4X4 AWD, different brand tires f/r OK?
#1
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4X4 AWD, different brand tires f/r OK?
The new-to-me FJ-80 I bought has different brands of tires on the front and rear axles, but are all of the correct size. The tread design and all the ratings are essentially identical, too. The vehicle tracks well, no pulling or wandering.
However, after checking the tirerack.com site, I found that the Michelin LTX's have a 5% slower rotational speed than the Dunlop Rovers on the front axle. Given that the rig has AWD with a viscous center diff, should I be concerned that the center coupling is being overworked? The Tire Rack Land Cruiser expert said "no worries" and to not lose any sleep over it. He also said that just buying two tires to match wouldn't do any good because of the mismatched remaining tread depth and they should be replaced in sets of four.
Currently, all four tires have 90% tread remaining, so I'd like to keep them. Would, say, inflating the Rovers 4-5 psi more than the LTX's to increase rolling radius and lower revs per mile closer to the Michelins be an effective band-aid (observing max inflation pressures)?
I'd like to minimize expenses on the Crusher. I'm already planning on shelling out serious ducats on all fluid change outs (engine, tranny, all diffs and x-fer case, coolant) to synthetics, a major tuneup plus belts and hoses (what I routinely do to any "new" used vehicle), and tires weren't supposed to be part of the program. Thanks in advance for your advice!
However, after checking the tirerack.com site, I found that the Michelin LTX's have a 5% slower rotational speed than the Dunlop Rovers on the front axle. Given that the rig has AWD with a viscous center diff, should I be concerned that the center coupling is being overworked? The Tire Rack Land Cruiser expert said "no worries" and to not lose any sleep over it. He also said that just buying two tires to match wouldn't do any good because of the mismatched remaining tread depth and they should be replaced in sets of four.
Currently, all four tires have 90% tread remaining, so I'd like to keep them. Would, say, inflating the Rovers 4-5 psi more than the LTX's to increase rolling radius and lower revs per mile closer to the Michelins be an effective band-aid (observing max inflation pressures)?
I'd like to minimize expenses on the Crusher. I'm already planning on shelling out serious ducats on all fluid change outs (engine, tranny, all diffs and x-fer case, coolant) to synthetics, a major tuneup plus belts and hoses (what I routinely do to any "new" used vehicle), and tires weren't supposed to be part of the program. Thanks in advance for your advice!
#2
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I'm not familiar with the FJ80, but are you sure it has a viscious center diff like an Audi quattro? I thought it just had a plain good ol normal center diff, in which case you should be fine.
If so I would refer to the owners and service manual to see what it says, but I know Audi and SUbaru as examples do not recommend having different tires. On the SUbi's I believe their is even a disconnect plug if you change to the space saver spare. In short for a viscious diff it is not recommended to have different size tires, as the diff uses the fluid coupling for torque tranfer. Think like an auto torque converter that never locks while pulling heavy loads, it heats up.
If so I would refer to the owners and service manual to see what it says, but I know Audi and SUbaru as examples do not recommend having different tires. On the SUbi's I believe their is even a disconnect plug if you change to the space saver spare. In short for a viscious diff it is not recommended to have different size tires, as the diff uses the fluid coupling for torque tranfer. Think like an auto torque converter that never locks while pulling heavy loads, it heats up.
#4
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I think your safe running in 2wd but even if your in AWD I would guess the truck would not have a problem being that the 4 wheels are pretty much even tread wear and similar tires, you could always buy 2 tires to match the front or rear and trade the other 2 in for a discount or someone here.
I know with Audi if you need 1 new tire you have to shell out for 4 new 1's and Chrysler is the same but they just make POS, I've know people who had problems with the AWD system with identical tires on all 4s turning was the problem
Either way I think your fine, the previous owner probably ran that way for the life of it but how the hell does a tire turn 5% slower, is it heavier or does it just stick to the ground, maybe thats just from a start not from aroll
I know with Audi if you need 1 new tire you have to shell out for 4 new 1's and Chrysler is the same but they just make POS, I've know people who had problems with the AWD system with identical tires on all 4s turning was the problem
Either way I think your fine, the previous owner probably ran that way for the life of it but how the hell does a tire turn 5% slower, is it heavier or does it just stick to the ground, maybe thats just from a start not from aroll
#5
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FJ-80 is permanent AWD 4X4 with viscous center diff and locker, plus lockers f/r. The Tire Rack site shows that the tires on it now, all OEM size but different brands f/r, have a 5% revs/mile difference. Previous owner just stuck those on, so no long-term history yet. Ah well, I'll probably just go with what's on there, it came with a driveline warranty just in case. Thanks.
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#8
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FJ 80's are full time AWD, not 4x4. I wouldn't worry about the difference. Just put the taller tires on the front end, there's more weight up there and with the cornering and braking, they'll wear down faster.
#9
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its2slo, sorry, they're 16's.
My99, not to split hairs, but why isn't it a 4X4 w/AWD? It's actually a more versatile, but similar setup to the Gen IV 4Runner. It has full-time 4Hi, 4Lo, transfer case with PTO, locking center, front and rear diffs. Isn't that a 4X4, or should it be called something else? I'm no 4X4 authority, but an FJ-80 seems to cover the bases and more, and the design was carried over to the FJ-100.
My99, not to split hairs, but why isn't it a 4X4 w/AWD? It's actually a more versatile, but similar setup to the Gen IV 4Runner. It has full-time 4Hi, 4Lo, transfer case with PTO, locking center, front and rear diffs. Isn't that a 4X4, or should it be called something else? I'm no 4X4 authority, but an FJ-80 seems to cover the bases and more, and the design was carried over to the FJ-100.
#10
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Originally Posted by BT17R
its2slo, sorry, they're 16's.
My99, not to split hairs, but why isn't it a 4X4 w/AWD? It's actually a more versatile, but similar setup to the Gen IV 4Runner. It has full-time 4Hi, 4Lo, transfer case with PTO, locking center, front and rear diffs. Isn't that a 4X4, or should it be called something else? I'm no 4X4 authority, but an FJ-80 seems to cover the bases and more, and the design was carried over to the FJ-100.
My99, not to split hairs, but why isn't it a 4X4 w/AWD? It's actually a more versatile, but similar setup to the Gen IV 4Runner. It has full-time 4Hi, 4Lo, transfer case with PTO, locking center, front and rear diffs. Isn't that a 4X4, or should it be called something else? I'm no 4X4 authority, but an FJ-80 seems to cover the bases and more, and the design was carried over to the FJ-100.
I love 80's, was gonna get one if I could find a decent one. Unfortunately this 4runner was too good of a deal to pass up
Last edited by My99; 03-21-2004 at 03:11 PM.
#11
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Kyle, no problemo. My 80 has the center locker that can be engaged with a button in 4Hi, and automatically engages in 4Lo. The f/r diffs can be engaged in 4Lo only (makes sense) in the sequence of R/F+R with a switch.
Yeah, ih8mud site is a good tech reference. They, and about half the world, are Land Cruiser fanatics, that's for sure. The other half are 4Runner fanatics with some misguided Rover/Jeep/D-C fanatics thrown in.
I admit to being a Land Cruiser fanatic, though. This is my seventh, and second 80 series. Nothing else comes close to my needs except the current 4th Gen 4Runner that in many ways surpasses the FJ-100, IMHO. The upcoming FJ-110 series is overdue, and should be something if you don't mind getting a mortgage on a motor vehicle.
Yeah, ih8mud site is a good tech reference. They, and about half the world, are Land Cruiser fanatics, that's for sure. The other half are 4Runner fanatics with some misguided Rover/Jeep/D-C fanatics thrown in.
I admit to being a Land Cruiser fanatic, though. This is my seventh, and second 80 series. Nothing else comes close to my needs except the current 4th Gen 4Runner that in many ways surpasses the FJ-100, IMHO. The upcoming FJ-110 series is overdue, and should be something if you don't mind getting a mortgage on a motor vehicle.
#12
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Originally Posted by BT17R
The upcoming FJ-110 series is overdue, and should be something if you don't mind getting a mortgage on a motor vehicle.
Realistically, to walk out the door with a 100 series, the minimum cost would be $60K.
Bob- The first thing I thought when I saw the picture of your truck was, "needs bigger tires."
#13
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Originally Posted by Woodbert
The first thing I thought when I saw the picture of your truck was, "needs bigger tires."
Last edited by BT17R; 03-21-2004 at 06:00 PM.
#14
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Originally Posted by BT17R
So true. I have a solution in the works, stay tuned. Lots more choices in 16" tires, I'm finding.
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