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Discussion Starter #1
Finished working on TAs (https://www.m5board.com/threads/2008-m5-135k-bank2-throttle-actuator.606764/) and got the car running smooth, and next morning, i see heavy vibrations , and a distinct clunking sound only while accelerating. Car runs smooth while going down hill, no sound. Car revs super smooth in Neutral.
I had taken the car out for a spin previous night, and was ripping it on the highway to make sure the TAs were clean.
Clutch and flywheel were installed in the car few months back that required removal of drive shaft and exhaust pipes. Car was never driven hard since then due to failed TAs.
There are no errors stored in any of the modules.
Just wondering if i should take it back to mechanic,or DIY on the drive shaft.
There is an oil leak from the end of the drive shaft going into the rear differential. If the car is on an incline, oil can be seen
dripping out.
 

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Finished working on TAs (https://www.m5board.com/threads/2008-m5-135k-bank2-throttle-actuator.606764/) and got the car running smooth, and next morning, i see heavy vibrations , and a distinct clunking sound only while accelerating. Car runs smooth while going down hill, no sound. Car revs super smooth in Neutral.
I had taken the car out for a spin previous night, and was ripping it on the highway to make sure the TAs were clean.
Clutch and flywheel were installed in the car few months back that required removal of drive shaft and exhaust pipes. Car was never driven hard since then due to failed TAs.
There are no errors stored in any of the modules.
Just wondering if i should take it back to mechanic,or DIY on the drive shaft.
There is an oil leak from the end of the drive shaft going into the rear differential. If the car is on an incline, oil can be seen
dripping out.
If no errors, and you started to drive harder then it sounds like its possibly some part of the exhaust/headers or rubber hangers under load causes this vibration...TA's wouldnt cause this, doubt leaks in Drivshaft area would cause this (btw how does the rubber flex disc look like? I would check that next)

Sent from my SM-N950U1 using Tapatalk
 

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Getting the exhaust down and all of the heat shields off is a real pain. Once that is done the driveshaft is not that bad as long as you have four hands. Then you can check the Gibo, carrier bearing and CV joint. The seal for the rear diff is really easy to change. With the rear diff leaking you have to do the rest anyway to get to the seal.
 

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Discussion Starter #4
I just didn't have the time to take this all down. I took it back to Mieneke, where a good experienced lead mechanic had worked on replacing the clutch. The driveshaft bolt had come loose, causing the clunking sound and vibrations. He tightened it and had checked everything else. Car is good to get back on road !

Next project: PCV replacement lol. Any clues how to get to the two in the back near the firewall.
 

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Discussion Starter #5
Getting the exhaust down and all of the heat shields off is a real pain. Once that is done the driveshaft is not that bad as long as you have four hands. Then you can check the Gibo, carrier bearing and CV joint. The seal for the rear diff is really easy to change. With the rear diff leaking you have to do the rest anyway to get to the seal.
Car is back on road, however, its rear differential is leaking oil now.
I took the exhaust down, the drive shaft down and have taken off the seal. This was painful, and I spent, slowly but surely, about 6 hours today.
I have ordered the seal. what is a "Gibo" ? should i replace anything else while the whole thing is down ? I don't mind spending another 6 hours just to change the shaft bearing, but don't want to touch it if there is no issue with it.
 

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The Gibo is the big rubber coupling that joins the driveshaft and transmission, just do a visual for checking and cracks. The carrier bearing can be hand checked for smoothness and looseness. The CV joint that bolts to the rear diff can be hand checked as well and you can tap the cover back and visually look at the grease for metal. Keep in mind that the transmission is fixed and the rear diff is fixed and all of the joints are really unnecessary.

Not sure if you are there yet but I hope you marked the yoke and rear diff. When you tighten the nut you don't want it to over travel. There is a crush washer on the inside if the diff that sets the backlash for the gears.
 

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If you don't want to wait a week for the $40 seal you can get one from a local seal/bearing supplier for a few bucks. It will be 8 or 9mm thick instead of 10mm but that wont matter. It will most likely be nitril instead of EPDM but that is an upgrade for oil service.
 

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Discussion Starter #8
The Gibo is the big rubber coupling that joins the driveshaft and transmission, just do a visual for checking and cracks. The carrier bearing can be hand checked for smoothness and looseness. The CV joint that bolts to the rear diff can be hand checked as well and you can tap the cover back and visually look at the grease for metal. Keep in mind that the transmission is fixed and the rear diff is fixed and all of the joints are really unnecessary.

Not sure if you are there yet but I hope you marked the yoke and rear diff. When you tighten the nut you don't want it to over travel. There is a crush washer on the inside if the diff that sets the backlash for the gears.
This is good for my review!!

Right now, the goal is to replace the seal, i have ordered genuine from ECS Tuning.

The flange and the nut had a mark already for alignment when i opened it.
 

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I struggled getting the CV out of the yoke. Make sure the car is in neutral and the hand brake is off so you can rotate the drive shaft and get to both notches of the CV joint to pry it out. And don't think that you will get it without dropping the whole driveshaft. Ask me how I know?
 

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Discussion Starter #10
The inside of the flange is filled up with some yellow greasy stuff, what is it and where do i get it so i can put it back while sealing it all up.
 

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If I had to guess it would be an EP-2 grease for the splines. I wouldn't worry about it too much but if you want to add some grease you could use almost anything. I'm sure BMW has something recommended and really expensive.
 

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Discussion Starter #12
A bit of history on this thread lol.

Car was amazing, till the idle valve actuators started acting up. They finally decided to always come up in limp mode and I couldn't drive the car anymore. The car's clutch also started acting up. The oil consumption was also going up crazy, from about 1500 miles per Quart to 650 miles.

In the last 6+ months, i haven't driven the car much.
I got the clutch replaced and flywheel replaced. (Driveshaft wasn't done correctly).

I fixed the actuators, and managed to have 2 good working pieces from bunch of old used ebay items, and new plastic gears. I also fixed the PCV valve.

After fixing the actuators, took the car out for a spin, and was ripping it one night and came back home. Next morning, whole car was shaking during a silly slow drive and the drive shaft was loose. Got it fixed again.

I think the loose drive shaft stressed out the differential seal and it has started leaking oil when car goes on a slope downhill. Otherwise, it holds oil .

The engine oil consumption has been fixed also with the replaced PCV valves. Car runs like a dream now, and I have observed about 300 miles for 0.1 Quart.

I just wanna get this back on road lol, and waiting for the differential seal.

Thanks for all the help folks !! Without your help, and some youTube, this would have been tougher.
 

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Discussion Starter #13
Ok, update: put everything back and oil doesn't leak anymore.
Now, surprise!! I saw my cats were removed lol, no wonder i have high emissions all the time, for 3 years now.
Cats were probably removed by previous owner.
934545
 

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Washington state no longer does emissions tests. In my county they never did. For older cars you just had to spend X$ based on age to repair and you would get a pass. You can sell your decat headers and recover some money.
 

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Discussion Starter #17
Well, the check engine light is ON due to high emissions. So our inspection will fail here in NJ.

Sometimes, the catalyst efficiency test passes and the light goes off, and this is how i passed emissions 2 years back.

I want to keep the car in original condition, and will have the cats installed.
Is this a good DIY project? repair Pal shows about 10 hours of labor.
 
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