B2 Piston W124
 

I am finally ready to deal with the B2 Piston problem with my W124.

Here is some information about my car:

Vehicle: 1989 300CE
Engine: 103.983
Chassis: 124.050
Transmission: 722.358 (4speed / 6 Bolt / Large Case)

According to the link below:
http://transmission.articles.mbz.org/b2/

I will need the following parts (Prices in Canadian Dollars):

107 270 04 32 ___B2 Piston $163.50
005 997 70 48 ___B2 Piston Seal Ring (to the cover) $5.20
126 277 08 50 ___Plastic Bushing for Updated B2 Piston $5.63
006 997 73 47 ___Seal that holds in the bushing $5.15
126 270 44 77 ___K1 Spring Kit NO PICTURE - $15.22
126 277 25 55 ___Seal - Not sure if I will need this one PART # CHANGE – 140 277 03 55 $8.00
126 271 11 80 ___Transmission Oil Pan Gasket $13.78
126 277 02 95 ___Transmission Filter Kit $33.30
xxx xxx xx xx ____Transmission Fluid REGULAR ATF
xxx xxx xx xx ____3 New Front Crossmember Bolts

http://img28.exs.cx/img28/4126/PETER2.jpg

http://img28.exs.cx/img28/3025/PETER1.jpg

Questions:

1. Does anyone here have experience with a B2 Piston repair on a W124 and were you able to do it with the transmission still on the car?

2. Does anyone have any suggestions or comments about the parts list I am about to order? Am I missing any parts?

Thank You

There's this

best of luck,

Thanks Norm. I already had that link from before and it is a good one.

Today's update:
I went to 3 Mercedes dealers and spoke with their top mechanics and 2 of them said that I will need the B2 band and 1 said it is the B2 Piston. This is without looking at the car just by my description of the problem I am experiencing. The B2 band requires the removal of the transmission and taking it apart (6 hours to remove and reinstall). Replacing the B2 Piston according to the 3 people I spoke with can be performed while the transmission is still on the car (2 hours). So I ordered the following parts today:

107 270 04 32 ___B2 Piston $163.50
005 997 70 48 ___B2 Piston Seal Ring (to the cover) $5.20
126 277 08 50 ___Plastic Bushing for Updated B2 Piston $5.63
006 997 73 47 ___Seal that holds in the bushing $5.15
126 270 44 77 ___K1 Spring Kit $15.22
126 277 25 55 ___Seal - Not sure if I will need this one PART # CHANGE – 140 277 03 55 $8.00
126 271 11 80 ___Transmission Oil Pan Gasket $13.78
126 277 02 95 ___Transmission Filter Kit $33.30


According to the link below:
http://transmission.articles.mbz.org/b2/

It is recommended to buy 3 New Front Crossmember Bolts. Will someone please call Rusty at 1-800-741-5252 and ask him what the part numbers are. The car is a 1989 300ce. That telephone number doesn't work for me.

Thank You

The problem is not removing the B2 piston; it’s removing the piston seal and bushing. Those tutorials do not tell you how to do that.

How hard is it to replace the piston seal and bushing?

.
It is very heard to remove them thru the piston bore, from the out side. The space is limited, even if you made a hook type puller the B2 band would be in the way.
The easiest method that I found is to remove the valve body and plate, Then remove the B2 band guide by pulling it out of the case, once removed you will have greater assess to the B2 piston seal and bushing. With a brass drift punch, tap the original aluminum bushing and seal out of the case. If you are lucky the seal and bushing will pop out if not then from the piston side crush the seal in, too loosing it then tap the bushing until it comes out. Caution: the B2 seal and updated plastic bush gets installed from the out side of the case, thru the piston bore. Before you start make sure you have adequate clearance. I would post some pictures but they are not up on my web site yet.

Parts finally arrived. Caution 56k Users.
 

Here are the parts I bought today.
I have some more that will be arriving tomorrow.

1. B2 Piston Part Number on Box
http://img160.exs.cx/img160/6335/dsc023701eb.jpg

2.B2 Piston Upper - Actual Part Number 126 277 11 38
http://img160.exs.cx/img160/9715/dsc024092ck.jpg

3.B2 Piston Bottom
http://img160.exs.cx/img160/5514/dsc023755av.jpg

4.B2 Piston pictured on top of oil filter (size reference)
http://img160.exs.cx/img160/9086/dsc02370a1wy.jpg

5. B2 Piston Closeup
http://img160.exs.cx/img160/506/dsc02376a7oo.jpg

6.B2 Piston Seal Ring (to the cover)
http://img160.exs.cx/img160/6241/dsc023974fs.jpg

7. Plastic Bushing for updated B2 Piston
http://img160.exs.cx/img160/9836/dsc023884yr.jpg

8.Seal that holds in the bushing
http://img160.exs.cx/img160/8062/dsc024000bo.jpg

9. K1 Spring Kit
http://img160.exs.cx/img160/6452/dsc024060bz.jpg

10. K1 Spring Kit
http://img160.exs.cx/img160/1835/dsc024076ek.jpg

I also bought another part that I just realized I don't know what it is for. I'm not sure where I read something suggesting that I need it. Anyway, I have it now.

1. Seal Ring
http://img158.exs.cx/img158/1575/dsc023926gc.jpg

I'm pulling for you on this one lino! :D

According to the link below:
http://transmission.articles.mbz.org/b2/

It is recommended to buy 3 New Front Crossmember Bolts. Will someone please call Rusty at 1-800-741-5252 and ask him what the part numbers are. The car is a 1989 300ce. That telephone number doesn't work for me.

Thank You

At the risk of getting a dirty look for being a little off topic, I want to say that those are very nice and clear pictures of the parts!
What kind of camera did you use, and at what resolution? (how close were you while taking them?)

Thanks! :)

-Larry

It's the Sony DSC-P31 2.0 megapixel.

Thanks for the compliments. It means a lot to me. I'll tell you why... It's a very cheap camera and when I first started taking pictures with it, I was told that my pics were very unclear and I had to take them over again. That was for the spark plugs which was in another thread. I spent hours taking photos over and over and over and over again to get the best results possible. Now I usually take 10 pictures of each item and select the best one and edit. Resolution is set to the max, which is 1600 fine. I take my pictures in a room and use a halogen lamp as well for more brightness. I am very close while taking them. Only inches away. My next camera will probably be something with a much better lens.

For camera info check out this site:

www.dpreview.com

Your extra part is an extra teflon sealing ring for the B2 piston; you already have the updated piston with one attached, so you shouldn't be needing it.

Are you certain? The seal ring is much smaller than the one that came on the B2 Piston.

trans
 

What kind of symptoms does that B2 piston cause?? Is it an up shifting problem?