Just bought a '96 T100 SR5 4x4 xtracab 5 speed 126k miles

This past week had timing belt, water pump, new tensioners, coolant flush, fuel injection cleaning, and changed all diff/tranny/transfer case oil.

1) Shop found 2 almost full teeth clinging to the magnetic drain plug on the front diff, no shavings in oil. Should I assume that they were consecutive teeth on the R&P? Should I install some manual hubs and just wait for it to grenade, then unlock the hubs so I can still get home? What kind of reliability do you think it will still have missing two teeth? The tech fished around with a magnet and didn't fine any other pieces.

2) When cold, truck idles high at ~1500 rpm with the clutch fan making a ton of fan noise until i get moving. After warming up, idle hovers around 1200 and sometimes drops to between 900-1000 rpm. Is this normal? I asked the shop about it and they said to get a tank of fuel through it and call them if it is still doing it because it could be from the fuel injection cleaning.

Any suggestions or help on these two problems?

Hi!

WRT your front axle, it's only locked if the 4WD light is lit on the dash. I don't think you'd need manual hubs. One side of the front axle is disconnected in 2H, this is all controlled by vacuum.

If you park the truck in a quiet place and open the window, there is still some vac pressure after you stop the engine. You should be able to to hear the thing moving as you shift between 2h and 4h with the ignition on. When there's no vacuum pressure left, 4wd light does not come on, proving that that light's only on when the axle's locked.

So driving in 2H only one of the wheels is connected to the diff; the input and other wheel are free, you should still be able to drive it.

WRT your idle it should idle at 700ish after it's warm with a/c off and no load from things like power steering.

Here's the idle speed procedure from the 97 manual:
IDLE SPEED
INSPECTION
1. INITIAL CONDITIONS
(a) Engine at normal operating temperature
(b) Air cleaner installed
(c) All pipes and hoses of air induction system connected
(d) All accessories switched OFF
(e) All vacuum lines properly connected
HINT:
w/ EGR: All vacuum hoses for EGR system, etc. should be properly connected.
(f) SFI system wiring connectors fully plugged
(g) Ignition timing check correctly
(h) Transmission in neutral position
2. CONNECT TOYOTA HANDûHELD TESTER OR OBD II SCAN TOOL (See page EMû8)
3. INSPECT IDLE SPEED
(a) Race the engine speed at 2,500 rpm for approx. 90 seconds.
(b) Check the idle speed.
Idle speed: 700 ? 50 rpm
If the idle speed is not as specified, check the IAC valve and air intake system.
4. DISCONNECT TOYOTA HANDûHELD TESTER OR OBD II SCAN TOOL

If you want to verify ignition timing it should be at 12.5 to 22 BTDC. With a jumper between TE1 and E1 on the diagnostic connector under the engine, it will shift to 8-12 BTDC, at 700 rpm idle.

i would go to manual hubs regardless. a 4:10 diff front is very easy to find. go check pirate. i bet you can get one for $50-75. i think i may still even have the one from my 4runner from when i upgraded to 4.56. it was non-ADD though, so you'd have to go with manual hubs.

Do I have 4.10's if my Axle Code is A10A? I figured that my axle ratio was a 3.9 or something similar and that 4.10's came on Auto SR5's w/ 31" tires?

I wonder if the front diff can still be used for a while with 2 teeth missing?

Are 2nd Gen 4Runner and Pickup 7.5" front diff's the same as the T100's? Does the T100 just have longer CV's to make up for the increased width?

that is correct...you could go to the junkyard and pick up a 7.5 out of any 86-95 truck if you find the correct ratio...ive got a buddy getting ready to sell his front third with 5.29s if your planning on a lift and doing the rear... <img src="/forums/images/graemlins/evil.gif" alt="" />