Temperature Data

[Sandroad]

Temperature data from a stock ’04 LC with 114,000 miles. I’m chasing a new odor of too-hot oil that’s worrisome and ended up getting some baseline on several components. Ambient air temp was 50. I took all these within 10 minutes of shutdown after a 165 mile trip, with this pattern:


75 miles at 70mph
Short fuel stop
90 miles at 70 mph
7 miles at about 40 mph
Temperature measured parked in my garage, all within 10 minutes of shutdown

From front to back, all temps in F and taken with a new infrared thermometer.

Radiator 184
Battery 92
Fan clutch 144
Serpentine belt tensioner 144
Engine oil filter 166
Power steering pump 132
Power steering reservoir 121
Outer CV, both sides 86
Front differential 122
Front U-joint, front driveshaft 94
Transmission 132
Transmission oil pan 113
Rear U-joint, front driveshaft 124
Transfer case 147
Front U-joint, rear driveshaft 151
Muffler 168
Rear U-joint, rear driveshaft 97
Rear differential 118
Rear wheel bearing, both sides 84

I’m going to keep checking temps and looking for leaks. T-case seems a bit hot and the new odor is of gear oil or grease. The hottest driveline component is a U-joint, so that will get some attention too.

 

[badlander]

The U-joint temps caught my eye as well but though they are out in the rushing air they are probably getting a lot transfer heat from the diff's so maybe that is normal. Everything else looks good.

 

[AimCOtaco]

I've found that if I fill my steering reservoir to the max mark it will sometimes blow off some fluid when it gets up to temp the first few times. It stinks like something is really wrong when this happens. Might check that if you've recently topped it off. Thanks for sharing your numbers.

 

[Skidoo]

I have seen transfer case temps in the 180 range, I think you will find they run warm.

 

[Supra88]

Sure it's not valve seals leaking onto your manifolds/exhaust? That's a common problem on the 100?

 

[ton504]

Ive serviced hundreds of lx450, lx470, lx570, gx470, and gx460s. The transfer case fluid is always the "worst".

Typically the first major service at 30k, the front and rear will have fine metal flakes/powder(break in/hypoid bevel gears?) The center diff will just be discolored but still clear(helical gears?)

The 60k services, the front and rear diff oil comes out clear with a hint of discoloration. And the center diff comes out the same as the 30k which is always darker that the front/rear. Im not sure the capacity but it always less pumps to fill the center. Not a lot of fluid to cool it off. And this is partly why I think the temps are higher for the transfer case and the ujoints. Im sure the transmission plays a role in the heat transfer.

The short version: the center diff oil comes out more discolored but still clear across the board. So I'm guessing they run a little warmer than the front/rear. Prob due to less oil capacity and being connected to the transmission(heat transfer)