Suspension for towing

[Toy Tow Denali]

We recently sold our 2015 Yukon Denali and replaced it with a 2021 Denali. We tow a heavy boat and trailer (approx 8,000 lb). the 2015 towed well, just getting too many miles. It had an air compressor which would balance the load whether the trailer was there or not. We searched for months to find a 2021 with a trailer package ( which includes a brake controller, which was a standard option on the 2015 Denali). When we hooked up the trailer to our new ride, the rear suspension sagged from the trailer weight. The 2021 only had the mag suspension (just like the 2015, but no air adjustment for load. Are there any aftermarket solutions to the problem? We may be resolved to sell the 2021 and look for some other car for towing. We like the Yukon as we live in a hot climate where stuff melts in the truck bed. Sol looking for a similar vehicle. May have to go to Ford. Kind of an oxymoron to say a vehicle has a towing package when you can't tow...

 

[StephenPT]

Why not trade it in on a Denali or AT4 w/ Air Suspension? It is an option, but not a heavily constrained one that makes it hard to find. Just do an inventory search on GMC's site. Ford Expedition has it as well, but also an option so you'll have to search for it. The additional sag you're noticing is because of the IRS on the 21+ GM SUVs versus the solid rear axle you had on your '15 (plus air suspension). The Expedition also has IRS so without air suspension it's going to sag more as well.

 

[Silverado4x4]

We recently sold our 2015 Yukon Denali and replaced it with a 2021 Denali. We tow a heavy boat and trailer (approx 8,000 lb). the 2015 towed well, just getting too many miles. It had an air compressor which would balance the load whether the trailer was there or not. We searched for months to find a 2021 with a trailer package ( which includes a brake controller, which was a standard option on the 2015 Denali). When we hooked up the trailer to our new ride, the rear suspension sagged from the trailer weight. The 2021 only had the mag suspension (just like the 2015, but no air adjustment for load. Are there any aftermarket solutions to the problem? We may be resolved to sell the 2021 and look for some other car for towing. We like the Yukon as we live in a hot climate where stuff melts in the truck bed. Sol looking for a similar vehicle. May have to go to Ford. Kind of an oxymoron to say a vehicle has a towing package when you can't tow...

Why not just add air bags to the rear, you can inflate yourself or get a compressor and just hit the button, way cheaper then trading and buying again. Here is a example but are other kits out there https://www.sdtrucksprings.com/inde...=54725&zenid=45e67b044f03f076631c964805b81d54

 

[Chad G 1979]

Are you using a weight distribution hitch? If not, that should be added. And how much sag are you talking about? Inch or 2? And that 8000 lbs is getting close to your tow limit of this vehicle depending on motor\options\etc..

 

[StephenPT]

Why not just add air bags to the rear, you can inflate yourself or get a compressor and just hit the button, way cheaper then trading and buying again. Here is a example but are other kits out there https://www.sdtrucksprings.com/inde...=54725&zenid=45e67b044f03f076631c964805b81d54

Bags are not an option on this '21+ IRS setup. The shocks go right through the coil springs, where a helper bag is also intended to go...

 

[WalleyeMikeIII]

You definitely need a weight distributing hitch if you are at 8000lbs.

2021 Trailering Guide says 8000 is max for a Yukon, 7900 for a Yukon XL. If you got the max tow.

Denali had available air suspension, but is a separate option from Max Tow package.

But, at 8000 lbs, you best have nothing much in the vehicle besides the driver, or you have likely overloaded the truck. 8000 lb trailer probably has 800-1000 lbs of tongue weight, add in a 200 lb driver, you are inching up on the 1600 lb payload of the vehicle itself.

Suggest:
- Weight distributing hitch on the boat
- Brakes are a must on the boat trailer
- Put your rig together how you normally tow and go weight it on a CAT scale.
- Use the trailering calculator in the My GMC app.

I tow a 4900 lb boat with basically no sag, but I have the air suspension

 

[Silverado4x4]

Bags are not an option on this '21+ IRS setup. The shocks go right through the coil springs, where a helper bag is also intended to go...

Yup your right that totally slipped my mind but yes the weight distribution hitch is the way to go.

 

[Toy Tow Denali]

Are you using a weight distribution hitch? If not, that should be added. And how much sag are you talking about? Inch or 2? And that 8000 lbs is getting close to your tow limit of this vehicle depending on motor\options\etc..

we don't have a weight distribution hitch for the boat. We are planning on getting an airstream trailer and will get a distribution hitch as our tows will be farther then just down to the lake. The drop is about 2 inches. I have a multi-height adjusting ball hitch to lower the trailer tongue and try and level the load, which helped a little, so weight distribution may be the only answer...

 

[Toy Tow Denali]

You definitely need a weight distributing hitch if you are at 8000lbs.

2021 Trailering Guide says 8000 is max for a Yukon, 7900 for a Yukon XL. If you got the max tow.

Denali had available air suspension, but is a separate option from Max Tow package.

But, at 8000 lbs, you best have nothing much in the vehicle besides the driver, or you have likely overloaded the truck. 8000 lb trailer probably has 800-1000 lbs of tongue weight, add in a 200 lb driver, you are inching up on the 1600 lb payload of the vehicle itself.

Suggest:
- Weight distributing hitch on the boat
- Brakes are a must on the boat trailer
- Put your rig together how you normally tow and go weight it on a CAT scale.
- Use the trailering calculator in the My GMC app.

I tow a 4900 lb boat with basically no sag, but I have the air suspension

great thoughts. Thankyou. We have a triple axle trailer with electric brakes which work through the brake controller (now an option on Denali rather than base equipment). I do need to weight both vehicles and will do next month!

 

[301Bobbo]

Why not just add air bags to the rear, you can inflate yourself or get a compressor and just hit the button, way cheaper then trading and buying again. Here is a example but are other kits out there https://www.sdtrucksprings.com/inde...=54725&zenid=45e67b044f03f076631c964805b81d54

When you go to order and update with make and model those bags are removed. IRS won't allow aftermarket bags or jounce springs. Bilstein 5100s seem to be the only option and a WDH