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1982 240D
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6 Posts
Discussion Starter #1
Hello all. I got a 1982 240d, automatic transmission (722.18) for free (!!) from a coworker a few years back. I've been out of the country but now that I'm back I have been driving it regularly.

It never has shifted very smoothly, but you could always get a shift out of it by letting up on the accelerator a little bit. I've been down the vacuum road, replaced fittings, removed doors and climate, but always had a little trouble with the VCV giving a good range of vacuum to the modulator. I did adjust the new modulator, counter clockwise for "softer" shifts quite a ways.

Before yesterday I had never had any slips or flares. I got about 4-5 slips and flares yesterday as well as a grinding-clunk when starting out in drive. All these problems started 2 days after it started making a low pulsing noise at highway speeds. (Sorry for all the unscientific language.)

Driving along in 4th down the highway trying to get it home to the garage to look at it. The transmission finally slipped out of gear and I haven't been able to get it to shift into gear at all. It runs great but won't go anywhere : (

ATF level is fine. Is this a torque converter issue? Is the tranny shot for good? any advice will be great!!!

After having done some research, I've found out (for the first time somehow?!) that my transmission symptoms for the past several months are similar to having a bad B2 piston.

My fear is that I tried to fix that by playing with the vacuum alone and waited too long. Could an unattended b2 piston have ruined my tranny? If i replaced it at this point is there a possibility for resurrection?

I would be completely convinced that the b2 piston is the only problem except that mine won't even go into reverse!

I hope I don't have to part it out, I've poured a lot into this thing. It's my favourite car I've owned. I'll be sad if it has to go.
thanks in advance,
mcDane
 

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1982 240D
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6 Posts
Discussion Starter #3
i'm new too, but it seems you enter the forum for your body style and click "new topic" icon in the upper left below the ads. it looks similar the reply button you just hit...
 

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10 Posts
i'm new too, but it seems you enter the forum for your body style and click "new topic" icon in the upper left below the ads. it looks similar the reply button you just hit...
cant fin the icon, where do I must be, in what section? in control panel? in active topics? today's post?
 

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2001 Volvo V40
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2,954 Posts
It never has shifted very smoothly, but you could always get a shift out of it by letting up on the accelerator a little bit. I've been down the vacuum road, replaced fittings, removed doors and climate, but always had a little trouble with the VCV giving a good range of vacuum to the modulator. I did adjust the new modulator, counter clockwise for "softer" shifts quite a ways.

It appears that you had a vacuum leak somewhere, not enough vacuum was "fed" to the modulator, which caused the rough and late shifts. You cannot solve the vacuum issue by adjusting the modulator, or at least, it isn't advisable, because transmission damage can occur.

By turning the modulator the "soft" direction, you have set the oil pressure inside the transmission too low. If it is really low, it might not be high enough to keep the transmission in gear, brake bands and couplings start slipping etc.

How old is the oil and filter of the transmission?

What you can do is check the oil pan of the transmission, to see if there is any loose parts there.

If the transmission was working, I would suggest getting the vacuum system fixed, adjusting the modulator according to specs (with a manometer attached to the transmission) and see if that helps, but now that the transmission isn't working that might be throwing good money after bad.

You can inspect the B2 piston, to see if that is still operational. B2 is used for 2nd and 3rd gear by the way.

Maybe it is the time to change the transmission into a four-speed manual...
 

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1982 240D
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6 Posts
Discussion Starter #7
I'm slowly digging into this thing. It's getting cold outside and I've had other car woes taking precedence.

I've taken the pan and filter off... there is a little glitter in the fluid but no alarming pieces or large chips or signs of serious wear. The fluid is bright red still.

I've also taken the B2 piston out and was very surprised to find that it isn't broken! The seal does need replacing though (now anyway).

I'm still not convinced that I need to replace the tranny but that could just be me in denial.:rolleyes:

p.s. There is plenty of vacuum in the system and no major leaks so i have a 'range' of 18 to 0 if I let up on the pedal and let the 2/3 valves close. The problem there is that the VCV isn't delivering a 'smooth' range through the pedal stroke.
 

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2001 Volvo V40
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2,954 Posts
If you attach a vacuum gauge to the line going to the transmission, you should see instant and smooth (certainly after the 2/3 valve is actuated) reaction to throttle movement. If not, either the valves are not working properly or a check valve was installed in the vacuum line instead of a damper (seen that once).
 

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2003 Mercedes S430
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806 Posts
I'm not sure what you are meaning when you say "convinced" since our job here is not to convince you of anything.

In my experience, as both a vehicle owner and a dealer, when a transmission behaves like yours, it is shot. All of the oil changes in the world won't bring it back to life. Being an 82 model, this thing is nearly 30 years old.

Pull the trans out and buy the overhaul manual. You can build this unit yourself and save lots of cash. It is not a hard job. Be safe when doing this job.
 
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