Just an update on this unidentified ball-ish thing I found in my transmission pan.
I am beginning to think that it is a berry/seed that was lodged in the transmission pan gasket and THEN fell into the pan when I dropped it down. The object is burnt so I suspected it has been near the tranny/exhaust system for a while.
The good news is I now know how to remove (& reassemble) my valve body. There is great information on this forum, especially if 722.6 related – though you might be forced to look outside the 163 area
The better news is my transmission is running great and it’s QUIETER. I didn’t realize how bad the transmission sounded before - really whiny. Shifts are smooth and only a slight flare at 60mph on 4-5, but just once so far. A transmission shift-point reset procedure should fix that.
So here is what I did with some cautions. (If you have any comments, those might be helpful for the next home mechanic tackling these fixes.)
Part I. Drain and Disassemble.
1. Couldn’t budge the pan drain plug (with allen key) so MityVac’d out transmission fluid through dipstick tube, about 3 liters
2. Put the ML320 on ramps, front only – truck nose up about 10in – placed safety stand and blocks.
3. Twisted transmission electric plug down (counter clockwise), and removed plug.
4. The plug was dripping ATF so left hanging with blue paper towel around it to drain/wick any ATF from the pin connectors.
5. Removed six torx-30 bolts and fasteners – as carefully as I could with a socket wrench.
6. Dropped pan and checked for anything amiss with 197k+, circa 1999 aged fluid.
7. Found aforementioned round thing in pan, FREAKED, and then posted on this forum.
Part II. Valve body
8. Left pan off and collected dripping ATF under truck for the next week while I gathered the courage to pull the valve body off – my original goal.
9. Total combined ATF collected => 5.72L (of black gunk, looked like espresso and smelled burnt)
10. Removed the adaptor plug housing using a deep socket wrench (9mm?). ML320 exhaust is adjacent to work area so did these procedures with engine cold.
11. Used torx-30 and socket wrench to remove 10 bolts holding the valve body/housing/conductor plate.
12. Carefully placed valve body onto a clean garbage bag and tray and transported to my workshop (i.e. kitchen island) – CAUTION: I tried to be as clean as possible since I didn’t want to have to wash any internal parts with solvent or water – figured a new ATF filter and flush should do what is needed on what I didn’t wipe off.
13. Removed solenoid covers, three screws securing 6 solenoids on conductor plate, pulled solenoids from plate, removed conductor plate. CAUTION: Didn’t force anything and organized where everything came from.
14. Sat down and studied valve body & housing – while ATF continued to drip all over garbage bags and tray.
NOTE: So this is where I chose NOT to believe the recommendation by 43sqd.
16. Decided to open valve body and check for presence of plastic check balls
17. Removed leaf spring from bottom
18. Removed selector valve and two screens from two solenoid holes.
19. Removed 19 of 20 torx-30 bolts using a socket wrench.
20. Stripped the 20th bolt and again FREAKED.
21. Regained composure and called neighbor to borrow an electric impact driver.
22. Successfully removed last torx bolt (not as stripped as I thought, just needed more torque and direct pressure).
23. Carefully slid/opened valve body from separator plate. Removed dowel.
24. Checked top of separator plate for any items stuck to it – none found.
25. Carefully slid/opened separator plate from lower housing & again check for items on the bottom of the plate – none found.
26. Used a printout ‘map’ of the valve body channels to look for plastic check ball locations.
27. Wicked away ATF where plastic check balls were located and found all four require balls.
28. Wicked away ATF where metal check balls were located and found all 8 metal balls and central screen too.
29. Confirm that all check balls were present and looked like “bearings” as previously described.
30. Did not clean or otherwise disturb channels or interior of valve body or housing.
31. Did not remove side plates or any other valves
32. Wiped the separator plate off with lint free paper towel – both sides
33. Reassembled in reverse order.
34. Torqued all 20 bolts to 71.5 in-lbs (8nm). Tighened short side – to long side row order.
35. Attached leaf spring and selector valve – CAUTION: make sure selector value is correct orientation – Reference and read forum notes of others breaking the plastic on installation to tranny.
36. Clipped on new OE conductor plate.
37. Wiped off solenoids and lubricated same o-rings with new ATF, installed by gently, but firmly, seating through plastic plate – remember to reinstall the two screens.
38. Installed solenoid clips and plate holders – torqued to about 45 in-lbs (couldn’t find specs but side screws are 4nm & previous top bolts are 8nm)
39. Wiped down exterior top of valve body, particular attention to sides where it attaches to transmission – the well machined and smooth surfaces.
40. Covered up valve body, drank a Guinness (two actually) and took a break.
41. Cleaned around pan opening and wiped out the plug adapter opening.
42. Wiped inside tranny area where valve body attached – machined smooth area.
43. Installed valve body to transmission – careful not to touch anything or contaminate – the underside of SUVis really dirty. CAUTION: don’t force anything and line up well – particularly plastic selector valve. Torqued screws to 8nm.
44. Installed new adapter by lubricating plug adapter o-rings and tightening seating adapter center bolt – hand tightened as unable to locate torque spec. CAUTION: Adapter is tightening metal screw to metal socket both housed in plastic.
45. Installed pan gasket on clean pan, lined up pan and torqued retaining bolts to specification in alternating order.
46. Cleaned electric plug with MAF cleaner multiple times. Let dry. Seated and locked into new adaptor plug.
47. Got up, danced a jig, and realized I still needed to fill with tranny fluid.
Part III. AT Fluid
NOTE: Definitely NOT looking for any opinions with regard to ATF here, but just telling you what I did and will update you on any further issues.
48. Poured 3 liters Fuchs 3533 (236.12) down dipstick tube.
49. Started engine, 10 seconds in each gear: P,N,D,4,3,2,1. Left engine running.
50. Poured 2 liters Fuchs 3533 down dipstick tube. Left engine running 10 minutes.
51. At 90 F engine gauge temp, checked fluid level. Did not register on aftermarket dipstick.
52. Began pouring Shell 134 (236.14) down dipstick in 3-4oz increments, alternating dipstick check and pour. NOTE: dipstick checked when in Park.
53. At 5 L + 0.5 qt (236.12 & 236.14 , respectively), ran through gears 20 seconds each: P, N,D,…,1.
54. Brought up to level of lower 80 F mark on dipstick – engine at normal operating temp, but in Park.
55. Total fluid added: 5 liter of 236.12 and 1.09 liters of 236.14. Collected 5.7 liters of old ATF – about a beer can’s amount of ATF missing from normal operations before this maintenance. That might explain the transmission whining sound . . . and all the gunky stuff on the under carriage.
56. Took a 3 mile neighborhood drive manually shifting through all gears up and down and autoshifting in Drive.
57. Checked ATF level in Park and registered at lower 80 F mark.
58. Parked for 2 hours.
59. Drove 15 miles to meet family for dinner (around town driving). Drove back.
60. Check transmission fluid level. In Park, right at lower 80 F mark. However, still stopped but in Drive gear (with spousal assistance), ATF level is centered between low and high 80 F mark. Right on the money!
PART IV. Follow-up and Notes.
61. I plan to do multiple partial drain and refill of 134 ATF in 500 miles and again at 1,000 miles. Right now, assuming my tranny is 8.5 L capacity, it is 59% (5L) of 236.12, 13% (1.1L) of 236.14, and 28% (2.4L) of 236.10 old espresso.
62. I figure that after 197,750 miles, I don’t want to shock the system too much. You know us old guys are prone to heart attacks and embolisms
63. Keep your work area as clean as possible.
64. Kitchen garbage bags are clean, cheap, and easy work/transport/cover up tools.
65. Use an electric impact driver (18v or stronger) to REMOVE screw/bolts. A socket wrench is slippery when oily – only one quasi stripped bolt this time but one time too many.
66. Purchase more ATF than what you think you may need. If you sourced it locally, you can usually return it. If you source it via mail, waiting for more to arrive is painful.
67. Also, it would likely be better to use only a single type of ATF. Mine are all MB spec list approved, but just at different times in the ML’s life.
68. Definitely use a fill funnel with a screen or filter on it. After pouring the first bottle of ATF, there was a piece of white plastic the size of a finger nail clipping that was caught by the filter screen. Whew!
Hope this is helpful. Any comments would be appreciated for others tackling this, but I am off to my next project: fuel line and filter change. Thanks.