[hdrewh]

On my '09 E90 328i, MT, 51k miles, I just replaced transmission fluid with Redline D4ATF. Shifting into all gears is slightly more "notchy" than before, 1-2 being the worst, 2-3 a little less so, etc. Not an improvement as I was expecting.

I only put about 50 miles on the car so far, do I need to just give it more time? Is this to be expected from the higher viscosity of the D4 compared to OEM or Redline's D6? Or could I have screwed something up, too much or too little fluid? I followed the DIY here, everything went fine, car was level.

Thanks for any input.

[bimmertt]

I noticed the same thing with the D4. Switched to D6 and it is a little better. Think I'll switch back to OEM next time I change it out.

[Atomicteal_M3]

Is there a DIY for this? I've been looking to do this.

[Wires]

Switch it back to OEM. I swapped Redline into my Acura's M6, and it was BRUTAL. Notchy, hard shifting and stiff. Swapped it back to OEM, and it when back to butter shifts. Some tranny's need the OEM additives to operate properly.

[litxus]

Switch back (to OEM fluid), as I would assume it doesn't cost all that much for manual transmission compared to auto. I had some redline in my E46 before and it felt like a downgrade, especially in cold mornings (about 30f degrees or lower). In winter my 2nd gear would barely go in, and then 3rd would be a struggle also. Now saying that, I think OEM is probably better for all types of conditions but other fluids might be better for others.

[ctuna]

D6 was better than OEM for me.

[Tom K.]

When Redline MTL was put in my E46 5 speed at about 70k miles, I noticed a marked improvement in very cold temps and generally smoother shifting overall.

Tom

[hdrewh]

Originally Posted by BLKLYZ

Is there a DIY for this? I've been looking to do this.

http://www.e90post.com/forums/showthread.php?t=80198

[chronologic]

Originally Posted by ctuna

D6 was better than OEM for me.

I second that.

[nydog]

I use MTL. Made the switch at about 45k miles, it feels great. Improvement over OEM.

[jeffro535]

I had the OEM fluid on 6MT for the 335 changed by the the dealer at 30k miles and the the trans showed an immediate improvement. So much for "lifetime fill". Also, I changed the fluid on the old E36 with Redline MTL and noticed a huge difference, but changed again to Royal Purple a couple of years later, because it was all I could get locally at the time and it actually got notchier. Will change it back to MTL when I get a chance.
for the OP, my experience is you can tell the difference in the first 50 miles, but takes about 500 for it take full effect.

[subieworx]

I have has great luck with redline mtl in these transmissions. Always results in smoother shifting. My favorite though, especially for a car driven hard on hot days, is 1.2 quarts of d4atf and 1 quart of redline 75w140.

[krhodes1]

Originally Posted by litxus

Switch back (to OEM fluid), as I would assume it doesn't cost all that much for manual transmission compared to auto. I had some redline in my E46 before and it felt like a downgrade, especially in cold mornings (about 30f degrees or lower). In winter my 2nd gear would barely go in, and then 3rd would be a struggle also. Now saying that, I think OEM is probably better for all types of conditions but other fluids might be better for others.

You would assume wrong! While it doesn't hold much, the OEM gearbox oil for an e9X is crazy expensive. Currently $136 for a 5L jug from Bavarian, maybe a little cheaper elsewhere. 5L is the smallest quantity you can buy, unless a dealer is willing to let you bring your own container and they have a drum of it. Which seems unlikely considering it is officially "lifetime fill".

5L is two changes though.

Interestingly, Mike Miller recommends Redline for longevity reasons, but says you will definitely have worse shifting until the box warms up. I'm sticking with OEM until the warranty runs out.

[rdub315]

Originally Posted by ctuna

D6 was better than OEM for me.

+1... just had D6 put in, and shifts are much smoother!

[gtaccord]

Changed mine to D4 and didn't really notice much of a difference over stock fluid.

[calicolorado]

I used the same fluid that you used and got a different impression. My shift feel improved by 50-75%. Perhaps we had significantly different mileage on our OEM fluid. You might try MTL-it's a little heavier according to my parts source. I have MTL in a 40 year old gearbox and it shifts very nicely. We also put it in my brother-in-laws' '85 535i recently. It definitely was an improvement.

[Surly73]

The viscosity for the fluids being discussed covers quite a range:

lowest to highest:
D6 -> D4 -> MTL -> MT90

What I like about MTL and MT90 is that they are designed from the ground up as a synchromesh fluid and not an ATF that "happens to work", which is why I choose them. The viscosity of MTL is closest to MTF-LT1 and -LT2. -LT3 is thinner, more like D6 I believe. A lot of times, however, I think that recommended fluids may be chosen for shift quality and not for longevity.

In my E90 6MT I don't notice a big difference between new MTL-viscosity fluid and new genuine LT3.

[TittoBlunt]

My indy recommended BG Synchroshift. I definitely felt an improvement. The only thing I would say is that in the morning, it's a bit notchy but as soon as you get it through a few gear shifts, it's super smooth. Had it done at 70k.

[hdrewh]

OP here. I switched to Redline D6 and have no improvement, every shift is more notchy than OEM. I called my dealer to ask how much they would charge for a fluid change, out of curiosity but also if the price wasn't outrageous beyond the cost of the fluid I might just have them do it.

SA's reply was that they wouldn't even do it...."with lifetime fluid, the particles in the fluid actually bond with the transmission components, and if you change the fluid you could shock the transmission".

Direct quote

[litxus]

Originally Posted by hdrewh

OP here. I switched to Redline D6 and have no improvement, every shift is more notchy than OEM. I called my dealer to ask how much they would charge for a fluid change, out of curiosity but also if the price wasn't outrageous beyond the cost of the fluid I might just have them do it.

SA's reply was that they wouldn't even do it...."with lifetime fluid, the particles in the fluid actually bond with the transmission components, and if you change the fluid you could shock the transmission".

Direct quote

Dealerships can be stupid. I really do not understand why they always give you bs if you are paying for the service, as it is not like you are asking them to change the fluid for free. Tell them that someone changed it by mistake or something and you need to change it to OEM fluid so it can "bond"... with the boot up SAs as.....

[krhodes1]

Originally Posted by hdrewh

OP here. I switched to Redline D6 and have no improvement, every shift is more notchy than OEM. I called my dealer to ask how much they would charge for a fluid change, out of curiosity but also if the price wasn't outrageous beyond the cost of the fluid I might just have them do it.

SA's reply was that they wouldn't even do it...."with lifetime fluid, the particles in the fluid actually bond with the transmission components, and if you change the fluid you could shock the transmission".

Direct quote

Do they actually send these guys to classes on making up this BS? Unbelievable.

IIRC, Mike Miller's recommendation for these gearboxes is Redline MTL, and just shift very gingerly until the box warms up when it is cold out.
I bought the 5qt jug of the OEM BMW stuff from BavAuto and will use that until the warranty runs out.

[thecadman99]

Try some pennzoil synchromesh. I've been running it for several weeks now (switched from OEM) and having very good luck with it so far.
Only about $18 for 2 quarts from your local auto parts store.