Help - stuck on road 722.3 no 3rd/4th gear - PeachParts Mercedes-Benz Forum

ps2cho · #1 11-13-2011, 05:40 PM

I rescaled rear transmission pump this weekend but couldn't line up gears. I looked and the spring looked like it served that purpose - to fit gears in once you move.

Driven 300mi on i10 just broke down. No 3rd 4th gear.

Did I screw this up?

I did notice fluid is high though. Can't think of a way of taking some out no way to drain it

Solid Snake · #2 11-13-2011, 05:48 PM

Quote:

Originally Posted by ps2cho

I rescaled rear transmission pump this weekend but couldn't line up gears. I looked and the spring looked like it served that purpose - to fit gears in once you move.

Driven 300mi on i10 just broke down. No 3rd 4th gear.

Did I screw this up?

I did notice fluid is high though. Can't think of a way of taking some out no way to drain it

Crack a trans cooler line to get some out; don't know how else to help you...

whipplem104 · #3 11-13-2011, 06:22 PM

I am thinking that you sheared the governor off. If you messed the auxilary pump, it drives off of the governor. Is your car a 2nd gear start? Or does it shift out of 1st? just not into 3 or 4? Not much to do but drive it how it is or tow it. If it is the governor you can take the aux pump off an remove the gears then put a new governor in. You can do all this in the car.

ps2cho · #4 11-13-2011, 06:23 PM

Done. Not much came out but fluid looks fine does not smell burnt...ugh!!!!

Merkey · #5 11-13-2011, 06:59 PM

I am Ps2cho's father, and trying to help from afar...
We resealed the rear pump, but here is what I read about the function of the rear pump, I dont think its related.

Secondary Pump:
Secondary pump is required only for towing and tow-starting
vehicle. It is designed as an external gear pump and is positioned in
rear section of the transmission. If needed, secondary pump is driven
by centrifugal governor shaft. Secondary pump operates only if engine
is not running and vehicle is rolling (tow-starting procedure), while
brake band B-2 slowly engages. Pump stops operating when vehicle comes
to a stop or if transmission has shifted into 4th or 5th gear (engine
running).

However, we also resealed the Kickdown Solenoid.
We took it out, replaced the 3 "O" rings, and replaced it.

Here is what it says, and what he is experiencing...

WILL NOT UPSHIFT
Incorrect governor pressure. Defective governor assembly.
Check for stuck kickdown solenoid or for constant voltage to solenoid
caused by a defective fuel pump relay or sticking kickdown switch.
Valve body dirty or valves sticking. Repair or replace valve body.

If we did something wrong with the Solenoid, would this make sense?

cbc atl · #6 11-13-2011, 07:55 PM

I posted this on the other site to see if anyone has an idea as well.

Click here to view

Merkey · #7 11-13-2011, 08:08 PM

Thanks.
Main thing is he is safe, and now in a rest area.

He let it cool and tried again, but it would not shift up from first.

d.delano · #8 11-13-2011, 08:30 PM

I know you probably don't think its related, but if the FSM tells you to line the gears up and you didn't - that's probably the issue right there. Trans worked before you messed with it. Hopefully you didn't do any damage and can put it right.

Sure is a bummer when you go in thinking you're going to fix something and either it turns out to be much more of a pain than you expected or you make things worse, or both. I do it all the time. It's a learning experience.

My old man always says - it if ain't broke don't break it. I myself would have lived with that leak until the trans came out for a rebuild.

ps2cho · #9 11-13-2011, 08:42 PM

Manual does not mention about reinstallion at all....just says put it back in basically.

d.delano · #10 11-13-2011, 10:37 PM

I thought I saw in your last post that the ATSG book said the drive lug on the pump gear had to be pointed up. Did you do what the book told you to do? I think I read that you stated you put it in misaligned because it was 'impossible to do it' the way the book told you.

My point is if you did it any other way than the book told you to do it, there's your problem. I mean, why do you think the book tells you to do it a certain way? Because the tech authors know you will do it another way? It's an automatic transmission. You shouldn't play around with it like that. You did it wrong and there's your problem.

If I'm missing something here then please correct me. You had a functioning transmission with a leak before you did the work. You now have a nonshifting transmission. Coincidence? Happenstance? Freak occurrence? No. You made it happen with the work you did. Perhaps your next move should be to go back in and reverse whatever it was that you did wrong. I'd bet big money if you went back in there and aligned the drive lug like you were supposed to you would get to 4th gear again.

See this is why you don't muck around with automatic transmissions unless you have the expertise. They aren't usually shadetreeable items.

You have a distinct edge however, Sun Valley Mercedes Dismantlers is in the SoCal area. They are probably the best MB transmission rebuilders in the country aside from perhaps MB. You have an out, come what may. Good luck to you.

bunksbbq · #11 11-13-2011, 10:39 PM

I agree with the earlier post, you sheered the governor gear. Happened to me not too long ago. While originally replacing the smaller governor gear, I didn't touch the secondary pump. A couple of weeks later, it failed again, this time stripping both plastic gears to lots of little pieces. While doing that R&R, I pulled the secondary pump. Inside I found a small spring that had migrated down from the valves. This was what was stopping the govenor and causing it to strip out. Since the secondary is only for tow starting, I just replaced it without the gears. You've got a good 5 hour job ahead but easily done from under the car. Good Luck.

ps2cho · #12 11-13-2011, 11:53 PM

I am home, but the car is stranded and I am gonna pick it up tomorrow some way or another.

---

Let me explain this better:

Aux pump/2ndary pump seal was leaking so I removed the pump:
I couldn't align the gear up, but I assumed that the spring acted as a way that the gear would align itself.

---------------

There is a low level noise in 2nd gear, but the car moves. What could have happened here? Possibly the gear broke? Most importantly, what could have happened that is causing the non-shifting issue? How would a broken governor gear cause a non-shift? Or could it be caused by collateral damage?

I eliminated kickdown switch while I was on the road -- something has broken internally.

--

d.delano, I don't need you to talk down to me. I already mentioned that I attempted to align it. I will not be belittled by you so quit it or leave the thread I need no counseling from you. Error was made, what's done is done.

sptt · #13 11-14-2011, 12:52 AM

Agreed! d.delano...ps2cho has save me thousands with his DIY threads. Never see you popping up to help anyone out! These threads are for "repair it yourself" people. If he wants to attempt his own repairs he sure the heck can! Stay out if you're not gonna help!!!

Adler · #14 11-14-2011, 09:55 AM

Quote:

Originally Posted by sptt

Agreed! d.delano...ps2cho has save me thousands with his DIY threads. Never see you popping up to help anyone out! These threads are for "repair it yourself" people. If he wants to attempt his own repairs he sure the heck can! Stay out if you're not gonna help!!!

Indeed !The forum is to help and assist, not to....

ad

Merkey · #15 11-14-2011, 12:21 PM

I worked with him on this.
We did not remove the governer, only the secondary pump that engages the square drive peg on the end of the governer shaft.

I have just looked thru both the ATSG PDF and a Mercedes factory PDF, and nowhere is there a mention of lining up the pump and governer drive. In fact the way it is set up, the drive gear is spring-loaded, as as soon as the governer rotates it would engage.
This is NOT like the front pump/TC setup, that MUST be correctly positioned.

One thing I did spot that we may have missed, is that there is a small threaded shaft called the "Axial Support" that passes thru the secondary pump, and is secured with a nut. The end of this shaft has a small slot in the end, and in one of the manuals(which I just found) it mentions making sure that the slot is horizontal... There is only about 45deg or less movement in this shaft, and its slot, and horizontal is at its maximum clockwise position.

Whilst tightening the nut would rotate the shaft to its stop position... which would be horizontal, I am unsure where we set it, as I only just fornd that info...
Anyone know what the Axial Support does?

I am also concerned about a failure of the Kickdown Solenoid...
Anyone know if it fails in the open position, and what the result would be?

What I find odd, is the way this problem manifested itself... The drive was uneventful, and almost 300 miles long before he slowed down, and only then did the trans start acting up...