DIY: manual transmission and diff fluid change

[Dackelone]

Originally Posted by Ashock

Is it too soon to change out the transmission fluid again? Or should I do it since it seems the fluid has degraded.

Never too soon to change your fluids(oils). What could it hurt? Its cheaper than a new trans. Change it and report back. Maybe try Redline's MTL that everyone is raving about.

[Iron Man]

Originally Posted by Ashock

So I've run D4-ATF in my 6MT 128i for about two years now. I think I've put about 20K KM's so far with the D4. I loved the feel of the D4 after initial change and it's been giving me consistently smooth shifts. I used to have a problem getting into first gear with the original fluid that BMW put in the car. Ever since moving to the D4-ATF, I never had that problem come back.

Now, after a couple years of running this fluid, it seems my 1st to 2nd shifts are getting tougher and requires a bit of strength to go into gear. I'm feeling slight degradation in shift quality between 2nd and 3rd as well.

Is it too soon to change out the transmission fluid again? Or should I do it since it seems the fluid has degraded.

Can you just sample it, without draining the whole thing, then refill what you sample out? If so, you could send a sample to Blackstone to see if it has sheared too much already.

[wolfe]

You probably could, but I believe it's best to take a sample from the middle of the drain as it'll give you a more accurate picture of what's going on.

[Iron Man]

Originally Posted by wolfe

You probably could, but I believe it's best to take a sample from the middle of the drain as it'll give you a more accurate picture of what's going on.

That has more to do with engine oil, since your dealing with fuel contamination, not with tranny fluid.

[Ashock]

So I swapped out the transmission fluid last weekend and replaced it again with Redline D4 ATF because I had extra lying around from last time.

The world seems right again. Shifts are smooth and effortless. I used to have a weird situation where engaging the clutch in first gear was rough and it felt like the clutch wasn't smooth or something. The car would sometimes stutter when I let out the clutch. After changing my oil, transmission, and diff fluid all at the same time last weekend, that jerkiness/clutch uneven sensation has gone away too.

[Ginger_Extract]

Just did this. This how to was handy, but I had the same thought as a few others, having changed the MTF on other vehicles, why not let gravity work for you. So I ran 3/8" tubing (thanks Joe O. for the size) from the engine bay downwards. Only snag, was when the tubing literally snagged against the chassis at some point and began dribbling out fluid as I was pouring it. Oh well.
Swapped in Redline MTL, having used their products with success in the past. Verdict is out on the difference in feel, maybe a bit more direct, but that's about it. Old fluid had 30k miles on it, was brown in color, still smelled like MTF, which is to say, nasty.

[mmmusty]

Hi guys,

ive been thinking about replacing my diff and transmission fluids, but not sure at the end of the day which fluids to get for each. any of you guys that have done this and can guide me to which to get?

thank you!

[fe1rx]

Originally Posted by mmmusty

Hi guys,

ive been thinking about replacing my diff and transmission fluids, but not sure at the end of the day which fluids to get for each. any of you guys that have done this and can guide me to which to get?

thank you!

Go here and plug in your model details:

http://www.redlineoil.com/application.aspx

[lakefront]

Just did this recently and the DIY came in very handy, especially for torque settings and such. Went with Redline MTF and there is a noticeable difference in shifting smoothness. Really nice. Used the "tubing method" to fill from above, just under 2 quarts to fill. Used 1/2 inch tubing, was a perfect fit in the fill hole on the trans and the 2 quarts went in amazingly quick.

[l2iceman]

Hey everyone, my rear diff seal or axle seal is leaking, so I'llbe bringing it in to my mechanic for a gasker/seal replacement. Since this involves draining the diff fluid, what weight oil is recommended for it? It's a 2011 135i dct. My mechanic loves to a royal Purple, but has various weights, so not sure which is good for this car.

[Dackelone]

Originally Posted by l2iceman

Hey everyone, my rear diff seal or axle seal is leaking, so I'llbe bringing it in to my mechanic for a gasket/seal replacement. Since this involves draining the diff fluid, what weight oil is recommended for it? It's a 2011 135i dct. My mechanic loves to a royal Purple, but has various weights, so not sure which is good for this car.

BMW uses Castrol SAF-XJ or SAF-OX 75w140 GL5 gear oil. Lots of guys have been using Redline 75w90 GL5 gear oil - with no problems.

See what your mechanic recommends. ?


Dackel

[l2iceman]

Thanks Dackel. I dropped the car off. My mechanic suggestsed the 140weight as it'll provide more protection for me since I will be tracking the car 4-5 times per season.

[Suprgnat]

My transmission fluid at 17,450 miles next to fresh MTL. Meant to do it much earlier... Oh, and added a Dimple plug though swishing through the old fluid with a magnet yielded no particles.

[Iron Man]

Originally Posted by Suprgnat

My transmission fluid at 17,450 miles next to fresh MTL. Meant to do it much earlier... Oh, and added a Dimple plug though swishing through the old fluid with a magnet yielded no particles.

Have you thought about sending a sample for testing? Color doesn't necessarily indicate oil life, unless it has a burnt smell to it.

[Suprgnat]

Originally Posted by Iron Man

Have you thought about sending a sample for testing? Color doesn't necessarily indicate oil life, unless it has a burnt smell to it.

I might. I wasn't having any issues; I had really meant to do this as a break-in change at 1200-2000 miles and kept saying "tomorrow, tomorrow."

[Iron Man]

Originally Posted by Suprgnat

I might. I wasn't having any issues; I had really meant to do this as a break-in change at 1200-2000 miles and kept saying "tomorrow, tomorrow."

Gotcha. I believe I have read some research though that on transmissions, most metal wear occurs in the first 5-15,000 miles, so you're probably still good with regard to break-in.

[mechavore884]

Originally Posted by Dackelone

BMW uses Castrol SAF-XJ or SAF-OX 75w140 GL5 gear oil. Lots of guys have been using Redline 75w90 GL5 gear oil - with no problems.

See what your mechanic recommends. ?


Dackel

LOL brohesive you just answered my question subconsciously hahaha

[1mang]

Does anyone know what the size of the gaskets for the manual transmission plugs and differential plugs are? Also, does material matter? Aluminum, copper, etc?

[1mang]

After further research, its recommended that the entire plug (including o-ring) needs to be replaced after each service? Seems overkill...what do you guys think?

https://www.fcpeuro.com/products/bmw...ug-23117531356

[DaanBMW]

done it twice, re-used the plug each time.

[Dackelone]

Originally Posted by 1mang

After further research, its recommended that the entire plug (including o-ring) needs to be replaced after each service? Seems overkill...what do you guys think?

https://www.fcpeuro.com/products/bmw...ug-23117531356

I've change my manual trans(& diff) fluids three times - and reused the plugs. But yes, the crush washer is built into the screw plug. Luckily the plugs aren't that expensive.

Screw Plug With Gasket Ring M18X1,5 bmw p/n 23117531356

[JHZR2]

Originally Posted by 1mang

Does anyone know what the size of the gaskets for the manual transmission plugs and differential plugs are? Also, does material matter? Aluminum, copper, etc?

My diff plug has a green elastomer gasket. Since there's no drain plug, I'm not terribly concerned about excessive loss out a fill plug...

But I was surprised that there was no gasket or metal washer around the fill or drain plugs on my mt.



I'm also really surprised at how clean both the diff and MT fluids were after nearly six years (but only 15k miles).

I used Fuchs Sintopoid 75w-90 in the diff and Pentosin FFL-3 which crosses per ZF to the right MTF for my gearbox. It's mainly a Porsche DCT fluid, but is an MTF per ZF. Shifts great.

Despite the cleanliness of the fluids, I wouldn't mind getting a magnetic drain plug for the MT. Anyone know the plug spec??