Drive Shaft Spline Prevention Questions ?

Rockit · #1 02-18-2015, 04:36 PM

I've been doing a lot of gathering info on why the drive shaft splines break from other posters. It seems a seal goes bad and road grime then rusts the splines until they break? Is that true?

Can anyone tell me, if there are 1 or 2 drive shafts that can break from the transfer case?

As preventive actions some guys have been replacing the seals and greasing the splines. Anyone know what the part number is on the seals?

"Q" do you think you can insert a picture and circle the failing shaft or shafts with the seal number and the correct BMW fluid to use in the transfer case. We should make this a sticky and service the axels every 15k miles.

On my 6 cylinder motorcycle with a drive shaft you have to use special molly grease when you change the tire and you have to lube the shaft splines or they rust and strip.......I wonder if you have to do the same here. This is the best grease I use on splines GD-525 Moly Grease Synthetic | Guard Dog Moly Lubricants

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Ricky Bobby · #2 02-18-2015, 04:53 PM

Apparently there is an AC drain which drips onto the exposed section of driveshaft and if not greased properly the splines can dry out and rust. I think some members have moved the drain over to prevent this, but honestly I haven't seen it becoming an issue on pre-facelifts until well over 100k miles.

David.X5 · #3 02-18-2015, 05:42 PM

Just did this. costly repair...

The transfer case has two driveshafts coming out of it - one to the front, one to the rear.

The rear is a flange with a rubber guibo. I don't recall hearing any problems with that except the rubber wearing out at high miles, and that is an easy repair.

The front has a female spline on the TC (front drive shaft has male spline). It is sealed from the TC fluid by something that looks like an engine freeze plug. The spline does not see TC fluid. There is a rubber boot on the end of the front drive shaft that should keep water/debris out of the spline. Keeping grease in there does seem like a good idea. Perhaps we all just need a new boot designed with a grease fitting on it...

The input and output shaft seals on the TC that keep the fluid in can also go bad and begin to ooze, but that is usually not catastrophic - you should notice the drips and have time to get them replaced.

Its painful just because BMW charges so much for the danged parts. The dealer wants something like $800 for the front drive shaft that does not have a universal joint or CV joint in it. This should cost much less than a front axle that has two CV joints (and can be bought from reliable sources for $300-$500). Likewise, BMW doesn't sell the output spline piece of the transfer case, but tells you a whole new transfer case is needed for $3000 or so. BTW, There are places to buy the output spline if you do need one.

Ricky Bobby · #4 09-08-2016, 10:58 AM

Bumping this thread as I think I should do some preventative action -

Does the front shaft drop down pretty straightforward, without removing other components? I was under the X two weeks ago doing the fuel filter and it looked pretty easily dropped - would like to clean/grease the splines with some good marine moly grease and be sure AC drain is not dripping on it, at 89k miles I am due to check it out and hopefully not have to worry about it for a long time.

RealOEM shows this diagram, I am debating getting a new front flex disc as well as the dust cover and ring (Parts #1, 7, and 8 - about $120 for all) when the driveshaft is dropped - if the spline is good, at least I will have a new disc - would the front guibo be easily replaced if the shaft is dropped?

I pm'ed axgordon as he recently posted that he has preventatively cleaned/greased the shaft and still going strong 200k miles later - and Joshdub I messaged you on E53 FB group I believe, as I think you did yours recently although you replaced it but you have over double my mileage.

David.X5 · #5 09-08-2016, 11:13 AM

You have to remove the guibo to drop the front driveshaft. If it's the stock version, nothing else has to come out. The aftermarket longer spline version makes it harder

Ricky Bobby · #6 09-08-2016, 11:59 AM

OK understood - so if I'm removing it I probably would want to replace it - thanks David!

Joshdub · #7 09-08-2016, 02:10 PM

Rockit,

Only the front driveshaft (Tcase to front diff) is the problem child. The splines that enter the Tcase wear/strip over time from rust or use. When it strips the male end of the driveshaft and the female input on the tcase become ruined. Dealers will only replace the tcase as a whole, but you can get a new female input for a couple hundred bucks and swap it in.

Yes replace the guibos and maybe the front diff seal while you're in there. I don't think you can replace the Tcase seal without taking apart the assembly.

RB,

Theoretically you are supposed to be able to remove the front driveshaft/guibo without removing everything else. After a couple minutes of wiggling I just went ahead and removed the whole tcase with the front DS still installed (made a nice handle). My problem was I couldn't get the DS to slide back enough into the tcase to get everything over the numb on part #4. Part #7 is a metal sleeve with a rubber "seal" integrated into it and loosely rests on driveshaft. It was also in the way when I was trying to slide the DS into the tcase. I think #7 was primarily the problem as it took up an inch or two of play.

My driveshaft was worn to the point where I was uncomfortable putting it back in as is. realistically it was probably fine for a while longer but I'd rather not have it strip on me while driving. My guibos were worn but not terribly so.

I think the main problem is the lack of length of the splines of the DS. Allegedly if you extend the front DS splines by half an inch you can still service it without removing the Tcase. That is what I would do for prevention. The engagement area on the stock splines is just laughably short.

Ricky Bobby · #8 09-08-2016, 02:37 PM

^Thanks Josh that is super helpful - I'm HOPING when I get around to this that mine still looks pretty decent since my miles are still low, but you're right, laughably short engagement of spline -

I pm'ed another member who dropped his twice to clean and regrease and still going over 210k miles strong - he sent me this Pelican Parts link as it explains the process decently well, I assume you followed this and removed the stiffening plate?

Weird that you couldn't drop it without dropping the whole Tcase -

BMW X5 Front Driveshaft and Flex-Disc Replacement (E53 2000 - 2006) | Pelican Parts DIY Maintenance Article

Joshdub · #9 09-08-2016, 02:41 PM

I did not follow the Pelican one (didn't know they had one), I followed the Bentley procedure. Looks like his #4 piece just popped off and mine didn't nor did I realize it could at the time so I didn't force it. That was probably my problem.

I did remove the stiffening plate as it made getting to the front guibo a pita.

srmmmm · #10 09-08-2016, 06:01 PM

My original front shaft was replaced at 136,000 miles. Replacement was well greased when it was installed into a used TC that had 76,000 miles on it (to reduce repair cost).

To date, I've got 173,000 miles on the driveshaft and 249,000 miles on the TC with no issues, so a good grease job is the definite preventative maintenance procedure. And was still willing to pack it up heavy, tow my 190HP lake toy, bring the CEO and her rear seat security team along for a 700 mile trip in 95 degree heat this past weekend!

2002 X5 3.0 309,000 miles
2014 428i 21,500 miles

2004 325i sold at 123,600 miles
2001 325i sold at 66,000 miles

1970 Firebird - Under restoration

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