Help - stuck on road 722.3 no 3rd/4th gear
 

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...

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.

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

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?

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

Click here to view

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.

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.

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

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.

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.

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.

http://www.w124-zone.com/downloads/p...on/2pump-5.jpg

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

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.

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!!!

Placing bets on Kickdown Solenoid to win before it's post time.

My bet is on the bit that has been removed and replaced => the governor.

My limited understanding of these transmissions leads me to think that the governor would be better off being called the "manager" (or think of it as old fashioned English slang where the boss / manager was often called "governor" or if you're from Northern England "Gov'ner").

Anyway if you look through all of the faults with shifting remedies in the ATSG manual you'll see governor as a possible problem area for (virtually?) every fault.

I think if the governor doesn't work; the fluid (at pressure) doesn't get directed correctly. I think it goes to failure mode where nothing or little is allowed to engage.

To clarify -- the governor is what the aux pump connects to?

Once I get her home I'll take the pump off again to try and figure out what's going on.

I'm just hoping I don't need to rebuild the whole thing...:(

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

ad

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...

Bang goes the governor theory then - though a dodgy one might explain some of the other problems your son has been experiencing (see the other posts).


Anyway I can't see the axial support in the ATSG manual (I'm on page 31 and 32 at the moment looking at the secondary pump removal and installation)...

and I can't see it on the parts diagram here =>

http://www.ganzeboom.net/images1/ganzeboom/parts/Mercedes/722.3,%20722.4.pdf

Can you post some more information on it or tell me which part number it is in the pdf file posted above?

In a worst case scenario I can take a 722.303 to bits at quite short notice to get some pictures for you guys if you need 'em. Stripping that one down is on the to do list anyway - I can just bump it up the list if you think it might help.

To eliminate the kick down solenoid you should just have to disconnect it. It you are worried that it is sticking they seem to be pretty simple things. Just remove clean and inspect - bit of grease if you want to be 100% sure it is moving as it should.

Awesome link thanks!

OK, OK...
Now I am seeing a possibilty...
The Axial support is part #687 on the last page #68.
Its on the LH side of the trans grouped with the Govenor assy..

Now I think I can see what it does and the possibility of that being the issue...

Looks like when the slot in it is rotated to the horizontal position, the fork on the opposite end rotates, and is the keeper that holds the govenor shaft.
So, it keeps the Govenor in the correct position.

Its possible the govenor is out of position, and thats why this happened.
My biggest concern is that the govenor or its gear... or the drive gear on the output shaft is damaged...

Where we went wrong was not reading the Govenor removal section.... as we were not removing the govenor!

The only time you don't make mistakes, is when you don't do anything... and as the boss's or women in our lives will tell you... that is just as bad!

Anyway, Ps2cho is onroute home with the TE on a flatbed behind him..
I am sure he will be posting a thread on what the result will be...

Ph2cho, Huge bummer! I currently have my tranny down and just did a partial rebuild. I'll be re-installing it later this week. Your post and site have been a great help. If mine goes belly up then I've lost 250 bucks in parts and time. Then I'll just buy a rebuilt tranny. Good luck and let us know the outcome.

The 300TE is the garage safe and sound now...so I got under the car to try again.

http://www.w124-zone.com/downloads/p...on/diagram.jpg

So you can all see it. #43 + 44 show the different positions.

I took off the nut and attempted to get it to lock in place, but was unsuccessful. I am not sure if its a tight fit, or I need a better tool, I don't know. Maybe someone who has done this step can pipe in and say how they did it or if it was tight.

Are you guys now planning to remove the governor and start over?

(It seems like a plan to me)

That's the plan for me. Gotta unbolt exhaust to drop tranny down. Just not enough space...

I really need to confirm the gov is not stripped.

I am reading there is snap ring inboard that requires an mb tool to release...any alternative?

Removed the governor from my 91 300D a few years ago. I know the clip was a little hard to get to but I used needle nose plyers and long thin screw drivers. I found the gear broken (plastic). Cost of part was less than $2 before tax from dealer. My car has 1st gear start so it stayed in 1st. Remove the rear crossmember and let trans drop as far as it will. Push the trans as far as posible to the right side of the car and put a block of wood somrwhere to hold it there. Remove the snap ring that holds the gov cover and remove the cover. Try to turn the gov and if it turns than you have found the problem.

It is very important that you keep the gov clean. Also, If the gear is broken or stripped than check the rear pump before you reinstall the gov. The gov gear also drives the rear pump.

That is all I remember from when I had mine out. That was about 5 years ago.

Paul

Thanks! So its possible to get the governor out just by pushing the transmission to the side? Is there enough space to get the clip with screwdrivers then?

I'll give it a shot and see what I can do.

If you have a spare hand - perhaps you can take some pictures for us?

I have had two incidences with the governor and secondary pump in two of my cars. Since it sounds like the axial support was not in the right position, it allows the governor to move back and forth, once the car was brought out to speed the the governor will stay in position, but if slowed down and put in lowerr gear the governor will move around. On the opposite side of secondary oil pump sits the governor, there is a cover over the governor, This is where the governor is most likely pushed against and is stuck. There is a gear on the governor which if metal would of broke the small pin located on the governor making the governor rotate freely not up-shift. If the gear is plastic it would of broke and will need to be replaced. The car will have to be towed or driven in 2nd gear to a shop, the transmission will have to come out to open up the rear end of the trans and assess the damage.

Any Question, just Ask
Sean

Alright, I tried to get that governor cover off and it won't budge in!! Unless its supposed to be tough? All of the rest of those covers press in 1/2in, but this wont.

My thinking is that the governor is pressed up against the cover. So I went first to the pump to check it:


Phew...looks OK!! Seems that the pump engaged fine, so its gotta be with the governor and I HOPE that since I don't see any damage, the governor just slipped sideways towards the drivers side and no damage occurred.

I tried to get a photo of the output shaft of the gov but its pressed in (AGAIN, strong indication its too far over.) I couldn't get a good photo, but it looked okay too.

http://www.w124-zone.com/downloads/p...n/recheck1.jpg

http://www.w124-zone.com/downloads/p...n/recheck2.jpg

Got it now!

What do ya know...governor spins :)

I'm thinking the diagnosis was correct!

http://www.w124-zone.com/downloads/p...n/recheck3.jpg

Gonna try now and get the governor out without dropping exhaust, and if not I may just try and reposition the governor, lock it down and give it a shot.
Curious though why there seems to be rust? Does this end of the governor not get fluid?

I am trying to find what position/orientation the governor is supposed to be in when reinstalled. Anybody know?

Nevermind not rust....

OK --- I cannot get governor out completely. I tried pushing the tranny as far over as I could and still not enough space.

I did get a good look at the gear though and it looks perfect.

So all that is left is to try and lock this baby back down. I can "feel" the axial support grab and move about 1/6th of a turn further than any other location I tried, but I cannot get it to go verticle. I can only get it to 9'oclock instead of the disengaged 6:30 position.

Any ideas?

EDIT: nevermind I feel silly its only supposed to be 9'oclock. Looks like I got it! Time to put it back together and see what happens!!! Fingers crossed.

Ok I ran into a little issue that I want to check before going further....

Even though the A/S is horizontal which according to the manuals is correct, when loose it still moves 1/4inch forward/backward. Is this normal? I want to make sure that is normal if anybody remembers or not before tightening and putting it back together...

Or does it not matter because once tight, the nut should pull it outwards anyway?

The governor should not spin freely. It should spin as you rotate the drive shaft, if it rotates freely, the pin on the governor that secures the gear has broken off, making the governor needed to be replaced.

I put it back together and no luck -- still only does 1st and 2nd gear, and it slips between both depending on load.

Back to the drawing board.

It spun when I first removed the cover and the axial support was not locked. After I removed it, rotated it 90 deg and put it back in and locked the axial support, it would not spin freely.
I'm guessing I really need to drop exhaust and remove the entire thing now.

This sucks, but I don't believe I should need to remove the aux pump right? Just the nut for the axial support?

Bummer you didn't get it fixed. I'll keep my fingers crossed for you. It be interesting to see what you find when you get it all laid out on a bench.

At this stage, I dont think he needs to remove the whole trans.
I am thinking just remove the exhaust from the manifolds, and fan shroud to allow the rear of the transmission to drop. This will allow him to pull out the govenor.
From there he can look at the govenor, and the mainshaft drive gear.
Its not clear from the manuals and diagrams I have seen how the govenor looks and is assembled.
Anyone got pics or knowledge?

I read on one post that the mainshaft gear is plastic... anyone know?
Clearly, if the Govenor is spinning freely, then it has lost engagement with the mainshaft gear... either by being out of place, or a gear is stripped. If the mainshaft gear or Gov gear is plastic, that would be the weakest link.
Looking at the Assembly drawing, it looks like you could replace the mainshaft gear by removing the tailshaft housing... but maybe its not possible

If the gears are broken, will the rear cover need to be removed to replace everything?

And as long as the exhaust is dropped and the transmission hangs down, I should be able to do everything without removing the transmission right?

Like I've said before I've not as yet pulled a 722.3 to bits but I think that the construction is similar enough to a 722.1 in the way that the gear set clearances are all measured and adjusted from the rear of the transmission. If you remove the back end part of the casing you might (just might!) find that the gear set tries to slip out of the transmission if it is hanging down under the car at an angle. This could cause you more trouble that you don't need. Even though it seems to be more work I do advocate transmission removal at this stage just in case. I also think you'll be able to see what is going on better - it will probably be easier to work on too.

You can do this in the car. Normally the gear on the output shaft does not break on the .3 only the .4. Undo the nut on the shaft to the aux pump. It turns just a little. Remove the snap ring from the governor cover and remove the cover. If the transmission is lowered enough it will come out the side. You might have to pry the transmission over to the side a little to make room. If you have to remove the output housing it is ok. There are shims just put it back together the way it came apart. It is a fairly straight forward stacking of components.

Awesome, Whipple, thats what I thought.

If you have pulled one out, based on the what we think happened, is it possible that the gear just moved out of position without the Axial support engaged?

Found a great thread with some photos of the rear end although its a 722.4...

722.4 does NOT have a 2nd pump right?

Does the 722.4 use a plastic gear while the 722.3 uses a metal gear?

http://www.peachparts.com/shopforum/tech-help/209298-successful-722-4-rebuild.html

I'm gonna be dropping it down Monday and should know by the end of the day what actually happened once I can see inside and have the governor in my hand.

If I need to remove the rear cover, looks like I need a 30mm 12pt deep socket to remove the nut?

Looks like you guys hit nail on the head

Got the transmission down low enough to get the governor out. Governor is definitely munched. Looks like the main gear is munched too -- think so also?

Some metal shavings, but I am gonna have remove the rear cover anyway. I will replace fluid and filter and magnet out anything in rear cover. I think since I only drove it a mile when it blew its probably okay. I'll assess when I get the cover off to see if its just shavings or chunks like the photo:

ALSO -- No snap ring that you have to press in that the diagram shows. Its missing completely!

http://www.w124-zone.com/downloads/p...ssion/gov1.jpg
http://www.w124-zone.com/downloads/p...ssion/gov2.jpg
http://www.w124-zone.com/downloads/p...ssion/gov3.jpg

722.418
 

1.Had/Has Plastico Gears.
2.Early models HAD the second (Rear) Pump.

The 722.4 is the "Poor Cousin" of the 722.3.
(ANY Cheap,semi-functional part they could squeeze inside the casing they did.)

Have you got any quotes for the cost of a replacement governor yet?

They want $289 for governor and none in the U.S.A either -- Germany shipped! so looks like ill find a good used one somewhere....

EDIT: Also good news...I can check out the speedometer gears since my speedo wobbles and replacing the cable did nothing (replaced cable 3x in fact!!)

PM sent

Anyone know if I can separate the transmission from the driveshaft without removing the entire flex disk from driveshaft? Can I just disconnect it transmission output-side? I ask because I struggled doing it this way and I am wondering if I can pry it enough to make space or will I need to take it off completely?

(I have a pry bar now if needed).

Might have a source for governor FYI.

You should be able to pry off the flexdisk. Its just stuck. Just be sure to note it’s position and orientation for refit. Once the prop shaft is disconnected, it will slide back a couple of inches, but not enough to work without taking off the disk completely.

Why do you think you have to replace the whole governor? I would think you should only have to replace the two stripped gears. Does the governor look damaged?

That seems like a possibility to me too - but on the other hand the ATSG is full of just swapping the governor for a new one - there isn't a how to repair / rebuild your governor section. But I bet someone does it. However for speed I'm guessing it will be quicker to swap...

If it was up to me, the choice of replacing two gears that are obviously shot and cost less than $10 compared to replacing a $200+ part that is probably not broken is easy. Its pretty hard to screw up a govenor. You already have to pull the rear cover to replace the drive gear, but once thats done you're finished with the hardest part. Replace the small gear on the govenor itself, button it back up and test it out. If the govenor is bad, you'll know right away. Going back in to replace it is easy enough to justify the time spent.

Just my opinion, but you might want to give it some thought.