I have searched and I think that the Discovery has a computer that won't let the tranny shift until it warms up.

Mine takes a good ten to 15 minutes of driving before shifting normally and I was wondering if it is supposed to take this long?

It is parked outside in about 10 degree weather (even less if wind chill, etc.)


Why is it that only Land Rovers do this, as I have never heard of a different brand doing it?

 

Completely normal, it's just trying to get your trans fluid temp to normal operating temps faster. here lately in the NE it's been 15-20 degrees at night and it takes a good 10 minutes for mine to shift normally from cold start.

 

I am assuming you have a D1 based on your avatar. Can you please describe the symptom more specifically. Does it stay in first for few minutes no matter what the speed / throttle opening is? Does it go into second but not into third. Do you let it warm up when you start it in 10' weather. If, I am correct, the D1 shift pattern is controlled by a link from the throttle plate / the governor / maybe a vacuum modulator???.

On the other hand, the DII like a 2004 is electronically controlled and engine / transmission fluid temperatures determine when the lockup torque converter clutch comes on.

 

Well if you have a DI this is not the case.
If you have a DII then LR's are NOT the only car to do this, my Montero was the same way, as was my Infiniti, and Mazda.
It is actually a emissions thing, when a engine is cold it is the least efficent that it can be. Same thing with the catalitic convertors.
Cold cats do not due their job, that is why your exhaust smeels funny, it is raw untreated exhaust gas.
If you drive when the engine is stone cold your MPG will suck a$$.
By delaying the up shifting you force the engine to turn faster RPM which will warm the engine faster.
Let it idle and warm up for 10 mins before you drive and see what happens.

 

1995 D1

It will stay in first for about ten to fifteen minutes, well after the engine is warmed up. I let it idle for about 30 seconds before driving.


I can do 30 at 5000RPMs and it will not shift, I do not want to do that continuosuly however, so I go down to about 20mph at around 3000RPMs

Even after stopping and shutting the car off, then starting it up again (after engine has been warm for 5 minutes) it still stays in first.


If D1s do not do this, what else should I be looking into? If it is a vaccum that controls this I can see that being a problem, as my hoses are old and cracking, but that doesn't seem right

 

This is NOT a feature, it is a emmissions thing, but only on DII's with a electronic transmission.
YOU HAVE A PROBLEM!
You CANNOT spin a cold engine at 5,000 RPM, you WILL blow it up.
When a engine is cold the oil is thick, it has not reached all of the engine parts after 30 seconds, your pistons are egg shaped, your lifters are not full of oil, you are doing serious damage to your engine.
When it is that cold out you need to let the truck warm up for 10 mins or so.

Now as for your problem, you need to check your transmission fluid level.

 

When was the last time you changed your transmission fluid, how many miles on the D1.

 

190k miles

I only do that once the engine is at operating temp... before that I go around 3500 if I have to, but I try to keep it lower

My fluid level is good, but should I drain the tranny fluid and put new stuff in? It smells slightly burnt, but nothing terrible

 

I have to assume that the tranny fluid has never been changed, as no other fluids had been.

This means the filter has probably never been changed.

Is it simple, just a tedious job to change the filter? Should I?


I think that I would need to change the fluid, drive for 2 or 3 days, then change again, since it has not been changed either ever, or for a LONG time


Any thoughts?

Also... what other things could be causing this?

 

The reason its "holding" on is because the governor in the tranny is likely to be partially blocked up with crud, probably due to lack of servicing, as the box warms up, the oil gets thinner and can manage to get around ok, so the box shifts as normal. Poor condition (old / burnt / contaminated) ATF fluid will have the same symptoms as well.

I would suggest you change the box fluid and filter with a "cheaper" fluid, and run the truck for 2 or 3 hundred miles. Then chnage the oil and filter again with a higher spec / proper fluid.

ATF fluid is detergent based, so it will "clean" the box out, how everquite oftenthe problem can get worse as more "free" dirt cleaned / loosened by the new fluid blocks it up even further. So be prepared to need a new tranny, But its DEF worth trying a fluid / filter change flush first..