Tires too close to leaf spring?

[nuakameba]

Hi all - I just changed out the suspension on my 91 FJ-70 from stock to OME, adding a couple of inches of lift (thanks for the tips from the forum on that topic). That allowed me to put on a new set of wheels and tires - Series 52 Rock Crawler 16X8 6-5.5 4.25 BS wheels, and ProComp 285/75R16 XTREME AT tires. I tried to order the wheels with 4in or less backspace, per comments on the forum, but all I could find from the dealer was 4.25in backspace so I decided to order and try it out.

Sure enough the rims in the front rubbed against the caliper, but a quick grind-down of .8cm or so from the edge of the caliper did the trick, and the front wheels fit fine otherwise.

But in the back I'm a bit worried about the fit. On the inside there is only about 1 centimeter between the tire and the bolt on one of the U-shackles around the leaf spring. And between the body of the vehicle and the wheel on the top-backside of the wheel, there is also very little space (maybe 2-3cm) between the wheel and the body of the vehicle.

I'm worried that when I get the truck onto some rough terrain, there will be enough flex in the system to push the tire into the bolt on the leaf spring and tear it open like a bag of chips. I have attached a picture here to point out the trouble spots, so just imagine between the yellow arrows that there is 1cm gap on the bottom and 2-3 on the top.

So my question is, first of all - is this a problem, and does the system 'flex' enough in moving over rough ground to push the wheel against the body or spring? And if the answer is that there is some risk, what's my next move? Should I come up with some spacers to put behind the wheels - and if so how much is safe to add?

Thanks! In all my reading on the forum I haven't seen exactly this concern come up with adding new wheels and tires.

Nuakameba

 

[Hulsty]

IMO its a problem and could flex into the bolt, get the correct offset rims, another inch of offset would be good.

 

[crushers]

tire flex could be the issue as Hulsty mentioned.
spacer or better yet the proper back spaced rim.

 

[xkennx]

I have the same problem with my armored 70 series - some reason people think the really wide tire and the TLC105 wheel is the best combo. (on sharp turns at decent speed they will touch the suspension) I prefer the TLC200 G9 steel rim (that is the 17x7 and not the 17x8 that comes on GX/GXR models)

As much as I hate to tell someone to put a spacer on (not a good idea for armored cars) you can install one to get you more clearance - this will be the cheapest solution for you.

Here are pics of a LT265/75R16 and I had over 3.5cm of clearance. It did touch the leaf springs a few times during test drives - but what killed it was the plate at the bottom of the leaf springs cutting right though the rubber

 

[nuakameba]

Thanks folks - that was what I thought. I looked into new back rims, but it looks like I would need to special order them to get the right offset. So I ordered a pair of 1.5" wheel spacers, which I know is not ideal but hopefully will do the trick. I'm surprised that in all the forum discussions about wheels and tires, the only problem that people generally discuss is with hitting the front caliper. Anyway, thanks again for the feedback - I really appreciate it! Now if those spacers would just hurry up and arrive...

Nuaka

 

[Glenn-BJ74]

Follow the wheel spacer installation instructions carefully and each time you service brakes - otherwise you risk the spacer coming loose - do not over torque

 

[buschmaster86]

ID RATHER GET A NICE -40 NEGGATIVE OFFSET THEN THOSE SPACERS !

 

[Josie'sLandCruiser]

Hi All:

I have been running some 1.5 inch (38mm ?) bolt-on wheel spacers on the rear axle of my FJ40 for several years now.

I have had no problems, but installed the spacers to the wheel lugs with blue LocTite, and torqued to 90 foot-pounds.

I use a torque wrench to double-check the wheel spacer nuts every time I have the rear wheels/tires off the truck.

Good luck!


Alan

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Thanks folks - that was what I thought. I looked into new back rims, but it looks like I would need to special order them to get the right offset. So I ordered a pair of 1.5" wheel spacers, which I know is not ideal but hopefully will do the trick. I'm surprised that in all the forum discussions about wheels and tires, the only problem that people generally discuss is with hitting the front caliper. Anyway, thanks again for the feedback - I really appreciate it! Now if those spacers would just hurry up and arrive...

Nuaka