4 Speed Auto Help Required

[Deep Dish V35]

Does anybody know how the 4 speed auto operates? Relays/solenoids/switches/sensors?

Heres my situation

A few days ago my Check Engine Light came to life. I assumed this was to do with the plenum mods I had recently done. My hand held OBD scanner was unable to identify the issue or clear the fault.

But then today.... Shifting from N to D, there was a longer gearchange pause than normal.

Half an hour later, shifting from P to D and I noticed the pause was much longer.

Then leaving home at 5pm, reversed out, shifted to D... and I get nothing. Engine revs but no transmission load, just like I was still in N.... i check its actually in D, massive pause, then the car moves.

So naturally Im a bit worried...

Get to the first slow corner, accelerate and the car revs but doesnt go faster...

At this point I Shift into tiptronic and thankfully I take off normally. Driving along I switch back to D and all seems normal, until I get to a roundabout.... and the thing wont accelerate out of it.

So the situation is: When in D, 1st gear does not engage. You can feel a very weak shudder thru the car, but no transfer of power to the rear wheels. But when in tiptronic, all 4 gears work perfectly.

So what im trying to work out is; what part of being in D controls the way 1st gear engages? How is it that I can still use 1st gear in tiptronic but not in D? And has anyone else had this happen?

Im not stressed about it.... much

[Commsman]

1st things 1st, have you checked the trans fluid level & quality? You may be lucky & a fluid change or top up will fix it.

[sonicii]

I'm thinking this too.. or possibly even a shifter linkage issue?

[PN-Mad]

^^^^ these two guys are the first thing to check.

After that- essentially its the same as the motor. You need to find a tranny shop with a scan tool (apparently there is a good one down there in MV autos or something, right?)

That will tell you if a solenoid is cooked, and what to replace. There is simply too much going on in there for a home mechanic to change parts and hope for the best. The diagnostic will pin it.

Hope it turns out OK.

[Deep Dish V35]

yep i had already planned to do both today.

to me it seems electrical. i can drive along at 25 in D with no drama, but when it kicks back it doesnt engage anything. At the same time I can put it in tiptronic and select first gear with no issue.

if it was a mechanical issue, first gear wouldnt engage in either situation.

I assume the valve body uses the same system between auto and tiptronic, so im leaning towards it being a faulty relay or wire

A funny little side note.... this is not the first time my car has died for some reason when i was heading off to visit a new girl who was DTF (if you know what i mean). So it seems my car might be jealous. Anyone seen the movie Christine??

[scotty nm35]

It could be blocked filters in the valve body too. When was it serviced last? Check the fluid level first, if that's ok take it for a service at MV.

[Deep Dish V35]

had new fluid flushed thru whole system a year ago

will get the CEL reset in a couple hours. Whats the chance of it being a kind of limp mode for a fault due to the bypassed EGR sensor?

[scotty nm35]

The clutches are slipping, generally means a rebuild is in order. Get the trans specialist to drop the pan and check it for clutch material, I bet it's caked.

What fluid did they flush it with? Mine had similar symptoms when I bought it, I assumed they flushed mine with dextron III at compliance causing the damage to the clutches.

[sonicii]

Highly doubt it has anything to do with a limp mode or bypassed EGR.

Limp mode will normally lock in a particular gear (2nd or 3rd) to allow you to drive it home.

If it isn't an external mechanical issue, I think it sounds like an internal transmission fault, as the electronics don't have the ability to select 'no gear' when the shifter is in D, it only switches between forward gears.

As for what it could be is anyone's guess.. could be a clutch pack, valve body fault, line pressure solenoid. or a host of other possible causes.

[Deep Dish V35]

well today it doesnt drive at all. Put it in tiptronic and the AT Check light came on,

JUST managed to crawl it 4kms to a repairer i trust, Adam.

if the valve body has to come out, im getting it modified

[n15m0]

The clutches are slipping, generally means a rebuild is in order. Get the trans specialist to drop the pan and check it for clutch material, I bet it's caked.

What fluid did they flush it with? Mine had similar symptoms when I bought it, I assumed they flushed mine with dextron III at compliance causing the damage to the clutches.

what type of fluid is recommended for auto 5 speed transmissions?

[scotty nm35]

Nissan Matic J or Nulon Synthetic are the only fluids I would recommend.

[t5iv]

Your car is jelly of your new mrs? That's hillarious! On the plus side, someone is selling another box here for about $1k or so. Once you fix that box, you can go sort out the other.

[Deep Dish V35]

ive seen 2nd hand boxes for around 700.... yep will prob be easiest to just swap the box, then fix this one while its out (if its fixable)

car has just been connected to a consult scanner, no luck. it has absolutely no friction in any forward gear. reverse is still good.

Edited October 4, 2012 by Deep Dish V35

[Deep Dish V35]

turns out the scan tool was not a "consult" so i've organised for another bloke to come plug his machines into the car to see what he can find.

System was flushed a year ago using Nulon SYNTAF-4 auto trans fluid and has had not a single sign of any problem until yesterday

It has been suggested by another trans specialist that the first main clutch may have died or maybe the trans fluid pump... both require full disassembly.

Adam and the boys at Wesbourne Park Auto, cant thank you enough for your time today, even though nothing was found i was given some good advice. Always very helpful.

For the record

replacement gearbox quote =$1900

full rebuild first quote =$3000-$4000 not including valve upgrade kit

Edited October 4, 2012 by Deep Dish V35

[sonicii]

Your car is jelly of your new mrs? That's hillarious! On the plus side, someone is selling another box here for about $1k or so. Once you fix that box, you can go sort out the other.

That other one for sale is a 5sp auto box..

[Deep Dish V35]

^^ yep plenty incompatable variants out there.

4sp

4sp 4wd

5sp

6sp

cvt8

to fit a different gearbox requires different loom and computer. no thanks

and to think, not long ago i couldve bought a stagea for $4k and tranferred it all over - gearbox, engine, turbo, loom, ecu, 4wd, front panels....

one person has just said it could be a simple electronic issue... may just need the valves dropped and solenoids replaced (sounds easiest to me, lets hope so)

another person has already suggested, if the gearbox comes out, to get the torque coverter stall rate increased....

as far as the transgo shift kit goes , ive only seen ones to suit 5 speed boxes... anybody seen them for the 4 speed RWD?

Edited October 4, 2012 by Deep Dish V35

[scotty nm35]

4 speed kits are available, I heard the 4 speed boxes are actually stronger but I have no hard data on that. I think they can just fit more clutches inside them if you build it.

It is not an electronic issue, if the solenoids are faulty it will throw a solenoid code. Mine has no 5th at the moment and 1st 2nd and 3rd aren't happy. No fault codes just slipping clutches.

Do not get a high stall converter, I tried one with mine and had to disconnect the torque lockup clutch in the end. All you will do is lose power and response. I ended up going back to the stock converter with a heavy duty lockup clutch.

PM me if you need info, not many people understand these cars and you can end up spending much more than you need to. Best option may be to do a manual conversion, at least it's adding value, or just replace it with a wrecker 4spd auto with shift kit.

[Deep Dish V35]

does anyone happen to know the ID number for the 4 speed RWD gearbox in a 2001 model?

[Howaitonaito]

RE4RO1b nissan have been using that box for decades my mates A31 cefiro has the same box. Its strange to hear problems in them