Torque Converter Not Disengaging?

_Shonky_ · Nov 21, 2013

G'day guys, first time caller, long time listener

I'm having some dramas with my 07 Nissan Navara D40 Auto.
About a week ago my overdrive off light came on my dash even though I don't ever turn it off or even touch it. As soon as that happened it would drive normally at higher speeds of 60-70 above but on take off its as sluggish as sloth waiting in line at the RTA. Pushing the O/D button achieves nothing and changing the gears to 1st or 2nd doesn't affect it either. I've since taken it to my local Nissan Dealership and they've informed me that the torque converter has locked up and won't disengage and will need a completed transmission overhaul of up to $5000. I don't believe it'll cost me that much because not 6 months ago, they wanted to charge me $2500 for an alternator on my Patrol... If anyone might have experienced anything like this and have a much better solution to my issue that would be greatly appreciated.

Thanks

Shonky

4 naving · Nov 21, 2013

I doubt the converter has locked up as it would stall when you come to a stop. id check all the easy stuff first like oil level and condition, electrical connections and fuses. does the over drive have a fuse.

Old.Tony · Nov 21, 2013

Welcome to the forum.

It's sad that you had to arrive with another story of a dealership that talks out of its arse but that's the hand we're dealt so let's get on with it.

4 naving is spot on the money - the torque converter can't be locked up. Overdrive might be locked OUT, the TCC solenoid might be faulty, the torque converter might have developed a fault (around the TCC) but if the TC was locked you'd be needing a clutch to get going.

First thing I'd do is rummage around the engine bay. There are two primary places I'd be looking. From the image in my garage, that I've linked to here:

The first fuse box in the left area of the picture holds relays for the transfer case. Pull EVERYTHING out (one at a time) and reinsert it TWICE. What you're doing is cleaning the electrical contacts.

Now, in that pic, I've labelled the ABS unit AND the air filter. Behind the air filter and beside the ABS unit (to the left) is another box and surprise surprise, that little bugger has fuses and shit in it too. Same deal as the first box - remove, replace. Take note of any that have obvious corrosion signs on them - you might be well served to give those a spritz of WD40 while they're out.

I'd start there. Electrical gremlins are the worst bastards to find, and doing this spring clean (it's bloody spring now, after all!) will only help to eliminate one area of concern.

Next area is the plugs on the side of the transmission housing - remove, spray, reinsert.

Then see how it goes. Look, it's possible that the overdrive has failed - but let's (as we should always do) look at the less expensive option before we start suggesting to pull the 'tranny out of a 797F and use it instead of the (somewhat weaker) Navara box.

JPMC · Nov 22, 2013

Something else Old Tony forgot is to check and clean the earth terminals in the engine bay under the ECM and behind the air cleaner. There maybe a Transmission one under the ute too, can't say I've looked for one before though.