W123 200 1978 722.118 shift hard - Page 2 - PeachParts Mercedes-Benz Forum

Diseasel300 · #16 08-15-2017, 10:42 AM

If you have good vacuum at the modulator, you know the modulator is holding vacuum, and you know that the modulator is good, there's not much left but a worn transmission or driveline components.

If the valve body is worn or you have a piston sticking, you can get some very abrupt shifting behavior. When is the last time the fluid and filter were changed? If it's been a while, start there. Disgusting old fluid can cause nothing but headaches and certainly does the transmission no good at all. If the fluid has been changed recently, was it replaced with the correct fluid?

dmaglione · #17 08-15-2017, 10:51 AM

Ciao Diseasel300,

Unfortunately the oil and filter was replaced 1 moth ago and anyway regularly every 2 years. Also the fluid in the torque converter has been replaced. We used the Dexron ATF3.
Honestly I believe that something is worn inside. The main problem is that in Italy is so difficolt or at least impossible to find a mechanic able to treat vintage tranny. I'm able to buy a restored one but I don't think is so easy to find it. Anyway after spending 3000 euros to make a new engine (and is now perfect) and have this problem on tranny is very very terrible. I', just waiting to receive a vacuum meter for oil pressure and see the oil pressure value. thanks a lot for your kindest help.
Really appreciated

dmaglione · #18 08-16-2017, 10:57 AM

Quote:

Originally Posted by dmaglione

Ciao Diseasel300,

Unfortunately the oil and filter was replaced 1 moth ago and anyway regularly every 2 years. Also the fluid in the torque converter has been replaced. We used the Dexron ATF3.
Honestly I believe that something is worn inside. The main problem is that in Italy is so difficolt or at least impossible to find a mechanic able to treat vintage tranny. I'm able to buy a restored one but I don't think is so easy to find it. Anyway after spending 3000 euros to make a new engine (and is now perfect) and have this problem on tranny is very very terrible. I', just waiting to receive a vacuum meter for oil pressure and see the oil pressure value. thanks a lot for your kindest help.
Really appreciated

here som pics of my mercedes

dmaglione · #19 08-17-2017, 02:47 AM

Hello guys, one question about the problems with my transmission:

1) with gear in "Neutral" should the car moving a little bit forward when you press the accellerator? SHould the torque converter be broken and this caused this effect?
2) Why with the accellerator down, some shift slip a little bit?

Also the problem when you goes from N to D (kick in the ass) should be caused by faulty torque converter? The vacuum line is good and the vacuum value is perfect.

Thanks a lot

Diseasel300 · #20 08-17-2017, 12:49 PM

The torque converter should be the least of your problems. Cars of this vintage don't have a lockup clutch.

All of your symptoms point to problems in the valve body or simply a worn out transmission in need of service. There could be more than one issue at play here. I'd start by finding someone reputable that can work on the transmission and diagnose if it's something simple or if it's time for rebuild/replacement.