Hey guys,

My 1998 KE Verada's auto spit the dummy and i've put a 1996 (TE?) Magna gearbox in.

now it wont shift into first (1st) gear when its in the drive position, its like its in neutral.

if you shift into L then shift into Drive around 2.5/3krpm it will select 2nd/3rd/4th like normal, it just wont select first gear.

funny thing is, that if you reverse and then shift into Drive it will creep forward like its in first and even accelerate slightly (foot down like 2mm) then it just sort of "pops" out into neutral.

i've changed pulse generators, valve body, inhibitor switch, speedo drive, continuity tested all solenoid control wires back to the ecu. tested the ecu and everything appears fine.

im pretty sure its something to do with the 1st/reverse solenoid, though i havent actually tested it yet.

now from what i understand the Verada had a gearbox box which is slightly different to the magna's, i believe the magna had a two way clutch and the verada had something else.

im almost thinking the earlier box needs first and second solenoid powered to select first.

has anyone experienced this before?

or better yet, can some one with a 1996 magna take a picture/write down the wires with come out of the soleniod/temp control plug ontop of the gearbox just behind and below the battery :)



Cheers,
Craig.

Tried putting the 3L Magna ECU in?

Verada has the same gearbox as any 4sp Auto 3.5L Magna, but the 3L and 3.5L Auto boxes are different, so the ECU will be different as well.

Wouldn't be cable adjustment?

Wouldn't be cable adjustment?

I have correctly adjusted the shifter cable, and all the gears work fine manually shifting.

Tried putting the 3L Magna ECU in?

Verada has the same gearbox as any 4sp Auto 3.5L Magna, but the 3L and 3.5L Auto boxes are different, so the ECU will be different as well.

the 6G72 ecu which the replacement gearbox was from didnt work in the Verada, i assumed there are some additional wires which would need changing in order to start the car with the 3.0L ECU.

its deffinaltly a 6G72 gearbox thats been fitted.

i know the ecu's are obviously different, but whats interesting is the gearbox wiring is the same, even down to the wire colours.

im very interested in finding out what exactly the difference is between the 3.0L and 3.5L gearboxes that requires matching ecu's.


goes much better with the shorter ratios :)

Yeah if you change ECU's you'll probably need to change the harness to match too.

yea not really interested in running a 3.5L with a 3.0L ECU though.

considering the wiring for the gearboxes are identical, it has to be something reasonably simple thats different.

perhaps a duty cycle on the first gear solenoid,

does anyone know where some original wiring diagrams are? not the haynes manual one.

Probably should have got a 3.5auto then lol This is the unfortunate situation with having the ECU and TCU embedded in one unit, you can't mix and match that easily. The 3.5 will run fine on a 3L ECU though.

Best to pm madmagna about the difference in wiring and if it can be rewired, he might have done something similar to a 3rd gen in the past.

it was laws of economics that prevented me from getting the proper gearbox.

anyhow, i think your missing the point.

it shifts fine between 2nd/3rd/4th, perfect infact.

it actually also tries to down shift into 1st if you WOT it in 2nd.

first works perfect when manually shifted into L.

its very close to working correctly.

does anyone know if MUT's can test/change duty on solenoids?

I hve seen a few 3.0 running the 3.5 trans with no issues straight off the 3.0 TCU so I can not see there being an issue the other way either.

I would also suggest that if the trans will manually select first bun not in "D" then there is poss an issue with the TCU sectin of the trans (unlikely) or with the inhibitor switch.

Generally if the TCU is kaput the trans will default to 3rd gear only and will not shift

yea,

so i used my head and went door knocking at some local automatic shops. found a very helpful crowed who photocopied part of their repair manual for me.

http://img503.imageshack.us/img503/7973/sols.th.png (http://img503.imageshack.us/my.php?image=sols.png)

this pretty much shows whats going on.

the stock gearbox has a sprag on first gear. the ecu turns off the underdrive and first gear solenoid until 6mph, then turns on the first gear solenoid.

how ever the gearbox im using has a one way clutch which needs both the under drive and first gear solenoid turned off to initiate first gear.

so there's going to be a bit of thinking involved to try and keep the first gear solenoid from turning back on. but im sure a reasonably simple circut should do the trick.

oh that also explains why 3.0L can run 3.5L gearboxes, as the only reason first gear solenoid turns off is for smooth downshifts and reduced engine braking.