XPLORx4

aka 9.3% off. That translates to a 9.3% reduction in power to the ground, 9.3% increase in engine load for a given rpm, etc. etc. I'm sure the % error isn't expressed as simplistically as that, but you get the point. Did you ever notice if you carry around 4 passengers in your truck that it feels more sluggish, tends to accelerate more slowly? Well, that's a lot what changing tire size without regearing is like. The bottom line is that an increase in transmission shift times after a 9.3% increase in tire size is completely normal.

No, the TCM isn't set to shift at certain RPM's and certain speed, it's set to shift at certain RPMs, and certain engine loads, in addition to other factors such as the VSS and the TPS values. That's why if you accelerate gently, the transmission will shift much earlier than if you accelerate rapidly. Bigger tires with unchanged gears increase the engine load for a given RPM and TPS value input.

Yes. Link

Unfortunately, the Pathy ECM (Engine Control Module) and TCM (Transmission Control Module) cannot be reprogrammed to compensate for larger tires. Resetting the computer won't help, since the computer isn't aware of the more-difficult-to-rotate-with-stock-gearing tires. It only resets the fuel trims, it doesn't change the fixed programming of the TCM and PCM. All it knows is that it's now harder to accelerate. It doesn't know WHY it's harder to accelerate. The effect is actually not much different than towing or carrying a lot of heavy cargo. That's why my initial response said "lighten your right foot or regear". The description matches exactly my experience after converting from 235/70R15 tires to 31x10.50R15's. I noticed that my truck could barely even get into overdrive and stay in overdrive at 70mph on level ground. That's what motivated me to regear.

Fueler has it right. The higher gearing (numerically lower @ 4.363:1) with larger tire sizes not intended for use with the higher gears will force the engine to work harder than it used to. The transmission programming and gearing is designed to shift at certain TPS position, RPMs and/or certain engine loads. With the engine working harder to turn those bigger tires the higher gears, the engine load is higher for a given RPM, so it will take longer for the engine to reach the pre-set engine load value to trigger the transmission to shift. If your right foot is lighter while accelerating, then the engine load will be lower, triggering the tranny to shift at lower RPMs. Regearing will compensate for the larger tires, so the engine and tranny can be restored to pre-tire-size-increase performance.

Yep, that sounds about right. No way around it except to lighten your right foot a little or regear.

Congrats on the new FJ. I hope it serves you as well as your Pathy has! On your new FJ, be sure to keep a close eye the inner fenders for body cracks as you rack up miles. <--150+ page discussion thread! Looks like it may be a design flaw, but apparently Toyota is addressing the problem, and the issue may be already fixed in later VIN#'s.

If you have a '98 QX4, I doubt have a drive-by-wire throttle. Does your TB look like the one shown in the upper left corner of this photo?

Maybe you need a new distributor. The coil is built-in to the dist.

Hi, I just looked at your profile, which says your rig is a stock QX4 with 16" wheels, but the year is shown as "1987". Do you mean 1997? Anyway, the "pump" you're referring to is actually an oil pump in the AWD transfer case that is, if I understand correctly, powered by the rotation of the front driveshaft. Disconnecting the front drivetrain from the wheels results in the pump not rotating, which (I suppose) is a bad thing! However, some people have been successful in installing manual hubs on AWD R50's. The question I would put forth is: Why do you want manual hubs? Are you just hopping on the bandwagon, or do you have some REAL justification for wanting them? As for cleaning the TB, it must be done with the engine off. Remove the rubber intake elbow on the TB, and spray TB cleaner into the butterfly valve as you manually open/close it. (Place a rag under the TB opening to catch any TB cleaner that will certainly drip out.) Reassemble the intake ducting, then restart the engine to help burn away the TB cleaner in the manifold. For further cleaning, if your rig is a '97, you should be able to use the EVAP port just behind the butterfly valve to ingest SeaFoam into the intake to clean it. Search the forum or the 'net for "SeaFoam" for more info. The part circled below is the EVAP hose which you can disconnect (from the EVAP purge volume control valve) to ingest SeaFoam (instead of disconnecting the brake booster hose):

zonian- Getting better gas mileage is totally the wrong reason to get a snorkel. There are way simpler ways to achieve the ram-air effect to get cool air through the intake. Take off the lower part of the intake that's behind the bumper, in front of the wheel well. Cut open the plastic underneath the left turn signal and put a wire mesh screen (such as a rain-gutter guard or crawl-space vent screen) over the cut-out. Use a 3" or 4" plastic flexible drain pipe or dryer hose to connect the hole under the turn signal to the bottom of the intake.

The difference in your new mileage vs old mileage is 15.9/14.44 - 1, or about 10%. If your observed mileage has gone down since installing the 31" tires, then that's the expected result. And to be honest, a 10% observed change is actually pretty good! Here's why: 31" tires are larger than the originally-installed size of 235/70R15. This will introduce an error in the speedometer and odometer. 235 tires are about 28" in diameter. 31" tires are 31/28, or 10.7% larger. The larger-sized tire will cover more actual distance than your odometer indicates. In other words, your odometer will read 10.7% lower than you've actually traveled. Additionally, 31" tires are heavier and have a little higher rolling resistance, which will tend to reduce fuel economy. Finally, the 4.363:1 final drive ratio (ring/pinion gears in the differentials) in your 97 XE is intended to be used with smaller tires in order to help keep the engine operating in its most efficient RPM at typical highway speeds. The larger tires shift the RPM lower, forcing the engine to work a little harder (i.e. out of its power band) at typical highway speeds. All of these factors combine to work against good fuel economy.

It's not motor oil. It's the oily separation of the CV joint grease. (Over time, grease separates in the same way that natural peanut butter separates and needs stirring.)

First, there is no inspection cover to pull off. You'd need to remove the entire diff to "inspect" the gears: Second, you should be aware that the stock LSD is actually not that effective in very high-bias-traction conditions (i.e one wheel has lots of traction, one wheel has nearly no traction). The phrase "limited slip" differential is sort of misleading. It should be called a "limited traction-equalizing" diff.

No, it's not from too much grease. You've cross-threaded the spindle. That's why it won't go on further. Remove everything down to the bare spindle and clean it all off to inspect the threads. And, sorry, I can't remember which side of the bearing locknut faces outwards.

Try completely removing the rotor, hub, and bearings to expose the bare spindle. If the threads on the bearing locknut aren't stripped (or if the other side of the locknut is still OK), you might be able to screw it on to help clean up the damaged threads. If that doesn't work, try using a dremel tool to carefully recut the threads enough to get the locknut on. If neither of those approaches works, you may unfortunately need to replace the spindle. You can probably find a used one from a wrecked Pathy at your local junkyard. Since the bearing locknut is basically what holds your wheel on, you really don't want it to take chances with it if the locknut cannot be securely fastened due to damaged threads.

Subsequent orders for the bumper never apparently materialized. I had been sending inquiries directly to the builder of my bumper, but that's the last I'd heard from anyone about it.

Can't fit 32" diameter tires on the stock 17" wheels. The backspacing won't provide enough clearance to the strut. To upsize the tires, you'll need new wheels. There's a dude on the 4x4parts forum caled "kidrock". He put some 22" wheels on his ride. I think he's trying to find a way to fit 26" wheels. He's sorta nuts, 'cause he'll never squeeze 26" wheels and tires in there, but it might give you some ideas on tire size, wheel offset, etc.

That size won't fit. If you're lucky, you might be able to get some 255/70R17's on, but you may not have enough clearance between the tire shoulder and the lower spring perch on the strut. Best thing to do is the have your tire retailer perform a test-fit before committing to the purchase.

CDN$200 for ATF + diffs may not be that unreasonable. Amsoil and Redline fluids run between US$10 and $12 per quart. A full tranny flush requires about 10 quarts ATF, the t-case needs about 2-1/2 quarts ATF, and the diffs need a total of 5 quarts of 75W90. That's 18 quarts! When I flushed the tranny with Amsoil ATF, my friends jokingly chanted "ka-ching ka-ching" as each quart poured in.

I no longer run synthetic oil in my engine ever since it developed a rear main seal leak. However, I did use M1 5W30 for many miles without problems. I'm also running Amsoil SVG in the diffs and Amsoil ATF in the tranny.

Congrats on the new ride, dude!

I've always been able to unclog them by removing them (by squeezing their plastic tabs from the under-hood side), then inserting a needle (or safety pin) into the nozzle. I also use the safety pin/needle to aim them.

Yes, but beware. They're pressed in very tight, and I had to whack each one several times with a 2-lb. sledge to get them out.

Do you need EXACT measurements? If so, sorry, my struts are attached to the truck. However, from memory, I would guess the studs are no more than an inch in length, with the top few mm being unthreaded.