G8RB8

It seems we're weak on auto transmission troubleshooting and repair. If you have info, links, how-tos, or anything to contribute to the knowledge pool post it up. Let's see where we really are.
http://www.ganzeboom.net/images1/gan...3,%20722.4.pdf
http://www.w124performance.com/docs/...722_repair.pdf
http://www.w124performance.com/docs/...2_Mitchell.pdf
http://avtopedia.ru/akpp/722-3%20722-4.pdf
http://members.rennlist.com/pirtle/s4atrans.htm

GregBBRD

I think I know some...but "spreading" that information around is tough.

SMTCapeCod

Here's some info-- NOTE: Some is for Mercedes applications of 722!

UncleMaz

AUTO TRANS DIAGNOSIS - 722 SERIES
Article Text (p. 7)
1996 Mercedes-Benz C220
Copyright © 1998 Mitchell Repair Information Company, LLC
Wednesday, January 26, 2000 12:03PM

TROUBLE SHOOTING

TRANSMISSION SLIPS IN ALL GEARS
Incorrect modulating pressure. Modulating pressure control
valve or pressure relief valve is dirty or sticking. Vacuum line to
transmission vacuum capsule clogged or leaking. Working pressure
control valve dirty or sticking. Low working pressure. Defective
primary pump.
Transmission Slips When Starting Off In 1st Or 2nd (Reverse
Is Okay)
Band B-2 shift valve sticking. Band B-2 piston worn or
damaged. Band B-2 adjusted incorrectly or worn or damaged. Adjust
brake band B-2 by installing a longer thrust pin (if necessary). If
transmission operates properly with selector lever in "2", but not in
"3" or "D" position, one-way clutch may be slipping.
Transmission Slips In 2nd Gear Or Shifts From 1st To 3rd Gear
Check control valve B-1 for ease of operation. Replace valve
body (if necessary). Remove and install brake band piston B-1, check
sealing ring and replace (if necessary). Replace brake band B-1 and
thrust body for B-1. Command valve binding.
Transmission Slips During 2-3 Upshift Or Slips Initially,
Then Grabs Hold
Check modulating pressure and adjust (if necessary). Check
for temperature throttle installation (if equipped). Valve body worn
or damaged. Replace valve body (if necessary). Replace inner plates of
clutch K-1 or recondition clutch (if necessary). Check front cover
Teflon ring.
TRANSMISSION SLIPS DURING 3-4 UPSHIFT
Check and adjust modulating pressure. Governor damaged or
working pressure incorrect. Valve body worn or damaged. Replace valve
body (if necessary). Check Teflon rings supporting clutch K-2. Replace
inner plates of clutch K-2 or recondition clutch (if necessary).
INTERMITTENT NO 5TH GEAR
Check loose connections at throttle valve switch. Check for
poor or loose wiring connections between TCM and transmission. See
WIRING DIAGRAMS. Ensure proper TCM is installed.
NO 5TH GEAR OR TRANSMISSION SHIFTS TO 5TH UNDER LOAD
Check and repair vacuum line between intake manifold and
ignition control unit.
NO POSITIVE ENGAGEMENT IN REVERSE
Check plates and sealing rings on brake B-3 piston. Replace
if necessary.
HARSH ENGAGEMENT WHEN SHIFTING GEARS
Incorrect working pressure. Check and adjust modulating
pressure. Check vacuum line and connections for leaks. On vehicles
equipped with diesel engines, check vacuum control valve. Coolant
entering transmission oil cooler and contaminating transmission fluid.
Replace radiator. If necessary, replace all friction linings and/or
replace transmission.
HARSH ENGAGEMENT WHEN SELECTING "D" OR "R"
Idle speed too high. Check pressure receiving (pick-up)
piston in valve body for ease of operation and correct installation.
Replace valve body (if necessary).
NOTE: Pressure pick-up requires a running period of approximately
2 seconds. Harsh engagement may occur during repeated shifts
between "N" and "D". If harshness takes place within 2
seconds, condition is considered normal.
HARSHNESS ON 4-3 DOWNSHIFT
Sealing ring on release end of band B-2 worn or damaged. Band
B-2 piston worn or damaged. Band B-2 thrust body damaged.
CHATTER DURING UPSHIFT
Valve body malfunction. Check and repair or replace valve
body.
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.
UPSHIFTS AT HIGHER SPEEDS THAN SPECIFIED
Check pressure control cable engagement, condition and
adjustment. Check for stuck kickdown solenoid or for constant voltage
to solenoid caused by a defective fuel pump relay or sticking kickdown
switch. Check governor pressure. If regulator pressure is too low,
replace centrifugal governor. Ensure control pressure regulating valve
is operable.
UPSHIFTS AT LOWER SPEEDS THAN SPECIFIED
Check pressure control cable engagement, condition and
adjustment. Check full throttle stop by accelerating engine and
ensuring throttle valve rests against full throttle stop. Readjust
throttle stop (if necessary). Check governor pressure. If governor
pressure is too high, replace centrifugal governor. Repair or replace
valve body.
NO KICKDOWN
Check throttle control and pressure control cable engagement,
condition and adjustment. Connect kickdown solenoid to battery and
check for proper operation. Replace solenoid (if necessary). Check
kickdown valve in valve body. Replace valve body (if necessary).
NO 4-3 OR 3-2 DOWNSHIFT
Control pressure cable out of adjustment. Leaking vacuum
hoses and/or connections. Ensure brake shaft piston is operable.
Replace valve body (if necessary).
UNCONTROLLED DOWNSHIFTS OUTSIDE RANGE OF KICKDOWN SWITCH
Remove kickdown solenoid. Check "O" ring on kickdown solenoid
for damage. Check kickdown switch for sticking in pushed-in position.
Replace switch (if necessary). Check for kickdown solenoid stuck in
opened position. Replace kickdown solenoid (if necessary).
POOR ACCELERATION FROM STOPPED POSITION
Check stall speed. If stall speed is 400-700 RPM less than
specified value, one-way clutch in torque converter is slipping.
Replace torque converter (if necessary).
PARKING PAWL WILL NOT ENGAGE
Check rear engine mount. Replace engine mount (if necessary).
Check adjustment of selector rod. Adjust selector rod (if necessary).
SELECTOR LEVER DOES NOT ENGAGE IN "R" OR "P"
With engine running, clean centrifugal governor and ensure
correct operation. With engine not running, check operation of detent
piston in lower cover.
ENGINE WILL NOT START IN "P" OR "N" POSITION
Adjust shift rod and starter lock-out switch. Replace starter
lock-out switch (if necessary).
SMOKE IN EXHAUST (FLUID LOSS)
Diaphragm in vacuum control unit defective. Transmission oil
is being drawn from engine through vacuum line. Replace vacuum control
unit (if necessary).
FLUID LOSS BETWEEN TORQUE CONVERTER & PRIMARY PUMP
Seal torque converter oil drain plug. If leak continues,
replace radial sealing ring and "O" ring on primary pump. Check
primary pump "O" ring groove for porosity. Replace primary pump (if
necessary).
HOWLING NOISE WHEN CHANGING GEARS (UNDER FULL LOAD)
Replace transmission oil filter.
HOWLING NOISE WHICH INCREASES AS ENGINE RPM INCREASES
Check primary pump and replace if necessary.
1ST GEAR & REVERSE TOO LOUD
Replace front planetary gear set. Reverse and 1st gear are
louder than forward (driving) gears due to gear reduction. If noise
seems too loud, or if in doubt, a similar vehicle should be used for
comparison.
3RD GEAR TOO LOUD
Replace rear planetary gear set.
RATTLING NOISE AT 1500 RPM IN ALL POSITIONS EXCEPT "R"
Brake B-3 plates are vibrating in transmission housing.
Replace brake B-3 plates, install damper spring and set release
clearance to minimum value.
LIGHT GRINDING NOISE IN "P" & "N" POSITIONS
This condition is normal if a "rolling" noise of front
planetary gear set is heard. If noise seems too loud, or if in doubt,
a similar vehicle should be used for comparison.
"ROLLING" NOISES WHEN DRIVING IN REVERSE
Disc brake B-3 release clearance too great. Adjust release
clearance to .06-.08" (1.5-2.0 mm) or replace disc brake plates.
Outside plate carrier of clutch K-1 contacts piston.
Primary Pump Bushing Loosens After A Short Operating Period -
Dowel pins for centering transmission to engine are not in place.

G8RB8

So, there's some pretty good resources out there.
Of course there's always the service manuals.
Anyone else?

linderpat

no, but in for the subscription

G8RB8

Come on Greg everyone knows you're the guru. Give it up.

Dozman

Steve cattenaeo

Bertrand Daoust

Great thread.

Will be helpfull for sure.

Thanks for starting it.

Speedtoys

Funny how "slow engagement into gear from park" isnt on that list, but everything else is.

G8RB8

Another link to the WSM (just in case)
http://www.2010.cannell.co.uk/manual...s_porsche.html

G8RB8

I have that! What's the fix?

G8RB8

Hey if enough people think it's worthy can one of the mods stick a link in the FAQs thread?

Landseer

Agreed! This is a huge missing link for owners.

All I have a are a few pictures...for now.

gbarron

This thread is a keeper for OB models! Fixed the problem on my 86.5. Ordered the kit from my local MB dealer for a grand total of $20.

https://rennlist.com/forums/928-foru...rt-number.html