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Well my family and I got ready to take our maiden voyage with our new popup camper today. But I had to scrub the mission just as we were leaving because the rear axle appeared to be sagging very noticeably. Needless to say the kids were not happy with me. I just didnt feel comfortable with the setup if I couldnt explain why. Disclaimer that I have never towed before.

The rear looked to have about 2 inches of clearance and the front looked to have about 5 inches. It looked bad. At least to me. I didnt have the foresight to take a photo because I was feeling a bit overwhelmed. ;) I was expecting a slight dip but not that much. Whats more, when i disconnected the trailer it still appeared to be sagging. Not as extreme, but not level either.

Yesterday I took my camper to a Cat Scale to weight it. I loaded the camper with full water and 90% of all our gear. It was just me, 35 lb of tools, and 40 lb of car seats in the car. nothing else. Below are the specs for my Ascent, the camper, and the weigh results.

Subaru Ascent Limited 7 Passenger
GVWR: 6000 lb
GAWR (Stated with 20" stocks wheels, But I have 18" liquid metal shadows and Michelin Defenders)
F: 3021 lb
R: 3296 lb
Max Cargo: 1158 lb

Forest River Rockwood 2318G
GVWR: 3263 lb
Tongue Weight: 400 (I weighed the tongue with a Sherline scale before I left to Cat Scale)

Cat Scale Weights
Steer Axle: 2400 lb
Drive Axle: 2820 lb
Trailer Axle: 2560 lb
Total Axle: 7780 lb

Before we left for our camping trip I added the following weight...
To the camper: I added 100 lb of more gear to the rear
To the car: 4 more passengers totaling 233 lb, 110 lb of gear in the rear (pillows, cooler)

I feel like that's within tolerable limits for the Ascent. Am I missing something?

Has anyone else experienced this? Or have any helpful knowledge?
 

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The rear will compress a couple of inches at full or near full tongue weight. The Ascent is supposed to carry the bulk of the weight on the rear, so, that's nornal. It's also why the Ascent has a higher GAWR-R rating, even though at the curb weight, it's front weight biased at 54%/46%.

Do remember that the tongue weight comes off your cargo weight. Your Ascent cargo weight is on the sticker on the Driver's side B-Pillar. Subtract your tongue weight to determine the total weight available for passengers and cargo.

We pack most of our stuff in the trailer when we have a full passenger complement onboard the car.

Here's my heaviest tow, at really near trailer GVWR of 4,395 pounds. We have a tandem axle, so, our tongue weight is lower than on a single axle of the same weight.

Regardless, note the rear squat.
4387


Different day, same loading...
4388
 

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Has anyone had better experience and less sag after a lift? I was looking at the Primitive site and they said, "The rear springs are up-rated to not only improve HANDLING but to allow greater loads with less sag." I'm wondering if this is true?
 

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Has anyone had better experience and less sag after a lift? I was looking at the Primitive site and they said, "The rear springs are up-rated to not only improve HANDLING but to allow greater loads with less sag." I'm wondering if this is true?
Greater loads:
On a technical level, sure.

On a real world level, concerning allowing greater loads, absolutely not. It's illegal to exceed GAWR-R, or GVWR, no matter what springs you use. And, the Ascent springs will properly carry full GAWR-R or full GVWR.

It may make handling such loads a bit more or less comfortable, depending on what suspension feel you prefer.

Improved handling:
For most on road use, probably. For off roading, it may make things bumpier due to being stiffer.
 

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Sounds like you are well within the limits and have nothing to worry about! Sorry you missed your first trip because of it too.

Here is my Ascent with load of 4,780lbs. Rear wheel and front wheel clearances seem to match yours. No problem at all towing this load.

 
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Nope. Not to date. And you WANT some rear squat (to the Ascent's load limits, or less) - (what you want is the rear to be able to compress without bottoming due to load, instead of being stiff and becoming a fulcrum). Without it, the rear becomes a fulcrum sooner than later, lifting the front. The front weighs more than the rear, which counterbalances tongue/rear cargo weight. That pushes the fulcrum effect farther out. The springs giving, push the fulcrum effect farther out. Making the rear stiffer makes it act more like a fulcrum at different loads. So, it's a tricky thing.
 

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I disagree Rob Mauro's technical assessment. I ran rear air shocks on mid '90s V8 AWD Ford Explorer (towing cap 7500 lb). Hooked up the trailer then leveled the Explorer. By stiffening up the rear suspension with the added load, the front and rear suspension were balanced over bumps and undualtions, the rear end didn't bob up and down, and handling was improved. Of course there was no artificial stability augmentation like what's more common now, the operation of which might be compromised in some way by air suspension it wasn't designed or tested to accommodate.
 

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Right, but the Ascent rear doesn't bob up and down. Otherwise, I'd agree. I was addressing the specific question as it pertains to the Ascent. There are no air bags available, and the only available shock options (to date) make things stiffer, which has a varying degree of advantage, depending on weight. Less weight, worse outcome and higher lever action off the bat. More weight, and simply a stiffer ride, but, no affect on the undulation that doesn't exist on the Ascent.

So, we're not disagreeing. I'm being Ascent specific. ;)

What I want is an adjustable suspension for the Ascent. I am still working on that, whether bags, shocks, air, etc. That MAY satisfy all ends of the towing weight spectrum.

I disagree Rob Mauro's technical assessment. I ran rear air shocks on mid '90s V8 AWD Ford Explorer (towing cap 7500 lb). Hooked up the trailer then leveled the Explorer. By stiffening up the rear suspension with the added load, the front and rear suspension were balanced over bumps and undualtions, the rear end didn't bob up and down, and handling was improved. Of course there was no artificial stability augmentation like what's more common now, the operation of which might be compromised in some way by air suspension it wasn't designed or tested to accommodate.
 

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Well my family and I got ready to take our maiden voyage with our new popup camper today. But I had to scrub the mission just as we were leaving because the rear axle appeared to be sagging very noticeably. Needless to say the kids were not happy with me. I just didnt feel comfortable with the setup if I couldnt explain why. Disclaimer that I have never towed before.

The rear looked to have about 2 inches of clearance and the front looked to have about 5 inches. It looked bad. At least to me. I didnt have the foresight to take a photo because I was feeling a bit overwhelmed. ;) I was expecting a slight dip but not that much. Whats more, when i disconnected the trailer it still appeared to be sagging. Not as extreme, but not level either.

Yesterday I took my camper to a Cat Scale to weight it. I loaded the camper with full water and 90% of all our gear. It was just me, 35 lb of tools, and 40 lb of car seats in the car. nothing else. Below are the specs for my Ascent, the camper, and the weigh results.

Subaru Ascent Limited 7 Passenger
GVWR: 6000 lb
GAWR (Stated with 20" stocks wheels, But I have 18" liquid metal shadows and Michelin Defenders)
F: 3021 lb
R: 3296 lb
Max Cargo: 1158 lb

Forest River Rockwood 2318G
GVWR: 3263 lb
Tongue Weight: 400 (I weighed the tongue with a Sherline scale before I left to Cat Scale)

Cat Scale Weights
Steer Axle: 2400 lb
Drive Axle: 2820 lb
Trailer Axle: 2560 lb
Total Axle: 7780 lb

Before we left for our camping trip I added the following weight...
To the camper: I added 100 lb of more gear to the rear
To the car: 4 more passengers totaling 233 lb, 110 lb of gear in the rear (pillows, cooler)

I feel like that's within tolerable limits for the Ascent. Am I missing something?

Has anyone else experienced this? Or have any helpful knowledge?
Right, but the Ascent rear doesn't bob up and down. Otherwise, I'd agree. I was addressing the specific question as it pertains to the Ascent. There are no air bags available, and the only available shock options (to date) make things stiffer, which has a varying degree of advantage, depending on weight. Less weight, worse outcome and higher lever action off the bat. More weight, and simply a stiffer ride, but, no affect on the undulation that doesn't exist on the Ascent.

So, we're not disagreeing. I'm being Ascent specific. ;)

What I want is an adjustable suspension for the Ascent. I am still working on that, whether bags, shocks, air, etc. That MAY satisfy all ends of the towing weight spectrum.
Well my family and I got ready to take our maiden voyage with our new popup camper today. But I had to scrub the mission just as we were leaving because the rear axle appeared to be sagging very noticeably. Needless to say the kids were not happy with me. I just didnt feel comfortable with the setup if I couldnt explain why. Disclaimer that I have never towed before.

The rear looked to have about 2 inches of clearance and the front looked to have about 5 inches. It looked bad. At least to me. I didnt have the foresight to take a photo because I was feeling a bit overwhelmed. ;) I was expecting a slight dip but not that much. Whats more, when i disconnected the trailer it still appeared to be sagging. Not as extreme, but not level either.

Yesterday I took my camper to a Cat Scale to weight it. I loaded the camper with full water and 90% of all our gear. It was just me, 35 lb of tools, and 40 lb of car seats in the car. nothing else. Below are the specs for my Ascent, the camper, and the weigh results.

Subaru Ascent Limited 7 Passenger
GVWR: 6000 lb
GAWR (Stated with 20" stocks wheels, But I have 18" liquid metal shadows and Michelin Defenders)
F: 3021 lb
R: 3296 lb
Max Cargo: 1158 lb

Forest River Rockwood 2318G
GVWR: 3263 lb
Tongue Weight: 400 (I weighed the tongue with a Sherline scale before I left to Cat Scale)

Cat Scale Weights
Steer Axle: 2400 lb
Drive Axle: 2820 lb
Trailer Axle: 2560 lb
Total Axle: 7780 lb

Before we left for our camping trip I added the following weight...
To the camper: I added 100 lb of more gear to the rear
To the car: 4 more passengers totaling 233 lb, 110 lb of gear in the rear (pillows, cooler)

I feel like that's within tolerable limits for the Ascent. Am I missing something?

Has anyone else experienced this? Or have any helpful knowledge?
I'm getting a lot of rear sag as well when towing. The car still handles fine, but tire wear is a big issue. When the rear suspension sags, the rear wheels bow out at the bottom and cause excessive wear on the inside corner of the tires. I found this out the hard way when I got a flat tire on a road trip. The rear tires looked fine from the outside, but had totally worn through on the inside corner to the point that the steel bands were poking out like porcupine spines. I'm going to increase rear tire pressure to see if that helps, but stiffening the suspension is probably a better solution.
 

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Increasing the air pressure will increase the wear down the center of the tire so its actually going to effectively reduce the amount of tread contact with the pavement. If you tow that extensively you might need to get your alignment reset before travel by loading the cargo compartment to get equivalent rear drop as when loaded for towing.
 
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