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TECHNICAL MOTOBRICK WRENCHING In Remembrance of Inge K. => The Motobrick Workshop => Topic started by: DavidATL on January 15, 2017, 09:43:19 PM

Title: transmission fluid poll
Post by: DavidATL on January 15, 2017, 09:43:19 PM

I'd like to improve the 1-2 shift on my K75.

This is my second K-bike and neither had a great 1-2 shift. I don't know all the history of my current bike but I believe it has BMW Super Syn that is at least 10 years old. No idea regarding mileage but the bike only has 19k. The transmission drain plug is about as dirty as the rest of the underside so it was not changed recently.

Given the unknown but multi-year age, any change is warranted and will probably improve things. Even so, I thought I'd consult the Motobrick hive via a most unscientific method: the voluntary anecdote-based poll!!!!! So...

What do you use?

These seem the most popular:
- BMW Super Synthetic gear oil SAE 75W140
- Mobil 1 75w140
- Mobil 1 75w140 + Liqui Moly 2019 MoS2 Anti-Friction Gear Lubricant
- Redline Heavy ShockProof

or some other witch's brew of dead dino squeezings and slick-as-snot nasa goop?
Title: Re: transmission fluid poll
Post by: Chaos on January 15, 2017, 10:33:58 PM
Valvoline synthetic 75-90 helped mine, but that 1 - 2 shift is never going to be buttery smooth.  Best bet is to spend some time on a Ural, after crunching that box of rocks the K will seem like an automatic.
Title: Re: transmission fluid poll
Post by: The Mighty Gryphon on January 15, 2017, 10:37:04 PM
I use synthetic gear lube(no specific brand, but mostly Mobil 1) to which I add about 2-3 heaping tablespoons of 1.5 micron molybdenum disulfide powder.  It takes about a hundred miles to completely treat the internals, but I have noticed a noticeable improvement in the smoothness of shifting, especially down from 3rd to 2nd and 2nd to 1st.

I also lube the transmission input shaft splines with Honda Moly 60 to help the clutch disengage smoothly.  This is another maintenance item that helps with downshifting.
Title: Re: transmission fluid poll
Post by: DavidATL on January 16, 2017, 05:41:45 AM

...
 Best bet is to spend some time on a Ural, after crunching that box of rocks the K will seem like an automatic.


now that is funny, right there. :-)



...
also lube the transmission input shaft splines with Honda Moly 60 to help the clutch disengage smoothly.  This is another maintenance item that helps with downshifting.



I did this right after I purchased the bike last summer and it did make some improvement. It was pretty dry but fortunately didn't have significant wear on the splines. I have 2 or so applications left of Guard Dog moly (aka unobtainium).


I know the K transmission will never shift like my prior Hondas. But the rest of the bike MORE than makes up for it! :-)



Title: Re: transmission fluid poll
Post by: The Mighty Gryphon on January 16, 2017, 09:44:02 AM
Put some of this stuff in your transmission and it will help make things more like a Honda.

http://www.ebay.com/itm/391442186584?_trksid=p2057872.m2749.l2649&ssPageName=STRK%3AMEBIDX%3AIT
Title: Re: transmission fluid poll
Post by: Laitch on January 16, 2017, 09:46:44 AM
Have you adjusted your clutch cable and lever free play?
Title: Re: transmission fluid poll
Post by: K1300S on January 16, 2017, 10:43:31 AM
redline 75w90ns
Title: Re: transmission fluid poll
Post by: wmax351 on February 12, 2017, 04:26:08 PM
The Redline shockproof stuff is ideal for this application.
Title: Re: transmission fluid poll
Post by: billday on February 12, 2017, 05:37:05 PM
+1 on making sure your mechanism is adjusted correctly.

And spline maintenance is essential.
Title: Re: transmission fluid poll
Post by: DavidATL on February 12, 2017, 07:24:06 PM
Release lever free play is a shade over 3mm measured when cold. Might be 3.5.
Title: Re: transmission fluid poll
Post by: jay1622 on April 20, 2017, 11:38:24 AM
The Redline shockproof stuff is ideal for this application.


Wanted to ask if you're using this stuff, and if so, which one? The only shockproof line that matches up is...


https://www.redlineoil.com/product.aspx?pid=44&pcid=4


Is this the one?
Title: Re: transmission fluid poll
Post by: K1300S on April 20, 2017, 11:54:18 AM

Wanted to ask if you're using this stuff, and if so, which one? The only shockproof line that matches up is...


https://www.redlineoil.com/product.aspx?pid=44&pcid=4


Is this the one?

try here
https://www.redlineoil.com/Products.aspx?pcid=8

there are three levels.  lightweight version is roughly the needed one.

i wouldn't use it in a tranny though. wouldn't hurt, but the 75w90NS works fine.  i only use shockproof in my race car differentials.  we call it "blue goo"..for a reason.  whatever you put it in will forever be coated in the medium blue color the oil is.
Title: Re: transmission fluid poll
Post by: RobP on April 23, 2017, 04:08:43 PM
Hey Gryph - how much of that aforementioned Moly powder do you add to the transmission?   
Title: Re: transmission fluid poll
Post by: Laitch on April 23, 2017, 04:14:35 PM
Hey Gryph - how much of that aforementioned Moly powder do you add to the transmission?
See Reply #2, RobP.
Title: Re: transmission fluid poll
Post by: wmax351 on April 23, 2017, 04:23:38 PM

Wanted to ask if you're using this stuff, and if so, which one? The only shockproof line that matches up is...


https://www.redlineoil.com/product.aspx?pid=44&pcid=4 (https://www.redlineoil.com/product.aspx?pid=44&pcid=4)


Is this the one?


I'm using the heavy. It's fluid friction/viscosity is equivalent to the normal 75w90 GL5 that is recommended.


Ostensibly you could use the light stuff for a little less fluid drag. It supposedly still has adequate film thickness, but is a bit thinner viscosity wise. .



Title: Re: transmission fluid poll
Post by: jay1622 on April 23, 2017, 09:34:45 PM
So, Castrol stopped making the SAF-XO, and changed things over to Syntrax. BMW-Motortad has its own SAF-XO now, which I got for $19 a quart. I put that in tonight to both final drive and gearbox. I've got a ton of residual liquid-moly in there, so I'm going leave it at that for now and see how she responds.


Random thought... That BMW SAF-XO is made here in the US. I wonder who is making it for them.
Title: Re: transmission fluid poll
Post by: F14CRAZY on April 23, 2017, 09:47:44 PM
I run Supertech (Walmart) 75w90 synthetic blend mostly because that's what I use in my Subaru transmission...in that application this oil provides the best shifting. Dudes over on the Forester forum have looked over the technical data on this oil and it's good stuff protection wise. And it's cheap. I change it every other engine oil change.

If it helps, the owner of BMW of Grand Rapids, when I had them replace the seal in my final drive, said that changing the oil in the final drive often is more important than the brand or "quality" of the oil and suggested doing it at every oil change.
Title: Re: transmission fluid poll
Post by: BrickMW on April 25, 2017, 11:16:52 AM
I add about 2-3 heaping tablespoons of 1.5 micron molybdenum disulfide powder.


Hey gryph, +1 on the link, mine will be here Fri :2thumbup:


Is that 2-3 TB's per ?? (Gearbox/Final Drive/Liter of Lube?) Mix before fill? or spoon in powder to gearbox before/after lube?
 :beer:
Title: Re: transmission fluid poll
Post by: The Mighty Gryphon on April 25, 2017, 11:53:35 AM
I added mine about two months after I changed the oil.  Stuck a funnel in the transmission filler and put in two rounded tablespoons of powder.  The powder is kind of light and fluffy, so I figure it all just floated on the oil until I rode the bike a while.  After about 20-30 miles the shifting started to feel easier, especially the down shifting. 

I don't know if the powder settles when the bike is parked, but I have noticed that if I don't use the bike for a week or more, it takes a couple minutes for the transmission to feel real smooth again.

For the final drive I use one rounded tablespoon.   Basically, I am trying to use about half a bottle of powder for each bike.

I have heard of people using an old blender to mix the moly powder into the oil before adding it.  I will probably mix it in with the oil before I put it in the next time which will be this fall when I do my winter maintenance jobs.  I suppose you can just put it in the oil bottle and give it a good shake for a couple minutes. 

Just remember to avoid the temptation to put it in the engine.  The stuff is so slippery it will keep your sprag clutch from working.  I found that out the hard way when I used a bunch of moly assembly paste when I did some engine work and a week later the sprag wouldn't engage.  Had to flush the engine to get it out and make the sprag work again.
Title: Re: transmission fluid poll
Post by: DavidATL on September 04, 2017, 04:51:18 PM
I know this is bumping a rather old topic. sorry ...

It's been about 300 miles since I put the first tablespoon of moly powder in the transmission. The first 200 were marginally better. Today's 100 mile ride was MUCH better. I plan to follow up with a 2nd tablespoon at the next service. Thanks for the great suggestion!
Title: Re: transmission fluid poll
Post by: stokester on September 04, 2017, 09:22:43 PM
I know this is bumping a rather old topic. sorry ...

It's been about 300 miles since I put the first tablespoon of moly powder in the transmission. The first 200 were marginally better. Today's 100 mile ride was MUCH better. I plan to follow up with a 2nd tablespoon at the next service. Thanks for the great suggestion!
I'm considering trying it although I use Mobil 1.  Thanks for the update.
Title: Re: transmission fluid poll
Post by: Laitch on September 04, 2017, 09:47:44 PM
NAPA 80W90
Title: Re: transmission fluid poll
Post by: BlitzenGruv on September 05, 2017, 12:55:55 AM
Don't know what's in mine. It's blue, so I know it's synth.
I use dino 80/90 2/3 with 1/3 STP in the Brit boxes and they shift slick.
Title: Re: transmission fluid poll
Post by: bizzaro on September 17, 2017, 08:03:35 PM
Having second thoughts on the molly though.  It may help some, but I think most of it ends up as sludge in the bottom of the tranny and final drive.  My drain plugs were covered with the junk from my last oil change. :dunno2:   This time around I shook the molly up in the bottle by adding a little at a time, shaking, doing it again, and again etc.  It worked..... short of.  Kind of lumpy at times, not bad though, and a lot of it settles to the bottom.  If I use molly again, I will add it dry to the top of the fresh oil via the filler hole I think.  Last time I changed the transmission and final drive fluid, I tried to stir the molly into the oil in my measuring cup. :hehehe :hehehe That's how that went.
Title: Re: transmission fluid poll
Post by: MIbrick on September 17, 2017, 08:21:27 PM
If I do it again I will add it dry to the top of the fresh oil via the filler hole I think.


This is how I did it for both the transmission and the FD. It didn't occur to me to pre-mix and pour. Next time, I won't use a plastic funnel to dump the powder in, though. Probably use a paper funnel that I can just dispose afterwards. Probably didn't help that I used the same funnel that I'd used to fill said transmission and FD, so it was already wet with lube.  What an effing mess.
Title: Re: transmission fluid poll
Post by: bizzaro on September 17, 2017, 08:30:35 PM

 Probably didn't help that I used the same funnel that I'd used to fill said transmission and FD, so it was already wet with lube.  What an effing mess.

 :hehehe :hehehe :hehehe :hehehe Yea, that shit can get away from ya!  Need to carefully plan for it's use. 
Title: Re: transmission fluid poll
Post by: Blue on September 17, 2017, 09:01:00 PM
The liquid moly mixes well and does not pool at the drain plugs.
Title: Re: transmission fluid poll
Post by: bizzaro on September 18, 2017, 06:31:27 AM
Link to purchase? Fleabay again?  IE; where did you purchase your liquid molly?? It definitely sounds like a better option for me. :2thumbup:

I found this info below searching the web for the liquid molly.   It must be true...............it was on the internet! :eek:

Engineers and scientists have tried for years to use Moly in oils but they had been unsuccessful because they could not find a way to keep Moly in suspension. Once Moly was put into suspension it would gradually settle out. It was easy to see it come out of suspension because a black sludge would collect on the bottom of the oil containers. In engines it would settle to the bottom of the crankcase or clog oil pathways and filters.
 
Title: Re: transmission fluid poll
Post by: Christopherguzzi on September 18, 2017, 10:21:58 PM
Super Tech 75W-90 Synthetic Blend Gear Oil. :2thumbup:   Shifts incredibly smooth no matter what gear. :riding:
Title: Re: transmission fluid poll
Post by: Blue on September 19, 2017, 04:54:10 AM
Guard  Dog SLA-1261 Moly For Gear Oils.  It says for gear oils, not to be used in engine oils. 
Title: Re: transmission fluid poll
Post by: jay1622 on September 19, 2017, 06:46:52 AM
I found this info below searching the web for the liquid molly.   It must be true...............it was on the internet! :eek:


Having just finished rebuilding my gearbox, which had moly in it... I will say this is true, but (on a good note) there does appear to be a saturation point (you don't need a lot). I had residual moly on EVERYTHING, and there was significantly more (residual build-up layer) on the bottom of the gearbox and down toward the drain channel. However, there was still a significant amount suspended in the oil itself. The only consistent drawback is every seal (input, output, clutch rod, shifting roll & gear shaft) had hints of moly creeping past the wiper portion of the seal. Based on my personal experience, I'll be using 10%-15% of what I was using before; I was using way too much. Note: I didn't detect any more/less slag on the magnet. The thought that the residual moly/sludge would capture metal frag and slag and not allow it to pass to the drain plug magnet.
Title: Re: transmission fluid poll
Post by: Blue on September 19, 2017, 07:13:26 AM
Mobil 1 75/140 Syn gear oil and Guard Dog liquid moly the past 20 years and nearly 200 thousand American total miles.  It's a good combination.
Title: Re: transmission fluid poll
Post by: bizzaro on September 19, 2017, 04:18:13 PM

Having just finished rebuilding my gearbox, which had moly in it... I will say this is true, but (on a good note) there does appear to be a saturation point (you don't need a lot). I had residual moly on EVERYTHING, and there was significantly more (residual build-up layer) on the bottom of the gearbox and down toward the drain channel. However, there was still a significant amount suspended in the oil itself. The only consistent drawback is every seal (input, output, clutch rod, shifting roll & gear shaft) had hints of moly creeping past the wiper portion of the seal. Based on my personal experience, I'll be using 10%-15% of what I was using before; I was using way too much. Note: I didn't detect any more/less slag on the magnet. The thought that the residual moly/sludge would capture metal frag and slag and not allow it to pass to the drain plug magnet.

  Next time I change gear oil I will be vary judicial in my Molly dust application. I would say a little bit goes a long way. 

Great job on your tranny thread.  Really good documentation, vids and all.  Excellent job, so thank you for that. 



"Guard Dog liquid moly",.............................. Blue, you do know Guard Dog is out of business right? 
Title: Re: transmission fluid poll
Post by: frankenduck on July 19, 2023, 04:44:44 PM
Half a tube (25g) of this in the trans oil:
https://www.amazon.com/Liqui-Moly-2019-Anti-Friction-Lubricant/dp/B00CPL8UPY

How I determined that amount: Since LiquiMoly doesn't have any directions on the product I emailed their tech support several years ago to find out what would be the correct amount for 0.8L of gear oil in a transmission.