Replacing Transmission Fluid - 5 Speed Manual

[AnuketTi]

Originally Posted by bazar01

Redline MTL is a gearbox oil 75W-90. Not recommended for BMW. Might be too thick. Still better than running dry though but you'll never know what it's doing to your synchronizers.
BMW recommends ATF, Dexron or Pentosin.

Originally Posted by BlackBMWs

Interesting, I know using this in my 5 series manuals have made shifting smoother and quieter. Thanks for the feedback, I'll research further.

Cheers!

This is interesting as I was considering using something thicker in the tranny as I figured thicker would mean smoother shifting and less wear and tear at operating temperatures.

I can see how it might make for stiff or sluggish gear shifts when cold... but are there any other issues heavier transmission oil can cause?

Would a synthetic oil have any negative effect on the transmission? Can different oil additives impact anything inside the box?

[BlackBMWs]

Originally Posted by AnuketTi

This is interesting as I was considering using something thicker in the tranny as I figured thicker would mean smoother shifting and less wear and tear at operating temperatures.

I can see how it might make for stiff or sluggish gear shifts when cold... but are there any other issues heavier transmission oil can cause?

Would a synthetic oil have any negative effect on the transmission? Can different oil additives impact anything inside the box?

What I have experienced is that with BMW fluid in my 5 series trannies, I had reverse gear shifting issues when cold. With Redline, those issues disappeared and felt smoother. Out of satisfaction there, I carried that over to other manuals. I haven't ruined a tranny yet, and one of them was still running strong at 432k miles.

[AnuketTi]

Originally Posted by BlackBMWs

What I have experienced is that with BMW fluid in my 5 series trannies, I had reverse gear shifting issues when cold. With Redline, those issues disappeared and felt smoother. Out of satisfaction there, I carried that over to other manuals. I haven't ruined a tranny yet, and one of them was still running strong at 432k miles.

Would I be right in saying there are no electrical components inside the manual transmissions on these cars? If that is the case, other than potential cold shifting issues I can't imagine what other detrimental effect a thicker oil / lubricant would have on the transmission.


On another Note: Apart from keeping the car level and having a pump handy, are there any other procedures or tips to refilling the manual transmissions? I would like to flush it out, but don't have the appropriate pump to do this... so it looks like it will be a drain and fill process for me.

[BlackBMWs]

While there may be better methods, I just get the car level on stands and use a Harbor Freight hand pump to fill quickly. I used the little bottle pumps, but heck. two strokes and your done to me beats pumping many time with the little bottle pumps.

Next time the Norcal crowd meets, maybe we can organize a tech maintenance day where we address simple maintenance points like this.

and BBQ.

[paul somlo]

Originally Posted by AnuketTi

Would I be right in saying there are no electrical components inside the manual transmissions on these cars?

You would be right.

I've been using Redline D4 for two years now. I started using it after a partial rebuild of the gearbox, so I can't really say whether it improved shifting or not. It is interesting that the folks at Metric Mechanic recommend plain old ATF for best shifting.

[bazar01]

Originally Posted by AnuketTi

Would I be right in saying there are no electrical components inside the manual transmissions on these cars? If that is the case, other than potential cold shifting issues I can't imagine what other detrimental effect a thicker oil / lubricant would have on the transmission.
.

there is one electrical switch for the reverse light but it is sitting on top and rides on the reverse shift rod. it's sealed so no worries.

If you are in CA, where weather is nice and don't get a lot of below freezing temps, cold shifting may not be a problem with heavier gear oil. But be ready to switch immediately to ATF if you notice some notchy shifting or grinding to prevent synchro wear.

[AnuketTi]

Originally Posted by paul somlo

You would be right.

I've been using Redline D4 for two years now. I started using it after a partial rebuild of the gearbox, so I can't really say whether it improved shifting or not. It is interesting that the folks at Metric Mechanic recommend plain old ATF for best shifting.

Cool! Thanks! I was checking on the Redline D4, it almost sounds like the MMO or Snake Oil of transmissions... LOL!

It is for just about all automatics and manual transmission across a broad range of brands and models. Does this mean there is a fair amount of BS from manufactures asking customers to use a specific OEM oil only?

I might try the D4 since I can acquire it for a good price or another more advanced Synthetic.... and maybe slightly heavier.

Originally Posted by bazar01

there is one electrical switch for the reverse light but it is sitting on top and rides on the reverse shift rod. it's sealed so no worries.

If you are in CA, where weather is nice and don't get a lot of below freezing temps, cold shifting may not be a problem with heavier gear oil. But be ready to switch immediately to ATF if you notice some notchy shifting or grinding to prevent synchro wear.

Thank You. Good to know. I am indeed in CA and in the Bay Area, we get cool weather but never freezing type weather. I think for now, I am going to stick with an advance ATF, probably a synthetic.


By the way, does anyone know if I have to flush all the old oil out or can I just drain and refill? I wondering if there is a risk of incompatibility with the existing oil.

Maybe do multiple changes over the course of 500 miles?

[jca]

Originally Posted by AnuketTi

Considering the advance of oil technology, I'm going to look for a synthetic ATF to use to flush and refill the tranny. Not sure how to flush it on jack stands though.

An alternative to flushing would be to drain and fill now, then drain and fill again in 5000 miles or so. John

[AnuketTi]

Originally Posted by jca

An alternative to flushing would be to drain and fill now, then drain and fill again in 5000 miles or so. John

My primary concern is the compatibility of the oil I put in and what might be in there right now.

It looks Red, so I would assume it is ATF of some sort. I am thinking of replacing with a synthetic ATF, or something like Dexron Synthetic.

[zoner]

Originally Posted by AnuketTi

My primary concern is the compatibility of the oil I put in and what might be in there right now.

It looks Red, so I would assume it is ATF of some sort. I am thinking of replacing with a synthetic ATF, or something like Dexron Synthetic.

If you let the gearbox drain completely (on a level surface), there is not going to be enough residual oil in there to be problematic if you refill with ATF.

While BMW does recommend ATF for these gearboxes, I know people that have used standard gear oil (GL-4 only!) with no problems. On some gearboxes (e.g Borg Warner WC-T5) it is critical to use ATF because of lined friction surfaces on the synchros.

I've used Redline D4 ATF in both of my ti's gearboxes with no problems. Shifts like butter!

[AnuketTi]

Originally Posted by zoner

If you let the gearbox drain completely (on a level surface), there is not going to be enough residual oil in there to be problematic if you refill with ATF.

While BMW does recommend ATF for these gearboxes, I know people that have used standard gear oil (GL-4 only!) with no problems. On some gearboxes (e.g Borg Warner WC-T5) it is critical to use ATF because of lined friction surfaces on the synchros.

I've used Redline D4 ATF in both of my ti's gearboxes with no problems. Shifts like butter!

There is a sticker on the side of my transmission that says ATF..

[COOPERDB]

This is one of the subjects that I came here looking for

information on -

Great Thread ---