No kick down or auto downshifts

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Mon, 03/11/2014 - 22:25
Phonecia1
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Hello all. Vehicle is'89 300GD automatic. The auto transmission will not kick down or down shift when engine labouring in high gear.  When pedal pressed to floor to activate kick down switch there is a clicking sound (probably coming from gear box). I have changed the switch for new one, but  no different. The gears change ok manually. I have noticed a small vacuum pipe which is lying disconnected on top of  the cylinder head cover. I can not find where this pipe has come adrift from. I have not yet traced the other end of this pipe, but it does go  in the direction of the gear box.Any one any ideas please?. Cheers. John.

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Tue, 04/11/2014 - 01:06
#1
cox.adrian
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Re: No kick down or auto downshifts

  take a look at your vacuum switch top of rocker box

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Tue, 04/11/2014 - 13:19
#2
John757
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Re: No kick down or auto downshifts
The other end of the disconnected vacuum pipe connects to a small outlet on the rear of the fuel injection manifold intake chamber on my 460 petrol... and goes down to the gearbox.. im not sure if yours is the same as yours is deisel but have a look for a small cast nipple lacking a pipe.. if the engine is running it will suck against your finger due to the vacuum, when connected correctly it tells the gearbox when you are revving...and assists with gear selection i belive... aslo the lack of vacuum will cause running issues at low speeds. to the engine.. hope this assists you
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Tue, 04/11/2014 - 13:29
#3
stig
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Re: No kick down or auto downshifts

'aslo the lack of vacuum will cause running issues at low speeds. to the engine' 

 

Not on a diesel....

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Tue, 04/11/2014 - 18:01
#4
prwales
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Re: No kick down or auto downshifts

this engine is too slow to have kickdownwink

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Tue, 04/11/2014 - 22:05
#5
Phonecia1
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Re: No kick down or auto downshifts

Hello all. Thanks for info, will investigate. My G engine runs very well, alright it won't set your hair on fire but it gets to 70 ok and will run all day doing this. These are off road vehicles, my Eclass serves me well for the fast driving. Regards. John

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