Moving up to 37’s, advice requested (1 Viewer)

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You don’t need to lift it more to fit 37s. If you want to be able to fully cycle your shock, you’ll need to trim the fenders no matter what size lift you have, so why not just keep the springs you have. And like everybody else says, get 17. 17x9s with a -25 offset seem to fit nice.
x2. Your current 2” lift is sufficient if you use wheels with the correct width and backspacing.
 
The springs were to address 2 issues. ive got too much sag in the rear while loaded, so I need to increase spring rate in the rear. I thought I had a 3 inch lift when I ordered my delta arms, now my caster is at 8 degrees.

I am not going to run a six inch kit to maximize travel. Pretty sure going that high causes all kinds of other issues with center of gravity.
 
The springs were to address 2 issues. ive got too much sag in the rear while loaded, so I need to increase spring rate in the rear. I thought I had a 3 inch lift when I ordered my delta arms, now my caster is at 8 degrees.

I am not going to run a six inch kit to maximize travel. Pretty sure going that high causes all kinds of other issues with center of gravity.
Gotcha. Totally get new springs
 
With the 3L arms I was able to run 1" less bump stop in the front. My bump stops are equivalent to 2" with my 2.5" suspension lift.
Just throw spacers on top of your coils to see how everything settles in. You can also space down you shorter shocks. There is several ways to do it on the cheap.
 
37s are the sweet spot for a 80, very little or no cutting well be needed with the set up you have ;)
 
37s are the sweet spot for a 80, very little or no cutting well be needed with the set up you have ;)
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The late and great Tools R Us touted the use of 37s. When discussing the added strain on the drivetrain he simply would say by going to the bigger tire, all trails are easier and you do not have to work as hard to clear obstacles. Since the drive train was not worked as hard, you were actually imparting less stress to the components. Now, if you drive like Ironman Stewart, that point is mute.

As far as rim size, I like the tires to flex. More sidewall equals more flex. Fit the smallest diameter rim to clear brakes and maintain your choice of tires. ProComp has recently discontinued some 16" sizes as an example.

I am currently running 35s but thinking long and hard about going to 37s after I finish everything else on the rig.
 
Skip the extra lift. If possible move the front axle forward...but my advice is to put the 37s on and take it to a body shop and have them articulate the suspension with the larger tires and trim the body and inner fenders where needed.

I did this on my 85 4Runner, 2" lift and 38.5" tires and 5.29s back in the day. Dual t-cases, ARB'd F&R...That was the best "wheeler" I have ever had, made me look like I knew what I was doing in Johnson Valley back when I wheeled with the Tin Benders!
 
Skip the extra lift. If possible move the front axle forward...but my advice is to put the 37s on and take it to a body shop and have them articulate the suspension with the larger tires and trim the body and inner fenders where needed.

I did this on my 85 4Runner, 2" lift and 38.5" tires and 5.29s back in the day. Dual t-cases, ARB'd F&R...That was the best "wheeler" I have ever had, made me look like I knew what I was doing in Johnson Valley back when I wheeled with the Tin Benders!
I've already got the 3L arms installed from Delta which pushed the axle forward an inch and produced some caster. My Caster is at 8 degrees, makes me think the front end needs to come up a bit. And the rear is sagging when Im loaded for a trip. Im sure the 100 lbs rotti in the back doesnt help with that. It seems to me that $700 in springs would correct both issues, and give the wheels a bit more up travel. I am all about keeping the truck as low as possible, and the steering isnt pulling. I may order the rear springs first and a spring spacer for the front. But that will be a conversation with Dobinsons to make sure I'm pairing appropriately.

I hadnt thought about hiring a body shop to do the trimming, but it makes an awful lot of sense when you hear it. They would be experts in sheet metal welding.

After I get the wheels and tires squared away, the next set of mods will be low range gears for the transfer case, and Land Cruiser Haven seems to think they can get a full 3 pedal conversion. The idea of a turbo cruiser, stick shift on 37 appeals greatly to me.
 
More caster with bigger tires is a good thing.
This seems to get overlooked, bigger tires benefit from more caster
 
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More caster with bigger tires is a good thing.
This seems to get overlooked, bigger tires benefit from more caster
Any idea where the caster sweet spot is? I saw factory is set at a max of 2 degrees, and I was hoping an inch of lift would put me closer to 4. I’ve got Firestones lifetime alignment, so I can get it dialed in as frequently as I want
 
Any idea where the caster sweet spot is? I saw factory is set at a max of 2 degrees, and I was hoping an inch of lift would put me closer to 4. I’ve got Firestones lifetime alignment, so I can get it dialed in as frequently as I want
You lose caster as lift height increases.
 
Any idea where the caster sweet spot is? I saw factory is set at a max of 2 degrees, and I was hoping an inch of lift would put me closer to 4. I’ve got Firestones lifetime alignment, so I can get it dialed in as frequently as I want

For 37"s the optimal caster would probably be 4 - 5 degrees positive. But you might need a double cardon shaft or part time to avoid vibes.
 
Any idea where the caster sweet spot is? I saw factory is set at a max of 2 degrees, and I was hoping an inch of lift would put me closer to 4. I’ve got Firestones lifetime alignment, so I can get it dialed in as frequently as I want
Caster is not adjustable with a alignment on a solid axle.
 
Caster is not adjustable with a alignment on a solid axle.
Yes and no. There are methods to change your faster angle, such as brackets, amount of lift, and control arms.

I have aftermarket control arms that added caster, possibly more than I need to get within spec. Adding more lift will change the caster angle. But I agree there isn’t a factory adjustment.
 
Yes and no. There are methods to change your faster angle, such as brackets, amount of lift, and control arms.

I have aftermarket control arms that added caster, possibly more than I need to get within spec. Adding more lift will change the caster angle. But I agree there isn’t a factory adjustment.
I get it !! no Firestones lifetime alignment policy is going to dial it in for you 🤷‍♂️ . post 31

Or maybe your saying that you can get your castor numbers checked with a lifetime policy ? Big difference :cool:
 
what @JunkCrzr89 said. Key is to have the backspacing such that the rim is centered over the mounting plane... ie, 9" wide rim with 4.5" backspacing...

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These are summit raptors on 37's.... I rub a bit when turning and compressed, but will be getting longer arms up front + a little trimming and that should solve it.
 
what @JunkCrzr89 said. Key is to have the backspacing such that the rim is centered over the mounting plane... ie, 9" wide rim with 4.5" backspacing...

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These are summit raptors on 37's.... I rub a bit when turning and compressed, but will be getting longer arms up front + a little trimming and that should solve it.
Looks clean, though Summit sells other models with a bit more negative offset at -25 v. the -12s you have there. What's great is they're hub-centric, lightweight and affordable (thanks, China).

I prefer a bit more neg offset myself for a more aggressive stance else it looks like it's sitting on stilts. I'm at 17x9 -38 running 37x12.5 KM3s.

 
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I'm on 37's as of a few months ago. Delta 3L arms up front but now I rub my Shortbus... 2-3" ish Dobinsons lift w/ stock length rear panhard with Delta bracket. Wheels are RRW RR-7 beadlocks 17x8.5/-25. Maxxis Razrs that measure a very true 37. Does it rub? I don't really know yet as I havent cycled it too much yet. Daily driving around town and hitting some ruts and such and no issues so far.
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Looks clean, though Summit sells other models with a bit more negative offset at -25 v. the -12s you have there. What's great is they're hub-centric, lightweight and affordable (thanks, China).

I prefer a bit more neg offset myself for a more aggressive stance else it looks like it's sitting on stilts. I'm at 17x9 -38 running 37x12.5 KM3s.



Looking cool is one thing, not rubbing is another. -12 offset is the key to minimal rubbing and not chopping up your rig for clearance.
 

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