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-   -   83 240D tranny won't shift past 2nd gear. (http://www.peachparts.com/shopforum/tech-help/97988-83-240d-tranny-wont-shift-past-2nd-gear.html)

dmorrison 06-28-2004 11:42 PM

83 240D tranny won't shift past 2nd gear.
 
Got the daughters 240D on the road but have some tranny issues.
A brief history. Bought the car in Feb. Slipped 2-3 and 3-4 and shifted early. Repaired all the vacuum leaks and the tranny seamed to operate normally.
Over the last couple of months rebuilt a bunch of stuff. Those items applying to the vauum and or tranny are the following.

Tranny
rear seal replaced, nut torqued to 120Nm
tranny fluid and filter replaced, to the correct level with the correct fluid.
vacuum lines detached and cleaned with brake cleaning fluid, dried and reinstalled.
tranny cooling lines to radiator replaced.

The vacuum system.
all lines removed and cleaned one at a time so they were replaced correctly.
air switches on top of valve cover, new cams and operation confirmed correct.
Vacuum pump to booster hose replaced.
All 1,2 and 3 way rubber connectors replaced.
All vacuum operating units checked and operate normally, except 1 door lock which is isolated.

The car runs normally except the transmission will not shift above 2nd gear.
Did a search and could not fine anything specific.
The scar will start in 1st and shift normally into 2nd gear, no flare, jerk,delay etc. But will stay in 2nd gear all the way up to 30MPH. when slowing it will shift into 1st in a normal maner.

I will check the black vauum line for 15inch of vacuum until full throttle then should go to 0 inches.
I will also apply vacuum to the modulator to make sure that the diaphram is not damaged, It should hold a vacuum, from what I have been told. If it does not then the modulator is the problem.

Any other advice??

When the car was purchased we antisipated a new tranny, but after fixing the vacuum leaks it ran fine. That was confirmed by a Mercedes mechanic who drove the car and by the Service Rep that I use at the dealer, who has a 240D. They both said the cars tranny was operating fine.

If the two items check out OK. I was going to bring it to the dealer for an estimate and/or diagnosis.

Thanks

Dave
7709

dmorrison 06-29-2004 11:08 PM

anyone??

LarryBible 06-30-2004 07:36 AM

Dave,

It really sounds like you're on the right track by checking vacuum AT the modulator. All that gadgetry on top of the valve cover that simulates the vacuum of a gas engine can be tricky.

Yes the modulator should hold a vacuum from your mity vac, or whatever you're using, forever. Also, I think the modulator might be adjustable by spacing with washers or something. Luckily, as I'm sure you already know, the modulator is cheap and easy to replace.

Oh yes, I remember now also, there is an orifice in the tee that comes off the main vacuum line that leads to the brake booster. If this orifice is not in place the trans won't shift correctly. It seems like I did some searching and found some info about this with some detailed info about that line and orifice. As I recall, my daughters car was doing the opposite though, it was shifting into higher gears way too early, so the orifice probably doesn't apply to your problem. I'm sorry I can't remember more about it.

If your vac measurement and modulator testing don't reveal a problem, you might rig up your mity vac to apply a measured vacuum directly to the modulator to see if it reacts as it should. That would tell you if the problem is with your vacuum gadgetry on the valve cover or the modulator on the tranny.

Oh yes, also don't overlook the vacuum module gadget on the back of the injection pump. There is linkage that hooks to that gadget from the linkage on the engine side of the IP.

I'm sorry I can't be of any more help. I passed the ASE test on automatic transmissions, but you may have noticed from some of my posts that I'm just a manual transmission sort of guy.

If none of this helps, keep posting or email me and we will continue to dig into this problem. It's gonna be a long drive in second gear to College Station for that Aggie girl if we don't get it fixed.

BTW, I'll bet you're staying nice and cool with your parallel flow condensor and 134.

Fly safe and good luck,

autozen 06-30-2004 11:08 AM

It could be that you are looking at a new transmixer, but I would recheck that nut that holds the flange on the tailshaft. You mentioned in your post that you changed the seal and torqued the nut, but did you stake it down.

Peter

dmorrison 06-30-2004 03:12 PM

autozen

Stake it down???? what language does thou speak. What do you mean by "stake"

I did torque it to 120NM per the manual. And hamered the nut into the "opening" to lock it in. Everything else in the tranny is Ok, I think
:eek:

Larry, and all

I checked the vacuum on the modulator. It held vacuum for about 10-15 seconds which should be fine for shifting.
I'm using Steve Brotherton's article on tranny adjustment.

http://www.continentalimports.com/ser_ic20242.html

Did this after I checked the vacuum going to the tranny. Only 3-5 inches of vacuum, should be 15". I traced all the way back thru the vavle cover airswitches and hoses. The vacuum comming out of the Inj. Pump Vacuum Valve is not correct. Only 3-5 inches. So that is where my proplem is. 22 inches coming out of the vacuum pump "T" at the booster hose. I have tried to adjust the injection pump vacuum valve but can not get much change out of it. I will try to clean it since it is $162 for a new one. Don't know if I can use brake cleaner solvent to "clean it" I'm sure I probably got it dirty when I pressure washed the car.

Dave

dmorrison 06-30-2004 04:02 PM

1 Attachment(s)
Well it didnt' take long for the frustration to start.

I checked the inj pump valve and I not sure that is it. All the pressure around the unit id 3-5inches. So it can't govern the flow if only 3-5 is there.
Below is the diagram of the vacuum system.

Maybe someone can confirm this with me, I don't think the diagram is correct? If you follow the line from the vacuum pump thru the white line and the first Y it then goes to the second Y and this goes to the transmission???? that would mean the transmission get full vacuum from the vacuum pump and it woudl not go thru the inj pump valve and the air switches on the vavle cover, Am I nuts or do you guys see it this way also.

Item's #4 are the 3 way rubber connectors.

With this diagram I don't see how the air switches or inj valve are inserted into the system. the diagram is from Performance Products, But the one in the Mercedes technical manual has the same flow.

If this is how its set up in the 240D then I should have 22 inch at the black line going to the tranny, I don't so obviously either the diagram or the car is incorrect.

Dave

autozen 06-30-2004 05:49 PM

Stake it down is a legitimate term. It means to lock it in place. What does hammer the nut into the opening to lock it in mean? There should be a lock tab on the nut to bend over unless you are using a prevailing torque nut. If that nut comes loose it can cause the problem you are describing, I believe. I'm not a transmission guy. I know it's a pain, but if you don't find anything else, it's worth checking.

Peter

C32AMG 06-30-2004 08:39 PM

Vacuum is not the problem, it ONLY controls shift feel, hard or soft shifts, not timing. Since you removed the tail flange there is a possibility the governor drive gear was damage. With the car rear wheels in the air, remove the governor cover, with the car running in gear the governor body should turn. With the car not running if you can turn the governor body by hand, the gear is bad. Try disconnecting the kick down switch under the gas pedal. If the car still does not shift then the problem could be valve body or internal.

dmorrison 06-30-2004 09:58 PM

autozen

"Stake it down is a legitimate term".

I'm sure it is but I was not familiar with the term. Yes I did bend over the locking tab on the shaft nut.

"What does hammer the nut into the opening to lock it in mean?"

That is the official term for, "I don't know the correct name, Stake"
Thanks for the info.

C32AMG

I did not remove the tail flange, only the yoke to replace the output shaft seal.

I will check to downshift switch.
But I am puzzled, The only connections to the tranny are the modulator valve and the speedometer cable. I am not familiar with the black vacuum cables involvement with the downshift switch on the floor. I though the down shift was controlled by the air switch cam on the valve cover. I will look into this.

Went to the dealer today and got some conflicting info. 2 shop formans discussed the problem with me and felt it might be the governor. The 15 inches of vacuum, they said was not correct on the 722.117 tranny. One said the governor should allow the tranny to shift and override the vacuum. The Service Advisor I use said it won't, He owns 3 240Ds and used to have a shop.

So tomorrow I will stop by the dealer and talk to the 123 expert. If we bring the car there he is the one who will look at it. That way I should get the correct info, I hope. :confused:

Time to buy a 722.117 manual.

Second Item. I was informed that the W123 transmission was usually in need of a rebuild after 100,000- 150,000 miles due to the paper gaskets that were used initially in the tranny. Over time, water would build up and ruin them which woudl lead to a tranny rebuild. The 2 shop formans said the 722.117 tranny did not have this problem and is a rather strong transmission with very few problems. So is the idea of a rebuild really necessary, or could we be just talking about adjustments.??

Dave

autozen 06-30-2004 10:33 PM

Dave, You are too funny. We are going to have to develop a common language.:D

I'll try to run this question by Paul down at Mercedes Werkstatt in the South Bay. Paul rebuilds these things every day. He doesn't just build MB transmissions along with others; It's all he does. He's probably one of the best in the country. I can't ask Peter Shmidt anymore, because he retired and moved to Mexico. If he doesn't have any good answers, no one does. My schedule is tight, but I'll see what I can do considering the holiday weekend and all.

Peter

dmorrison 07-01-2004 06:39 PM

Well, talked to the tranny guy at the dealer who does the 123 and older cars.
He feels it is the IP vacuum valve.
The readings I told him about and what I did led him to conclude that.
His advise on the 722.117 tranny was that it did not have a problem with paper gaskets going bad after 1000,000-150,000 miles, as the 722.2and.3 did. It was the reverse band clutch wearing out or failing and causing a cracked tranny housing.

His recommendation is to replace the IP vacuum valve and the 2 air switches on the valve cover. He said that they had seen many a tranny rebuilt or replaced due to a bad IP valve which led some shops to believe the tranny was bad.

The IP valve, due to its critical control of the tranny. He had a shop in SFO and had rebuilt trannys ruined quickly due to a bad IP valve. Their shop included the new valve in all there rebuilds.

The air switches on the valve cover due to them leaking. I put the mityvac on one opening and blocked the 2 remaining openings, The unit would pull air thru the plunger shaft. So he recommended that they be replaced.

If the IP valve fixed the problem and the tranny operated normally. I may have the tranny adjusted and the bands and clutches looked at. If it still gives us any doubts well replace it. He recommended to replace the IP valve especially if you istall a new/rebuilt tranny.

Ive ordered the IPvalve, $162 and the air switches, $36 ea. And I'll keep you guys posted.

He also mentioned that the change of fluid and filter may have caused the problem to come to the surface IF it's an internal problem, governor or valve body. He indicated htey see this quite often. The old worn out tranny can't stand the new fluid and it finally give up.

Dave

dmorrison 07-02-2004 08:42 PM

Success

Went to the dealer today and got the 2 airswitches that go on top of the valve cover. And the IP vacuum control valve. Installed them and the car is now operationg normally. engagement, upshifts and downshifts all seem normal.
A lot cheaper than a new tranny. :D

The tranny guy I talked to at the dealer said that a lot of trannys have been replaced or rebuilt due to the bad IP vacuum valve. So take note.

Installation was quick. Unbolt the 2 allen bolts. Disconnect the 2 vacuum lines. Unclip the IP lever and install the new unit. DO NOT ADJUST the new unit. It is factory set for the car.

Also thought I had miss adjusted, or a bad steering box.
Got a "clunk" rotating the wheel. Found the power steering pump dry when I was replacing all the fluids so I wondered about damage to the pump and the steering box.
figured out that the noise was comming from inside the car, not the gearbox. Found a wire harness connection jambing in the column flex disks.

So a good day. Don't need a new tranny and don't need a new steering box.
The car is on the road and usable.

Now onto the Air conditionaing. :mad:

Dave

autozen 07-03-2004 09:28 AM

Dave,

Thanks alot for the follow up report, so others have useful info to store away. I have not come across your problem yet, but I deal with different MBs everyday, and it may happen. I'll be prepared to check this as a possible cause. I may not be able to remember my own phone # most times, but things like this I never forget.
Thanks again,
Peter

dmorrison 07-07-2004 08:48 PM

Adding one more post. The 1-2 shift is a little slow but I'm happy with it. We are noticing that the 2-3 shift is a little delayed. Very little. The mechanic who worked on the car for the previous owner, told me he had adjusted the modulator valve to try to fix the 2-3 and 3-4 flare. So the modulator is now out of adjustment. It will probably be cheaper to put a new modulator in ($35) then to get the dealer to adjust it. I'll look onto that. Before I do that I'll try adjusting it, nothing to lose!

Also I added 2 cans of R12 to the AC. I could not find any leak in the system. I have a sniffer and tried for quite some time. So I'm hoping the AC problem was just years of a slow leak. I will put some dye in it so I will be able to find any leaks easier. My pressures are 22 low and 225 high. They should be 22 and 265 so I know I'm still a little low on freon. I had 10psi when I checked the system. It takes 42 Oz. Ive added 24oz. I'll add the additional freon with the dye.
If it does have a leak I'm almost certian it is the low or high pressure hose. They do look a little old. All conections would not set off the sniffer.

Dave

seafood54 01-10-2006 01:01 PM

no 3rd or 4th AND tranny lockout?
 
very informative exchange on this thread.. thanks for the previous efforts..

A bit of history before my question..

my '85 300D has been suffering similar transmission troubles.. not going into 4th,, which was attempted to be remedied by a non-MB tranny guy, (a very experienced tranny guy and a friend who only has my best interest in mind)

His efforts included rebuilding the tranny twice. Problem persisted. The car had to "relocate" from Boston to Ohio, so I flew in and began my drive back to ohio, expecting to have to make the trip in 3rd gear.

I found that I was able to "trick" the tranny into 4th by momentarily slipping the shifter into neutral from "D" and back into "D" This made the expected back road trip into an interstate highway trip and everything went fine on the way home to Ohio.

Since then, the car started refusing to go into 4th, then added to its nastiness, a refusal to go into 3rd. SO.. we began thinking of it as an "around the town" car and simply kept the speed under 30mph..

NOW.. "Pain", (my name for this 300d, see below) has a new tactic. Today it added a new trick. From Drive, and with the engine running, it refused to go into reverse or park. If the engine is off, the tranny shifts into Park or Reverse just fine.

SO.. while my new ohio MB mechanic in on vacation in the Land of Enchantment, should I be trying anything to remedy my PAIN?

thanks Frank


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