Friend of mine continues to fight with his '91 2.5L 300d. He recently had a mechanic swap engines for him after he lost an oil pump in the original, so now he has a '93 engine in a '91 body. The swap didn't go that well, his auto-transmission never worked right (at times the engine would rev high but very little torque was sent to the wheels) and he figured that it was slipping, so he had the same shop swap his old trans ('91) behind the newer '93 engine. Apparently the owner of the shop was 'busy' with other work and had his 'apprentice' do the trans swap for my buddy. Result: the car runs, but the trans won't shift out of the first gear. The mechanic told my friend that the trans is broken...

Now, I don't know much, but I don't see how a good running trans (ran well when the engine blew) would just break sitting on the floor of a shop. My guess is that there is some type of vacuum issue that needs to be solved.

I need to help my friend - he's at wits end with that 'mechanic' and needs to get this car on the road and doesn't know what to do.

Appreciate links and tips for troubleshooting this condition. I'll try to take the custody of that car for a while so I can try different things for him and see if we can bring it back to a running condition.

UPDATE: just doing some searching found some stuff on the Bowden cable and stuck kick-down switch?! A short recap of what the kickdown switch does, please - guessing here: it down-shifts and keeps it there until you release it?...

THx,
James

__________________
1987 Mercedes 300SDL; SOLD
1985 Mercedes 300D; SOLD
2006 Honda Pilot - wife's ride; 122K;
1995 Toyota Land Cruiser - 3X locked; 182K

I would be checking the work very carefully. I would make sure that the linkage is set correctly - kick down switch isn't stuck and that they've put enough transmission fluid in it!

__________________
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!

Something as simple as the kickdown switch could be closed. The engine would not change up till revs had approached the top end. Shorted electrical cable to it from being pinched for example. Same with any control cable or rod from the engine to the transmission.

I would go for the cable or rod first. I do not know the setup on your car but there has to be a mechanisim that tells the transmission where the engine is revwise. This cable or whatever jammed could do what you are experiencing.

As you said transmission in and out should not change anthing internally. I am assuming without knowing that the years spread in engines has not changed the linkage style to the engine. Keep an eye open that they did not bend or break any part if they handled the transmission too rough.

Sounds logical - I need a link to the vacuum diagram(s) - the engine is a '93 but the trans is a '91 (oh joy!). I've looked thorugh the DIY links but could not find the links to the vacuum diagrams, little help please.

__________________
1987 Mercedes 300SDL; SOLD
1985 Mercedes 300D; SOLD
2006 Honda Pilot - wife's ride; 122K;
1995 Toyota Land Cruiser - 3X locked; 182K

Tranny (722.418) will Upshift without Vacuum

Adjusting the "Bowden" Cable (Tranny to Accelerator Linkage) moves the shift
points Up or down the RPM scale. (It would still shift,though later) Not It.
Adjusting the Vacuum Modulator ONLY Stiffens or Smooths the Shifts. Not It.

The Clowns have Boogered the Mechanical Shift Linkages
(Shifter Console Lever to the Operating Lever on the side of the Tranny.)
OR
Somehow Boogered the Kick Down Switch and/or it's wiring.
(It's underneath the Accelerator Pedal)

Tranny Diagnosis by I.net is always a crapshoot

Always a Chance the "Expert" REALLY screwed up and Dropped the Thing
re-installing it!

The '91 722.418 doesn't know (or care) what's up front "Making Turns".

Control Input is achieved through:

RPM (Delivered through the Torque Converter)
Accelerator (Delivered through the "Bowden Cable")
Vacuum (Delivered VIA the VCV and Vacuum Valve on th side of the Tranny)
Electrical (Delivered VIA the Kickdown Switch and wiring)

Since It's a Known symptom of a BAD Kickdown Switch to Inhibit UPSHIFTING
I'm betting on it.

__________________
'84 300SD sold
124.128

Thanks CompressI

__________________
1987 Mercedes 300SDL; SOLD
1985 Mercedes 300D; SOLD
2006 Honda Pilot - wife's ride; 122K;
1995 Toyota Land Cruiser - 3X locked; 182K

I drove the cart last night - it wouldn't shift no matter what I did with the accelerator pedal. It was late and they couldn't get it on the lift anyway. Looking at the other (older) trans from that car I pointed out the solenoid for the Kick Down switch and the mechanic was 'surprised' to see it

I don't even think they hooked that cable up to the solenoid on the trans... What would be the default behavior if the other end of the Kick Down switch wasn't even connected?!

__________________
1987 Mercedes 300SDL; SOLD
1985 Mercedes 300D; SOLD
2006 Honda Pilot - wife's ride; 122K;
1995 Toyota Land Cruiser - 3X locked; 182K

722.3XX

Attached Thumbnails

 

__________________
'84 300SD sold
124.128

Ive heard of a similar problem once on a toyota cressida (carby engine) - the shop had swapped engines and used the same tranny - somewhere in the process they had managed to do something that caused the governor to jam its opening petals. It resulted in the transmission being stuck in 1st.

it was resolved by an aging auto trans mechanic who removed the governor, cleaned it and put it back in.

__________________
2012 BMW X5 (Beef + Granite suspension model)

1995 E300D - The original humming machine (consumed by Flood 2017)
2000 E320 - The evolution (consumed by flood 2017)

Out of curiousity I'd like to learn more about the Governor on this trans - I found this article that explains what the trans GOV does: HowStuffWorks "Automatic Transmissions: Hydraulics, Pumps and the Governor"

The governor is a clever valve that tells the transmission how fast the car is going. It is connected to the output, so the faster the car moves, the faster the governor spins. Inside the governor is a spring-loaded valve that opens in proportion to how fast the governor is spinning -- the faster the governor spins, the more the valve opens. Fluid from the pump is fed to the governor through the output shaft. The faster the car goes, the more the governor valve opens and the higher the pressure of the fluid it lets through.

It wasn't clear to me if the governor is at the end of the Engine's output shaft (on the front of the trans) or at the back of the Transmission's output shaft. I sure hope I won't have go tearing into that thing...

__________________
1987 Mercedes 300SDL; SOLD
1985 Mercedes 300D; SOLD
2006 Honda Pilot - wife's ride; 122K;
1995 Toyota Land Cruiser - 3X locked; 182K

It's at the back, and is coupled to the driveshaft speed. The front pump and modulator pressure (engine speed), the gear selector (desired gear), bowden cable (what is input torque), and governor indication (car speed) are all inputs to the computer (aka "valve body") to select proper gear.

You need several weirdo snap ring pliers to remove the governor on a 722.3/.4.

__________________
James Marriott
2003 Buick Regal
1983 300D (228k, frau Auto)
1996 Suburban K2500 (192k, 6.5 turbo diesel/4WD towmaster 10,000)
www.engineeringworks.biz
1987 300SDL junker 170k
1982 300SD junker, 265k

Hey guys, I'd love to know if the Governor on the 722.4x trans is accessible from the outside and if it can be removed/cleaned while the trans is still in the car?! Does anyone have a pic of this thing for proper id.

Thx -
James

__________________
1987 Mercedes 300SDL; SOLD
1985 Mercedes 300D; SOLD
2006 Honda Pilot - wife's ride; 122K;
1995 Toyota Land Cruiser - 3X locked; 182K

What you need is the FSM and an ATSG manual for the 722.3/4

(For example #687 ,If not specifically inserted correctly , Sorrow.)

Attached Thumbnails

 

__________________
'84 300SD sold
124.128

Thx CI -

Here is a recap from today's troubleshooting session:
o Checked the fluid level while engine running and car level (proper level between marks)
o Checked all the shifting linkages - no bends, breaks, or jamming. Nothing out of place - looked like pretty good job under there. Shifts smoothly and clicks fine into each detent.
o Checked the kick down switch - proper resistance On/Off using ohm meter
o Checked voltage to the solenoid by having the car running and checking the voltage to the solenoid while helper pressed the Kick down switch On/Off. The voltage went from 0V to about 13.5V as expected.
o The solenoid was replaced with a tested one earlier this week by the mechanic.
o Disconnected the bowden cable from the throttle linkage and went for a drive - no change, still stays in low gear (1st or 2nd) can't really tell - it just won't shift up from that one gear. Went like this: from stand still, foot down on the accelerator, it accelerates VERY slowly gaining momentum and once the turbo kicks in it is roaring and revving very high (didn't catch how high but near the top of the range for sure). Foot off the accelerator and it will coast fine on its own slowly declerating. (The one-way clutch makes the deceleration very gradual when foot off the pedal.) Nothing out of the ordinary there...
o Wanted to check the Governor but we couldn't figure out where it is. Noone there knew either. (Got this pic of its proper location after the fact).
o We took pan and filter off the '93 spare trans that my friend owns and it looked around in there. Looked very clean, no burned smell or anything.

I have suggested to my friend that he asks the mechanic to swap the Valve Body from the '93 (722.418) spare into the '91 trans that's currently in the car - according to your suggestions above.

So that's his next step (later this week). Do you think it's worth trying to take apart the Governor and attempting to clean it (carefully) then re-assemble?

__________________
1987 Mercedes 300SDL; SOLD
1985 Mercedes 300D; SOLD
2006 Honda Pilot - wife's ride; 122K;
1995 Toyota Land Cruiser - 3X locked; 182K

As compress ignite posted above the governor is at the back on the left hand side on a 722.3 / 722.4

You can see more of the parts in this pdf

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

__________________
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!