davocol

Hey all

My girlfriend recently purchased a series II EA falcon (4 speed auto and 3.9 CPI) and it has a strange problem. When you are driving along at about 80 kph and the revs slip below 1500 the car starts to shudder. It feels like it may be coming from the auto. I have taken it to the transmission place and he replaced a rear bush. This has still not fixed the problem. One suggestion was the tailshaft however it only seems to do it in 4th gear and not third gear. The shuddering stops once you start going about 100 kph.

Can anyone shed any light on what it could be?? It would be much appreciated as the problem is driving me mad.

Thanks

__________________
Now the proud owner of an AU xr8 220... OHHH YeAh

donuts2001

I know exactly what it is, it's the lock in converter on your 4speed Auto. When you reach 4th gear on your Auto, the converter "locks in" so that the car puts the power directly from the motor to the tail shaft instead of through the torque converter.

Have a similar issue on my car around the 70km/h-80km/h range where there is a slight vibration, but this is probably due to my speedometer being out.

You will mainly notice the lock in converter just as it's starting to engage around that speed, and it will go away if you speed up or slow down between the 70km/h-80km/h range.

If the vibrations are very noticable it may be because your speedo's out. Get a mate to drive in front of you on the highway at 100km/h in another car and follow him in the EA and see if it shows the right speed. If the speedo is out significantly you will need to get the speedo gear changed on the auto(easy to do)

Other then that, you could just do what I do and ignore it... because it won't hurt anything.