|
|
|
#1
|
|||
|
|||
Transmission K4 A040 -722.201 renovation
Is it possible to renovate a K4 A040 -722.201 Transmission in Oman?
What qualities do I need to search for in order to find a shop? Or is there a chance to renovate myself? From what I learned from Frank my transmission is pretty worn and I have too many sounds, noises, bangs ... I believe it might be time to renovate. Can you give me hints what to do. In the US I'd just get the transmission shipped to Sunvalley or some other renown shop over winter...but here in Oman? If I had parts for replacement...could I do the job myself? What tools would I need...what parts? Has someone done this before? Best, Martin |
#2
|
|||
|
|||
So far I experience two problems with my transmission:
1) Bang when shifting from P to R or 4...then another bang when pulling off a start (with some throttle). Frank was saying "When that 2-1 shift is made one band (B1) is released, and the torque load that it was holding is taken by the freewheel/sprag clutch. Your description of a bang suggests that the freewheel rollers and ramps have become quite worn, and as a consequence a considerable amount of slack must be taken before the freewheel grabs. As you drive off, and the 1-2 upshift speed is reached, band B1 is reapplied for 2nd gear. A flare ("binding") in that shift points to a worn band (B1) or leaking B1 servo piston. " 2) noise of potentially the primary pump. This mechanical noise is audible at all times. Is the reason for the noise a worn gear in the pump? If it were 'only' these worn parts. I'd need a) B1 band, freewheel rollers, ramps b) Leaking B1 servo piston (is this o-ring or something else?) c) seal kit for the transmission Martin |
#3
|
||||
|
||||
Answer
http://www.ganzeboom.net/images1/ganzeboom/parts/Mercedes/722.0,%20722.1,%20722.2.pdf
722.118 Automatic transmission rebuild (Monster DIY) European Import Transmission Manuals . .
__________________
ASE Master Mechanic asemastermechanic@juno.com Prototype R&D/testing: Thermal & Aerodynamic System Engineering (TASE) Senior vehicle instrumentation technician. Noise Vibration and Harshness (NVH). Dynamometer. Heat exchanger durability. HV-A/C Climate Control. Vehicle build. Fleet Durability Technical Quality Auditor. Automotive Technical Writer 1985 300SD 1983 300D 1984 190D 2003 Volvo V70 2002 Honda Civic https://www.boldegoist.com/ |
#4
|
|||
|
|||
Wow whunter!
This is great information. I am really eager to tear my trans apart tomorrow if I had time and parts. Tools needed seem to be fairly typical. Where is a good place to get the replacement parts? My problem is always that I need to ship the stuff to the Middle East and is often more expensive than the parts itself. First question: Can I get the transmission out without removing the engine? |
#5
|
||||
|
||||
Answer
Quote:
Every internal part will attract a vast quantity of dust, dirt, and grit like magic. Pelican Parts ships world wide, and can get any available part. There is no reason to remove the engine if you have jack stands to support the car high enough, I remove transmissions this way all the time. These work for me (Maximum Lift Height 23-1/2 in.). I STRONGLY recommend buying a Low Lift Transmission Jack. Transmission Jack - 450 Lb. Capacity Here are some basic transmission removal DIY's. 722.118 Transmission Removal and replacement DIY 300SD Transmission removal and install .
__________________
ASE Master Mechanic asemastermechanic@juno.com Prototype R&D/testing: Thermal & Aerodynamic System Engineering (TASE) Senior vehicle instrumentation technician. Noise Vibration and Harshness (NVH). Dynamometer. Heat exchanger durability. HV-A/C Climate Control. Vehicle build. Fleet Durability Technical Quality Auditor. Automotive Technical Writer 1985 300SD 1983 300D 1984 190D 2003 Volvo V70 2002 Honda Civic https://www.boldegoist.com/ |
#6
|
|||
|
|||
Quote:
Du bist ein Schatz! Thanks for all the great information. A clean space is of concern indeed here in the lands of deserts and sand (very fine sand is in the air all over the place). There is almost no way to avoid this. Another thing is to get parts shipped especially if parts are missing in between the job and tools. Your tool recommendations are great. So I'll wait most possibly until I am back with the car in the US. Any recommendations how this trans might survive another 5K miles? Does Lukas additive help for a while for any of the symptoms? Martin |
#7
|
|||
|
|||
Martin,
When we were discussing symptoms in your last thread about this trans, I made this suggestion (on 2/28/13): "Should you consider a trans replacement, I think that the first choice would be a 722.0 from the 4.5L version of the 108/109 cars, and which was also used in the W116 and R107 cars. It is much more plentiful (at least in the US) than the 722.2 which you have. I would also try to source it in Europe. You could check with Stretch/Army and Cho. There are some modifications required, the most significant being shortening of the driveshaft (the bell housing is 3/4-1" longer)." If you are bent on maintaining originality, then rebuild the 722.2 trans, however, replacing with a 722.0 type, will be the more satisfactory solution I think. MB discontinued use of the 722.2 with V8s after your car, and discontinued use with the I6s in mid-1973! Last edited by Frank Reiner; 03-05-2013 at 01:47 PM. |
#8
|
||||
|
||||
Martin - Just a thought. Have you checked with the Mercedes agent in Oman? They must have shipments coming in regularly which may reduce shipping costs. They may also have a source of reconditioned transmissions. There must be a need for rebuilt transmissions for Mercedes Taxis etc in the Middle East.
Google says Zawawi Trading Company is the Mercedes Benz Dealer. They may even be able to do the rebuild for you - even if cost is high, it may save you money in the end. Don't like the idea of you heading off through suspect countries with a transmission with known problems. Maybe ship car back home and use public transportation for your travels!
__________________
Graham 85 300D,72 350SL, 98 E320, Outback 2.5 |
#9
|
|||
|
|||
Quote:
I did not forget what you said. I just don't know the consequences using a 722.0 trans in my car. Did you say I need to shorten driveshaft etc...and it has only 3 gears starting in 2nd gear. There might be more headaches lurking... I just don't know. |
#10
|
|||
|
|||
Quote:
I am looking for a shop who can renovate a MB transmission but was not successful so far. I can try the M dealership. There is NO public transportation in these countries here. Martin |
#11
|
|||
|
|||
Martin,
For reference here are the changes that would be required to use a 722.0: 1) A spacer ring for the pilot of the torque convertor (T/C); the pilot of the T/C is smaller than that of the fluid coupling. Lathe work. 2) Re-bending of the cooler lines; the connections on the bell housing will be 3/4"-1" farther aft. 3) Lengthen throttle pressure rod by 3/4"-1". Lengthen (if column shift) or shorten (if floor shift) selector rod by 3/4"-1". 4) Relocate rear mount crossmember 3/4"-1" aft. Typically the range of the slots in the floor and crossmember are sufficient. 5) Shorten the forward section of the drive shaft by 3/4"-1", OR, if luck smiles, the splines in the shaft will accommodate the shortening. The torque multiplication in the T/C will make up in part for a start with a 2.39:1 gear (2nd), vs. 3.98:1 (1st). All vehicles using the 722.0 trans (V8s) perform quite adequately, even with final drive ratios as tall as 2.24: and 2.47:1. Vehicles with the 722.1 (4,5,6 cyl.) also normally start with the 2.39:1 ratio, and use final drives as tall as 2.88:1. |
#12
|
|||
|
|||
Quote:
All these changes seem possible and reasonable. However the low torque and high rev engine (3.5) vs the higher torque and low rev engine of a 4.5 concerns me a bit. Do you really think the 4.5 transmission and a 3.5 engine are a good match...or just a compromise? Martin |
#13
|
|||
|
|||
Martin,
"Do you really think the 4.5 transmission and a 3.5 engine are a good match...or just a compromise?" A very fair question indeed. It would seem that the best answer has been provided by Mother Benz: with the introduction of the next chassis, the W116, for the flagship cars, the 3.5L engine was equipped with the 722.0 (aka "3-speed") trans!! The weight of the W116 is 100lbs. less than yours, in both the empty and max. GVW configuration, the final drive ratio is the same (3.46:1), if one wished, a 3.07:1 was an option, and the engine specification was the same as yours. The 3.5L engine was restricted to Europe, the 4.5L was available in Europe and the USA. Why was the 1st gear start feature eliminated from the V8 trans? It requires that the full engine torque be transmitted by the freewheel unit/ sprag clutch. It turns out that that device is simply not strong enough, and is subject to the type of deterioration and wear that you are experiencing. |
#14
|
|||
|
|||
Quote:
You are saying the problems I am seeing are 'normal' in a sense because the transmission was not well designed...did I get that right? And the 722.0 as the successor was a better design? The torque converter in the 722.0 can make up for the loss of 1st gear. On another note about where the transmission noise is coming from... The noise (suspect was the primary pump) is there also in neutral...meaning that it can't be the differential or center bearing. What deterioration/wear is causing this noise in the primary pump? Martin |
#15
|
|||
|
|||
Martin,
"You are saying the problems I am seeing are 'normal' in a sense because the transmission was not well designed...did I get that right?" Rather than "normal", I would say that trouble with the freewheel unit is "inevitable" when it is subjected to the torque of the V8 engines. Band wear and piston seal leakage are functions of use; entropy and all that, you know. "And the 722.0 as the successor was a better design? The torque converter in the 722.0 can make up for the loss of 1st gear." The 722.0,.1,.2 transmissions are, from the stand point of mechanical components, all the same transmission, with variations in the bands, band servo pistons, and number of friction discs in the clutch packs. The three transmissions are all the same design. The number of gear ratios which are accessible, and under what circumstances, is determined by the arrangement of the various control valves in the valve body. Yes, the torque convertor does make up in part for starting with the taller 2nd gear vs. 1st. "On another note about where the transmission noise is coming from... The noise (suspect was the primary pump) is there also in neutral...meaning that it can't be the differential or center bearing." Correct. (I'll take a bit of liberty here with punctuation.) "What!? Deterioration/wear is causing this noise in the primary pump!?" Yes. Okay, the pump is an eccentric gear type (The larger ring gear has internal teeth, with a smaller externally toothed gear meshing inside it.). And as mechanical things are wont to do, the teeth wear from their original shape and become noisy. |
Bookmarks |
Thread Tools | |
Display Modes | |
|
|