David,

Your thoughts about the B1 (yellow) being an upgrade might be correct.
I too have replaced the 'blue' and 'green' with success.

When I ordered the 'yellow' for the B1, it was listed on my invoice as a "repair kit" which could also mean "upgrade" see snippet from original invoice.

I haven't replaced the yellow one yet as I was planning to do it at the next fluid change. Your (this) post is motivating me to get under the car and see if it will fit and what improvements it makes to my 1-2 hard shift.

My 1-2 shift can really thump at times and I'm concerned about things downstream such as the diff gears and half shafts on the rear axle. It's already elongated the bolt holes on my front guibo/flex disc and now has to be replaced.

Thanks benedict, yep, that's the same number on my invoice too.

These sorts of shifts can be hard on motor mountings, I think mine have failed so on the 'to do' list.

Oddly enough, the b1 valve shown in the diagram has straight sides which might be a positive for upgrade theory.

http://www.benzworld.org/forums/atta...1&d=1285215432

I may be wrong, but there also appears more springs along with an aluminium pin.

http://i225.photobucket.com/albums/d...pselszyt0t.jpg

I have these extra bits also. Now we just need to find the bulliten from Mercedes to explain where and what to do with them,ha.

These guys have a lot of helpful diagrams.

Having read several pdf's on 722.x transmissions, not one has the B1 valve with a tapered body, see pic below.

http://i.ebayimg.com/images/g/VYwAAO...ia/s-l1600.jpg

See there kit here (eBay)


http://www.ebay.co.uk/itm/722-3-722-4-Gas-Kit-Superior-K722A-G-MERCEDES-BENZ-81-/320738190639

Image 2 explains B1 replacement and possible benefit - it looks as though we have the 'yellow' valve for earlier 722.3 transmission according to note 6 below?

http://i.ebayimg.com/images/g/4~sAAO...ic/s-l1600.jpg

Okay, after a bit more research my theory is as follows.

The existing red b1 valve currently in the car has the older style 2 spring configuration (see 2 - 3 spring train side note below)

http://i225.photobucket.com/albums/d...psrbixap9y.jpg

My guess is this has now been replaced by the 3 spring train for better shifts, hopefully the yellow carrier will fit also, if not it may be a case of changing out the springs only - most of the upgrade kits featured above offer this option for either 2 or 3 spring set-up

Reading various articles and notes above, a lighter spring will result in softer 1 -2nd shift.

In terms of putting the springs together, please see below pic. We may be able to swap out the end cap (right of pic) if fitted to original. Also, with regard to the 'yellow' comment, the reference is almost certainly a spring as opposed to the carrier colour as originally posted.

http://i225.photobucket.com/albums/d...psluwus6gx.jpg

Is there any tricks to removing or installing the cover plates since I would imagine a fair bit of spring pressure needs to be overcome?

The K1/K2 are pretty easy as spring well recessed inside valve body, perhaps half inch protruding which needs compressing.

B1 a little harder as the cover runs across another adjacent spring, this pops out once the cover is removed so be on your guard, only small but fiddly all the same. B1 spring is longer and dies have a tenancy to bend on itself under compression, good tip from Stretch, use a screw driver bit and socket to avoid rounding/burring screw heads - these are not Phillips but regular slots heads, wound in pretty tight too.

That kit says it is for gas. Does the diesel need a different one?

Yup, only using the kit diagrams to identify B1 piston and others. There seems to be two schools of thought as to what the b1 pistons does, not 100% sure but if the k1/K2 are worn likely B1 is too.

Please post back your findings as I am sure one or two are following with interest.

It is nice of you to post all the great pictures of various parts and diagrams -- thank you. Is your trans 722.414?
I found this bulletin (if you haven't seen it) attached below.

Pl keep posting p/n and pics -- I'm trying to resolve trans issues on my 300e 2.8 W124 -- it's a gas model - don't know how much is similar - it's 722.433. So far only replaced the K1 kit - haven't been able to find part numbers for K2 or B1.

On EPC, for my car, unfortunately there is no "spanner" icon on the similar page as on your post#17.

So I gather it must be an upgrade for the three specific 722 transmissions on the bulletin.

Best.

n/p benusa, always good to swap ideas around. i know mine is a 722.4 but not sure on the last two digits, next time on EPC will have a look.

That's an excellent document, very helpful.

I ended up sending one of the threads to MB parts guy, he then tracked down part numbers from that. It's a while back, but there should be a link earlier on in this thread to how this cross referencing was achieved, let me know if you can't find it.

If I were US based, might have opted for the aftermarket upgrade kits, you can then use their part diagrams and hopefully tech support.

You probably already know, but just in case..
The next time you are working there...the full trans # should also be stamped on the transmission itself. On mine it is just above the ATF pan on the opposite side where the pressure modulator is.

Cheers for that, I did look last night on EPC which revealed 722.435

With regard to the spanner icon, this might only appear on up to date dealership EPC software, just in case you were using something older.

Still not a 100% sure on my B1 replacement although I hope it's a direct swap over. My guess is that although the last few digits changed it may have only been to signify the piston upgrades, if so adding a later piston configuration should be okay (in theory)

Going to swap out the B1 piston tomorrow, ATF draining overnight to avoid dripping sleeve syndrome.

Came across this in an effort to resolve B1 assembly procedure, the pdf link above shows the alloy pin at the other end of spring v previous images.

Not sure if covered in this document as half way through.

http://www.w124performance.com/docs/mb/transmission/722.6/trans_722.6_ATSG_2004.pdf