four bolt pan transmission problem,

[w113dude]

Hello to All,

I have a four bolt pan automatic transmission on my 72 250C, the side ID tag is missing so I'm not sure exactly which model it is, the problem is that it's skipping gears, in addition just before shifting it's making a whooshing sound, I check oil level, I checked the vacuum connection the the transmission, this is my fist auto transmission that I'm working on, so any Ideas?
I did look in the forum but I couldn't find much info. on this later model transmissions.

Thanks
Shaun

[ja17]

Hello Shuan,

The W113 cars never used this transmission. Thats why there is not much ifo here.

#1 try a fluid and filter change to see if it helps. While the trans pan is off, retorque all the bolts holding the valve body in place. Inspect the pan for damaged  parts or  excessive clutch material


#2 replace tha vacuume modulator if #1 does not work.

[w113dude]

Thanks Joe,

I have gone through step one but no luck, so I'll try the vacuum modulator.

Cheers,
Shaun

[w113dude]

Joe,

I checked the vacuum modulator it does hold vacuum, does this indicate that is working or not necessarily.

Thanks
Shaun

[ja17]

Hello Shaun,

**Note to other on-lookers, this information is not pagoda relevant, it deals with an later tranmission. Check the accellerator linkage rod which goes back to the transmission. Lengthening or shortening it changes shift characteristics. The vacuume modulator has a allen pressure adjustment inside. the vacuume line must be removed and you need a gauge to set it. Normally these are factory set. Check the tightness of the bolts holding the valve body in the transmission. Do you have any bits or peices in the trans oil pan when it is inspected?

[w113dude]

Joe,

I didn't see anything unusual when changing the oil, I'll play around with the transmission linkage rods to see if it'll make any changes before touching the vacuum modulator out.

Thanks
Shaun 

[w113dude]

Hi Joe,

Should the modulating valve on the transmission hold vacuum? on the transmission it holds but bench testing does not.
Also after driving for 200 miles or so I emptied the transmission and found black burnt particles and metal shavings, Does this sounds like a complete overhaul? or changin the modulating valve will take care of it.

Thanks
Shaun

[ja17]

Sounds like you have issues other than the modulator.  The black paste and particles is clutch material. How much black material and how big are the metal particles? A good used trany for this model is not that hard to come by.  Where are you located?   1968-1972 is the vintage, (four and six cyl gas engines). Make sure it is a four bolt pan. After 1973 the trans is different.

The modulator should hold vacuume. At this point a lot of debris has circulated into the intricate valve body and cluch plates are worn and damaged.