I need to know where the vacuum line on the modulator goes to and how to hookup the shifting valve on my 82 300td. I installed this engine in a jeep cherokee and can't get it to shift.I did replace the modulator. will appreciate any help.Thanks Lou ljtorelli@aol.com

The line from the modulator connects to a Y connector thats connected to the vacuum control valve on the injection pump. Here is a pic. You'll see the yellowish thing on the rear of the injection pump that has a black hose that goes to a green check valve. Then a Y is connected, one side of the Y goes to the modulator, the other to the EGR.

You should still get shifting without the vacuum hooked up. It will shift really hard though. So it's likely something else.

Attached Thumbnails

 

__________________

Thanks for the quick reply.So even with no vacuum it should shift? I can't understand .This engine trans assembly came out of my car and was working fine.What else could give this problem? The fluid and filter are new and up to level.

The vacuum that goes to the transmission controls how soft or hard the shifting is. Too much vacuum causes flaring and soft shifts, not enough causes hard shiftshence hard shifting with vac leaks that plague these cars. So if you completely remove the vacuum you will get really hard shifts. Are you sure the linkage is putting the trans into gear all the way? If you've put the engine and trans into something else you've probably had to modify the linkage. So I'd make sure it's going into gear all the way.

__________________

Thanks I will check that over more carefully .Lou

I checked over the linkage and all seems fine. I'm stuck.What bothers me the most is it worked fine when I took it out of the car.Any help from anywhere is welcome. I even moved the shifter while moving.No difference.The forward and reverse works fine but no shifting.Thanks Lou.

How did you wire the kickdown solenoid? The symptoms you describe: fine in forward (first) and reverse, but no upshifting, point to a problem with the kickdown system. The solenoid is at the right rear of the transmission.

__________________
James Marriott
2003 Buick Regal
1983 300D (228k, frau Auto)
1996 Suburban K2500 (192k, 6.5 turbo diesel/4WD towmaster 10,000)
www.engineeringworks.biz
1987 300SDL junker 170k
1982 300SD junker, 265k

As far as I know the kickdown is mechanical by use of linkage.The engine trans combo was from an 82 300td but I think the trans is older.When I bought the trans filter the one listed for an 82 did not fit.It took a few tries before I found the correct filter.As far as any electrical hookup there isn't any.I could take a look which I will do now.I looked and found it and I didn't hook anything up to it yet.I failed to mention this trans wasn't used for a couple of years because of the difficulty of this project.Could something have siezed up that can be freed up without dismantleing the entire trans? I'm thinking maybe the govenor This trans has a number stamped 722.120 on it .Thanks for any help.Lou