Author Topic: failed fluid coupler (Read 12086 times)

merrill · « **on:** September 07, 2015, 13:16:17 »

well I believe my fluid coupler failed last night.

I was driving with a buddy and I noticed the motor rev but the it seemed the transmission was not transmitting the power to the road.
At the next stop I moved the shift selector to "2" pushed the accelerator pedal to the floor to select first.
The car took off then the motor rev'd again and then we heard a loud pop and that was it.

rolled to a stop, we could see the transmission fluid behind the car.

Had the car towed to my house, I need to crawl under it today to have a look.

After searching the forums I have read that these do fail and leaking fluid under the car can be a symptom of a failing TC.

Benz Dr. · « **Reply #1 on:** September 07, 2015, 14:33:05 »

Look for a hole/s in trans cooler lines or hoses.

merrill · « **Reply #2 on:** September 08, 2015, 23:40:46 »

Well, the fluid coupler is shot, it broke at the seam.

I crawled under the car tonight and i could spin the transmission half by hand.

now to find a replacement 4 bolt fluid coupler.

merrill · « **Reply #3 on:** September 12, 2015, 19:45:56 »

Turns out finding a good used or rebuilt unit is harder than I thought.

Adsit co has 5 "good used" for $395 but there are risks dealing with them
Buds benz has one for $1150 + 500 core. This is 3x what my transmission guy says they should run

I have a call out to Gernold and a few others for assistance.

One thing to note is I cannot find a shop to "rebuild" these. My transmission guy has 25 needing re welding.
If anyone knows of a shop that would run 26 units please let me know.

ctaylor738 · « **Reply #4 on:** September 14, 2015, 14:00:12 »

You might try these guys. I bought a rebuilt trans and coupler from them about a year ago. I had a good experience with them.

sunvalleymercedes@gmail.com

merrill · « **Reply #5 on:** September 14, 2015, 15:45:53 »

Chuck
hi,
yes, I am working with Marc at sun valley. He has 25 units needing repair as well.

Thank you - Matt

lurtch · « **Reply #6 on:** September 15, 2015, 00:27:34 »

After living with unexplained fluid loss for a long time, I broke down and had my shop pull the transmission for a look. They replaced the torque converter because there was an stress crack where the spline boss is welded into the drum. The crack was so difficult to see it was only found after they used shop air to pressurize the unit. They charged me US $700 for the rebuilt one.

Now the large piece of cardboard that I park over is always bone dry. Woo Hoo!

Larry in CA

merrill · « **Reply #7 on:** September 15, 2015, 22:44:34 »

The search continues for a repair shop and / or good used unit. (without dealing with Adsit co or paying buds outrageous prices)

Thanks everyone for their input.

Joe / Dan replied to your messages. hopefully you received them.

Matt

merrill · « **Reply #8 on:** September 28, 2015, 22:34:02 »

replacement fluid coupler installed this weekend. took about 10 hours to R/R the transmission. (I had a few issues)

I have attached some photos showing the inside of both halves of the FC.

Thanks to everyone that helped me with this project.

merrill · « **Reply #9 on:** February 12, 2016, 12:53:06 »

I have driven the car a few times since the r/r of the fluid coupler.

drives and shifts ok, however the normal "whine" when accelerating is now louder and heard at idle and thru the gears. The volume does decrease once I get to cruising speed.

After some research is looks like the noise is coming from the primary pump.

Need to reach out to Joe or a transmission shop for advise.

ja17 · « **Reply #10 on:** February 12, 2016, 14:56:15 »

Matt, Did you make sure that the fluid coupling was back all the way in the transmission during installation? The cogs in the coupling must engage the front pump during installation.

merrill · « **Reply #11 on:** February 12, 2016, 16:25:00 »

Joe,
hmm,
cant remember for sure, the FC did slide on and i believe i heard it seat.

though, i do remember that there was little tolerance between the flywheel and the fc because I had not aligned the dowel pins.

thoughts?

ja17 · « **Reply #12 on:** February 13, 2016, 07:06:43 »

Normally, if you have clearance once the transmission is drawn together, then you are still engaged. If the FC becomes disengaged and uncoupled, then it has no clearance when drawn together tight and damage occurs. So you might be OK here. Remove the trans pan. You should find some clues there.

Benz Dr. · « **Reply #13 on:** February 13, 2016, 19:13:47 »

I spray paint a white area on the FC before I install so I can see if there are any leaks after running. Small amounts of red trans fluid shows up very nicely on a white background but is very difficult to see on bare steel.

I have a guy down the road from me who is good enough to weld anything back together. Whether or not he would do a job like this is not something I could say at this time. I would imagine it would require a jig, a way to test for leaks, and it would need to be perfectly aligned.

merrill · « **Reply #14 on:** February 14, 2016, 00:47:35 »

ok,
so. I dropped the transmission today, unfortunately I cannot pull the F/C off of the transmission.
(its still under the car on a transmission scissor jack)

Any tips on getting the F/C off. I tried to use the 4 bolts to wiggle it off.
I do recall when I removed the old one it took a while for it to come loose.

also, I found these 2 washers under the car, not sure where the go.

Tyler S · « **Reply #15 on:** February 14, 2016, 03:43:20 »

Those aren't washers!! Those are ball bearing cages!!! Something let go somewhere! Input shaft/cover bearing? Could have been damaged when the FC let go. Could be the reason you cant get the cover off.

ja17 · « **Reply #16 on:** February 14, 2016, 04:58:33 »

Sounds like a damaged front pump. Bolt a piece of uni-strut across the FC, then tap it out.

merrill · « **Reply #17 on:** February 14, 2016, 14:38:59 »

Tyler
yep, bet that is what those are, I was working on another project in the garage and had a very small sealed bearing for an electric motor come apart. that is probably where those came from.

Joe,
ok, will try to bolt something to the FC to tap it off.
I may just send the whole think to Mike at Mercedes Dismantlers.

Benz Dr. · « **Reply #18 on:** February 15, 2016, 02:28:04 »

I thought those bearings on the input shaft were more like needle bearings and not ball and cage so I don't think they're from your trans. Besides, how would they get out to begin with?

Tyler S · « **Reply #19 on:** February 15, 2016, 02:44:53 »

Thats the worst feeling when you put something back together and have what you think is an extra part. Then realize its not even from the same vehicle. Guys at the dealer used to "add" spare bolts to another tech's magnet dish mid repair as a joke.

ja17 · « **Reply #20 on:** February 15, 2016, 14:38:59 »

The front pump has only a brass type bushing. It will most certainly be damaged. At one time you could order this part separately and it was inexpensive. If the gears are damaged or the walls of the pump are damaged, you may need a whole pump. Most likely your rebuilder has good used units. Newer MB models have a screw in pin which keeps the converter from moving out of place during installation (a good inexpensive fix for a expensive problem). Obviously you were not the first to have this problem Matt. Sometimes you just have to pay for your education! I learned the same hard lesson many years ago.

Benz Dr. · « **Reply #21 on:** February 15, 2016, 21:04:19 »

Joe;

You and I rarely talk yet I know what you're thinking almost before you say it.

BTDT enough times to say I completely agree.

Tyler S · « **Reply #22 on:** February 16, 2016, 03:09:04 »

I still think the pump or bushing could have been damaged when the FC let go. When it broke in half there was no longer any support from the flex plate/flywheel for keeping things in line. I guess we will see shortly.

ja17 · « **Reply #23 on:** February 16, 2016, 15:30:37 »

Ah yes, Dan my friend, we pay for our education one way or another!

merrill · « **Reply #24 on:** August 03, 2016, 22:56:38 »

Well Marc was able to get to my Transmission this week.

Turns out the fluid coupler was welded to the front pump. We are not sure how that happened.
Marc thinks maybe there was low fluid and it got hot.

anyway, unfortunately the torque converter is ruined. they had to pry the pump and coupler apart and broke off the tabs that drive the pump.

with some luck we will find a replacement FC (without breaking the bank) and i can get back on the road soon.

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Author Topic: failed fluid coupler (Read 12086 times)