DIY: manual transmission and diff fluid change

[TheSt|G]

Originally Posted by dcaron9999

I asked two mechanics if they could do this for me, and they refused claiming the cover could crack since it is cast iron...

Yeah, I'm adding it to my new fined cover/heatsink, which is aluminum.

[Dackelone]

Originally Posted by TheSt|G

Yeah, I'm adding it to my new fined cover/heatsink, which is aluminum.

Do you have a picture of said alu diff cover?

[TheSt|G]

Originally Posted by Dackelone

Do you have a picture of said alu diff cover?

Sure!

Next mod when I get some free time, along with the little item behind it. I don't like doing things more than once, so I tend to do it all the way the first time.

[Iron Man]

Originally Posted by TheSt|G

Sure!

Next mod when I get some free time, along with the little item behind it. I don't like doing things more than once, so I tend to do it all the way the first time.

Where did you get you get the diff cover and how much was it? If you don't mind me asking. Looks nice.

[TheSt|G]

Originally Posted by Iron Man

Where did you get you get the diff cover and how much was it? If you don't mind me asking. Looks nice.

Quaife sells them, but no one in the US stocks them from what I saw. So I ended up ordering it from Birds UK and having it shipped over here. Given the shrinking pumpkin size, any heat sink we can get is a big help for diff heat capacity management.

[spacemonkey1112]

Just read through this beautiful thread and I feel like an idiot for waiting so long to Change my diff and trans oil on my 06 325i (just broke 106k) im kind of disgusted how dirty it gets from pictures other forum members posted at 26,000km. Thanks for providing this!

[wolfe]

Well, it looks like Imageshack decided to remove several of the photos. I've re-uploaded them to imgur so hopefully that should fill in the gaps.

[Dackelone]

Originally Posted by wolfe

Well, it looks like Imageshack decided to remove several of the photos. I've re-uploaded them to imgur so hopefully that should fill in the gaps.

The BEST thing to do is upload your photos directly to 1Addicts. Just click on advance mode and use the paper clip icon to upload directly to our site. ~400mb files are the best size/file.

Dack

[wolfe]

huh.. good to know, thanks Dack. I'll try and move them over when I get some time.

[dcaron9999]

I thought I would post this relevant summary info from the Redline site with references to Mike Miller recommendations:

"Manual transmissions open up a whole load of topics, but the feedback is overwhelming that our fluids help improve performance and cold operation due to stable viscosity, balanced friction (so that syncros can slow down enough to match up), and more-than-sufficient antiwear additives.


Many who pull the transmission pan on their BMW automatics find this sludge and get satisfaction out of swapping the Longlife fluid for the correct Red Line product.

While respected BMW tech expert Mike Miller (and Bavarian, as well) confidently recommends MTL for every BMW manual gearbox without complaints, Red Line follows a baseline closer to the factory recommendations. The early gearboxes (through 1983) take our MTL, a 70W80 GL-4 fluid.

From 1986 to 1992, it is a bit trickier in that there are three different transmissions identified by a label on the passenger side of the bell housing. That with a green label and a 17mm hex drain plug uses MT-90, a red label and 17mm plug uses D4 ATF, and that with no label and a 15mm drain plug uses MTL.

From 1993 on, we recommend D4 ATF (yes, ATF in a manual transmission). The only late-model exception is the 2006 Xi trans, which takes D6 ATF.

Whew, that's a lot to remember. For the most part, these transmissions take less than 2 quarts. The typical exceptions are the 8-series cars before 2000 (just under 2.5 quarts) and the M5's 7-speed (from 2005), which requires just less than three quarts"

[dcaron9999]

I like the D4-ATF so far in my 6-speed manual 2011 135i. Helps with smoother shifting while driving on the street, and at the track. The only problem I have is its longevity. When abused at the track on a weekly basis, after 2 months, shifting becomes notchy again, leading to missed shifts.

Ive changed twice in the last 4 months, and changing it again today before hitting a renowned high speed track LCMT (Le Circuit Mont Tremblant).

The transmission is also noisier with the D4-ATF.

[TheRuss]

I've not long started running the MTL and the transmission feels smoother as a result. No louder either, plus it has the proper lubrication etc for a manual box.

[dcaron9999]

Originally Posted by TheRuss

I've not long started running the MTL and the transmission feels smoother as a result. No louder either, plus it has the proper lubrication etc for a manual box.

What did you run prior to this? How does it compare to that fluid? Do you track your car?

[TheRuss]

Prior to this I ran a Pentosin manual Trans fluid. It felt a little better than the old BMW stuff, but not much. The Redline gives a distinctly nicer shift.

As for tracking my car, no, I don't.

[DSSG]

I believe you did this at 1,200 miles? Changing the oil was a waste of resources. For example, the differential fill is nearly good forever which was implied by no drain plug. You mentioned the oil looked dirty, but this was due to an additive added to help with the break in of the gears.

I don't know what the BMW service interval is for the transmission, but I figure a reasonable number might be 50K miles. In fact, that number Redline tossed out to me regarding their own products. I'm assuming that BMW thinks their transmission deserve lubricants as good as Redline's?

There seems to implied in these threads that BMW is a party to some conspiracy to extend service intervals to reduce their costs for their maintenance programs. Nothing could be further from the truth.

Lubricant technology has progressed along with other automotive advances to provide longer service intervals. Motor oil doesn't need to be changed at 3,000 miles. You might notice that the BMW crankcase capacity is 7 qts, and that along with synthetic oils have made possible at least 10K mile intervals for engine oil.

Another example is some Mazda's have a 4.5 qt capacity with an interval of 7.5K miles.

[TheRuss]

I'd disagree. From used oil analysis it has been shown that the N54 dirties the engine oil much quicker than the 20k interval. (Mainly from fuel dilution.) I'd definitely not wish to leave my engine oil that long.

As for Trans fluid, regardless of standard intervals a fresh fluid is always better than a dirty one. It's up to the individual to weigh up a cost vs benefit basis on how often they want to change it. It's impossible to know if it's worth it, but I feel better with fresh fluids in my car.

Same goes for the engine oil. The car may not break down if I leave it to 20k intervals, but there would likely be more wear.

[Dackelone]

I stand by my... "the BEST oil is FRESH OIL!!!"


You today I ran into a guy who was trying to tell me he NEVER changes his oil... because... it is a sealed system and can not get dirty. I pity his engine's bearings.

[pj.rodriguez]

Originally Posted by Dackelone

I stand by my... "the BEST oil is FRESH OIL!!!"


You today I ran into a guy who was trying to tell me he NEVER changes his oil... because... it is a sealed system and can not get dirty. I pity his engine's bearings.

That's BS. I would have laughed and walked away.

[TheRuss]

You should've educated him. Please tell me he drives a diesel - that'd be even funnier!

Poor engine.

[Dackelone]

Originally Posted by TheRuss

You should've educated him. Please tell me he drives a diesel - that'd be even funnier!

Poor engine.

I tried!! But you know some people are beyond help. He is a computer geek and even had a Harley... he doesn't change his engine oil(s)... he only tops them up. I told him he is NUTS! Ohh well. More than pitying his engine I pity the person who buys one of his machines! Heck I treat my lawn mower with more love(OCI) than he does his rides.

Dackel

[TheRuss]

Yeah, that sucks. It's a bit like people that ride the clutch at traffic lights to hold themself still, instead of just using the handbrake. I always hope I never buy a used car from somebody who does stupid stuff like that!

I guess he wouldn't listen to the argument of fuel dilution, wear metals, moisture and combustion blow-by that all get in the oil then?

[Iron Man]

Originally Posted by TheRuss

I'd disagree. From used oil analysis it has been shown that the N54 dirties the engine oil much quicker than the 20k interval. (Mainly from fuel dilution.) I'd definitely not wish to leave my engine oil that long.

As for Trans fluid, regardless of standard intervals a fresh fluid is always better than a dirty one. It's up to the individual to weigh up a cost vs benefit basis on how often they want to change it. It's impossible to know if it's worth it, but I feel better with fresh fluids in my car.

Same goes for the engine oil. The car may not break down if I leave it to 20k intervals, but there would likely be more wear.

I agree. People fail to realize that during initial break-in period on your engine/trans/diff, metal levels are much higher than normal. I think it is definitely good to flush them out.

Really, people need to base their OCI based on how they drive and a UOA. From what I've seen, the N54/N55 breaks down oil relatively quickly, so an OCI of 5-6,000 miles would be my recommendation. If you drive nothing but highway miles, I could see going longer like 7,500 miles or so.