Posted on here over a week ago with info about my Auto Box potential failure. Now I have more time, I will post more specifics.

 

OK. Forgetting how the car was this is what happens now.

 

In Position 1, the car will not creep forward, and pressing the accelerator also has no effect, the revs just continue to go up, no movement.

 

In Position 2, the car creeps forward as it should, but I suspect it pulls off in 2nd Gear as the speed pickup isnt great.

 

In Position D, the car creeps forward as in Position 2. I suspect (but am not sure) that it changes into 3rd but basically when travelling at 40MPH the revs are roughly at 2700RPM (an experts tell me what gear this is?).

 

In Position R, everything is perfect, reverse has no problems.

 

Pushing overdrive off at any point doesnt have an effect, and neither does turning it back on. Hold mode starts the car just as it does in Position 2, and "Power" hasnt been tested yet.

 

Any advice? There is no slipping at all (think there was to start but not quite sure now) and the fluid is ok, there is also no mechanical noise that sounds like it shouldnt be there.

 

I have no choice but to drive the car at the moment, but dont know what to do from this point onwards.

 

Any help appreciated.

im know mechanic but ,

 

the overdrive button merely provides engine braking and the manual states, should not be used at high speeds and should only be used when climing or desending steep inclines

 

power and hold modes lengthen gear ratios i believe to get the most out of each gears

 

am sure some one will be along to give you some better (technical advise ) shortly!!

 

hth

Umm... isnt over drive for motorway cruising? If it not then i'd be doing 70mph @ 5k rpm (ish) over drive drops it to 3k rpm.

power mode removes topo gear and lengthen's all over gears, hold mode removes first gear and doesnt allow for harsh movements like a 'snow' mode

Oh and on my auto, over drive works in all gears, as far as i remember.

The Overdrive button is designed to give direct drive for High speed driving..... You can turn it off for round town driving.

 

Power and Hold modes - Power maximises the torque and acceleration by selecting the lowest gear all the time....

 

Hold selects the Highest gear or Holds the Highest gear.....

 

Thats especially useful for taking of in very wet or Icy or snow conditions

 

Hope this helps

 

Tony

The Overdrive button is designed to give direct drive for High speed driving..... You can turn it off for round town driving.Tony

 

so overdrive is or isnt a form of engine braking ?? , as i got that straight out my manual !!

so overdrive is or isnt a form of engine braking ?? , as i got that straight out my manual !!

 

it sure does improve engine braking with it off, you get non whatsover with overdrive on.

 

edit: so basically no its not a form of engine braking

overdrive helps engine braking, press the button during braking and you will see

Turning it OFF will improve engine braking.

it sure does improve engine braking with it off, you get non whatsover with overdrive on.

 

edit: so basically no its not a form of engine braking

 

thanks for clearing that up for me :)

 

this manual i got is very confusing i think it's trying to state what u said above but in a long winded drawn out way, lol

 

 

i mostly leave mine on though unless going up or down a steep rd etc.

 

does anyone take it on and off for varying driving conditions regulary??

Edited December 29, 200817 yr by ck300z

i only ever used it on the motorways.

so you have o/d off around town etc ?

Cant remember which way roundf it was now, been a while, but i only ever used it on motorway to lower the revs for cruising. No performance otherwise round town.

;)

Thanks for all the replies, but does any one have an idea on the magnitude of the problem i'm facing or any suggestions?

Thanks for all the replies, but does any one have an idea on the magnitude of the problem i'm facing or any suggestions?

 

Sounds like you may have "lost" 1st gear. My auto box lost 2nd and 4th (overdrive) and it needed a full rebuild. I hope yours is not so serious - mine cost £1200-ish to fix.

 

Umm... isnt over drive for motorway cruising? If it not then i'd be doing 70mph @ 5k rpm (ish) over drive drops it to 3k rpm.

 

Not necessarily. Overdrive is just 4th gear mate - these 'boxes are 3 speed plus an overdrive 4th; the car automatically shifts in sequence to the highest gear for cruising according to the conditions. The button on the gear shifter is to turn it off, thus only enabling the car to change between 1st and 3rd (much the same way as selecting 1 or 2 restricts the car from selecting a gear above the number chosen).

 

Richard:)

Excellent explanation Richard :bow::bow: