Does a Lift Actually Increase Tire Clearance Without Bump Stop Modification?

[stereww]

I'm doing a revival on a 1997 LX 450, drivetrain is complete and I am on to suspension and tires. I have gone fenderless and am wanting to avoid the tires sticking out past the body. My 1997 4Runner's tires poke out and it's always dirty. My solution is Kenda Klever R/T 35x10.5x17 tires and FJ steelies (17" x 7.5", +15mm offset). Hopefully I'll get some improvement in rolling resistance and rubbing clearance compared to 315s as well.

I am trying to keep my lift low. I would love to skip the lift all together to keep CG low as possible. I have read and read and the general consensus is that it takes a 2"-3" lift to fit 35" tires, but it also seems that most folks lifting 2" are not extending bump stops. I read a couple reports on mud here that state stock bump stop contact is at 16" and 15.5" shock length for the front and rear respectively. I understand there is some variation in those numbers depending on if both sides are compressed together or if one side is in droop and the other is in compression.

I compiled some dimensions for compressed length from various manufacturer's shocks designed for 0-3" lift. It seems for most manufacturers the shock minimum compressed length is at or below the shock length at the stock bump stops I listed above. This makes me believe they would be protected by the stock bump stops. I feel this also means that even if you have a 2-3" lift and stock bump stops, lifted shock length at full compression would be the same as stock shock length at full compression. I don't see how the lift is helping eliminate tire rubbing for those who haven't extended bumps. Are all these folks reporting little to no rubbing at 2" of lift never articulating and reaching full compression? Or am I missing something here?

Shocks	Bump Stops	OEM	Dobinson IMS	Bilstein 5100	OME Nitro	Fox 2.0	King
Extended Length Front		23.7	24.9	24.61	24.3	25.1	26.1
Compressed Length Front	16	13.9	14.8	14.96	14	15	16.1
Front Travel		9.8	10.2	9.65	10.3	10.1	10
Extended Length Rear		23.8	25.0	24.95	24.6	25.48	25.6
Compressed Length Rear	15.5	14.2	15.7	14.94	14.8	15.6	15.6
Rear Travel		9.6	9.2	10.01	9.8	9.88	10
Advertised Lift		0"	0-3"	2-2.5"	2.5"	1-2.5"	0-2"

Any anecdotal evidence as to how big a difference tire width makes in tendency to rub would also be appreciated.

 

[NeverFinis]

That is a nice table. Great work putting it together.

I believe many are running rear bump stop extenders, including myself. Not for tire rubbing per se, but my rear panhard lift bracket can possibly touch the frame cross member under full stuff without them.

I am running a thinner 35" tire than most, LT285/75R18 and extended length front radius arms. My truck is still a project truck, so I can't comment if the tires I am running are rubbing. I don't have the time at the moment to pull the springs to cycle the suspension.

 

[jonheld]

If your tires don't rub you can fit bigger tires.
LX450 4" Ironman. OEM bumpstops. OEM rims 315x75R16 Toyo AT3s for the street, 36x13R16 Swampers for the woods on 16" Procomp beadlocked steelies 4"BS.
The Swamper's larger lugs touch the inner rear fenders at full stuff, but it doesn't bother me and lets me know where the rear suspension is.
Fronts clear with no issue.

 

[mudgudgeon]

Any anecdotal evidence as to how big a difference tire width makes in tendency to rub would also be appreciated.

I'm running 305/70r16s. Had these with stock suspension for years, with no rubbing.
(these are 1" smaller radius than what you're looking at, but also 1.5" wider)

Rubbing happens at the extremities.

So, with a tire stuffed, and steering at full lock. Edge of the tire will run on fenders, floor pan etc

With 10.5" tires, you'll have more room before you max out the clearance.

If you would prefer no lift, fit the tires and do some testing.
You might be able to just add 30mm coil spacers to give you clearance for the tires

 

[stereww]

That is a nice table. Great work putting it together.

I believe many are running rear bump stop extenders, including myself. Not for tire rubbing per se, but my rear panhard lift bracket can possibly touch the frame cross member under full stuff without them.

I am running a thinner 35" tire than most, LT285/75R18 and extended length front radius arms. My truck is still a project truck, so I can't comment if the tires I am running are rubbing. I don't have the time at the moment to pull the springs to cycle the suspension.

View attachment 3871370

I quickly scrolled through some of you build thread. Are you still on the 2.5" OMEs? How far did you extend your bumps?

 

[stereww]

If your tires don't rub you can fit bigger tires.
LX450 4" Ironman. OEM bumpstops. OEM rims 315x75R16 Toyo AT3s for the street, 36x13R16 Swampers for the woods on 16" Procomp beadlocked steelies 4"BS.
The Swamper's larger lugs touch the inner rear fenders at full stuff, but it doesn't bother me and lets me know where the rear suspension is.
Fronts clear with no issue.

Unfortunately I could not find detailed dimensions for Ironman. Based on the 2" lift numbers I would be worried that the shocks designed for the 4" lift are bottoming out prior to hitting the bumps. I guess if you are hitting inner fenders the body has become the bumps, which I might be okay with as well.

 

[stereww]

I'm running 305/70r16s. Had these with stock suspension for years, with no rubbing.
(these are 1" smaller radius than what you're looking at, but also 1.5" wider)

Rubbing happens at the extremities.

So, with a tire stuffed, and steering at full lock. Edge of the tire will run on fenders, floor pan etc

With 10.5" tires, you'll have more room before you max out the clearance.

If you would prefer no lift, fit the tires and do some testing.
You might be able to just add 30mm coil spacers to give you clearance for the tires

It's getting a new suspension no matter what since the springs are sagging pretty good and the shocks are looking tired.

I think you are right, I will need to do some testing. I believe 30mm coil spacers would only provide additional tire clearance at straight and level. Once articulated, it will compress to the bumps just like if it didn't have the coil spacer. I would prefer little to no rubbing at all suspension positions.

No one has confirmed that I am thinking about this correctly still. At the end of the day if your minimum compressed shock length is the same before and after a lift, I don't think you gain any tire clearance when completely stuffed. My assumption is that most people just aren't flexing their trucks with a 2" lift and stock bumps to see the rubbing occur.

Also interesting, since most shocks weren't increasing their compressed and extended lengths a full 2" beyond stock (most were closer to 1"). You are going to sacrifice some down travel/droop after a lift with these. It almost seems as we are in the same situation as IFS vehicles where a lift doesn't improve clearance in anyway, it just changes your ride height location within the range set by the manufacturer. Obviously with lifts greater than 2" and extended bumps that's not true.

 

[mudgudgeon]

I believe the factory shocks still work with 2" lift and stock bump stops.

You are correct, if you keep the original bumpstops, lift doesn't give you any more clearance with a tire fully stuffed, although, it will reach that point less often with a lift.

With stock bumpstops, and a lift you get more overall suspension travel.

 

[Broski]

It’s also really hard to get a lift spring to fully stuff especially in a low speed full articulation situation.

 

[jonheld]

Unfortunately I could not find detailed dimensions for Ironman. Based on the 2" lift numbers I would be worried that the shocks designed for the 4" lift are bottoming out prior to hitting the bumps. I guess if you are hitting inner fenders the body has become the bumps, which I might be okay with as well.

I never saw the logic in limiting articulation. You're not at full stuff at speed. While cresting a rock you get a thump-thump-thump from the larger outer lugs and then it relaxes. No big deal.

What I will say, if you're running a front swaybar and crawling the rocks, be sure to reinforce/replace the axle mounts. They are poorly welded from the factory and will eventually tear off causing woe and strife.

Front Axle Sway Bar Tabs

These are heavy duty replacement tabs for the front axle. Factory tabs can be torn off which typically ends with a severed brake line. A repair not easily made while out on the trail.

landtankproducts.com

 

[NeverFinis]

I quickly scrolled through some of you build thread. Are you still on the 2.5" OMEs? How far did you extend your bumps?

No longer using 2.5" OMEs.

All Dobinsons now.
Front: 2.5" C97-146VT
Rear: 2.5" C97-147VT

Front Shocks: IMS45-60912
Rear Shocks: IMS59-60687

I have 2" extension on the rear bump stops only. None on the front but the axle is moved forward 1" to help with clearance.

 

[BruceFZJ80]

I never saw the logic in limiting articulation. You're not at full stuff at speed. While cresting a rock you get a thump-thump-thump from the larger outer lugs and then it relaxes. No big deal.

What I will say, if you're running a front swaybar and crawling the rocks, be sure to reinforce/replace the axle mounts. They are poorly welded from the factory and will eventually tear off causing woe and strife.

Front Axle Sway Bar Tabs

These are heavy duty replacement tabs for the front axle. Factory tabs can be torn off which typically ends with a severed brake line. A repair not easily made while out on the trail.

landtankproducts.com

this happened to me last summer while wheeling. Jon's right, not a fun trail fix

 

[Squeegee]

I'm doing a revival on a 1997 LX 450, drivetrain is complete and I am on to suspension and tires. I have gone fenderless and am wanting to avoid the tires sticking out past the body. My 1997 4Runner's tires poke out and it's always dirty. My solution is Kenda Klever R/T 35x10.5x17 tires and FJ steelies (17" x 7.5", +15mm offset). Hopefully I'll get some improvement in rolling resistance and rubbing clearance compared to 315s as well.

I am trying to keep my lift low. I would love to skip the lift all together to keep CG low as possible. I have read and read and the general consensus is that it takes a 2"-3" lift to fit 35" tires, but it also seems that most folks lifting 2" are not extending bump stops. I read a couple reports on mud here that state stock bump stop contact is at 16" and 15.5" shock length for the front and rear respectively. I understand there is some variation in those numbers depending on if both sides are compressed together or if one side is in droop and the other is in compression.

I compiled some dimensions for compressed length from various manufacturer's shocks designed for 0-3" lift. It seems for most manufacturers the shock minimum compressed length is at or below the shock length at the stock bump stops I listed above. This makes me believe they would be protected by the stock bump stops. I feel this also means that even if you have a 2-3" lift and stock bump stops, lifted shock length at full compression would be the same as stock shock length at full compression. I don't see how the lift is helping eliminate tire rubbing for those who haven't extended bumps. Are all these folks reporting little to no rubbing at 2" of lift never articulating and reaching full compression? Or am I missing something here?

Shocks	Bump Stops	OEM	Dobinson IMS	Bilstein 5100	OME Nitro	Fox 2.0	King
Extended Length Front		23.7	24.9	24.61	24.3	25.1	26.1
Compressed Length Front	16	13.9	14.8	14.96	14	15	16.1
Front Travel		9.8	10.2	9.65	10.3	10.1	10
Extended Length Rear		23.8	25.0	24.95	24.6	25.48	25.6
Compressed Length Rear	15.5	14.2	15.7	14.94	14.8	15.6	15.6
Rear Travel		9.6	9.2	10.01	9.8	9.88	10
Advertised Lift		0"	0-3"	2-2.5"	2.5"	1-2.5"	0-2"

Any anecdotal evidence as to how big a difference tire width makes in tendency to rub would also be appreciated.

I like this subject a lot. Yes, a lift helps you fit tires at ride height buuuuut that’s it. At the end of the day, no lifting your truck doesn not help you fit bigger tires unless your spring rate is to high and you lose uptravel. Under proper circumstances, the axle hits the bump stops whether you have stock springs or lift springs. I ran a dobinsons 4” lift spring with a 4” lift shock, 35s rubbed at full bump, I ran a 2” lift spring with the same 4” lift shock… tires rubbed at full bump.

 

[NeverFinis]

What I will say, if you're running a front swaybar and crawling the rocks, be sure to reinforce/replace the axle mounts. They are poorly welded from the factory and will eventually tear off causing woe and strife.

Front Axle Sway Bar Tabs

These are heavy duty replacement tabs for the front axle. Factory tabs can be torn off which typically ends with a severed brake line. A repair not easily made while out on the trail.

landtankproducts.com

This is on my todo list as my front sway bar axle mounts are really sus. I didn't know Landtank sold them but I got mine from Landcruiser Phil

 

[COS80]

I have 2" Ironman/stock bumps and 315/75R16s, and I've eliminated 99% of tire interference with button head front inner fender bolts and a tiny bit of plastic trimming as seen at the link in my sig. I can still hear the fronts barely contact when it bottoms out over high-compression bumps.

 

[stereww]

Update for all. I got the rig out with 35x10.5x17 tires and FJ steelies at +15mm offset. So far is is working exactly as I had hoped. I have some pretty steep off camber mounds at the property and got it at a good angle in some places front and rear and full lock. So far I haven't heard any rubbing front or rear. The tires still clear the front radius arms at full lock too. I think can get away with OME 861/862s and stock shocks. I'll probably follow up with a more detailed analysis when I get it on stands with the springs removed.

 

[SNLC]

Short shocks, such as 9-10” you won’t need to drop the bumps. Rear may rub a little under max compression in the wheel well.

Longer shocks need bump extensions because otherwise the shocks bottom out before you hit the bumps stops.

Shocks are not meant to be bump stops.

Cheers

 

[Bigtoepfer]

Longer shocks need bump extensions because otherwise the shocks bottom out before you hit the bumps stops.

I'm not an expert, so of course my experience is just mine.

I have 3" flexi springs, and I had the appropriate yellow dobinsons shocks and at least one was blown. I now have Skyjacker M9514 and M9557 which are VERY similar to the dobinson long travel nitros extended and compressed length. It was the closest skyjacker had to offer. And I don't have bumpstop extensions. Just factory bumps. I couldn't settle on what I wanted to get, so I just haven't got any yet.

I put zipties on the shock shafts and took them out to test after I installed. I have 35x12.5/17 on OEM 4runner SR5 wheels. Eimkeith RAM and PCK. No rubbing and the shocks didn't bottom out. It is possible they hit the end of their travel for extension though in the rear.

These were quite a bit softer than the dobinsons I had on there, or at least felt softer since at least one of the dobinsons were blown, but all were quite worn out. So I've had to reinstall my rear sway bar with extended mounts. Still no front swaybar because the roll was just a bit excessive on the road.

I don't currently have any rubbing from my tires, but I intend to go slightly smaller OD and narrower on the next set. Like 255/85/17 or 275/80/17. I'm also considering going down in lift as well, because I can fit in the garage now, but ideally I want to fit in the garage with a rack. Like OP I don't have flares, but I'm looking to go to slightly wider wheels, while still keeping it in the fenders. So I've been shopping around.

 

[NeilC]

I am contemplating shocks right now too. My current setup is OME stock height progressive springs with Tokico oem-like shocks. When I added my front bumper and winch, I added a 30mm spacer to the front which leveled the rig out. For 5 or 6 years, I was happy with that setup running 295/70/17s but felt the shocks were under-damped. I have started adding a good bit of weight to the rear for a mobile mechanic business I am starting in retirement. I have smaller tires(265/75/16) on it now but plan to go with 285/70/17s in the future so I am happy with my current lift in the front which is approximately 1" to 1.5" over a stock unloaded rig. The rear has settled down to stock height with the tool boxes, jacks, and jack stands. My front hub to fender measurement is approximately 21.5" but the rear is 20.5" so it looks loaded down in the rear. The rear OMEs being dual rate with good spring rates, 170/250 I think, feel fine under the weight. The stock Tokicos however have trouble.

I am thinking of simply putting a 30 mm spacer in the rear and getting better shocks, either Bilsteins or OME regular or Ls. I understand that the Ls would require more work like extended brake lines and maybe swaybar mount drops. I was worried about bumpstops but the Bilsteins have about the same compressed length of the OME Ls, so has anyone had issues with the Bilteins bottoming out the stock bump stops? There is now about 500 lbs extra weight in the back, which shocks would handle the extra weight better? Thanks.

 

[stereww]

I am contemplating shocks right now too. My current setup is OME stock height progressive springs with Tokico oem-like shocks. When I added my front bumper and winch, I added a 30mm spacer to the front which leveled the rig out. For 5 or 6 years, I was happy with that setup running 295/70/17s but felt the shocks were under-damped. I have started adding a good bit of weight to the rear for a mobile mechanic business I am starting in retirement. I have smaller tires(265/75/16) on it now but plan to go with 285/70/17s in the future so I am happy with my current lift in the front which is approximately 1" to 1.5" over a stock unloaded rig. The rear has settled down to stock height with the tool boxes, jacks, and jack stands. My front hub to fender measurement is approximately 21.5" but the rear is 20.5" so it looks loaded down in the rear. The rear OMEs being dual rate with good spring rates, 170/250 I think, feel fine under the weight. The stock Tokicos however have trouble.

I am thinking of simply putting a 30 mm spacer in the rear and getting better shocks, either Bilsteins or OME regular or Ls. I understand that the Ls would require more work like extended brake lines and maybe swaybar mount drops. I was worried about bumpstops but the Bilsteins have about the same compressed length of the OME Ls, so has anyone had issues with the Bilteins bottoming out the stock bump stops? There is now about 500 lbs extra weight in the back, which shocks would handle the extra weight better? Thanks.

I can't speak to Bilsteins on the FZJ80. I have 5100s on my 97 4Runner. I assume you are talking about the 5100s here as I believe they are the only ones Bilstein sells for these trucks that are also designed for a lift. You may have read already, but they are stiffer than stock so that might help with your extra weight. Some may call them harsh. I haven't had any bottoming out issues. I run without a front sway bar on my 4Runner so the stiffness helps make up for some of that. I have a rear tire carrier and a self built drawer system in the back, both of which I built myself, but I am extremely weight conscious. I have no where near an additional 500 lbs on the back of my 4Runner. Another option might be the Dobinson MRR. I was considering them myself. Especially if you plan to ride some without the 500 lbs of tools. You could have two different settings, one for loaded and one for unloaded.

As for the ride height, I also just installed the OME 861/862 and reverted to stock shocks. I prefer a slight rake unloaded over squatting while loaded. I don't think you need any lift with your current or future tire size. The lower your ride height, the better your CG. If I were you I would take that spacer on the front out and you are back to level.

To the rest of you following along. I have driven around with the new OME 861/862, stock shocks and 35" x 10.5" x 17s on +15mm offset for a couple weeks now with zero rubbing. A few more off camber tests on the property with success. I didn't get around to cycling it on jack stands. I've got a long to do list and a hard deadline for a 1,000 mile+ trip in a couple weeks. The wheels are right at the edge of the body without fender flares. I'm welding out front and rear bumpers now and it's going for a wrap on Monday. I'll post pictures afterwards.