Kirkian8624

I made the mistake of letting a family member who "could definately do it -" fix a transmission oil leak on my '99 ml430. It was running beautiful prior but had a significant leak that required frequent top-offs.

I bought a transmission oil level checking tool to maintain the proper amounts until the repair was started and again, everything was fine to that point.

I bought a new gasket and filter kit for the AT oil pan. He drained and flushed the AT oil, removed the old pan, replaced the pan, filter and gasket. All good. Up until when he over-torked and stripped the AT oil pan bolts and a couple of the holes. I rethreaded the holes and bought new bolts. Again, all good. Until -

It started off strong and was shifting through all gears fine. After about 200 miles it started a slight grinding at low speed and especially around corners. The grind quickly progressed from nuissance to "oh no!". It got loud and was accompanied by a strong ratcheting vibration from start through 3rd gear and again, especially on cornering. It went into limp mode at that point.

Due to the location of the racheting and vibration (pretty much dead center under the shifter) and the fact that it was worse with higher power transfer demands, I jumped to a bad transfer case conclusion.

Up on stands it went - grabbed a new oil catch pan (to try and save as much of that overpriced hard to find tranny oil as possible) - opened the drain plug and waited for the beautiful red flow, that never came!

Yeah, "Mr. Of Course I Can Fix That" took 2 weeks on a 1 hr job then forgot to put transmission oil back in the transfer case; it had been running dry for almost 300 miles.

The transmission itself was filled with the right kind and amount of oil and since it had been shifting fine I decided my bad transfer case conclusion was correct.

I ordered a used ("but in excellent condition") transfer case and low range motor - disconnected the drive shafts - dropped the old TC - mounted the "new" one - reassembled the drivetrain and filled the TC with new oil.

This all took a couple months to get and replace the TC. During these months, the battery died. It took about an hour to jump it but finally fired it up. It sounded great. No smoke. No rattling. No extra parts flying from the undercarriage. Also . . . No transmission.

The shifter moves fine. There is a VERY slight feeling like it is going in to gear (but may just be the vibration from the shifter) but there is no power to any gear. It revs and idles like it is in Neutral no matter where the shifter is and never feels like there is any connection from the gears to the drive shafts.

A "car guy" suggested that since the battery was dead it may just be that the secondary battery is dead too and that will prevent the transmission from engaging.

Is that a possibility?

My suspicion is that since it hit Limp mode just prior to the new TC, the computer has locked the transmission in neutral as a safety measure?

The battery no longer takes a jump (yeah, it was that dead) and before I replace it for $180 plus the secondary battery for another $100 I'm wondering if anyone has had this issue or if a consensus can push me one way or the other.

Replace both batteries or replace primary battery then scan and reset any transmission codes that may appear. So, I'm also looking for an OBD tool that can scan and rest MB powertrain codes - saw a few listed in a forum prior to all this but can't find them anymore . . .

Any help will be awesome!

Thanks in advance . . .

Aar Sto

Are you certain there is a secondary battery for that vehicle?

Kirkian8624

That's what I was told by another member and I found a part no for one. I have not yet tried to locate it but saw a youtube video of one being replaced on a 99 ml430 - so unless it's VIN specific, there SHOULD be one?

Maj. Dundee

There is no secondary battery for 1998-2005 MLs.

Whenever battery voltage goes below 10v while the battery is connected, all the modules recognize this and set there respective codes which causes Limp Mode.

Either one of the scanners below will read/delete every code in every module. If these codes are not deleted, the veh. will remain in Limp Mode.

http://www.foxwelltech.com/product/item-16.html

http://www.auteltech.com/Professiona...ools/393.jhtml

Kirkian8624

Thank you for such a quick and concise reply - I appreciate the help and the links to the scanners.

As for limp mode - can limp get to the point of no power to any gear at all and be what the issue is?

If not, have you heard of this issue or have an idea on what else could be causing it? Someone suggested a bad conductor plate . . .

I ask because putting $400 toward a battery and scanner to end up with a car that still won't move may just prompt me to scrap the car.

Thanks again!

Maj. Dundee

I previously stated that all modules will set codes when voltage goes below 10v, and that includes the ECM which controls the throttle actuation.

You have no choice but to get a scanner to read and erase codes. You cannot own any vehicle these days without a scanner.

Kirkian8624

Thanks again -

I may have used the wrong terminology by saying "no power to any gear . . ." - the engine revs fine but there is no transmission of that power to the drivetrain in any gear.

As for the scanner, I agree - I have a scanner that has served me well for all of my other vehicles for over 15 years and is still working - just not for this issue.

Cheers!

Aar Sto

You can get a new battery at Walmart for $120.

I would search for information on this scanner - Threre are some threads on MB sites suggesting that once you install the car software(includes a couple) to the scanner, that it will be able to read and clear codes in all the modules. I would confirm that and confirm compatibility with whatever phone or tablet that you have before purchasing, but it seems reasonable. You get the two free softwares installs so if it doesn't work out with the ML430 then you can use it for your next vehicle.

If your vehicle is fixed, your vehicle isn't going to run properly until you clear the codes. Even if clearing the codes doesn't get your vehicle running, the new codes it throws should tell you what is going on.

In the meantime check that the transfer case motor is installed correctly and that fuses 8 and 22 are good. Sounds like you might be stuck between high and low.

Kirkian8624

That is all great info. Thank you for the comprehensive response. I never got a notification about this post - it was in my spam, odd that the others weren't - but, yes, I agree that it seems to be stuck between high and low.

I'm optimistic that with a new battery and code reset, the transimssion/shifter linkage will reengage and solve the issue. If not, I'll drop the transfer case again and reinstall just incase - but it seemed pretty straight forward putting it in; tranny jack to line up the drive shaft connections, bolts there, finished raising it to the chassis, bolts there, connected the low range motor, flushed then filled with oil - called it a day?

Miss something?

Aar Sto

I would also be thinking that the new battery and clearing all codes for all systems will have your car out of limp mode and working again.

Check all the codes and write them down. Clear the codes. Test vehicle. If it isn't working then check the codes again and post them. Someone here can help you from there.

maneesh

Kirkian8624 - is there any update to this? Did your car run after battery replacement and code delete? Thanks.