[RedFireBeemer]

Anyone know what the service interval is for the rear differential fluid?

[Tierfreund]

It´s a lifetime fillling acording to BMW.
Just as the gearbox.
Of course, many will tell you to change it anyway, but I won´t. Show me a worn rear differential from a BMW that´s less than 15 years old and try to convince me that it could have been prevented with an oil change...

[sblument]

Just finished analyzing Mike Miller's enhanced BMW mx schedule. It doesn't specifically discuss the E90--it only implies that some of these extra items are applicable to the car. This topic has been discussed in a few other places on this board, but I wanted to hear back again from people on this topic.

Questions:

1. Has anyone asked a shop or the BMW dealer to replace the differential oil on the E90? If so what did they charge? I don't have the skills/tools/space to do it myself. I am not entirely convinced that it is necessary, esp. for $500 like someone posted it cost them on this board.

2. Mike's schedule calls for valve adjustments between 15-30k miles. Anyone know if this is applicable to the E90?

3. Timing belt/tensioner pulley/front cam seal: 5 years or 50k miles. Applicable?

4. Water pump: 4 years or 40k miles. Applicable?

5. Engine drive belts: 60k or 30k depending on type. Applicable?

[Hsv-Dan]

Originally Posted by sblument

Questions:

1. Has anyone asked a shop or the BMW dealer to replace the differential oil on the E90? If so what did they charge? I don't have the skills/tools/space to do it myself. I am not entirely convinced that it is necessary, esp. for $500 like someone posted it cost them on this board.?

Don't know about the cost, but for street use, easily go 100K miles, 50K with some track use. Certainly nothing to worry about. As said above, the BMW diffs are not prone to wear or failure.

Originally Posted by sblument

2. Mike's schedule calls for valve adjustments between 15-30k miles. Anyone know if this is applicable to the E90??

N/A

Originally Posted by sblument

3. Timing belt/tensioner pulley/front cam seal: 5 years or 50k miles. Applicable??

N/A

Originally Posted by sblument

4. Water pump: 4 years or 40k miles. Applicable??

This is an unknown with the new electric water pump used on these models. Watch the boards as your car ages to see how they behave.

Originally Posted by sblument

5. Engine drive belts: 60k or 30k depending on type. Applicable?

Similar to later models, I'd guess closer to 60k than 30.

[sblument]

Hsv-Dan,

Thanks for your responses.

[basti313]

Anyone know what the service interval is for the rear differential fluid?

It is a "lifetime" filling. But without changing it the "lifetime" is rather short I think.
You can use Castrol SAF-XJ. This oil is specially for BMW diffs.

I changed the oil in my E46 at 140k km. It was quite white, so there was a lot of water in the oil.

1. Has anyone asked a shop or the BMW dealer to replace the differential oil on the E90? If so what did they charge? I don't have the skills/tools/space to do it myself. I am not entirely convinced that it is necessary, esp. for $500 like someone posted it cost them on this board.

I would buy the oil and the two screws and go to a small garage. They do it for 20$...

2. Mike's schedule calls for valve adjustments between 15-30k miles. Anyone know if this is applicable to the E90?

The last BMW with adjustable valves was the E36 Euro M3.

3. Timing belt/tensioner pulley/front cam seal: 5 years or 50k miles. Applicable?

The E90s have no timing belt.

4. Water pump: 4 years or 40k miles. Applicable?

5. Engine drive belts: 60k or 30k depending on type. Applicable?

This is too early. The old water pumps were a risk but I haven't heard of a defekt water pump on a E90.
The newer drive belts are also very stable. No need to change them.

[Alan(iX)]

Originally Posted by RedFireBeemer

Anyone know what the service interval is for the rear differential fluid?

BMW Transmissions and rear differentials have "lifetime" oil.
Prior to free BMW maintenance, they use to suggest changing transmission and rear diff oils every 30k miles.
I had the auto trans and rear diff oil changed in my wife's E60 530 at 25k miles for ~$300.

Bavarian Autosport had an article on this subject in their Spring 2006 newsletter:

DIY BMW preventative maintenance:
- BMW lifetime fluid
- BMW ignition system
- BMW air filters & fuel filters
- BMW manual transmission fluid
- BMW belts and hoses
- BMW automatic transmission fluid

A few snips from newsletter:

Engine Oil:
When synthetic oil is used in an engine that is in good shape to begin with (i.e. does not significantly burn oil), we recommend a change interval of 5,000 to 7,000 miles.

A petroleum based oil should be changed every 3,000 miles or so.

Automatic Tranmissions:
At a minimum, we recommend changing automatic transmission fluid and filters semiannually (every other year) or at 50,000 miles. (An annual fluid change would certainly do no harm.) This is the best and most cost-effective way to assure a long, trouble-free life for your BMW’s automatic transmission.

Manual Transmission:
For all BMW manual transmission applications, we highly recommend fluid changes annually or every 24,000 miles.
For the early BMW applications, we use and recommend Redline MTL.
For later model BMWs that use the “lifetime” synthetic fluid, we offer this BMW replacement fluid.

Differential Fluid:
We recommend an interval of semiannual (every other year) or 40,000 to 50,000 miles as the maximum. (You certainly would not be doing a disservice to change the fluid annually or after 25,000 miles.)

complete article:
http://www.bavauto.com/newsletter/20...ter.pdf#page=4

[therealm3]

I am not a fan of "Lifetime" fluids and will eventually be changing my diff and tranny fluid. The problem I see for the E90/92 will be getting the fluid out of the diff. Far as I can tell there is no drain plug. Only a fill plug. I will rig up some sort of pump system when the time comes to get around this, but it’s very frustrating that BMW designed the diff cover this way.

[F32Fleet]

No drain plug on rear diff, so u have to suck it out which means you won't get all of the metal shavings.

There's no drain plug on the transmission either, and I have no idea where the fill plug is.

[rkg]

not true on drain/fill plug on the tranny. There is a both and have changed mine at the 1200 mile fluid change period as the M's. Diff needs to be pumped out ... german engineering is really starting to worry me since they are letting the accountants make decisions.

[therealm3]

Originally Posted by rkg

german engineering is really starting to worry me since they are letting the accountants make decisions.

yes, its a sad day when corners are cut in the name of a few more $ in profit or to save liability.

[F32Fleet]

Originally Posted by rkg

not true on drain/fill plug on the tranny. There is a both and have changed mine at the 1200 mile fluid change period as the M's. Diff needs to be pumped out ... german engineering is really starting to worry me since they are letting the accountants make decisions.

Where's the fill tube? It's not in the engine bay.

[sblument]

the fill tube is at the top of the differential

[rkg]

Sorry, I was referring to a manual trans for the drain/fill plug. I have no idea about slush box.

[sblument]

Today I had lunch with a colleague of mine who used to be a mechanic. He said that he thinks manufacturers such as BMW have gone with lifetime fluids in the diff and similar components due to the following reason: when the fluids were changed in the older diffs with drain plugs and no lifetime fluid, enough of the mechanics would mess up the procedure (no idea how) and the diff would have to be replaced at the manufacturers expense. They decided it would be cheaper to design them with lifetime fill fluids, and prevent this from occurring. He said the diffs will go 200k+ miles, etc.

I'm just relaying what I heard, not saying its gospel.

[F32Fleet]

Originally Posted by sblument

Today I had lunch with a colleague of mine who used to be a mechanic. He said that he thinks manufacturers such as BMW have gone with lifetime fluids in the diff and similar components due to the following reason: when the fluids were changed in the older diffs with drain plugs and no lifetime fluid, enough of the mechanics would mess up the procedure (no idea how) and the diff would have to be replaced at the manufacturers expense. They decided it would be cheaper to design them with lifetime fill fluids, and prevent this from occurring. He said the diffs will go 200k+ miles, etc.

I'm just relaying what I heard, not saying its gospel.

I've also heard that BMW didn't go to "lifetime" (ie, 100k miles) and 15k mile oil change intervals until they began to offer free scheduled maintenance on their cars. Was it a coincidence of new fluid technology or marketing?
From what I've read in Roundel, BMW's A/T's have a poor history long term (75-100k miles), so for those who have experience with them are even less enthusastic about lifetime fills.

Now I've asked BMWNA where the fill plug is on the A/T and they only tell me it's a sealed unit w/no fluid changes.


In reality, most people, regardless of intent, will not keep their cars past 100k miles where the benefit of more frequent fuilds changes would become apparent. My $.02