In DESPERATE need of help/advice - PeachParts Mercedes-Benz Forum

ajayindunedin · #1 09-04-2013, 11:08 PM

I am in dire straits and need all the help and suggestions that you fine folks may have to offer. I have a 1998 ML320, have owned it for years and never had many issues, have performed my own oil changes and replaced my radiator last year. I have a pretty decent amount of tact when it comes to DIY jobs, and when I started suffering from some performance issues, I decided it was time to change my tranny fluid.

I found an in depth, highly detailed step by step guide on another MB forum for changing the ATF since it is slightly more complicated working with the "filled for life" style transmission.

Anyways, so today I followed the guide step by step, drained just under 4qts and replaced it with just under 4 qts of Valvoline Max Life Dexron/Merc (as highly recommended as an alternative to the dealer ATF which I have had a mighty hard time acquiring in my small town)

Took her for a good long drive up to my buddies boat mechanic shop, it drove the duration of the trip pretty smoothly..when I arrived at his shop, I measured the ATF while it was at prime temperature and it read slightly lower than the "fill" line on the dipstick. so I added just a little more ATF, let it idle for a while, shifted through the gears multiple times and then attempted to drive back home.

Immediately upon driving away from his shop, my truck suddenly would not shift beyond first gear! I pulled over immediately at the first oppurtunity and checked the ATF level again. Miraculously, after only having added about 1/4 of a quart earlier at the boat shop, it suddenly read much higher than the fill line.

Luckily, having the tools necessary in my truck, I drained 1/4 of a quart, re-dipped and it read just a hair below the fill line. However, it continues to not allow me to shift out of first gear. I am baffled as to what could be the problem, it is not throwing a CEL and I am now at a complete loss as to what could be the culprit. Any and all advice/suggestions would be greatly appreciated on behalf of me and my family, as this is our sole means of transportation and we are on a temporary very tight budget.

Thank you..

PARSHOOT1 · #2 09-05-2013, 10:36 PM

How many miles on the car. What's the history on tranny fluid changes for your SUV? You mentioned the car started having performance issues..... elaborate what issues. Should be something on Pelican regarding your problem. Any luck doing a search?

Stretch · #3 09-06-2013, 01:05 AM

According to EverythingBenz - Mercedes-Benz Forum and Web Search Using Google the transmission is a 722.662. I have no experience with these newer transmissions but this forum and others is full of related threads

Here are some to start you off

PeachPartsWiki: 722.6 Transmission Fluid and Filter Change

http://www.peachparts.com/shopforum/ml-gl-g-wagen-r-class-unimog-sprinter/259116-722-6-transmission-fluid-change-pictures.html

Can't Know · #4 09-06-2013, 02:06 AM

Crawl back under and unplug the harness from the pilot bushing/connector on the front right of the transmission. If fluid comes out after it, then pull the TCM (E-TCU) and inspect it for signs of fluid incursion.

If so, use electrical contact cleaner spray and clean the TCM and socket, then change the pilot bushing.

Then take it to a properly-equipped shop that has the proper interface to talk to the TCM and clear the codes.

For whatever reason, fluid changes can sometimes trigger the pilot bushing to leak. When it does, it can flood the TCM, trigger P07xx codes and leave you in limp mode.

And you are presently in limp mode, so out makes sense to check out the pilot bushing.

Good luck.

oldsinner111 · #5 09-06-2013, 05:01 AM

you might too check Mercedes-Benz Forum and follow transmission reset.You might have trigger and overfill code.

Hirnbeiss · #6 09-06-2013, 07:44 AM

Wrong oil. It needs to be 236.10 or 236.12-236.14

MB 236.10 - Automatic transmission fluids (ATF, Specification 236.10) - Mercedes-Benz Specifications for Operating Fluids

http://bevo.mercedes-benz.com/d/d/en/Spec_231_0.pdf, p13ff

I would correct it before any other steps.

MAVA · #7 09-06-2013, 02:46 PM

Do as post #4, but do not use the factory fluid it just accelerates the wear on the 722.6, and do not use the stuff you used. Use Shell 134 it is the best for the 722.6 and cheap.. If you are in the USA, here is how you get it.

Distributor Locator - United States.

I would also do a fluid exchange. This is how you do it..

Here is how I do a transmission fluid exchange it:

1) drain the transmission oil, replace the filter, and fill the pan to the correct level(about four quarts, and use the shell 134 oil)-No need to do this..

2) get a five feet of 3/8" ID clear tubing and a clear(or) graduated 1 gallon painters pail. Mark the pail inside and outside at the two quart level with masking tape.

3) disconnect the top transmission cooler line from the top of the radiator, and slip on the 3/8" clear tubing on the cooler line. Clip the other end to the inside of the pail.

4) Start the car( its about 30 to 60 seconds!!) only enough to get the four quarts in the pail FIRST!

5) Add four quarts to the pan

6)Start the car to get two quarts. I would do this for about ten to twelve quarts.

This technique is a will exchange all the fluid in the transmission, cooler lines, and torque converter. If you want to get anal, get a helper to watch the fluid in the paint pail, and shift the car into each gear through each oil cycle to exchange the fluid through the valve body.

You have fresh fluid on every crevice of your transmission. Others will call this a flush technique, but you are officially exchanging old fluid for new fluid.

What you probably have is oil incursion in the transmission computer, or one of the speed sensors went caput... Your ML is in LIMP MODE

Here is great thread...

http://www.peachparts.com/shopforum/tech-help/325722-722-6-transmission-refresh-diy-questions.html

Best of luck,

Martin

RichardM98 · #8 09-06-2013, 05:32 PM

Sedans in MY1998 had a drain plug on the TC as well as the pan. Double check and if that is the case, drain both and refill to correct level. A new transmission (factory rebuilt) runs $3K-$5K so what's the point in not using MB factory recommended fluid to save $40 or so. But, hey, it's your car your money.

TMAllison · #9 09-06-2013, 07:02 PM

Sounds like "limp" mode, 1st, 2nd and R only.

clear the code, a cheap OBDii scanner won't clear it, and then drain and fill using factory approved fluids. 722.6's are touchy about their fluid type. Will stay in limp mode until the code is cleared. Pulling batt cables or cabin reset won't do anything. Pending what code it is, it may go right back to limp mode until the underlying problem is repaired and it cleared again.