Girl in need of some lessons on why my 1998 L navagator wont drive

[Anndee]

I have 1998 lincon navigator wont drive but goes in revers..

 

[German Engineer]

Hello Anndee,
You're not giving much information. And there are a lot of things that could potentially be wrong causing this.

Does the check engine light come on or not?
Do you have an OBD2 Scanner that can read out error codes? If yes what codes does it show?

The first and cheapest things you could do is check all the relevant the fuses (for this you'll need to have a diagram that lists and shows all the fuses your car has and then check all the fuses that might be related to transmission if any fuse is blown. Blown fuses are easy to spot. If you don't know how to tell if a fuse is blown google for pictures online. It's an extremely easy thing to do and check.)
The automatic transmission has electric components like shift solenoids that can go bad or if a fuse is blown not be powered and then of course not work.

Check the transmission fluid (Follow the instructions on the dip stick or in the manual, you likely need to check with the engine idling in park standing level). Is it filled to specifications? Is it discolored or smells burnt? Here two links how to check and what to look for:
AGCO Automotive Repair Service - Baton Rouge, LA - Detailed Auto Topics - How To Check AutomaticTransmission Fluid
AGCO Automotive Repair Service - Baton Rouge, LA - Detailed Auto Topics - The Color of Automatic Transmission Fluid

You could of course also have a mechanical failure. Or a broken shift solenoid and other possible things. But at this point with the little information you have at the moment anything is more or less speculation.

So try diagnose the problem as much as possible!

Depending on how mechanically inclined you are and depending on the error codes and the result of the simplest things you can do first, you then could additionally also drop the trans fluid pan and check for any shiny metal objects (not the black stuff just shiny metal bits of aluminum). If you did that for example and found any of those then you'd know there was a major mechanical problem.

For now there's really not much more to say at this point, I hope this helps. And if you're interested watch some YouTube videos on transmission symptoms, but don't take everything for granted there and be critical and watch videos of different experts not just one. There is sadly a lot of half truths and even some misinformation, but it certainly helps getting a better idea and what mechanics check for when the diagnose an automatic transmission.
ScannerDanner for example has a really good and trustworthy YouTube channel and also some videos where he diagnoses electric components of transmissions.

Good luck I hope it helps a little.

 

[J_C]

Welcome to the forum. You will probably receive more specific, applicable advice for your vehicle if you instead post in a Navigator (meaning Ford Expedition) specific forum, and only that forum so you don't receive redundant replies.

 

[RandomNerd2000]

You have a 4R70W trans more likely than not, which is in need of a rebuild. A google search would have answered your question easily, just google "4R70W no forward gears"

 

[CDW6212R]

You have a 4R70W trans more likely than not, which is in need of a rebuild. A google search would have answered your question easily, just google "4R70W no forward gears"

The Navigator has a DOHC 5.4 engine, I don't think the 4R ever was behind those. It should be the bigger trans, the newer big four speed, 4R100 I think it is.

First check the ATF fluid level, on level ground. That has to be within the cross hatched area of the dipstick.

 

[RandomNerd2000]

@CDW6212R AFAIK the 4R100s and 4R70Ws are within a split hair of the same transmission, with just minor differences and beefing up for the 4R100. Either way, no forward gears but having reverse is bad IF it's full of fluid.

OP, Have you tried the manual 1st and 2nd gears down at the bottom of the shifter?