2005 SL55 AMG revs but won't catch
Mercedes-Benz SL 55 ,2005, I have 2010 MB Nag1 in my jeep.THAT IS CLASSIC TRANSMISSION FAILURE.only why remains, here is my 80year tranny fix page on car. fixesit is no pure HydramaticMy USA car, list of tests on any box. (generic)the A/T box (automatic transmission)from 1939 to now over 80 years now installed in GM cars first USA.They changed radially over that time. pure Hydramatic to....then in 1996 GM went from Hydramatic to 4l60E BOX. the E MEANS ELECTRONICALLY SHIFTED VIA TCM/TCU OR PCM BRAINS.for 2.5_ decades now we run E boxes and is so common GM removed the "E" today.but is the same box.there are only 2 paths here.(diagnosis) a new box or do all things that can be done on car.So I will now list all ON CAR things.(most)1: check all fuses. (after all power lost to the TCM would make it fail)2: check ATF level on the dip stick per the glove box guide, (hot engine/trans) in PARK, running and DIP checked)Do not overfill the box or doomed it is, or it foams up and STARVES bearings in the box, RTM always read the guide.3:Next up is the OBD2 scan tool (2008 and newer is best) and we connect to DLC 16pin port and scan for P07xx errors.4:GOT DTC errors, then look them up, they tell you speed sensors are bad, even 3 of them or 6 A/T solenoids are bad.Or DTC for gear selector errors (PRNDL, TRS or P/N switch fails) 5:Okay, most sensors and solenoids can be replaced on car, just pan off. (varies) some speed sensors are super easy to change.6:So far no JOY, well the Tranny service manual shows how to use a PSI GAUGE at the pump and pressure ports. in all gears and N/P7:learn too that the TCM can go to limphome mode, that skips gears, even all but 1 gear too.DTC will be set.never do'snever mix ATF brands and grades.never over-fill the box, start with 1/2 max (dry box volume) and work jump to full hot.If you drain a box all you get there is 1/2 the AFT other 1/2 is in the TC clutch. so measure what came out and put back the same in quarts or liters.or go to any oil changing shop find the shop with full flush tranny machined, and bingo done right. Mixing brands or old and new ATF is wackoon a new or rebuilt dry box , add 1 qt of ATF to the clutch TC drive collar first, and 1/2 normal to pan the work up.never start a transmission that is dry. (means start engine)Pre 1996 cars:On old pure Hydramatic failure on car fixes are:step2 and 6 above! checked.TV cable bad, stuck out (rusted) will case huge delayed shifts even stuck at 2nd gear moving fast. (throttle valve)Vacuum modulator seen on box. It change shift points based on engine (vacuum) load.if bad it can do the same wrong things as TV failures.Gear linkage failures, pure mechanical link fails.Can not shift out of park is Park/neutral failures, and all cars work different here, some have lever solenoid lock out.COMPLAINTS ( huge but here is short list common)only one gear works, (moving) or only Reverse is dead.skips a gear or 2. or up shifts too soon or late.down shifted gears shift wrong or late or too soon.FLARE, (aka. false neutrals in any gear)Stalls engine, TCC clutch hard fail and TC no longer slips engine stalls.or is weak engine, fuel pressure 1/2 normal.Transmission will not allow me moving fast to use the engine as a brake, (engine at idle moving fast)Gross transmission whine (see #2)Transmission totally dead. see all above.jargon related, (EFI means electronics fuel injection that PCM runs)DLC is OBD2 port Diagnostic Link connector,16pins USA. D shaped, pin 16 power must be 12vdc or tool fails.DTC is Diagnostic trouble code.PCM is the power train (all) module, engine and transmission end even TCM insideTCM is transmission brain first seen here 1996 usa. the merged into PCM on most car, late 90's
9/14/2022 6:04:04 PM •
2007...
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