transmission temp light on/off
 

Hi.. I have some issues with my trans temperature light...
while driving mi 01 Discovery at low speed or doing lane... the light goes on... and if I start driving a little fast the light goes off.. same if I put the trans in "N" for a while.. the light goes off....

Does anyone has been into this problem???? need some advice.... I plan to change the trans oil filter... do you think this could help??? or maybe the sensor is failing... thanks for your help/comments....

I forgot.. the trans works fine.. no problems with it... just the light goes on in low speeds...

Check your fan clutch. When engine cold, spin fan by hand and release. Should continue about 1/4 turn, maybe less. Will feel like peanut butter inside. Engine warmed up, stop engine, spin by hand, release, if more than one revolution (freewheels) - it is time for a new clutch. At low speed, the fan provides cooling for tranny and everything else; at road speed the 50 mph breeze takes care of it.

Could also be level of tranny fluid, good idea to do fluid and filter 30,000 mile intervals, not the lifetime or 150,000 some do.

And can be switch. But the idea of it cooling off when driving makes fan clutch a possible.

Your transmission is overheating.
Check for debris between the radiator and a/c condenser.

ok.. good tips.... going to check them.... and of course going to change the oil filter and oil...

thanks a lot.. and posting comments later....

And if tranny overheating, engine is holding hands while they sit in the hot tub.... can't trust that temp gauge....

I just noticed my transmission light doesn't go on when I turn the ignition on. I've ben getting a hot floor too. My cooling system is working flawlessly.

The OP could also have a problem with the transfer case. On a D2 the TC and the tranny share the same warning light. But I would expect that a TC low on fluid would not cool off when engine speeded up.

Slang - see attached pix, the oil temp switch on transfer case (your's won't be this clean). Short that wire to ground and see if you get a warning light. If not, add to the list. But check tranny fluid and transfer case fluid.

thanks sava....ill move the tranny inspection up on the list.

Hi,
You may damage your transmission running it hot.
Reason- Fluid will not protect at extreme temperatures.
You'll toast the clutches eventually.

There is an interesting failure in the Range Rovers.

The Transmission fluid will overheat due to the lower 1/3 of the radiator being
clogged.

This means-
Coolant will not flow to the 1/3 lower part of the radiator. That part of the
radiator can't add to the cooling capacity.
The clog is actually the inner core of the radiator gummed up
where the coolant is.

Diagnosis - pull the radiator drain plug. Coolant comes out SLOW - bad radiator. Replace ASAP.

This will AID in cooling down the transmission fluid in the transmission.
Bunches of Range Rovers fail due to this problem.

I was thinking of buying a RR a few months ago which had a defective transmission.

Instead I happened on this Discovery II.

I would not ever drive with a transmission overtemp light on.
Anything you can do to cool down the system is good.

The fan clutch advice is good.
Plus - pull of the plastic shrouds and see if the radiator is full of dirt, grass, dust.
Reverse hose that out.

Fan clutch must be good.

When the truck is cold, try to spin the fan.
the fan should not spin easily.
The fan clutch should offer resistance even when cold.

A/C electric fan which doubles as an "way too hot" fan will need to be working too.

No drain plug to pull, and hard to reference what is fast flow and what is slow. D1's have tranny oil cooler built into radiator. D2 has separate tranny cooler, in front of radiator, so engine temp is no issue for tranny. Electric fan running is helpful at slow speed. And the temp light is for both tranny and transfer case, you don't want to rebuild either, so check fluid levels.