Introduction:

I have now had a season of wheeling to evaluate running 34" tires stock on a Gen 1 Montero/Raider. This write up actually covers 2 different 34" tires, the 12.5" wide TSLs, and the 9.5 wide TSLs when its done. I will cover the trimming needed, rubbing issues, power loss, and corrective measures. Pictures and tape measurements are included also. The pictures are 640x480, with a 1600x1200 high res link below them (my christmas present a Razr ve20 took the pictures). I tried to park the truck as level/flat as possible for this, but its not perfect.

Section 1: Vehicle Control Stats:

Vehicle: 1988 Dodge Raider with Off-Road Package
Engine: 2.6 Liter Inline 4 Cylinder with Weber Carb
Mileage: 145k miles on truck, 40k miles on new engine
Transmission: 5 Speed KM145
Gearing: Stock with rear Limited Slip.
Highway Driving: 10 miles round trip 6 days a week. And 120 miles round trip to Uwharrie for wheeling trips.
Off-Road Testing: Dry dirt, Rocks, Water, and Mud

Section 2: Wheel/Tire Stats & Info

There aren't many 34" tires out there. The most popular are the 33x12.5-15 TSL Bias Ply, 34x9.5 TSL-15 Bias Ply,34x10.5-15 LTB Bias Ply, and 34x12.5 TrXus M/T Radial. And yes that isn't a typo, the 33x12.5 TSLs are included.

33x12.5-15 TSL: 33.7" x 12.4" Actual Measurements, 60lbs Weight, 24/32nds tread

34x9.5 TSL: 33.8" x 9.5" Actual Measurements, 54lbs Weight, 27/32nds tread

34x10.5 LTB: 33.6" x 11.2" Actual Measurements, 58lb Weight, 22/32nds tread

34x12.5 TrXus M/T: 34.0 x 12.9 Actual Measurements, 64lbs Weight, 19/32nds tread

As you can see the so called 33" TSLs actually measure bigger than the 34x10.5 LTBs. So they are really a 34" tire. The only tire that won't be covered is the TrXuS which does measure larger at 34.0, but has less tread.

Section 3:Trimming and Hammering

This is the hardest part of course. You will need some kind of saw, a hammer, and grinder (optional). First off the front bumper end caps will need to be trimmed. There is a piece of metal that will be a good marker on where to stop. Besides it is pointless to cut back further than it, because the tires will hit that piece of metal. The other option is to take off the bumper end caps and don't even worry about cutting.


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Next is to hammer the metal part of the splash guard/inner fender back. Here a buddy of mine Bill used a grinder to cut some off to allow to bend it back easier. This isn't a must, it just made the hammering easier. You will also notice by the hole on the left that the TSLs made the plastic trim piece on the fender a "self re-moving item" as it is no longer there.


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Here is what you will end up with as resulting clearance with the tires on. You can also notice the other rear side black fender trim piece is still there, but it is battered being a rubbing point.


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The rear won't need any modification, but I am guessing you could eliminate any possible rubbing (I haven't noticed any...if there is any a tiny bit). I also opted to put the tires with more tread in the rear to avoid having more rubbing issues up front.


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[img]http://img181.imageshack.us/img181/7409/reartiresideviewon0.jpg[/img]
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Section 4:Rubbing, Tire Tread Depth, and LTBs

First off is rubbing. While there aren't really rubbing issues in the back, there will still be rubbing in the front. Some of it can be fixed by removing the black plastic fender trim pieces that will probably be self-removal items anyway (aka the TSLs or similar tires will rip them off).

Rubbing is most common when: Making sharp turns (less than 90 degrees), changing grade levels on streets (going over bridges etc), and entering parking lots that have a drop off/incline. And this is primarily due to the massive outter lugs that the TSLs have. So you may not have any rubbing issues if you run some other brand of 34" tire.When the tires are aired down to 10psi on the trails, the rubbing is virtually eliminated.

Next is tire tread depth. Of course the TSLs I have are used and not new. They start with 24/32nds tread depth new at 33.7". So used the tires are a tiny bit smaller, and will fit better. So I put the tires with the most tread in the rear because they won't be turning/rubbing. And then the last tread in the front where rubbing at full turn would be an issue. Here is a comparison between the front tires, rear, and new.

[img]http://img72.imageshack.us/img72/7166/fronttiretreadexamplepv7.jpg[/img]
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[img]http://img391.imageshack.us/img391/5808/reartiretreadexamplent6.jpg[/img]
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[img]http://img168.imageshack.us/img168/8942/sparetiretreadexampleneee7.jpg[/img]
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You can see there is a big difference between the front tires and new, but a much smaller difference betwen the rear and new. So its safe to say a new set of TSLs will fit, but you may need to do more hammering in the front. Worst case scenario is you end up doing a torsion bar crank in the front.

Say you opt for the LTBs which measure 1/10th of an inch smaller than the TSLs new, and have 2/32nds less tread. So you should have no issues running a new or used set seeing they are smaller. But just for reference I took some pictures of some good tread 34x10.5 LTBs off of Lorenzo's Isuzu and compared them to the TSLs on the back of my truck.

[img]http://img152.imageshack.us/img152/4214/33tslvs34ltbcomparisonzn3.jpg[/img]
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[img]http://img184.imageshack.us/img184/6445/33tslvs34ltbcomparison2ty6.jpg[/img]
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Section 5: Clearance Gains

The whole point of putting bigger tires on is to gain clearance. So I took some measurements from the rear differential, lower most skid plate, and door/rocker panel so you know what your gains will be vs stock/your setup.

[img]http://img187.imageshack.us/img187/482/doortogroundclearancefp8.jpg[/img]
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[img]http://img187.imageshack.us/img187/473/reardifftogroundclearandh1.jpg[/img]
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[img]http://img123.imageshack.us/img123/4614/skidplatetogroundclearazr3.jpg[/img]
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Section 6:The 34x9.5s,Comparisons, @ Spare Tire

Of course my next set of tires are the 34x9.5 TSLs that measure 33.8" new with 27/32nds tread depth. The 2nd half of this write up will cover the 34x9.5s on 15x6 alloys, and possibly a t-bar crank-body lift but I figured I would give some info now considering I do have the tires here. Below are image comparisons of the 34x12.5 TSLs on the rear of my truck, the 34x9.5 TSLs on no wheels in the middle, and the new spare 34x12.5 TSLs on the outside.

[img]http://img265.imageshack.us/img265/7531/34x125newvs34x95usedir8.jpg[/img]
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[img]http://img339.imageshack.us/img339/2421/34x125newvs34x95used2cy8.jpg[/img]
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[img]http://img530.imageshack.us/img530/8927/34x95upagainst34x125hy3.jpg[/img]
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[img]http://img75.imageshack.us/img75/2203/34x125new34x95used34x12sf4.jpg[/img]
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[img]http://img185.imageshack.us/img185/7128/34x125usedvs34x125usedbx2.jpg[/img]
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One of the often forgotten aspects of running bigger tires is fitting a spare tire on the back. Here is a picture of clearance between the spare tire (new) and the door handle cover.

[img]http://img185.imageshack.us/img185/4135/sparetiretodoorhandleclxa2.jpg[/img]
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Section 7: Power Loss and On-Road

Power loss is always a big concern when moving up to bigger tires. And in this instance you have just about the worst case secenario (only the TrXus weighing more). The 34x12.5 TSLs weigh 60lbs and the 15x8 Street Locks with 3.75bs are as heavy as it gets with steel wheels. So its safe to say the 54lb 34x9.5s on the much lighter 15x6 Alloys will help in with my power loss.

The first thing you will notice is the truck won't take off extremely fast. Its a truck after all so that shouldn't surprise you. Then you will notice if you want to avoid downshifting in hilly areas you will be using 4th gear a lot more than 5th. If you don't use 4th gear and keep it in 5th going up steep hills you will have to either A.) Downshift or live with B.)going down to 35mph by the time you get to the top of the hill.

On the highway it will take longer to get up to the 65mph+ zone. But after you get up there, you can get up to 75mph+ without many issues as long as you don't get behind slow people or come upon a steep hill. Other wise its not that bad running the bigger much heavier tires. As long as you can live with driving your truck like a truck and not a car you will be just fine.

Section 8: Conclusion

In conclusion yes you can run 34" tires stock with some trimming and hammering. But this is not to say you don't want to at least do a t-bar crank to eliminate rubbing up front. I haven't done it yet, but its only my list of stuff to do trust me. If you add a 2" Body Lift to this you should be pretty much set to tackle what ever you point your Montero/Raider at. Put on the 2.5" Toyota Shackles in the rear also (combined with the t-bar crank and body lift) and I would say you would be really tempted to move up to 35"s or 36"s. So while nearly bald 35" BFGs have been run stock, its safe to say if you want to buy new/good used tires 34" is the max unless you at least do a t-bar crank and possibly a lift. Part 2 of this write up will come later on this month/January when Angelo's 34x12.5 TSLs come off and the 34x9.5 TSLs go on.

[img]http://img184.imageshack.us/img184/230/overallshotmb6.jpg[/img]
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