STX 550 7 speed box

Hello, i think i want to have a little bit of a rant!! i have just bought a few months ago an stx 550 and the truck is going good no probs at all which is good with only 7k now on the clock but the gearbox irritates the shit out of me, you will be going along on the pan flat and it will not shift up a gear until certain speeds are reached, so for example if you are going along at 60kph it will just sit there in say fourth gear but will nearly be up on 2000rpm's you then go to 61kph and it will shift up a gear should you drop speed ever so slightly it drops down the gear again, seriously it's up and down the gears like a fiddlers elbow!! very annoying when you are driving on a speed limit, if you put it in manual mode to try and overcome this hurdle it won't physically let you change gear manually, is this how they all are?? what is the point having a manual mode when the effing thing will not let you change gear?? i had an audi s3 with a dsg twin clutch gearbox and that was a absolute work of art you could fire gears at that in manual mode as fast as you could pull on the paddles no problem at all, whats is even more annoying is how powerful the nav is it could quite happily turn the next gear on the flat, having said all that when you come to a very steep incline the thing cannot wait to get to top gear and it is then very reluctant to drop the gears when they are most needed it will nearly drop as low as 1000rpm sometimes before dropping the gears then sets off like shit off a shovel surely this is not right?? final stage of the rant is say you are wanting to overtake someone and have it in manual mode revs set already to pass just on the torque of the motor, you pull out give it some shoe and the shitty gearbox still drops yet another gear leaving it revving it's cock off and needing yet another gear change even though i had it in the gear I WANTED! anyone else found this with theirs? decent truck nice engine absolute shite gearbox in my opinion. Rant over!!

maybe get this changed to the rant section, then speak to nissan see if there new software for the tranny emu, If that fails look into a piggy back ecu from a transmission specialist and see if they can help with this...

How do you get the post moved to another section? sorry if this seems a silly question i have only joined this evening!

jimbo

G day mate i have same prob mate of mine has same prob i have spoken to other 550 owners all same prob the bloody 7speed lets the vehicle down just waiting for some auto transmision mob to come up with a fix the transmision just seems to get confused its very frustrating

All good mate I flagged it one of the admins will move it

another thing that seriously seems to confuse it is if say you were rolling up to a set of traffic lights and then they change to green so you go to accelerate again it doesn't know what gear to go into it really hesitates so it just seems to pick one! the wrong one! too low every time, does yours also do that?

Jimbo

Yes it sounds like you are drving my vehicle

Same, been well pissed off with mine, was even worse with the chip on, just drove around feeling like a slipping clutch.
Definitely the worst point of the whole car.
A mate recommended speaking to wholesale automatics, apparently absolute wizards with autos

Ive had my ute 2012 stx to wholesale automatics where they fitted a heavy duty nomad valve body and a temp gauge. The change in the trans could be described as more positive stronger lock up but it isn't as smooth as it was.
I like the way the box lugs a taller gear after all it has 550 torque at 1750rpm would be a pain if it was reving all the time.
I have found that if you want to pass put it in Ds not manual mode which gives you 500rpm over standard mode in each gear and feed the throtle on without pushing the pedal through the floor this give me more than enough excelleration to pass

Sounds like a prick of a box - go the manual everytime.

the 550 is only available as a 7 speed auto

Whats letting them down with fitting a manual box, is it the clutch or no-one has a box that can handle 550nm while having a transfer fitted?

I love my 7 speed. We test drove a BT50 and its gearbox was all over the place. Going up a hill it was constantly shifting between gears when it did not need to. Later I hear there a "fix" for this. Yet internet reviews were silent on what I though was a major problem.

I got the 2012 st and when sitting on a 100 u put your boot into it to get around traffic and it drops back to 4 th and stays there reving it's guts out.and won't shift unless you back off abit very weird other than that its reall good to drive its only ever since I put my chip in. Thinking on ringing chip it and see if I can get a custom tune to fix it.

yep my gearbox on my 550 is exactly the same , its nearly got me bogged a couple times , i found manual mode better for on the beach (soft beach) and just try keep it in the tourque band, i think nissan could of done a lot better

haha,

this is why when my engine dies im putting the v6 into mine with the 6spd manual,
already know a guy who can make me a bellhousing/clutch to suit

jimmy_jay89 said:

haha,

this is why when my engine dies im putting the v6 into mine with the 6spd manual,
already know a guy who can make me a bellhousing/clutch to suit

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The chassis on the 550 is 80mm wider than the 2.5 st would it fit ?
Would have thought nissan would have made it fit so they didnt have to change chassis if it does.

gunning1987 said:

Whats letting them down with fitting a manual box, is it the clutch or no-one has a box that can handle 550nm while having a transfer fitted?

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I'm sure Nissan could come up with a dual transfer box that can handle 550nm easily. If ford can for their 7.3L powerstroke diesels then Nissan can. The reason is probably more and more people are turning to automatics because of the easiness to drive them! I'll be keeping my little 3.0L d22 for a lot longer now

Sheesh, I've no real complaints with my 550's box. If I could change anything I'd probably ask it to choose 2nd gear when unladen from a standing start on light throttle.

nyway, as it is now, unladen I leave it to it's standard auto setting. Towing I (and friends who own 550's) slip it to Sport auto, whee the shift parameters suit towing a bit better.
I can override it all manually if the road speed allows.

jaymac90210 said:

I'm sure Nissan could come up with a dual transfer box that can handle 550nm easily. If ford can for their 7.3L powerstroke diesels then Nissan can. The reason is probably more and more people are turning to automatics because of the easiness to drive them! I'll be keeping my little 3.0L d22 for a lot longer now

Click to expand...

The facts is that for 99% of the people, for 99% of the time, a modern turbo diesel is much better suited to an automatic transmission than manual. An auto can be programmed to keep the engine singing in the middle of it's torque band more consistantly, and allows boost to build faster by proper torque converter choice.