550 gearbox slipping/ engine surge

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I would have to drive mine again to re check but it feels like a gear not a torque converter lock. With 7 of the buggers the RPM change is not very great. As far as I know the TC locks up very early on in the piece.

Either way what I said stands, it would be far better with more hysteresis in it so that whiecever it is doing stayed done for a decent period.
 
Hi guys here's a quick video in manual mode ,not the best but yer https://youtu.be/QvdGF8kznd8
Hey nedm1989 see that fella on your post point it towards the tccs( torque converter control solenoid) ? Iv actually considerd changing that out,if I can find one I will change it out and repost..just need to find one...
 
Iv come to a conclusion that it's a softwareware glitch from the ecu to the torque converter,next is to find a way for a update,or tcm remap...but is only a guess��
 
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I keep hearing conflicting stories about people tuning the gearboxes in these things, I think I remember someone on the navara 550 facebook page saying something about finding a place but not sure where they got up to, I find it hard to believe they'll tune a 350&370z but wont touch the 550s box even thought its the same thing but with a transfer case stuck on the end.

I've been trying to find something that makes sense about it all as even though it seems ok and I found nothing alarming in my atf when i serviced it, I will say I did mine at 80000k and imagine that has been the first time its been done, but I'll be doing it again in 40000ks.
 
I spoke toke to uprev about tuning my box. They are very well known for tuning the 370 box. They replied with this first.
"We would need the ecu/rom number to find out if your truck is supported. If you do not have an uprev cable to hook up to your vehicle you can go to one of our licensed pro tuners to find out or call the dealership with your vin number and ask what the latest ecu update number is."

And then the next day with this.
"We do not have support for the Navara im sorry to say."
My 550 is currently in the middle of installing bigger injecter nozzles, high flow turbo, piggy back ecus and obvi a fresh tune; and I'm really worried that the gearbox is gonna go since they are only rated to 600nm and already with my current work and tune done I was sitting at just over 700nm. Last time I spoke with wholesale transmission, they said they don't do a valve body for the box. :-/
 
It's not an issue man, I thought I posted in here about it already but maybe it was in another thread, the manual actually advises that the gearbox was made to do that and that's probably why if anything but nissan matic s is used the box slips because it won't have the correct friction modifiers in the atf for that exact application.
I used to be worried until finding the part in the manual saying this is totally normal, just a bit more comforting.
 
Hey bud,I find it hard to believe they are supposed to slip,mainly because others say there's doesn't do it...and mine hunts/revs wenever I go to put my foot down wich just creates a power loss especially when towing..it's horrible... but you may be right.....
 
Well I have fixed the dreaded 60km/hr surge in revs. Nissan has just replaced my torque converter and the transmission now shifts properly and no fluctuations in revs at various speeds. Didn't think it would fix it but it did.
 
Well I have fixed the dreaded 60km/hr surge in revs. Nissan has just replaced my torque converter and the transmission now shifts properly and no fluctuations in revs at various speeds. Didn't think it would fix it but it did.
Just come back for a look at the forum its been a while...how's it going after the fix mate? Still all good or sold the beast...cheers
 

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