Need Suspension Advice with Truck Camper and Timbren's on 3" TRD lift

UPDATE: I called Slee Off Road here in Colorado and Exit Off Road in Florida. They know each other and both said good things about each other lol. Slee said they don't have a lot of parts in yet for the new Tundra but said that Exit is trustworthy and Dobinson Springs are trustworthy but their other products are Chinese made. With that said, I've ordered Dobinson 770 lb springs to add to the rear and will be removing the spacer (like @Yaboy mentioned in the first response on this thread). These should do the trick along with the Timbren's. I'm going for a zero maintenance option but if this somehow doesn't make me 1000% happy, I'll be sending the Timbren's back and replacing with Loadlifter 5000 Airbags as a last resort. With those, I'd be installing on board air and hopefully find a way to make one of the open switches below the climate control into a height adjuster switch. It would be awesome to be able to adjust the rear height with each load for comfort and stability

ORIGINAL POST:
2022 Tundra with TRD 3” lift. Truck sags with minimal weight compared to my Tacoma (even without airbags) with the same camper. Tacoma had Firestone Ride Rites and E-trailer sold me on the Timbrens but I’m not sure they work. Truck still sags even after the “engineers” at Timbren sent me an additional 3” spacer. My concern is the steel spacer is limiting my up travel now. It prevents some sag but the truck leans back quite a bit on a slight hill and it feels bouncy in the rear on certain bumps.

 

You need some heavy coils that add lift in the rear and not a spacer, there are lots to choose from

 

Those only go up to 2" that I'm seeing and mine is 3". I did find a 2.5" option but am curious if that would be too much lift for my rear shocks. Dobinson has a spring rated for 770lbs in the rear and my camper weighs 750 dry. Those could work but don't want the ride to be too stiff when unloaded. I remember having 400 lb springs on the front of my Tacoma and it was way too stiff once I removed the steel front bumper.

In the end, I'm thinking airbags will suit me best because I can adjust for being loaded vs unloaded and maintain the ride quality. Higher cost is the downside.

 

3” spacer on the springs? Or a 3” spacer on the bump stop as seen in picture. The trd lift is 2” rear and you can get a nice 2” lift rear coil and pick weight to suit.

 

Looks like a ~2" spacer on the Timbrens, not the springs. And you're right the rear is 2" so I'm wondering if I could get a 2.5" Dobinson to make up for it or should I go with a 2" Dobinson rated for like 770lbs? Problem with that would be that the rear would then be super stiff in the rear when unloaded.

 

It may also be that you have more weight behind the rear axle. The extra weight would lift the front axle up making the the truck look lower in the rear. The Timbren's should provide a stiff connection between the axle and the frame. With mine they come in contact at about a 1" drop and then you can feel them stiffen up the ride. I don't have a rear lift so mine are the stock height.

If the problem gets worse when parking uphill. It would seem that there is more weight behind the rear axle in this condition causing more uplift of the front axle.

I think you would need to find a way to move some weight forward of the rear axle.

The Timbren's would be acting a the pivot point for the weight. I think this would be the same if you used airbags or some other stiff spring setup.

 

That’s the give and take of doing stuff, you’ll need to find middle ground and in time there will be more options.

 

Call dobinsons. The spring rate is for each spring, so x2 and you're golden. I have about 700lbs in the bed roughly at all times and sit great with my suspensions- rear dobinsons shocks, extended brake lines- (YOULL NEED THESE + longer shocks), dobinsons springs), dobinsons track bar, and I am running firestone airbags out back for when i tow my boat and camper.

 

I ordered Dobinsons and spoke to a few experts which seemed right in line with what everyone is saying. I'm leaning toward avoiding airbags if possible just because my old Firestones on the Tacoma did require some maintenance and would lose air in the winters. I'd just need to pony up for onboard air and a switch in the cab eventually. For now I'll be trying the Dobinson's rated for 770 lbs with the Timbrens. I did hear that I may need a different shock to accommodate for the stiffness of the Dobinsons but I shouldn't need longer shocks because they're already the 2" lift in the rear TRD shocks. As for brake lines and track bar, I shouldn't need those right? My brake lines should already be extended when Toyota put the TRD lift kit on. Not sure what the track bar is??

 

I'd imagine the weight of the camper does shift backward on a hill and lift the front but the front doesn't seem higher than usual in this position. The sag is minimal so I'm thinking the stiffer 770lb Dobinson's (which I just ordered) should help in conjunction with the Timbren's. My goal was to try avoiding going down one path and then ultimately pivoting to airbags. I already have a set of airbags from my Tacoma that I need to sell along with a million other parts.

 

I have a fully loaded Granby in my DCLB. I sent the empty and loaded weights of the truck to Alcan Springs in Grand Junction and told him I wanted a 2-2.5" lift and they hooked me up. I went with ADS 2.5 coilovers and Total Chaos UCA's up front.

 

CO

Coilovers in the rear?

 

No, leafs.

EDIT: My truck is a 2019 with leafs in the rear. Do the newer Tundras have coils in the rear like the FJ/T4R?

 

Ohh, yea new Tundras have IRS from the Land Cruiser. Big difference.

 

Ho-Lee-Shit, I did not know that. I imagine that would ride nice.

 

It's sooo smooth but unfortunately the rear springs are super soft and a lot of people say it feels softer in the rear than the front. Which is opposite of leaf spring trucks. Luckily it's just a quick swap to stiffer springs.

 

Nice. Definitely an easy swap. Good luck with it.

 

IRS as in independent rear suspension? Then no. Its a coil sprung solid axle on new tundras.

 

The shocks on your truck are meant for regular travel and now post trd lift have a spacer on the spring. This is not a good or ideal set up, if you swap the dobinsons and "flex" your suspension offroad or on road for that matter you run a major risk of damaging your stock shocks since they cannot accommodate for the dobinsons increased length. I am unsure if the TRD kit comes with new brake lines or not- def worth checking (seem to think it does tho based off memory). Rear track bar is 50/50, I'd do it if the TRD kit didnt come with one- helps center the axle

 

the TRD kit comes with a spacer and longer shock. With the Dobinsons and removal of the spacer, I should be just right. Am I kissing something?

not sure what you mean about rear track bar