DIY: Differential Fluid Change

signes wrote

I ordered a stubby 7mm hex from them for brake changes and it makes life a lot easier. Pricing is a ripoff but couldn't find it elsewhere.

Thanks to the OP for posting this, going to do next weekend.

Yeah, I also picked up one of those while I was on there. I agree....the pricing isn't the greatest, but they do have some hard to find items that'll save the BMW DIY'er a lot of frustration.

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Just as a follow up I have been running the Mobil 1 75w-140 with the LS additive in it and have had no troubles or chattering or grinding out of the diff. Cost 40 bucks for two containers.
**Follow up, after 500 miles the diff started to chatter bad on right hand turns so I went back to the FM boosted bmw fluid and within 20 miles the noise was gone. I know other guys running alternate fluids without issues but it dod not work out for me**

kawasaki00 wrote

Just as a follow up I have been running the Mobil 1 75w-140 with the LS additive in it and have had no troubles or chattering or grinding out of the diff. Cost 40 bucks for two containers.

Where did you buy this? Did you replace the plugs as well with new ones? I just changed my oil and found out the dealer stripped the drain plugs and luckily I bought new ones to replace.

happos2 wrote

Where did you buy this? Did you replace the plugs as well with new ones? I just changed my oil and found out the dealer stripped the drain plugs and luckily I bought new ones to replace.

Advance and auto zone carries it. Plugs have orings so no need to replace anything. Just a FYI after 500 miles my diff started to make noise, I ended up having to change over to the bmw with fm booster. I guess I need to update the original post

kawasaki00 wrote

Advance and auto zone carries it. Plugs have orings so no need to replace anything. Just a FYI after 500 miles my diff started to make noise, I ended up having to change over to the bmw with fm booster. I guess I need to update the original post

So the added LS additive the Mobil didn't do the trick? I think I might go with Redline as a lot of people have liked that. I also believe they make an additive you can put in after the fact.

Thanks for the info.

happos2 wrote

So the added LS additive the Mobil didn't do the trick? I think I might go with Redline as a lot of people have liked that. I also believe they make an additive you can put in after the fact.

Thanks for the info.

Correct, the Mobil with LS additive was still not enough. If you want to try something else I would go with the Royal Purple. Realistically I would say all the big ones, valvoline, mobil royal and redline are all going to be the same. If one works they will all work, if one doesnt work then the only option is going back to the FM bmw stuff. I am not a fan of adding booster on top of the original oil unless it is made by the same manufacturer. Most additives will never mix with the original fluid and will just sling around inside the diff as 2 different fluids.

Anyone tried Red Line 75W140 gear oil in their diff?

RBB wrote

Yeah, I also picked up one of those while I was on there. I agree....the pricing isn't the greatest, but they do have some hard to find items that'll save the BMW DIY'er a lot of frustration.

I had similar clearance issues with the e36 M3 Diff plugs. I got a 14mm hex wrench from sears and used a grinder to make it a stubby one. worked perfectly.

Sean05 wrote

6. THEN YOU HAVE TO SQUEEZE THE BOTTLE CAUSE ITS PRETTY THICK..(DO THIS YOU WILL ONLY NEED 2 1/2 BOTTLES. I HAD 1/2 OF 500ml LEFT...

So about 1,250 mL? Does anyone know the capacity specified by BMW for a service fill? I'm trying a different brand of fluid, need to add 10% LSD additive and would like to calculate how much LSD additive I need to put in beforehand.

Thanks

Here you go guys, Screenshots of my old TIS copy. OP feel free to add these to your initial post

Is there an issue going back to regular/ non-FM fluid? At 1200 mile service, dealer put in the regular/ non-FM fluid. At 30k mile service, the same dealer put in the fm fluid, but I never had an issue with noise. I did not know they put the fm fluid until the work was done and I saw the work invoice. I told them about it after but it was too late. They said it is the only fluid they carried/ dealer excuse. I will be doing my 60k mile service soon. Thanks in advance for the response.

subbed

How much does the FM modifier reduce the effectiveness of the LSD? This was answered before in another thread but wanted to get it in this DIY thread.

http://www.m3post.com/forums/showthread.php?t=980828&highlight=diff+fluid+change+%24468%3F


T

Considering swapping out my diff fluid. Can I re-use the factory drain and fill plugs, or do I need to order new ones? Do they use crush washers like the oil plugs?

No. The plugs have o-rings on them. If only they sold just the o-ring so we wouldn't have to buy a new plug each oil change. The plugs are around $7 each, so they're not that much.

marksae wrote

No. The plugs have o-rings on them. If only they sold just the o-ring so we wouldn't have to buy a new plug each oil change. The plugs are around $7 each, so they're not that much.

Thanks. So it's recommended to replace both plugs? Do you have part numbers by chance?

I replaced both the drain and the fill plug. P/N's are listed in link below. IIRC, the drain and fill plugs are the same. The link below states the same thing.

http://www.ecstuning.com/BMW-E90-M3-S65_4.0L/Drivetrain/Differential/ES205597/

marksae wrote

I replaced both the drain and the fill plug. P/N's are listed in link below. IIRC, the drain and fill plugs are the same. The link below states the same thing.

http://www.ecstuning.com/BMW-E90-M3-S65_4.0L/Drivetrain/Differential/ES205597/

Much appreciated. The local dealer near my work has several on hand, so I'm going to grab a couple.

Does you happen to know what the exact amount of fluid is? I'm seeing conflicting info in this thread.

I think it's 1.2 qts.

EarthboundMisfit wrote

Anyone tried Red Line 75W140 gear oil in their diff?

Yes, have about 15,000 miles on mine now. No problems and no noises at all. I previously had diff noise, they (dealer changed) and added modifier and it helped but still has occasional noise on tight corners. That's gone now with the Redline (make sure you get the limited slip version as there are two kinds).

I've been using the Redline mentioned above for the last 45,000 miles with no noise or problems - easiest DIY ever. I replaced the drain plugs - don't forget they have metal washers as well.