...um...this part doesn't look like the one I'm replacing...
 

1982 300D

Hi, guys.

I just had a 3/2 vacuum valve (on top of the valve cover) come in the mail. It looks different than the one I'm replacing. The one I'm replacing has two levers, the new one has one lever. Is this a revision of the part, or do I have the wrong part?

Thanks,

Pete.

If I'm not mistaken, the valve you are replacing does not have two levers.

What you actually have is two valves (one lever each) stacked on top of each other.

Ah, man!

What a pain.

I'm only half way there, and the one was expensive enough. I assumed the person I ordered it from would recognize that I needed both. I take it they are identical?

Pete.

Before you waste any more money on the 3/2 valves, confirm if they function solely for the EGR. I recently ripped out both 3/2 valves and all the associated hoses to the black box. The SD never knew the difference in terms of transmission performance.

Some 3/2 valves control the transmission. Most simply affect the EGR.

I believe they all technically affect the transmission vac, but usually not enough to really notice the impact.

mine did NOT have anything to do with the transmission...before i knew this i spent $60 on 2 new valves...ultimately i tore the entire thing out..the rubber tubing going from the line to the valve and vice versa had been leaking terribly also...

They don't.

The only time that the 3/2 valves cause a vacuum drop is when the the valve opens and applies vacuum to the EGR valve. This is momentary and won't affect the transmission.

The transmission circuit has a restrictor thereby minimizing any effects of an upstream vacuum drop.

All I know is that when I replaced those two plastic levers (not the entire valves, which I'm about to do, but just the little levers) it was like I had a new transmission. (seriously).

Pete.

I did this too...noticed nothing...then replaced the vavles..still noticed nothing...i then deemed those valves had nothing to do with the trans...pulled and em that was it...its different for each diesel certain models, yes certain no.

True, it can make a big difference if they were bad or leaking.

When I changed mine, I noticed no difference.

Boring out the "T"'s in the booster vac line made shifting all sloppy, and I'm still trying to remedy that.

Trace the lines
 

There is usually one source vacuum line going to the box on the valve cover. If there is a line going out to a temp. sensor near the engine thermostat & then to the EGR valve-you don't need them. The other line (if you have it) going back to the Injector pump area you should keep(transmission)& obviously the source line. Paul central FL
300CD '84

vacuum valve levers
 

maybe I'm imagining it, but Garner's 1-2 and 2-3 shifts seem smoother now than before installing the two little levers I got from diesel giant. For 10 bucks, it was worth it, as my old ones were worn through all the way. Just because it's a placebo doesn't mean it doesn't work!