W126? Or is it a W124? - PeachParts Mercedes-Benz Forum

Gregory · #1 01-25-2011, 08:56 AM

Is the 1987 300SDL a W126, or is it a W124?

What is the difference between the two transmissions, and how easy are they to be confused with each other?

See: 1987 300SDL Tranny, No Reverse

bustedbenz · #2 01-25-2011, 09:57 AM

300SDL is a w126. The 300D and 300TD are W124 after 1986 and W123 in 1985 and prior. Different bodies altogether.

No idea about transmissions.

Renntag · #3 01-25-2011, 12:34 PM

As busted has shared, you are asking about a W126. Just looking at the "S" designation, or 'Class', tells us that it is built upon a W126 chassis. Many components are shared between the W123, W124, W201, etc. This will depend upon vintage. The W126 spanned across the time of the W123 and W124.

More info: http://en.wikipedia.org/wiki/Mercedes-Benz_W126

BoiseBenz · #4 01-25-2011, 12:34 PM

If it's a six it's from a 124 or 126 only.

The .961 was the 86-87 300SDL version; the .960 was the 124 300TD version, with the only difference from the .961 being the oil filter housing, allowing the center bolt to be pulled separate from the cover to allow firewall clearance in the smaller car. A .960 can be put in a .961 spot, but the reverse won't allow oil filter service without changing the housings.

According to the ATSG manual, the final two numbers (722.3xx) indicate only the modulator fitting and setting. A .321 should have a black modulator and be set at 46 PSI. A .317 should have a black modulator and be set at 46 PSI (not a typo, the values are the same per "Transtec Mercedes 722.3 722.4" 12 page manual). Both settings tested at 31 MPH in drive.

vstech · #5 01-25-2011, 12:45 PM

the transmissions are different, in the 126 has electronic speedo, and the 124 has mechanical speedo...
the engines are identical except for motor mounts, and exhaust manifolds... and the oil filter shaft...

BoiseBenz · #6 01-25-2011, 01:31 PM

Quote:

Originally Posted by vstech

the transmissions are different, in the 126 has electronic speedo, and the 124 has mechanical speedo...

Is that an "easy" tailhousing swap like a 722.3 from a 123 into/out of a 126?

Gregory · #7 01-25-2011, 03:04 PM

My indy just called and needs more info about the "special tool" to swap the tail pieces.

Would a shop like Aamco have that tool? Can it be swapped without that tool? And where can the tool be gotten from? Thanks.

Renntag · #8 01-25-2011, 05:40 PM

Same reply as other thread. I have requested more info.

aaa · #9 01-25-2011, 07:05 PM

Quote:

Originally Posted by Gregory

My indy just called and needs more info about the "special tool" to swap the tail pieces.

Would a shop like Aamco have that tool? Can it be swapped without that tool? And where can the tool be gotten from? Thanks.

It's just a deep 30mm 12pt socket. Which is admittedly a bit rare. I've gotten them from Grainger's.

As for without, dicey but occasionally doable. The output flange nut is very lightly torqued, and has an indent punched in it to keep it from moving. Once this indent is bent out of the way it can be screwed out by hand or a more common similarly sized socket. Of course it's not exactly easy to bend this indent.

Gregory · #10 01-25-2011, 08:06 PM

Can anyone provide the torque spec for putting that 30mm nut back on? Thanks!

BoiseBenz · #11 01-25-2011, 08:25 PM

120 Nm, 88.5 ft-lb, THEN stake the nut to the groove. The special tools the manual references are three: torque wrench, deep socket (both understandable) and an unspecified crows foot for which I can't find a use.

aaa · #12 01-25-2011, 08:43 PM

Quote:

Originally Posted by BoiseBenz

120 Nm, 88.5 ft-lb, THEN stake the nut to the groove. The special tools the manual references are three: torque wrench, deep socket (both understandable) and an unspecified crows foot for which I can't find a use.

Huh, maybe someone had messed with mine before. A lot tighter than I'd expected.

Renntag · #13 01-26-2011, 10:10 AM

aaa and Boise, thanks for your help. I have been trying to get help here.

Greg, let us know your status.

Gregory · #14 01-26-2011, 10:19 AM

Thank you for all the good info.....I'm off to find the 30mm deep.

BoiseBenz · #15 01-26-2011, 01:00 PM

The ATSG procedure cautions: "When removing rear cover, ensure kickdown solenoid is not damaged. It may be necessary to loosen the solenoid and turn slightly."

Cover bolts are 13 Nm (9.6 ft-lb, 115 in-lb). Clean threads and coat with non-hardening sealant. DO NOT SEAL GASKET (if using new).

The "Automatisches Getriebe 722.3 Bestell-Nr. 6510 5762 02" procedure is to fit new o-ring to flange, slide flange on, tighten to 120 Nm, then "caulk nut to base of groove." No "here" arrows, caulk specification, or anything. Belt (o-ring) and suspenders (caulk)? The ATSG procedure makes no mention of the caulk, but reminds you to stake the nut to the shaft.

YMMV...