I just got some nice 275/65/18R tires (thanks Rennie if you are looking at this!), and was wondering the best approach to mount them on my LR3 w/o rubbing. I already have a GAP tool, and I;m willing to buy spacers if that's necessary. I was also wondering about the GAP tool and the best approach to changing the tire size in there without getting a check engine light. Thank you!

 

You will need about 1.75" or so of lift to clear

 

Dont forget to loosen every single suspension item to let the bushings relax into the new lifted position or they will rip apart.

 

Any good guides on how to do that? I've watched quite few youtube videos and they never mention anything like that.

 

Imagine a control arm installed and set to torque. Then raise the outside of the arm up 12 inches to simulate wheel lift. The rubber bushing will be twisted since the internal bushing dowel, which the bolt is ran though, does not move and it torqued to the frame. This is fine and in fact aids in suspension because the various bushings always want to twist back "home". But if you leave a bushing twisted, especially an old one, it will wear quicker and fail quicker. Also if the lift is a lot the bushings tend to want to "return home" and can give a slightly bouncing feeling to the ride - although on a truck this heavy one would probably not notice.

So its not different when installing suspension parts where one loads up the suspension, ideally with the weight of the vehicle, but jacking up the entire assembly to get the spindle height spot on works too. Then one tightens all the bolts down to spec before sending it off for an alignment. So basically you want to loosen the upper arm bolts at frame and the lower arm bolts too, at frame. Lower strut bushing too. Front and rear. In the rear the lower rose joint does not have to be touched though.

Really its up to you if you want to do, but its good practice and something any reputable 4x4 shop does when doing lift.

 

Dakota, is what you're describing only necessary when adding hardware like spacers? What if a heightened setting through the GAP tool is all that's being utilized? Since that's really just the stock EAS calibrated taller, do the bushings still need to settle in?

 

If one does something like a half inch I probably would not worry at all. An inch... I would consider it. More than an inch and the bushings twist is getting a bit much. Its a mechanical thing, so how its adjusted is not relevant. Spacers, I assume you mean strut, are irrelevant. They just lower the top the of the strut to counter the height adjustment.

 

Makes sense. For me - and this might help the OP - I just run around at stock calibration on my 275/65R18s and raise it up at the trailhead (via GAP) and then when I complete the trail, go back to stock. Those trail miles are a tiny fraction of the daily usage, and I won't worry about the bushings in that case.

 

Hey, OP here. I was just busy the last few days with family stuff and work (I worked on Labor Day, it sucks) and didn't have any time to reply. I finished putting my wheels on yesterday and have about a 1 inch lift using the GAP tool. I also fixed the "Tyre radius" in the CCF files as "400", as opposed to the "370" that was with the 255 tires and the speedometer is spot on (verified with GPS speedometer app on my phone). The GAP tool is so amazing, it literally pays for itself every time I use it. There's also no rubbing anywhere, even with turning and with speed bumps, and they looks pretty amazing. My only gripe is that huge rocks now get stuck in the tread spaces and I have to manually remove the more stuck ones. All-in-all, a wonderful tire set. Thank you again Rennie. There also might be some cobwebs that didn't get blown off by going 70mph on the freeway, hopefully the pressure washer will take car of that.

EDIT: I know from the looks of the pictures that they look dirty and old, buy be assured that these tires are almost brand new and still have their factory "whiskers" and no tread wear at all.



A closeup. I still need to clean these.

A side profile shot.