how to properly screw transmision oil pan - PeachParts Mercedes-Benz Forum

jose · #1 03-21-2008, 06:37 AM

i had a 1988 190e 2.3 automatic transmision us version i had a problem with the transmision oil pan it has a leak and i am having a hard time fixing it. i had the filter, oil and gasket replace but i can't stop the leak that coming from the pan (gasket) side

my question is that is there a technique on how to screw the pan how much tourque is neede to each screw, is there a squence on how to tighten the screws. let say screw no.1 is the pasenger side front, screw no.2 passenger middle, screw no.3 passenger rear, screw no.4 driver side rear, screw no.5 driver middel, screw no 6 driver front.

to who ever know the answer to my problem please share the answer and it is highly appriciated

Carson357 · #2 03-21-2008, 07:33 AM

i usually tighten all evenly and torque to 8Nm, what i also do is before i install the gasket i hold the pan up to the trans without the gasket, if it is bent or rocks back and forth too much i usually get a new one

jose · #3 03-21-2008, 07:53 AM

when you hold the pan without the gasket is it with the filter screwed or not becuase if the filter is screwd the pan won't reach the base of the transmision

vince · #4 03-21-2008, 09:11 AM

You may want to clean the side of the case very carefully and look for leaks other than the pan gasket. There are several areas on the sides of the case that are sealed by "O" rings. If those "O" rings leak the fluid runs down to the pan/case joint and it looks like the pan gasket is leaking. I just had to to replace the B2 Reaction Valve "O" ring for a leak that appeared at first to be a pan gasket leak. I had to drop the valve body, etc. A real PITA with the transmission in the car.

jose · #5 03-21-2008, 09:15 AM

Quote:

Originally Posted by vince

You may want to clean the side of the case very carefully and look for leaks other than the pan gasket. There are several areas on the sides of the case that are sealed by "O" rings. If those "O" rings leak the fluid runs down to the pan/case joint and it looks like the pan gasket is leaking. I just had to to replace the B2 Reaction Valve "O" ring for a leak that appeared at first to be a pan gasket leak. I had to drop the valve body, etc. A real PITA with the transmission in the car.

i'm sure that the leak is coming from the pan the parts or the side of the trans is dry i have check them already i thinks the pan is kinda diform

Kim Langley2 · #6 03-21-2008, 12:45 PM

The torque setting for the 722.6 transmission pan bolts is 106inch/pounds.

I would tighten them is a cross-hatch manner get all finger snug then start at the center and move out in an "x" manner > evenly spreads the load over the gasget..

John1 · #7 03-21-2008, 08:07 PM

Has the pan been off more than a few times before, if so the bolts holes are "countersunk" and need to be "flattened".

I owned a trans shop for 15 years and this is a technique a lot do not know.
No matter what you torque the bolts to or the pattern it still leaks unless this procedure is done.

If you wish I will detail more!

John1

jose · #8 03-23-2008, 05:25 AM

yes john1 i want the details on how it is done. it's kinda hard to fine a new oil pan here in the phillipines thanks

jose · #9 03-23-2008, 05:49 AM

kim langley i'll wait for john details on it's how too then try the x system technique thanks

jeffreyli86 · #10 03-23-2008, 08:17 AM

John. Please let us know some details!!

hey_allen · #11 03-23-2008, 09:44 PM

I don't know if it's exactly what John was talking about, but here is a trick I learned from my dad who is a mechanic.

While you have the pan off the car, brace under the lip with a piece of lumber or a small faced hammer, and then tap around the holes on the top side with a ball peen hammer.
The idea is to try to flatten out the bump that is formed from all the prior installations pulling the flange up toward the trans case.

I seem to remember being told that it was good to have it slightly pushed beyond flat, just so that it would pull flat when you torqued the bolts in. Don't go too far though, as you would cause a leak then.

If this isn't what you had in mind, John, please teach both of us something new!

Spelunker · #12 03-30-2008, 11:27 AM

Here's my technique: I wash and degrease the pan, bolts, and gasket surface of the transmission, making sure all gasket surfaces are clean and oil-free. This takes extra effort, but is well worth it. I apply the new gasket to the pan dry (I do not moisten with ATF or use any kind of sealant). With the pan seated on the transmission, all six bolts are fastened finger-tight. Then I torque the bolts to 8Nm, staring with the sides first and then the corners in a crisscross pattern. I will make a second pass with the torque wrench to double check tightness.

It is also important not to overfill the transmission, which can cause leaks. If the ATF fluid is not quite operating temperature (between 20-30C) it should measure about 12mm below the Min. mark on the dipstick.

John1 · #13 03-30-2008, 02:51 PM

Have been out of pocket and by no means meant to let anything hang.

Sorry again!

What "allen" is describing is exactly what we did with every pan.

The impotant thing is to use the "ball" end of the ball pen hammer hitting the center of each bolt hole.

Also make sure all surfaces are meticulously dry.

Thanks
John1

mendodiesel · #14 03-31-2008, 10:59 AM

106 inch/pounds is this accurate?

vince · #15 03-31-2008, 04:40 PM

8 nm = 71 in/lbs.