Well I just finished replacing the B3 reverse friction discs and resealing the front pump, cleaned the valve body, and put the trans back in the car. In the process of re-attaching the bowden cable to the throttle linkage, I broke the nylon adjuster collar. At first the car wouldn't shift out of second (cable too tight) so I just disconnected it and now it shifts, albiet too early, as one would expect. The thing is, it also slams pretty hard into Drive and the behavior didn't change with the removal of the cable. Once moving, the shifts aren't harsh at all, it just bangs when going into Drive.

I had the car at the dealer this morning for an alignment, and they told me that the bang into Drive was a B-2 issue, and that it needed an adjustment. It just seems strange since I didn't touch the B-2 piston or band at all while I was working on the trans, and it didn't exhibit this behavior before. I did, however, remove the B-1 piston to get the K-1 drum out, and I'm wondering if that had some effect? I noticed that when I put the B-1 band back in, the thrust pin for the pressure body was pretty loose. I did not remove the pressure body.

So I'm wondering if anyone has any guesses as to what the problem could be? If it IS the B-2 thrust pin, do I need to remove the B-2 piston to put in a longer pin, or can I just remove the B-2 Pressure body and put in a new pin that way? I know the B-2 piston can technically be removed with the trans in the car, but that seems like a huge pain in the butt, given how difficult it was getting the B-1 out when I had the trans on the bench.

Any insights greatly appreciated, thanks!

I would hold fire until the Bowden cable is properly fitted and adjusted. Then I would check the vacuum adjustment and see if that makes a difference.

I agree with you that it would be easier to tackle the B2 piston with the transmission out of the car...

...you might be better off replacing brake bands rather than just the pins if it turns out that the piston is moving freely. You are getting quite close to what some would call a rebuild.

I've put in some tips on how I removed a B2 piston from my 722.303 (junk) transmission here

722.303 in bits photo shoot

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1992 W201 190E 1.8 171,000 km - Daily driver
1981 W123 300D ~ 100,000 miles / 160,000 km - project car stripped to the bone
1965 Land Rover Series 2a Station Wagon CIS recovery therapy!
1961 Volvo PV544 Bare metal rat rod-ish thing

I'm here to chat about cars and to help others - I'm not here "to always be right" like an internet warrior



Don't leave that there - I'll take it to bits!

Oh yeah I forgot to say - as you've had your valve body in bits recently are you sure you put the valves associated with the B2 brake band back in properly?

__________________
1992 W201 190E 1.8 171,000 km - Daily driver
1981 W123 300D ~ 100,000 miles / 160,000 km - project car stripped to the bone
1965 Land Rover Series 2a Station Wagon CIS recovery therapy!
1961 Volvo PV544 Bare metal rat rod-ish thing

I'm here to chat about cars and to help others - I'm not here "to always be right" like an internet warrior



Don't leave that there - I'll take it to bits!

Thanks Stretch. Yeah, I'll wait until after the bowden cable is replaced to dig deeper. The "slam" is really more of a "clunk," and doesn't effect anything but the initial engagement. I REALLY don't want to take the trans back out, so I'll likely try the band adjustment before replacement if it comes to that. I THINK I put the valves back together correctly, I'll have to double check my pictures.

Pictures? Did you say pictures?

Post 'em up if you can / or are willing I'm sure others will be interested to see - I'd like to see if your later valve body resembles the earlier 722.3 ones...

__________________
1992 W201 190E 1.8 171,000 km - Daily driver
1981 W123 300D ~ 100,000 miles / 160,000 km - project car stripped to the bone
1965 Land Rover Series 2a Station Wagon CIS recovery therapy!
1961 Volvo PV544 Bare metal rat rod-ish thing

I'm here to chat about cars and to help others - I'm not here "to always be right" like an internet warrior



Don't leave that there - I'll take it to bits!

I guess you have correct fluid level, I can't understand why the B-2 adjustment could be the problem and more confusing since you never touch the B-2.
Could it be the B-1 I am not sure is it the self adjusting piston in your transmission, If the play on the brake band is to tight you should have a bind when the transmission change gear 2-3 and I guess if the play is to big it might slip in some gears except B1 since that brake band is only in use in second gear and if the play is to large I don't now if it will make a clunk from P-D.
I would wait and see if the problem persist.

Could the problem be a have something to do with the flexdisk on propeller shaft or something else in the drive-train.
Could also be that you got weight on the parking pawl and that make the clunk issue try to engage the parking brake before you put the transmission in park.
Could also be that you have some slack in final drive and when you shift in to drive the slack make a clunk.
Is it possible that you forgot to tighten the trans mount it could be loose or bad so transmission is moving.

You could also try shift from Reverse - low1 if you have a problem still you can rule out B1 it is not in use or shift from drive- low1 B1 is not in use either.
Remove the B2 piston is possibly with the transmission in the car and much easier to take apart since B2 spring is much less tension and you will press the B2 cover easily with your hand but I still don't think you have to do anything with the transmission.

I did take pictures of the valve body as I was disassembling it, I'll post them in the valve body thread I started once I get them off the camera.

Great advice on checking the different gear engagements, will do that tomorrow. Today it was only clunking some of the time. I'll also double check everything in the driveline. I put in a new mount and flex disc, but I'll check the torque again. Could be the center support bearing I suppose, that is definitely original and I stressed it when I loosened the driveshaft and pushed the front half out of the way.

Good to know that the spring tension is lower on the B2 plate cover.

Make sure its not something simple like the transmission crossmember tightened before the trans was fully unloaded. It would put stress on the drivetrain and thunk. Just loosen the 4 bolts that connect to the body slightly, cycle through the gears, then tighten to the correct Nm spec (can't remember -- 45nm?).

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Good idea, I'll loosen and re-torque the crossmember. I think the trans jack was still supporting the weight when I put the cross member back on.

To double check my reading of the FSM torque values for the flex disc, it's 120nm at the trans flange end but only 30-40nm at the driveshaft end, correct?

Risking the wrath of admins here by revitalizing an 11 year old thread but I'm interested to know if you solved this. I've had this slam into D after warmup also (it's lesser when cold) for a while. Tranny otherwise shifts fine. So reading up all the old threads before I attempt a fix.