[dejst]

For you 2011 Santa Fe owners,
If your thinking about replacing a bearing and seal in the coupler this may help. I've currently got mine tore apart and found the following;

Part Numbers are as follows;
Coupler Seal - National Part #710658, the number on the actual seal is 1900-044-041
Bearing is the same as what is in the video - 6008Z replaced with a 60082RSJ

I also had to do my Pinion seal which is a Hyundai Part#5305039100SM, the numbers on the seal are (SB2Y) 50x69x8

Note the bearing has no snap ring and is pressed in the opposite as what is shown in the video for my 2011 Santa Fe. Everything else was pretty much the same as what's in the video above.
Big Thanks to South Main Auto Repair for repair videos.

 

[dejst]

For you 2011 Santa Fe owners,
If your thinking about replacing a bearing and seal in the coupler this may help. I've currently got mine tore apart and found the following;

Part Numbers are as follows;
Coupler Seal - National Part #710658, the number on the actual seal is 1900-044-041
Bearing is the same as what is in the video - 6008Z replaced with a 60082RSJ

I also had to do my Pinion seal which is a Hyundai Part#5305039100SM, the numbers on the seal are (SB2Y) 50x69x8

Note the bearing has no snap ring and is pressed in the opposite as what is shown in the video for my 2011 Santa Fe. Everything else was pretty much the same as what's in the video above.
Big Thanks to South Main Auto Repair for repair videos.

Installed new parts and this did not fix thumping on acceleration.

 

[Tripplec]

Did the Main Auto mechanic say that was what the repair was for. I watched it last year. I think NOT!

 

[johnaauld]

Did the Main Auto mechanic say that was what the repair was for. I watched it last year. I think NOT!

If I remember right that was for back end noise and binding at low speeds.

 

[multispin]

I had the same issues others have mentioned. Felt like what can be described as a kicking or yanking or jolting. It's been something that has happened for years but I've never been able to figure out a way to reproduce since it wasn't very often. I remember it happening under warranty, but because it was so rare (once or twice a year) I doubt the dealership would have found anything. I'll also have to assume they checked the coupler during inspections for leaks and found none. So with that being said I think in my case this part failed very slowly, over the course of 4 or 5 years when I first remember a weird kick/yank/jolt.

I really started to notice it when I was traveling in an area with lots of hills last year. But shrugged it off as it went away when I came home. Then it started happening much more frequently, even in flat areas. It got to the point where it was always doing it when I was on a slight incline and making a left or right turn. Doing a three point turn always made it jump. Now that I could reproduce it whenever I wanted I decided to look into it because it was only getting worse. I was afraid it was the transmission failing, thankfully it was the coupler.

Now if you start researching this you will find tons of information from Russia. There are videos, forum posts and webpages dedicated to fixing this coupler. There seems to be a lot of different outcomes after fixing it unfortunately. Some people said the fix lasted a month, some a year, some a few years, and some even do preventive maintenance on it by refilling it every 2 years.

The common theme is that you will have little to no fluid in the coupler. When I opened mine, it had none. It wasn't bone dry, there was just a slight coating of fluid but that's it. After I removed the drive shaft to pull the coupler off it started leaking a black fluid immediately. I thought the rear diff seal was shot but it was only about 20ml and smelled like transmission fluid. Once I got the coupler removed I knew the fluid came from it.

Basically every Russian post I saw talked about replacing the oil seal on the coupler (Corteco 19026317B). I few people also replaced the bearing and seal on the part that connects to the drive shaft if it was making a noise. I had bought the parts to do this just in case, but my bearing was completely silent, had no play, and spun around fine so I left it alone. I didn't even need to take the coupler apart as I only removed the one oil seal. The south main auto video you find is about that bearing at the front being shot, it has nothing to do with the kicking or jolting. But it's possible to have both issues. The rear diff seal can also be leaking, but that was very rare from my searching.

Things I would have done differently.

Removed the drive shaft right away. I was really trying to avoid disconnecting the whole thing but I ended up wasting an hour. There isn't enough room to pull the coupler out without taking the drive shaft off. So that's 3 bolts on the coupler, 4 at the front, and 2 hanger bolts. I had two jack stands hold it up as I took it off. I also had the front end on jacks so I could put the car in neutral and park when turning the drive shaft.

I should have looked up a video on how to remove an oil seal, youtube it, you punch on hole, put a screw in the hole and simply pry it out. I was trying to be so careful with it and broke a couple tools not realizing how pressed it was into that hole.

Technically you can remove just the oil seal and refill it through the bearing, but there is a risk. You don't know how much old fluid is left in your coupler. I've read about people refilling from the bearing and the repair worked for a few weeks and others years. It's also very difficult to know when it's full, you are supposed to fill it, let it sit for a few hours and fill again. I honestly don't know, some fluid is better then none I guess. I decided I would just do it the way I saw in some of the videos and not fill it this way. Also some people were adamant failure was a result of not emptying out all the old fluid, depending how much old fluid was left, I don't think anyone really knew for sure.

To get access to the clutch plates you sort of have to pull the top part off with pliers or I even saw people tap screws into the three recessed holes. Since I removed the oil seal I didn't have a vacuum effect and I think it made it easier for me to pull it apart. The moment you remove the ring holding it down and flip it over, you are pretty much committed to opening it and reassembling it since the bearings will pop out of place.

How much fluid to add? I saw 150ml ATF everywhere, but I also saw a video of a guy filling up just past the plates. I probably did 160ml to 170ml as a medium. I'm not sure anyone knows what the true value and everyone gets it close enough. I used Valvoline MaxLife full synthetic ATF. I had some left over from when I did my transmission a few years ago. But people said any modern ATF would be fine.

What caused all the fluid to escape in the first place? This question has really bothered me, I know for a fact from my coupler the fluid escaped from the socket where the wires connect. But how is that possible, the fluid would have to travel vertically against gravity. Comparing the two oil seals I would say the new one was much more supple and the old one which was much harder. I think it's a safe assumption to say the oil seal eventually fails, this allows the fluid to then escape. I'm not sure the mechanism of the failure, maybe its a combination of the fluid becoming old, heat and the seal degrading. But I'm also guessing that if this has something to do with pressure/heat/boiling points maybe sometimes instead of venting out the electrical connection it finds a path through the rear diff and destroys your rear diff seal.


After refilling mine and replacing the seal I no longer have any kicking or yanking. Drives great, nice and smooth, I tested it for a good 30 min trying everything I knew that would cause it to kick or jump. How long will this repair last, I have no idea. From what I read it's dependent on lots of things driving style, hilly area, snow/ice, have the clutch plates been damaged too much being used without sufficient fluid, is the magnet also damaged. It's just a big question mark that will be different for everyone.


The only good news I will say is, before my parts came in I disconnected the coupler by simply pulling its electrical connector. This completely disables the magnet in coupler and got rid of the kicking and yanking. I drove around like this for a few weeks and didn't have a single issue and it drove beautifully. I would not hesitate to drive with it disconnected again. The bad news is you get "ESC off" and I think it was the drive train light flashing. Somewhere I saw someone get the ohms for the magnet, I wonder if sticking a resistor with this same value could trick the ecu into thinking it was still there to get rid of the annoying warning lights. I guess you could also simply remove the drive shaft making it a FWD vehicle, then you could leave the broken coupler plugged in so you don't get the warning lights.

 

[RVT]

I also have the same kicking from the rear diff area. 2012 Santa Fe AWD.

1: Happens when accelerating, especially (but not exclusively) uphill.
2: Happens only after driving the car for awhile. Generally 20 minutes or more. But the hotter it is outside, the quicker the problem will exhibit itself.

Was getting to the point I was fixing to disconnect the driveshaft, but then a couple of days ago I had the tires rotated, and it's stopped doing it. Completely.

Here's my theory.

1: What makes the computer want to send power to the rear wheels? When it thinks the front wheels are slipping.

2: What makes the computer think the front wheels are slipping? That they are spinning faster than the rear wheels. (The exact percentage difference depends on the computer code, which I'd have to look at to determine the amount.)

3: Your front tires wear faster than your rear tires. So, when the more worn tires are on the front, they are a smaller diameter than the rear tires. Over the same lateral distance the smaller tire will have to spin faster than the larger tire.

4: So, the code would look like this: When ((FrontTireSpeed - RearTireSpeed) > X ) AND (Throttle position > Y) ) THEN (Engage AWD).

Now, normally you wouldn't notice this happening if you have a Rear Coupler than is working the way it should. BUT what is happening is that the computer is sending power to the rear wheels a LOT more than it should be. This is causing the coupler to work a lot more than it's designed for. A lot more heat, boiling off the oil inside, and causing premature failure of the seal. Eventually this leads to the slamming and banging.

Note: This would also cause much higher fuel consumption, even on cars that did not have coupler problems, because the AWD would be kicking in more than needed.

So, if anyone has this issue, try a simple test. Switch you front tires to the back and see if the problem goes away. And let me know if it does.

 

[dejst]

Great information...thanks.

 

[dejst]

Did the Main Auto mechanic say that was what the repair was for. I watched it last year. I think NOT!

Your CORRECT, he did not say that. It wasn't a bad job to do and my seal was bad and bearing a little bit rough so it wasn't all for nothing. I think I'm going to take the coupler back out, change the oil in it and change the seal on the back of it. I believe this was the oil that leaked out when I removed the coupler and not from the differential.

 

[dejst]

I had the same issues others have mentioned. Felt like what can be described as a kicking or yanking or jolting. It's been something that has happened for years but I've never been able to figure out a way to reproduce since it wasn't very often. I remember it happening under warranty, but because it was so rare (once or twice a year) I doubt the dealership would have found anything. I'll also have to assume they checked the coupler during inspections for leaks and found none. So with that being said I think in my case this part failed very slowly, over the course of 4 or 5 years when I first remember a weird kick/yank/jolt.

I really started to notice it when I was traveling in an area with lots of hills last year. But shrugged it off as it went away when I came home. Then it started happening much more frequently, even in flat areas. It got to the point where it was always doing it when I was on a slight incline and making a left or right turn. Doing a three point turn always made it jump. Now that I could reproduce it whenever I wanted I decided to look into it because it was only getting worse. I was afraid it was the transmission failing, thankfully it was the coupler.

Now if you start researching this you will find tons of information from Russia. There are videos, forum posts and webpages dedicated to fixing this coupler. There seems to be a lot of different outcomes after fixing it unfortunately. Some people said the fix lasted a month, some a year, some a few years, and some even do preventive maintenance on it by refilling it every 2 years.

The common theme is that you will have little to no fluid in the coupler. When I opened mine, it had none. It wasn't bone dry, there was just a slight coating of fluid but that's it. After I removed the drive shaft to pull the coupler off it started leaking a black fluid immediately. I thought the rear diff seal was shot but it was only about 20ml and smelled like transmission fluid. Once I got the coupler removed I knew the fluid came from it.

Basically every Russian post I saw talked about replacing the oil seal on the coupler (Corteco 19026317B). I few people also replaced the bearing and seal on the part that connects to the drive shaft if it was making a noise. I had bought the parts to do this just in case, but my bearing was completely silent, had no play, and spun around fine so I left it alone. I didn't even need to take the coupler apart as I only removed the one oil seal. The south main auto video you find is about that bearing at the front being shot, it has nothing to do with the kicking or jolting. But it's possible to have both issues. The rear diff seal can also be leaking, but that was very rare from my searching.

Things I would have done differently.

Removed the drive shaft right away. I was really trying to avoid disconnecting the whole thing but I ended up wasting an hour. There isn't enough room to pull the coupler out without taking the drive shaft off. So that's 3 bolts on the coupler, 4 at the front, and 2 hanger bolts. I had two jack stands hold it up as I took it off. I also had the front end on jacks so I could put the car in neutral and park when turning the drive shaft.

I should have looked up a video on how to remove an oil seal, youtube it, you punch on hole, put a screw in the hole and simply pry it out. I was trying to be so careful with it and broke a couple tools not realizing how pressed it was into that hole.

Technically you can remove just the oil seal and refill it through the bearing, but there is a risk. You don't know how much old fluid is left in your coupler. I've read about people refilling from the bearing and the repair worked for a few weeks and others years. It's also very difficult to know when it's full, you are supposed to fill it, let it sit for a few hours and fill again. I honestly don't know, some fluid is better then none I guess. I decided I would just do it the way I saw in some of the videos and not fill it this way. Also some people were adamant failure was a result of not emptying out all the old fluid, depending how much old fluid was left, I don't think anyone really knew for sure.

To get access to the clutch plates you sort of have to pull the top part off with pliers or I even saw people tap screws into the three recessed holes. Since I removed the oil seal I didn't have a vacuum effect and I think it made it easier for me to pull it apart. The moment you remove the ring holding it down and flip it over, you are pretty much committed to opening it and reassembling it since the bearings will pop out of place.

How much fluid to add? I saw 150ml ATF everywhere, but I also saw a video of a guy filling up just past the plates. I probably did 160ml to 170ml as a medium. I'm not sure anyone knows what the true value and everyone gets it close enough. I used Valvoline MaxLife full synthetic ATF. I had some left over from when I did my transmission a few years ago. But people said any modern ATF would be fine.

What caused all the fluid to escape in the first place? This question has really bothered me, I know for a fact from my coupler the fluid escaped from the socket where the wires connect. But how is that possible, the fluid would have to travel vertically against gravity. Comparing the two oil seals I would say the new one was much more supple and the old one which was much harder. I think it's a safe assumption to say the oil seal eventually fails, this allows the fluid to then escape. I'm not sure the mechanism of the failure, maybe its a combination of the fluid becoming old, heat and the seal degrading. But I'm also guessing that if this has something to do with pressure/heat/boiling points maybe sometimes instead of venting out the electrical connection it finds a path through the rear diff and destroys your rear diff seal.


After refilling mine and replacing the seal I no longer have any kicking or yanking. Drives great, nice and smooth, I tested it for a good 30 min trying everything I knew that would cause it to kick or jump. How long will this repair last, I have no idea. From what I read it's dependent on lots of things driving style, hilly area, snow/ice, have the clutch plates been damaged too much being used without sufficient fluid, is the magnet also damaged. It's just a big question mark that will be different for everyone.


The only good news I will say is, before my parts came in I disconnected the coupler by simply pulling its electrical connector. This completely disables the magnet in coupler and got rid of the kicking and yanking. I drove around like this for a few weeks and didn't have a single issue and it drove beautifully. I would not hesitate to drive with it disconnected again. The bad news is you get "ESC off" and I think it was the drive train light flashing. Somewhere I saw someone get the ohms for the magnet, I wonder if sticking a resistor with this same value could trick the ecu into thinking it was still there to get rid of the annoying warning lights. I guess you could also simply remove the drive shaft making it a FWD vehicle, then you could leave the broken coupler plugged in so you don't get the warning lights.

View attachment 440180 View attachment 440181 View attachment 440182 View attachment 440183 View attachment 440184 View attachment 440185 View attachment 440186 View attachment 440187 View attachment 440188

It worked...I filled it with just over 150ml of ATF synthetic fluid and put in a new seal. The kicking/thumping is gone for now. Thanks for your response to the thread.

 

[amckie]

With regards to this point:

The only good news I will say is, before my parts came in I disconnected the coupler by simply pulling its electrical connector.

I would like to try this on my 2010 SF just to confirm it is the cause of the symptoms I'm feeling and I was wondering if there's a photo or a diagram that shows where the electrical connector is so that I can try this?

 

[cruzn]

I have a 2011 Santa Fe that also has vibration under acceleration from the rear coupler, HOWEVER, the issue in my case is only present in colder temps, less than 5-10°C; so in winter it's really bad. It's also very prominent just after turning a sharp corner (more than 90°), and accelerating, during the cold weather.

In regards to the previous comments above, I came across an excellent detailed Hyundai technical presentation that explains how it works:

CM 4WD (ITM) - online presentation

en.ppt-online.org

The specified fluid is 0.15L of Mobilfluid LT.
The Mobil data specs:

OpenGraphTitle

OpenGraphDescription

www.mobil.ca

The SAE Grade is 75W-80, but I don't know if that means that 75W-80 gear oil is acceptable.
Mobilfluid LT

SAE Grade	75W-80
Viscosity, ASTM D 445
cSt @ 40ºC	34
cSt @ 100ºC	7.2
Brookfield Viscosity, cP (@ -40ºC)	20,000
Viscosity Index, ASTM D 2270	180
Pour Point, ºC, ASTM D 97	-45
Flash Point, ºC, ASTM D 92	198
Density @ 15ºC kg/l, ASTM D 4052	0.875

I'm curious if adding a little Lucas oil stabilizer would make any difference.

In multispin's pictures, the clutch plates look a bit burned. Is the vibration a result from the clutches slipping excessively and not properly engaged or disengaged?

 

[GJFox]

Just wanted to drop in and say thank you to all that have posted in this thread, particularly multispin. It appears you all have saved me a bunch of money!

We had severe thumping/jolting from the rear end all the time while driving. It was bad enough that I removed the rear driveshaft for summer driving. Now that winter is back, I needed to get the AWD working again. I tore the coupler down, and like multispin, it had nearly no oil in it. With no obvious place where it was leaking from. Also, the clutch plates did not appear to be damaged. Maybe some dark spots on the frictions like multispin posted, but nothing major. Based on how bad our jolting was,I honestly thought my clutches would be badly burnt, however they appear to be perfectly serviceable.

I removed the back cover from the coupler, removed the secondary clutch plates and wiped the old oil off them. Replaced the clutch plates, added approx 150ml ATF, and reassembled every thing. Test drove it and did not have any thumping whatsoever. Hopefully this repair lasts, however I am fully prepared to redo it if necessary. Sure beats dropping $750-1500 on a replacement coupler. It does take a fair bit of mechanical skill and some tools though.

Tips I learned in the process:
-do not remove the 3 torx head screws on the coupler unit. This frees up the primary clutch pack, which contains a bunch of tiny parts that are tricky to reassemble correctly.
-Instead, just remove the snap ring and the big split ring that retain the back cover, then work the back cover off with big pliers. Its a pain to remove because of the seals trying to maintain the suction, and the friction from the big o-ring. And when you go to put the back cover on again, it must be aligned properly, there are notches in the coupler body that must be aligned with shoulders on the back cover. Once they are aligned a big c-clamp or two can be used to squeeze back cover down so that the big split ring can be reinstalled.
-To replace the front bearing, you must remove the electromagnet. Its held on with 3 nuts on the front face of the coupler housing. Once its removed, the bearing slides out quite easily. Then the seal can be knocked out with a punch and hammer from the back side.

Good luck to anyone attempting this repair!

 

[GJFox]

I also wanted to add, disconnecting the electrical plug from the coupler did not eliminate the thumping/jolting for me. I had to remove the driveshaft to make it stop. I don't know why this would be, unless the lack of oil in the coupler was causing the clutches to suddenly (and randomly) lock and unlock.

 

[Leyburn]

On the 2010 Santa Fe, does the AWD indicator lamp on the dash always light up when the AWD operates automatically?
Is checking / changing the oil the only preventative maintenance?

 

[GJFox]

I don't believe ours does. The AWD light only comes on when its locked on. I think that keeping tires the same size, with similar tread depth is important. Differences in tire size will cause heat in the coupler when its engaged.

 

[Leyburn]

Thanks GJFox, I've had a couple of instances of wheelspin pulling away on wet, muddy tarmac, I assume that the AWD cuts in momentarily but no AWD light seen on the dash. I'll probably have to find a muddy field to play in to see if the AWD engages automatically.

 

[Lou Marrello]

I'm pretty sure you're the first person we've heard here that has gone through so many of these. One isn't common. Two is rare. Three??? Perhaps it's just really rotten luck, but I really hate to buy into any 'bad luck' story without considering an underlying cause first.

First, can you tell us about the mode of failure of the first two, and the attendant symptoms?

Is there anything at all unique about your driving conditions? Do you drive often where the AWD would likely kick in?

Tell us about the history of your tires ... when swapped for new ones, and at what points in time, and with which tires. I'd be very interested to hear what's on the vehicle NOW.

Hi, I have a 2010 santafe as well. My first rear differential coupler replacement was June 2012, it was really jerking and grinding when backing up and turning the wheels at the same time. The second time was September 2014 same problem. Both time dry weather and dealer replaced under warranty.
Now it’s November 2019 and it’s starting to do it again, this time now dealer warranty, dealer quoted me $2705.88 tax included. Nice!
I’m trying to figure out a less expensive solution, the car is now nine years old with 90K. This has me thinking of the two alternators that got replaced under warranty the first two years and I’m now on my fourth battery.
I have liked my Santafe but I am really thinking hard about continuing with Hyundai!

 

[Leyburn]

Did the dealer tell you why the couplers failed in 2012 and 2014?