W123 230E auto: harsh gear changes when cold

[grahamf505]

Not sure if this is a problem or not....

When I first drive the car after its been left for a couple of days, the changes from 2nd to 3rd and 3rd to 4th are very harsh for the first half mile or so (these cars always start off in 2nd unless you flloor it from standstill). Rather than make a nice smooth transition up the gears, the box kind of jumps up from one gear to another in a very direct way (almost similar to when I flick my overdrive in on my Triumph TR4 when I've only got a light throttle on)

After half a mile, changes become smoother and once it starts to warm up a couple of miles further down the road, changes become beautifully smooth and stay that way.

The auto fluid is very clean and I beleive the 102K miles on the clock to be pretty genuine.

Not sure whether this might be caused by a partially blocked filter on the auto trans - I'm pretty sure it won't have ever been changed. I'm also concerned that I might be putting undue stress on the auto box internals that might be causing damage.

The only other symptom is that changes up from 3rd to 4th seem a bit lat (typically 3500 revs when I've got my foot on the throtle), howvere I can compensate for this by lifting off slightly and then it changes up.

Theres no undue slipping when changing up and everything else seems to be OK.....

Any thoughts anybody?
Graham

 

[eddie_E]

I have this with mine. I am still trying to decide if it's right or not as some poeple say thats just the way they are. I find it hard to beleive tho.

Suggestions i've had are it could be:
the box oil needs changing + draining the torque converter - but doens't sound like it in this case,
gear box mounts are failing,
drive shaft donuts are failing and/or need adjusting,
The vacuum pipe from the inlet manifold to the gearbox has a leak,
or I think it might be the gearbox oil pressure is too high and needs adjusting down a bit but i haven't seen anything to idicate if this can be done on a W123 or indeed a W124 like mine. Mine seems to change very quickly causing the jerking until warm.

 

[Dieselman]

It's probably down to the vacuum being low whilst the engine is still "on choke".
Either that or the ATF being a bit more viscous so the TQ transmits more torque thus giving harder shifts.
Personally I wouldn't be worried, I'd be a lot more bothered if the box was slipping.

 

[jaymanek]

I think this is most likely down to a vac leak/problem. Not sure of the specifics to check though...

 

[homefred]

Pressure is adjustable on 123. If i remember, its on the offside. A vacume module. Forget how to do it. As has been said, if its fine when warm leave it alone. Always remember a lot of these used to jump into third just as you were thinking of slowing down, annoying as hell

 

[petef]

Mines exactly the same, just commented on it this afternoon with the missus in the car and she actually agreed that it was very jerky, and felt as if it was snatching, then it went smooth and the gears glidded in !!! and i had my gearbox oil changed about a month ago ( 1991 230 coupe, 112,000 miles )