AU on Highway auto gearbox troubles

[rosebush]

AU sedan 99 Ser1...4 speed Auto

last few days after changing set of sparks plugs (not that plugs should have anything to do with this problem) but especialy when driving over 80km/hr in Drive in 4th gear it keeps kicking back into 3rd gear within a few mins (Even at 110km/hr...The only way to get it to go back into 4th gear again is to put it into manual 3rd gear???? If i leave it in 3rd gear it will stay in 4th gear the whole time and wont pop out??? but after putting it back into drive from manual 3rd gear at about 100 km hr within a few mins it kicks back again into 3rd without putting pressure on the excelerater...sometimes in drive it just wont even reach 4th gear and just stays in 3rd the whole time....It almost appears to be a wire problem?? is there some sensor box etc??? any advice to point me in the right direction would be nice thanks...(We cant loosen the bolt to check the fluid level either) but the gears are not slipping as such, just changing at odd times?? STRANGE???Thankyou

[frd906]

Why cant you lossen the bolt to check the fluid level,

[stavros68]

Change the loom to the auto only $10 from the wreckers should fix the problem

[The Monty]

Slipping back into, and staying in third is limp home mode, or LHM. This happens when there is going to be damage caused to your box due to a fault somewhere. It locks into third to ensure no more gear changing, and less chance of more damage happening.
My thought would be that your trans fluid is heating up due to a blocked feed line from your trans cooler that is in a series with the radiator. It can get clogged up after a while. I would suggest taking it in to a shop, and getting them to check it, flush it and service it (around $300). That will fix your problem.

[mik]

could it be dragging brakes? auto got plenty of oil in it?

[rosebush]

Originally Posted by frd906

Why cant you lossen the bolt to check the fluid level,

The bolt just wont budge, tried the 5/8 and 16 inch spanner and socket with no luck, dont want to damge the bolt to much...Might need to get some heat on the bolt maybe to get it off...

[rosebush]

Originally Posted by The Monty

Slipping back into, and staying in third is limp home mode, or LHM. This happens when there is going to be damage caused to your box due to a fault somewhere. It locks into third to ensure no more gear changing, and less chance of more damage happening.
My thought would be that your trans fluid is heating up due to a blocked feed line from your trans cooler that is in a series with the radiator. It can get clogged up after a while. I would suggest taking it in to a shop, and getting them to check it, flush it and service it (around $300). That will fix your problem.

If it was in LHM would the 1st 2nd and 3rd gear still work as well? as i dont seem to have a problem in these other gears, Also if it was in LHM why would it go into 4th gear in the manual 3rd gear position??? its all so very strange

[JC]

Try adjusting the shifter bar link at the gearbox. Mine did this on the way back from Qld, and i found that it was about 2mm too far back. Adjusted it and it's been fine, although sometimes it won't start in P -move to R, back to P and it's all good.

[frd906]

Have u ever had the box serviced? becuase i no for a fact that ford use lock tight on the bolts on the gear box

[mik]

its 15 mm i think?

[rosebush]

Originally Posted by JC

Try adjusting the shifter bar link at the gearbox. Mine did this on the way back from Qld, and i found that it was about 2mm too far back. Adjusted it and it's been fine, although sometimes it won't start in P -move to R, back to P and it's all good.

how do you know if this needs adjusting or not?? another thing its doing is starting in any gear, (I put the foot on brake in Drive and the car turns on) !! its only suppose to start in park or neutral??

[The Monty]

Originally Posted by rosebush

If it was in LHM would the 1st 2nd and 3rd gear still work as well? as i dont seem to have a problem in these other gears, Also if it was in LHM why would it go into 4th gear in the manual 3rd gear position??? its all so very strange

No, it would shift up from take off, and then lock into third eventually, and stay there.

When was the last time it was serviced?

[rosebush]

OK SO AFTER READING THE MANUAL I SUSPECTED MY PROBLEM WAS THE NUETRAL START SWITCH ON THE TRANNY, I DID THE TEST TO SEE IF THE ENGINE WOULD START IN ANY GEAR AND SURE ENOUGH IT WOULD. I ALSO CHECK THE REVERSE LIGHTS AND THEY DIDNT WORK EITHER (THAT IS ANOTHER SIGN OF THE SWITCH FAILURE) SO OFF WITH THE OLD SWITCH (VERY EASY, ONLY 2 SCREWS) BUT GOT A SPECIALIST TO DO IT AS HE ONLY QUOTED ME $80 FOR THE LOT WITH BRAND NEW SWITCH AND LABOUR (ADAMS IN CALOUNDRA, GREAT DUDE) AND A SECOND HAND ONE WAS QUOTED $60!!! FIXED THE PROBLEM STRAIGHT AWAY...hE ALSO GOT THE BOLT OFF SO I CAN CHECK LEVELS ETC, LEVEL WAS GOOD BUT OIL NEEDS A FLUSH BY THE COLOUR OF IT)...SO THERE YOU GO, STRANGE THINGS HAPPENED JUST FROM THAT SWITCH!!

[Mr Hardware]

Inhibitor Switch it's called

[rosebush]

Originally Posted by Mr Hardware

Inhibitor Switch it's called

Yes thats the one...Inhibitor switch" Thats what the specialist called it too....Just the car manual called it the switch a "nuetral start switch"...Im wondering how big and messy a job of actually flushing the whole transmission would be cause going by the colour of the oil and dont think its ever been serviced before...Any links to how I do this??

[Stattic]

probably not the best thing to do yourself as you need to get the fluid level on level ground, easiest to do on a hoist. too much fluid is also bad and of course we know too little is bad, save yourself the trouble of possibly damaging it and get it serviced. most places do an auto service for $120-150ish which is a change of the oil and filter.

[The Monty]

Youll need a full flush if it hasnt been done in a while. A service only takes the oil out of the pan, and whatever else leaks out, and tops it up, a flush is a flush of everything including converter, around 11L of fluid. It will cost around the $300 mark.

[rosebush]

Yes i have decided to get it done by someone else...to much oil to dispose of too...Thanks guys

[GK]

Glad you've got it sorted, and are getting a full flush.

I get my box serviced each year, and fully flushed every two to three.

All the best with it.

GK

[JC]

Originally Posted by rosebush

OK SO AFTER READING THE MANUAL I SUSPECTED MY PROBLEM WAS THE NUETRAL START SWITCH ON THE TRANNY, I DID THE TEST TO SEE IF THE ENGINE WOULD START IN ANY GEAR AND SURE ENOUGH IT WOULD. I ALSO CHECK THE REVERSE LIGHTS AND THEY DIDNT WORK EITHER (THAT IS ANOTHER SIGN OF THE SWITCH FAILURE) SO OFF WITH THE OLD SWITCH (VERY EASY, ONLY 2 SCREWS) BUT GOT A SPECIALIST TO DO IT AS HE ONLY QUOTED ME $80 FOR THE LOT WITH BRAND NEW SWITCH AND LABOUR (ADAMS IN CALOUNDRA, GREAT DUDE) AND A SECOND HAND ONE WAS QUOTED $60!!! FIXED THE PROBLEM STRAIGHT AWAY...hE ALSO GOT THE BOLT OFF SO I CAN CHECK LEVELS ETC, LEVEL WAS GOOD BUT OIL NEEDS A FLUSH BY THE COLOUR OF IT)...SO THERE YOU GO, STRANGE THINGS HAPPENED JUST FROM THAT SWITCH!!

There you go - I was close, but no cigar. Good result. I wonder if mine's on the way out then (based on the fact that sometimes it doesn't start in P)

[Mr Hardware]

I've got a spare inhibitor switch you can have for cheap JC if you don't have one spare already, BNIB

[rosebush]

Originally Posted by JC

There you go - I was close, but no cigar. Good result. I wonder if mine's on the way out then (based on the fact that sometimes it doesn't start in P)

Pretty sure thats a sign of it about to go....Think its a pretty common problem actually. Mr Hardware has one I think to sell....Easy as to fit and made a huge difference...

[Stav]

Just go to the wreckers and get the inhibitor switch man.Its held by 2 bolts from memory.