What is a torque converter?

I own a 1995 Ford Explorer XLT 4x4 6cyl 4.0 that has about 143,000 to 144,000 miles on it.

Just dropped it off at the dealer this morning on my way to work. Im sitting here waiting for them to call and let me know the damage.

My O/D light is flashing. Im having them read the code.

Plus when the car is warmed up I can smell an antifreeze odor, but there is no visible AF leaking.
(Could be some window wiper fluid that sprayed over the engine when a tube came loose)

Anyway, before I have then do any work on the truck,
I was hoping to post my code here to get some advise.

The truck runs perfect when the o/d light is not flashing.

I've been reading in previous threads about the torque converter and the TPS sensor.

Someone said a TPS sensor costs from 30 - 50 dollars. Im sure it will be twice as much at the dealer.....I read it only takes 5 minutes to put in, so I imagine the dealer will charge for an hour.

Can someone please explain to me what a torque converter is and approximately how much it costs to replace it.


Thanks,

Vonnie

The torque converter is what couples the tranny with the engine. It uses hydraulic principals to make torque. I am pretty sure the tranny has to come out to replace it, so although the part probably inst terribly expensive, the labor might be...

a torque converter is a fluid coupling that connects the engine to an automatic transmission. torque converters in general are not that expensive, though you can buy some pretty pricey high performance ones.

they will bang you on the labor replacing one since the transmission needs to be seperated from the engine.

labor alone on that job will probably run you $400 maybe more depending upon where you go.

The O/D light flashing is most likely being caused by something other than the Torque Converter itself. There are a number of sensors that can cause that, the TPS is certainly one, but there are a few others such as the speed sensor that is located in the back of the transmission. Does your cruise control work when the O/D light is flashing?

For your question about what exactly a torque converter is, you can pretty much define it as an automatic clutch. It goes between the engine and transmission, providing a non-solid link that will allow the engine to continue running when the vehicle is in gear and stopped. The principle behind it is like taking a bowl of water, putting a few ice cubes in it, and then stirring it with a spoon. The ice cubes will spin in the bowl, but you could reach in and stop them while you continue to stir the water. When you let go, they will start spinning again.

Since the torque converter is a non-solid link, there is a certain amount of energy that is lost between the engine and tranny -- this is where O/D comes in. At cruising speeds where the engine is in a decent power band, the torque converter can "lock up", essentially becoming a solid link. This is referred to as overdrive, and something that is controlled electronically in newer vehicles rather then mechanically.

Finally, the anti-freeze smell you are getting is most likely coming from the heater core shutoff valve. If you look under the hood on the passenger side, follow the hoses that come out of the firewall back toward the engine. You will see a valve with 4 heater hoses and a vacuum line -- and will most likely see a small amount of antifreeze leaking from it. This is very easy to replace and only costs around $25 at auto parts stores.

Good luck!
Blue

Ok the Ford dealer called me and gave me the codes.
674-Incorrect Gear Ratio
335- DPFE Emission Sensor.

Here is the damage, they said I need the following:

Transmission fluid and filter change $129.00
(they said the tranny fluid is burned-what ever that means)

DPFE Emission Sensor $187.82

Water Pump $311.00
(this is where Im getting my AF smell)

Ty Rod $276.86
Ball Joints $449.14
Computer Charge to read codes $68.00

I told them to change the water pump and put in the trans fluid and filter.

I dont think I need ty rods and ball joints.
They based their decision solely on the "clunk" noise.

If any of you have had an o/d light flashing problem,
you have had a clunk noise when the vehice comes to a stop. I told them the ONLY time I hear the "clunk" is when the O/D light is flashing. I'll have to investigate this more, at the moment I dont believe I need to have the ty rods and ball joints changed.

As for this DPFE (Emission Sensor) Im not having them put this in for $187.82, until I can find out where it is located on the vehicle. Hopfully with a little instruction, I may be able to put this in myself? Has anyone ever replaced this before?

Bluevolume,

yes my speed control works when the O/D light is flashing. The dealer didnt mention anything about my torque converter, thank god! They only mentioned what I have posted above.

I did replace the heater core shutoff valve a few months ago. That is the first thing I checked when I started smelling the antifreeze. It is very easy to replace, I did it myself with the help of a guy I work with.

The dealer is telling me the reason I smell the antifreeze is because my water pump is bad. They better be right! I told them to replace the water pump, which they are probably replacing right now as I type this message. If I spend $300.00 for nothing, they will have one wild woman on their hands.


Thank you all for your defining what a torque converter is.....now I have a clear understanding. I'm so thankful I found this forum.

Thankfully yours,

Vonnie

When ever in doubt...I go here.

http://auto.howstuffworks.com/torque-converter.htm

More than you required?

J

I was always taught that overdrive meant any gear ratio less than 1:1. So .70:1 would be overdrive as well as .65:1. It just means the engine spins slower than the driving wheels. When the torque converter "locks up", you just say it locks up. That's how the 5R55E feels like it shifts 6 times. When your RPMs drop very slightly, the TC locks up.

Part of the way the 5R works is that it applies the O/D ratio to 1st gear. So, you get 1lo (2.47:1) and 1hi (1.85:1), 2nd (1.47:1), 3rd (1:1), 4th (0.75:1). This way, Ford can have 5 forward speeds without using 5 forward gears. It's pretty smart if you ask me.

The DPFE is very easy to replace- two bolts, two hoses and a wiring harness. Its located on the drivers side of the engine towards the top. Do a search, its a common problem. A new one is only around $50 at Autozone.


$68 is a rip-off to read codes. All you need is a piece of wire and you could have gotten them yourself.

Yes buy the DPFE from Autozone. They call it EGR Valve Pressure Sensor. Next time you should just buy a code scanner. I bought one with an LCD screen for $35 from Schucks, that's about half of what the dealer charges, and this is reusable.

Originally posted by jobunn
A clunk when the tranny downshifts into first is very common when the overdrive light is flashing. It has nothing to do with the tie rods or suspension.

Click to expand...

I have this "clunk" when stopping, it is not audible, just a thud and it happens everytime I stop. If not it will do it when I let off the brake. I can't seem to figure it out. Maybe you have an idea? Is it axel twist or 1st gear? No flashing lights or codes.

I had that problem too. You need to remove the rear driveshaft from the rear diff, which will allow you to pull the driveshaft out of the transfer case end and grease up the splines really well with some good grease. No more clunk. Do a seach with key words like " rear driveshaft", "splines", and "clunk".

Originally posted by 2001ExpSport
I have this "clunk" when stopping, it is not audible, just a thud and it happens everytime I stop. If not it will do it when I let off the brake. I can't seem to figure it out. Maybe you have an idea? Is it axel twist or 1st gear? No flashing lights or codes.

Click to expand...

had the same problem on my X just grease up the slip yoke and the problem goes away.

I will do that, by chance do you know the size of the bolts on the yolk? I took them off a few yrs ago and for some reason I am thinking it's 12mm, which I need to get. If you know that would help, thanks!!!