 01-06-2020, 11:59 PM Thread Starter
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Help to get Smoother Ride for 03 Crew Cab

The 03 2500HD has 5100 Bilsteins and is leveled with Cognito keys. I’m running 285/70-17’s. Everything else is stock. I understand that a 2500HD truck isn’t going to ride like a luxury sedan. But, would like to invest to get it as comfortable and smooth as possible both without load and with load (I tow a fully loaded 24’ Toyhauler).

I’ve read that installing bags in the rear helps under load. Do the Sulastic Shackles help (with or without load)? What else should I do? If needed, I would also consider removing the cognito keys. Your help is greatly appreciated.
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post #2 of 23 (permalink) Old 01-07-2020, 05:37 AM
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New rear cab mounts made a quite a bit of difference in mine.


GM part # 25994881
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post #3 of 23 (permalink) Old 01-07-2020, 05:39 AM
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Saying that your truck is leveled, I want to see the front end geometry to see how bad your angles are. That will tell a lot, and I would guess that your front end it cranked up too high and contributing to your harsh ride. Realistically it shouldn't need turned up a whole lot to clear 285/17s but I also realize that each truck has its own quirks and whatnot. I have 305/65/17s on my 2002 and have no rubbing at ride height and with the front end fully dropped for sled pulling. So, lets see what your angles look like and we can go from there
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TRADED - 2002 2500HD Crew Cab Long Bed
SOLD - 2001 2500HD Ext. Cab Long Bed
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post #4 of 23 (permalink) Old 01-07-2020, 08:45 AM Thread Starter
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Quote:
Originally Posted by 77cruiser View Post
New rear cab mounts made a quite a bit of difference in mine.

https://www.youtube.com/watch?v=wJtHepnjGQs

GM part # 25994881
Thanks, I'll take a look at the cab mounts.
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post #5 of 23 (permalink) Old 01-07-2020, 09:04 AM Thread Starter
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Quote:
Originally Posted by DMAXfirefighter View Post
Saying that your truck is leveled, I want to see the front end geometry to see how bad your angles are. That will tell a lot, and I would guess that your front end it cranked up too high and contributing to your harsh ride. Realistically it shouldn't need turned up a whole lot to clear 285/17s but I also realize that each truck has its own quirks and whatnot. I have 305/65/17s on my 2002 and have no rubbing at ride height and with the front end fully dropped for sled pulling. So, lets see what your angles look like and we can go from there
Thanks for helping. Not exactly sure what pics work best to help see this so here's a few to start. I can take more if needed. Please just tell me what else you need to see.
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post #6 of 23 (permalink) Old 01-07-2020, 09:06 AM Thread Starter
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Just FYI....the pics are as follows - Full View side of truck, Side View of Front Passenger Wheel Well, Front Passenger Suspension Front View, Front Passenger Suspension Rear View
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post #7 of 23 (permalink) Old 01-07-2020, 09:41 AM
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Now this is me-some people will disagree, some will probably jump me, some will agree. I've had my 02 cranked way high, cranked up just a little, not cranked at all (cv angles parallel with ground), and lowered. I am going to tell you your front end is too high and that's where your harsh ride is coming from. Your cv angles aren't the most extreme I've seen, but they aren't great.

The torsion bars raise the truck the more they are twisted. As you raise the truck, you basically twist the bar harder to overcome the weight more. As you do this, you also lose the give of the 'spring' to absorb the bumps and imperfections of the road. If you lower the front down, and make the cv's and control arms more parallel with the ground instead of angling down, it will give the torsion bar more ability to absorb and dampen the bumps. Yes, the shocks absorb the impacts, but if the torsion bar 'spring' is too stiff to give, then the shocks can't do much.

The rear is going to be kinda stiff with no load, but its not horrible. The airbags are made to help support the load if you have too much squat when the weight of the toyhauler is on. I've not personally used the sulastic shackles, but have heard positive about them-several on here.

Like I said, there are people who will agree with my words, and there are people who will disagree. And part of what we can't tell is if the harshness you are talking about is from the front or the rear. But coming from a guy who has had seven different classic-body trucks on all levels except completely slammed on the ground all the way around, that is what advice I can give you

Name: Matt
ASE Certified, former GM Parts guy
John Deere Service Manager

Play Truck - 2002 LB7 2500HD Crew Cab Short Bed
Daily/Tow Rig - 2006 LLZ 2500HD Crew Cab Short Bed

SOLD - 2007 LBZ 2500HD Standard Cab Long Bed
SOLD - 2006 LBZ 2500HD Crew Cab Short Bed
SOLD - 2004 LLY 2500HD Crew Cab Long Bed
TRADED - 2002 2500HD Crew Cab Long Bed
SOLD - 2001 2500HD Ext. Cab Long Bed
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post #8 of 23 (permalink) Old 01-07-2020, 09:48 AM Thread Starter
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Quote:
Originally Posted by DMAXfirefighter View Post
Now this is me-some people will disagree, some will probably jump me, some will agree. I've had my 02 cranked way high, cranked up just a little, not cranked at all (cv angles parallel with ground), and lowered. I am going to tell you your front end is too high and that's where your harsh ride is coming from. Your cv angles aren't the most extreme I've seen, but they aren't great.

The torsion bars raise the truck the more they are twisted. As you raise the truck, you basically twist the bar harder to overcome the weight more. As you do this, you also lose the give of the 'spring' to absorb the bumps and imperfections of the road. If you lower the front down, and make the cv's and control arms more parallel with the ground instead of angling down, it will give the torsion bar more ability to absorb and dampen the bumps. Yes, the shocks absorb the impacts, but if the torsion bar 'spring' is too stiff to give, then the shocks can't do much.

The rear is going to be kinda stiff with no load, but its not horrible. The airbags are made to help support the load if you have too much squat when the weight of the toyhauler is on. I've not personally used the sulastic shackles, but have heard positive about them-several on here.

Like I said, there are people who will agree with my words, and there are people who will disagree. And part of what we can't tell is if the harshness you are talking about is from the front or the rear. But coming from a guy who has had seven different classic-body trucks on all levels except completely slammed on the ground all the way around, that is what advice I can give you
Thanks for the quick and insightful suggestions/recommendations. Just out of curiosity, if I replaced the UCA's with Cognito UCA's would that help or will is it still recommended to adjust the torsion bars regardless? I would prefer not to lose the level it currently has but if lowering the front is the only way to dramatically improve the ride, then that's what I'll do.
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post #9 of 23 (permalink) Old 01-07-2020, 10:48 AM
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Quote:
Originally Posted by Cm3dmax View Post
Thanks for the quick and insightful suggestions/recommendations. Just out of curiosity, if I replaced the UCA's with Cognito UCA's would that help or will is it still recommended to adjust the torsion bars regardless? I would prefer not to lose the level it currently has but if lowering the front is the only way to dramatically improve the ride, then that's what I'll do.
That in itself will not improve the ride quality. I have them on my 02, what they do more than help the ride is help correct geometry issues when the front is cranked a lot like yours. Yes, it can help some because with their design you can bolt the ball joint in on top of the control arm or below the control arm. If you bolt them in below, it helps raise the front of the truck, and you could then potentially lower the torsion bars down some and keep your current ride height. So I guess its kind of a yes-and-no-possibly kind of answer.

I swapped to the Cognito UCAs for a couple different reasons. I was doing a complete front end rebuild, they have a separate serviceable ball joint that is easily replaceable, and it helps correct alignment issues. But also when I did this rebuild, when everything came back together, I set the front end lower than before the rebuild. I went from cranked really high to being just a touch above having the cv axles parallel with the ground.
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Name: Matt
ASE Certified, former GM Parts guy
John Deere Service Manager

Play Truck - 2002 LB7 2500HD Crew Cab Short Bed
Daily/Tow Rig - 2006 LLZ 2500HD Crew Cab Short Bed

SOLD - 2007 LBZ 2500HD Standard Cab Long Bed
SOLD - 2006 LBZ 2500HD Crew Cab Short Bed
SOLD - 2004 LLY 2500HD Crew Cab Long Bed
TRADED - 2002 2500HD Crew Cab Long Bed
SOLD - 2001 2500HD Ext. Cab Long Bed
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post #10 of 23 (permalink) Old 01-07-2020, 10:59 AM Thread Starter
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Quote:
Originally Posted by DMAXfirefighter View Post
That in itself will not improve the ride quality. I have them on my 02, what they do more than help the ride is help correct geometry issues when the front is cranked a lot like yours. Yes, it can help some because with their design you can bolt the ball joint in on top of the control arm or below the control arm. If you bolt them in below, it helps raise the front of the truck, and you could then potentially lower the torsion bars down some and keep your current ride height. So I guess its kind of a yes-and-no-possibly kind of answer.

I swapped to the Cognito UCAs for a couple different reasons. I was doing a complete front end rebuild, they have a separate serviceable ball joint that is easily replaceable, and it helps correct alignment issues. But also when I did this rebuild, when everything came back together, I set the front end lower than before the rebuild. I went from cranked really high to being just a touch above having the cv axles parallel with the ground.
This is extremely helpful. Thanks so much. I may try swapping the Cognito UCA's, bolt the ball joint below the control arm and then adjust the torsion bars accordingly to get the cv axles as parallel to the ground as possible. Based upon what you mentioned, this may still give me some leveling but also should correctly align the CV axles to give a much better ride. Let me know if I misunderstood.
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