What's the worst that can happen?

[MilehighLR3]

The tire subject has been beaten to death, twice. But I have a question that perhaps will persuade me one way or the other . . . .

Using the rod mod, plus size tires to fit .. .. .the suspension system fails and drops to the bump stops . . .. can you still drive or is the plus size tire combo going to prevent you from turning? or reasonably being able to drive?

 

[USAFbuckeye]

I think that depends on how big you intend to go. You can run the 285's in access mode with a little rubbing in sharp turns. With the rod mod, I'm not sure you can go to the bump stops because of how the rod mod limits the physical travel of the suspension.

I have the mod, and run it full-time. I ran 285, nittos without the mod and had little trouble with them in access mode, but then again it was usually used to let my kids in the rig or to get it into the garage.

 

[Team Jeff]

I've got the 285 Coopers & I'd bet you could still drive - although slow only due to slight rubbing.

You bring up an interesting thought though. What are the types of suspension failures that are common? And how could you prepare for them? My guesses are,

1. Torn or leaking bag - one solution may be to jack the vehicle up, cut away the damaged bag & place a hard rubber shim over the damper shaft. Think C shape here. You could also possibly find a place that a wedge of hard rubber could be placed that would prevent the suspension from compressing. The latter seems like it would be much more prone to failure.

2. Computer failure of some sort, hardware is intact - Modify the airbags to take air from another compressor (could be the OE too if it's still running). This may be more difficult than it sounds, but would be worth some investigation.

My wife has a Expedition with 4 wheel air bags, I've had a few issues with leaks so now I have a "kit" in the car with extra air line, push fittings, etc. The Expedition uses a solenoid on each air bag / damper assembly, if there is no voltage applied the solenoid remains closed. If I remember correctly it takes around 5v to open it. I have not sorted a field method to add air and probably won't due to the fact that we almost never take her car off road. Makes sense in the LR.

 

[blackforestham]

Ewwwww. Any plus size tire will most likely rub during a complete suspension failure. I've had 285/65's and 275/65's on when the failures occurred. Both rubbed HARD inside the entire wheel well. The rod mod has no effect on the suspension dropping to the bumpstops. The air bags completely purge and the rig drops to the rubber bumps. There really is no way to prepare for one of these. Both of my failures occurred due to corroded wiring issues around and near the sensors. I've been diligent in blasting the connections with WD40 before heading out on the trails when I know that I'll be seeing a lot of water, snow or mud. I also have packed many connectors with dielectric grease to further increase my odds of water prevention and electrical glitches.

 

[hell pie]

Regarding what Team Jeff said about modifying the airbags to take air from another compressor, a company called Faskit makes a system specifically for the LR3. Here is a link to their webpage.

http://www.opcionesavanzadas.com/indexing.htm

You basically have the ability to fill up any of your four airbags with an external air source. You also have individual valve shutoffs, preventing the computer from deflating the airbags. There is a gentleman on the disco3 forum who has one of these installed.

The same gentleman also modified his LR3's airtank with a common schrader valve so that you can fill it up with an external air source. Following his idea, I did the same airtank mod on my LR3, but I find it's practical uses are limited. The suspension compressor is able to fill the airtank to over 200 psi; my outboard compressor can barely reach 100 psi. When my suspension compressor was dead last month, my LR3 was on the bumpstops. I had hoped to lift the vehicle by filling the airtank, but for the most part wasn't successful. I'm not sure if it is because the computer sensed the compressor was dead, or if it was because there wasn't enough pressure in the airtank.

 

[ryan-in-oregon]

Speaking from experiance. BFG AT 265/6518 will clear at the bump stops. I seriously doubt any other plus size will clear. You can not alter the strut to get you out. The bumpstop is integrated into the strut so you cannot alter that either. I know because I have had mine completely apart and repaired it my self. Your only hope is to install spacers on top of the struts and then install limiting straps to prevent the wheel from droping below its design. My failure was due to a punctured bladder. I also wouldn't recommend the BFG's the tire life is horrible with them. I'll be lucky to 20k out of mine. (I'm at 14k and about 2/3rds through the usable tread, mostly offroad use)

 

[MilehighLR3]

The rod mod has no effect on the suspension dropping to the bumpstops. The air bags completely purge and the rig drops to the rubber bumps. There really is no way to prepare for one of these. /QUOTE]

Thought so, as I understood the OE rod and the AM rods, they only "fool" the sensor. I recently had a compressor failure, drop to the bump stops and it dawned on me . . . what would happen if I had the rod mod and plus size tires . . . .

Maybe I'll fight the temptation to get the biggest gnarliest rubber and go just a little bigger.

 

[ryan-in-oregon]

Thought so, as I understood the OE rod and the AM rods, they only "fool" the sensor. I recently had a compressor failure, drop to the bump stops and it dawned on me . . . what would happen if I had the rod mod and plus size tires . . . .

Maybe I'll fight the temptation to get the biggest gnarliest rubber and go just a little bigger.

This is exactly the reason I chose the BFG AT in the first place!!! and trust me after taking three hours to get off the trial that only took me 45mins to get into I am glad I chose the BFG!!!

If anybody wants to see it on the bumpstops anyone with a faultmate msv can do it in about 30 seconds once connected...

 

[Boaz]

I have the Cooper Zeon LTZ's in 285/60/18 and have had the unfortunate experience of a suspension failure while in rock crawl mode out on the trail (compressor just overheated - fine again after it cooled down). I thankfully could still drive to a flatter spot. I would say that this size is the max that you could be comfortable with. Keep the total diameter under 31.5" and you should be fine. I have heard of guys running mud-terrains in 32.5"+ with the mods on, and losing the extra height at full speed on the highway. Total carnage in the wheel wells and lots of money to fix. No thanks for me. Hope that helps.

 

[SoCal LR3]

i'm running the 285 nittos and i had a suspension failure while mudding around a couple of months ago. dash went full christmas tree and it lowered to bump stops. i tried turning the car off and back on again- this caused the suspension to come back up, but after a couple hundred yards it would go full christmas tree and lower back to bump stops. i ended up driving home this way.

i did have some rubbing in the wheel wells but only when hitting bumps on the freeway. on smooth pavement it did not rub, although the ride was not nearly as pleasant as when the suspension was acting normally.

i expected a lot more rubbing (read: stranded) given that i'm running the oversized tires, but it wasn't as bad as i expected. maybe i wasn't at the bump stops? i was lower than access mode, but maybe there are different types of failures?