w123 transmission shifting
 

I recently bought a 1980 280E and am having some transmission issues. I have hardly any acceleration when coming from a stop. When I merge into traffic I have to wait for a large opening. When on the hwy I can accelerate without too much trouble but then I notice it shifts rather hard. From the searches I have done on this forum it seems like it might be vacuum related. I found a DIY for adjusting it but it is for a diesel car. Is it the same? The VIN on my car is 12303312070741 if that helps. If I am leaving anything out please let me know. Thanks in advance for any replies.

Take a close look at the linkage on the intake area, make sure that the throttle linkage is
opening the throttle completely!

Many times a "nylon" insulator wears out & causes the accelerator not to open completely.

That will make the trans act funny as well.

Thanks for getting back to me so quickly, between working long hours and poor weather I wasn't able to check it out until just yesterday. The throttle does move all the way but there is a lot of slack in the cable. Is that normal? One other thing, the car has over 244000km on it. How long do these transmissions last?