cold transmission = difficult gear changes?

[dark_knight]

i have a C56 / 02A transmission running on 85w-90 oil. it's mostly warm all year round here but of late, it's been bitingly cold coz our short rains are here. since i have to leave early some mornings, i noticed that gear changes are a little challenging until i've run a few miles and i guess the engine (& transmission) have warmed up a bit. sometimes my R won't engage at all so i have to use the trick of selecting 1st first then trying R, at which point it engages..

question is, should i be worried about my synchros being on their way to the retirement home or this is normal/typical behavior for this box type..?

 

[corofin12345]

i have the same problem too.. i just let her warm up and its fine then.. its annoying tho cause as you said, the odd grind happens going into gear when cold.. some fresh oil normally helps too tho.. i find it worse when the automatic choke is on as the revs dont fall as quick compared to when the engine is warm

 

[dark_knight]

choke?

automatic choke..?
my oil is only ~3 months (~4,000 km / 2,500mi) old so i'm sure it's not the oil..
it's proli just the design of the box..

 

[corofin12345]

"cold idle".. cars revs higher when cold..

 

[dark_knight]

alright. i get you now.. and yes, higher revs when cold are routine on mine too. warms up pretty quick and drops from about 1,100 to 750/800 revs..

 

[corofin12345]

seems a bit low... should be around 900rpm when warm and a bit higher than 1,100rpm when cold.. you could always adjust the idle screw tho.. the oil light starts to flicker around 700rpm or below.. it is funny tho cause once the engine is warm the gears are fine on mine (same box as yours btw)

 

[dac69er]

check your selector cable bushes and the sugar cube.

reverse is sometimes a bit of a pain, but normally not that bad.

 

[dark_knight]

other possibilities

@corofin12345: 900 revs at warm idle..? will check that out. car's always been happy at 800 but i guess i can check and change that.

@dac69er: i really doubt it's the s/cables and/or sugar cube. problem goes away after a short run. i's suspect when cold, the oil is sludgy and makes the gears not waft over each other. once warm, it's more viscous so the changes are smoother/easier..? just my thoughts..

 

[Paul_JJ]

seems a bit low... should be around 900rpm when warm and a bit higher than 1,100rpm when cold.. you could always adjust the idle screw tho.. the oil light starts to flicker around 700rpm or below.. it is funny tho cause once the engine is warm the gears are fine on mine (same box as yours btw)

750 RPM +-50 is a normal Idle on the warm engine with the AC off - according to my Starlet Service manual. With the AC on will jump to 1K.

 

[dac69er]

@corofin12345: 900 revs at warm idle..? will check that out. car's always been happy at 800 but i guess i can check and change that.

@dac69er: i really doubt it's the s/cables and/or sugar cube. problem goes away after a short run. i's suspect when cold, the oil is sludgy and makes the gears not waft over each other. once warm, it's more viscous so the changes are smoother/easier..? just my thoughts..

it wouldnt be the cables, but it could be the bushes or the sugar cube. if you arent selecting the gears positively then it can make it a bit hard to change. it will be due to the oil too, but that can make the problem worse.

try changing to a different oil.

 

[Texx]

i have a C56 / 02A transmission running on 85w-90 oil

Filling the box with a good quality 75w-90 transmission oil will probably improve things. Personally I use Castrol SMX-S 75w-85.

 

[corofin12345]

750 RPM +-50 is a normal Idle on the warm engine with the AC off - according to my Starlet Service manual. With the AC on will jump to 1K.

thats 2 low for alot of cars.. nearly every gt or glanza ive sat in has idled at 900rpm when warm.. your manual is for n/a starlets?

 

[Texx]

Base idle speed should be set at 700rpm with the diagnostic terminals TE1 and E1 shorted, with the short removed the idle speed should then be maintained by the ECU between 700-800rpm i.e. 750 ±50 rpm

Prior to any check or adjustment, all electrical systems including the A/C should be switched off and the engine should be up to running temperature. Running temperature would normally be after the radiator cooling fan has kicked in at least twice.

The stock rev counter is not an accurate way of reading engine speed, it's only a "gauge" i.e it's a means for the driver to estimate the operating speed of the engine at any given time.

 

[corofin12345]

good to know but i still wouldnt idle mine at 700rpm.. car would rattle itself to pieces...lol

 

[Texx]

good to know but i still wouldnt idle mine at 700rpm

What would you be using to check the idle speed?

 

[Paul_JJ]

good to know but i still wouldnt idle mine at 700rpm.. car would rattle itself to pieces...lol

It will rattle if it goes under 700 rpm - indeed!!! Having the idle at around 1K would increase the fuel consumption but in theory should provide better acceleration.

 

[corofin12345]

What would you be using to check the idle speed?

for the life of me i cant remember the name of the unit i used but we ran it off the crank pully and got 900rpm.. same as cluster weirdly enough.. these days i just adjust using my spanner method..(stoneage yes, but thats just me) after a full service of course... but i do find with iridium plugs that you can go lower.. but for me.. she hums at 900rpm

 

[Rev]

good to know but i still wouldnt idle mine at 700rpm.. car would rattle itself to pieces...lol

x2 Especially with a/c on and electric fans. On turbo timer I am at 1400rpm idle and 900 with a/c off. safc 2 used to check rpm At one stage I had a slight improvement using a thick copper wire on the igniter that gave better spark to the engine.

 

[corofin12345]

x2 Especially with a/c on and electric fans. On turbo timer I am at 1400rpm idle and 900 with a/c off. safc 2 used to check rpm At one stage I had a slight improvement using a thick copper wire on the igniter that gave better spark to the engine.

and lights

 

[Rev]

Lights seem ok after wiring and lights replaced ; car usualy idles up when lights go on.
( I found the turbo hot pipe was heating the metal of the light bulb that meant it heated up much more than designed to and on occasion was hot enough to melt the insulation )