The Germans making an overcomplicated solution to a small problem? I've never heard of such a thing

-J

I'm not sure if you have explained the difference between FSM and WIS before, but thanks none the less for posting the reference, it definately saves me time trying to hunt the details down. Looking at the Print, it looks super simple to get out provided I have enough clearance to get it out. On one of the Vacuum diagrams I noticed a note stating tha the 190 2.5 couldn't get the Modulator out with the transmission in the car. I got nervous for a minute but think I have clearance. I'll be sure to take pictures to share on this thread when I do it after I get the new modulator. ( I love pics in the other posts!) With the needle stem looking thing, is there any alignment or proper assembly order to worry about or is it simply drop int and screw the two retainer clip bolts back down?

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1990 300D 2.5 Turbo 150k miles
1999 F250 7.3L Powerstroke 225k miles 22mpg
Intro Thread

The 201 chassis is smaller and clearances may be reduced. On the 124 with 722.4 there appears to be plenty of room (see photo below). Shoot, if I could do it on a 500E, the 2.5T should be a breeze. The needle/pin thingy doesn't get aligned, it just drops into place, IIRC. The main thing is to clean the area around the modulator REALLY well before you remove it... you don't want any dirt falling into the bore. The new modulator comes pre-set and may work ok out of the box, but a slight adjustment may be required to fine-tune shifting.

My 87 and 93 mobulators both leak down in a few seconds. However, they both have different shifting problems. The 93 shifts hard. The 87 won't up shift at times after a long hour drive mainly.

I think i have the 93 problem pinpointed. There is 0 vacuum coming from the VCV valve. When i hook the mightvac to the line going to tranny modulator and pump it up, it shifts buttery smooth. Where is the adjustment procedure for the VCV ? I cant' find it in FSM. Also, is there some central place has all the tranny info someone can PM me?

For the 87, it could be a lot of things. I'm gonna try bypassing he BFS. I see how to bypass it and go straight from VCV to tranny. But what do with all the other lines going to the BFS and and that vacumm switch? Anyone have a pic of their setup. Ideally , i'm removing alda too. I'm excited to really simplify the vacuum mess under there.

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What Would Rudolph Do?
1975 300D, 1975 240D, 1985 300SD, 1997 300D, 2005 E320 , 2006 Toyota Prius

That's not good. The modulators should hold steady vacuum. Make sure the rubber caps are not cracked, replace them if they are, although that may not cure the problem. If it doesn't - replace the modulators.


The modulator only affects the shift firmness. The 87's upshift problem is most likely not related to the modulator.



Yep, that's a problem. It should be 15" vac at idle, dropping to zero at WOT. The modulator is working if it shifts smooth when vacuum is applied, although it still shouldn't leak down.



It's in Group 7, job 1826. Click here to view. The engine does not need to be running to do this, btw - have someone hold the throttle wide open, loosen the bolts, turn the VCV slowly until resistance is felt, tighten it down. 90% of the time, it will end up right in the middle of the adjustment range.


Try this, although some only applies to older models:
http://www.peachparts.com/Wikka/TransVacTune



Good idea. I did the same on both of my 87's with excellent results.



The rest gets disconnected and plumbing removed; cap off the stuff that can't be removed. Pretty much all of it can go away. I need to take a photo and add it to my website... isn't much to see though. Make the '87 look like the '93 and you have the idea.



I don't recommend removal of the ALDA but that's a separate debate. If you don't remove it, connect the fitting from the intake manifold directly to the ALDA and remove all the other tubes & plumbing that used to send boost signals to the BFS and solenoids.

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Dave
Boise, ID
Check out my website photos, documents, and movies!

Ahh got it. Thanks gsxr. My 1993 was just vac disconnected at the 4 way by the vac pump. Shifts so perfect now. I can't even feel it. Im thrilled. No , completely in love is more like it. Didn't know an auto could shift so good.

I'm also thrilled I can get rid of all that mess under the hood of 87. I've already got the Alda going directly to intake. Tomorrow will be fun. I'll take a pic of it when I'm done and put it up.

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What Would Rudolph Do?
1975 300D, 1975 240D, 1985 300SD, 1997 300D, 2005 E320 , 2006 Toyota Prius

I remember why I didn't think the 93 hard shifting was due to no vacuum - every other mb I've had ( including the 87 td I think. Need to check again) always shifts way late with no vacuum, at the shift points in the speedo about. This 93 shifted at right time just hard with no vacuum. Is this an improvement in tranny in the 722.4 ( I think that's the one)? Back to studying.

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What Would Rudolph Do?
1975 300D, 1975 240D, 1985 300SD, 1997 300D, 2005 E320 , 2006 Toyota Prius

If the '87 won't upshift after driving a while, change the fluid and filter. It is possible that the filter takes a little while to clog after being parked for a while, I've seen this before a couple of times.

However, this would also indicate either it's way past-due for a change, or it is losing friction material at a high rate, both bad.

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Gone to the dark side

- Jeff

The older MB diesels (1970's, maybe early 80's?) used a different transmission control system. On the W124's, the shift timing (early/late) is entirely based on throttle position from the Bowden cable, while the vacuum only affects shift firmness. The ALDA adjustment will also affect both - if the IP is too lean, you'll have your foot way into the throttle to get the car to move, resulting in late/hard shifts. On the flip side if the ALDA is removed on a well-tuned pump, and/or the full-load adjustment is set too high, you'll use very little throttle to move the car at a decent pace; resulting in too-early/too-soft shifts. BT, DT... but with a stock IP and stock power levels you should be able to get near-factory shifting as long as the tranny isn't worn out.

So i disconnected the Blue Fliyng-Saucer Disk on my 1987 TD last weekend and have been driving around this week. Car has shifted great. I have not done any long hour or more trips. Maybe this weekend. it is very easy and you can clean a lot of potential vacuum leaks from your system.

One thing i don't know about is the big black vacuum line that t'd off of top of BFD. See picture. It is totally disconnected now and sitting where the BFD used to be. I think it is just a vent as i have not had any vac problems all week.

To do this is real simple. The first pic is after with BFD and vacuum excess out of the way. Next one is before, and the last one is a close up of the Vacuum control valve connections . Anyone need a BFD?

Attached Thumbnails

     

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What Would Rudolph Do?
1975 300D, 1975 240D, 1985 300SD, 1997 300D, 2005 E320 , 2006 Toyota Prius

The big line goes to a vacuum reservoir in the fender. I'm BFS-less myself and there's I don't notice any difference with the reservoir hooked up or open. I keep it hooked up. Otherwise cap the line so it stays clean.

See page 5 of attachment Vac Diag 1 here -

Vacuum Diagrams 201 and 124

Sixto
87 300D

Mine leaks, I bought a used one to replace it, but have had it bypassed for the past 3k miles with no ill effects. I wondered why it didn't change anything to take it out of the circuit, ...?

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Gone to the dark side

- Jeff

GSXR, you are the man! I just did the manual waste gate convertion so I finally have boost, but now because or this thread I can finally get rid of my funky intermittent hard shift problem. You are a god send to us w124 om602 owners. Thanks

Ahh, the good old vac diag. Thanks sixto. I forget I have access to those sometimes and just ask on her. I'm getting a nice little collection of pdfs now. Here's a link i just found in another thread to transmission stuff. Haven't looked at it yet but while we're on the subject ...

http://w124-zone.com/downloads/photos/300TE/remove_tranny/transmission%20repair.pdf

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What Would Rudolph Do?
1975 300D, 1975 240D, 1985 300SD, 1997 300D, 2005 E320 , 2006 Toyota Prius

So i did change fluid and filters a while back. I think maybe its the bowden cable getting jammed possibly. Is that feasible? It's clip broke and it was hanging down half way to ground one day. Also since vac does not control shift points on these trans , then my problem isn't really vac related. Still glad to get rid of the BFS.

Another thing i notice is the car is really slow to take off when its cold. I'm going to remove alda tomorrow and see if that fixes that problem. Otherwise it could be trans needs some Trans X . Read that helped in another thread.

Ok. Sorry for the thread hijack. Hard shifting tranny with no vac leaks , you say? Mine was a vac leak Did the modulator help?

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What Would Rudolph Do?
1975 300D, 1975 240D, 1985 300SD, 1997 300D, 2005 E320 , 2006 Toyota Prius