I've been riding my '72 R75 more often since my '04 Triumphs are having difficulty getting started right now. I've noticed an issue with the R75. When I shift from 2nd to 3rd, it's not a smooth click like the rest of the changes. It's like the gears don't mesh nicely and I get a a small grind of soft. It's not audible over the engine, but I feel it in my foot. It also has a habit of dropping into a false neutral or back down into 2nd. I've tried varying the RPMs of the shift, but the problem persists.
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R75/5 not smoothly shifting 2nd to 3rd
- Thread starter ARMYMUTT
- Start date
I used to have false neutrals going from 4th to 5th. Oak Okleshen suggested that I hold my foot in the up position even while letting out the clutch for 5th gear. There's also the suggestion of pre-loading the shifter and then Oak's suggestion could be called post-loading the shifter.
In your case I'd do the easy things first. Make sure your clutch is adjust properly. There is a procedure written by Tom Cutter on this process...the write up is in the link in my signature line. Beyond that, you might be due for a transmission spline lube. If the clutch disk is hanging up when you pull the lever in, it could still be contacting the flywheel which then puts unwanted load in the disk while you are trying to change gears.
If you haven't been riding the /5 much, you might have built up some rust on the input splines which are not gumming up and creating this drag on the disk.
In your case I'd do the easy things first. Make sure your clutch is adjust properly. There is a procedure written by Tom Cutter on this process...the write up is in the link in my signature line. Beyond that, you might be due for a transmission spline lube. If the clutch disk is hanging up when you pull the lever in, it could still be contacting the flywheel which then puts unwanted load in the disk while you are trying to change gears.
If you haven't been riding the /5 much, you might have built up some rust on the input splines which are not gumming up and creating this drag on the disk.
ebeeby
Member
jhall
BMWMOA #24809
Synthetic Gear Oil & Blip The Throttle
You might also try a good synthetic oil such as RedLine 75W90-NS. Also, when shifting, with clutch still in and gentle pressure on the shifter, blip the throttle. If those two things improve but do not fix it, next step may be to grease the splines, as mentioned above. Good luck!
You might also try a good synthetic oil such as RedLine 75W90-NS. Also, when shifting, with clutch still in and gentle pressure on the shifter, blip the throttle. If those two things improve but do not fix it, next step may be to grease the splines, as mentioned above. Good luck!
taran1900
Member
Every /5 I have ever ridden felt like I was shifting gears on a deuce and a half.
pglaves
#13338
The first time I ever rode the R60/5 I bought for Voni for Mother's Day, when I downshifted from 3rd to 2nd for the first time I actually stopped and looked back to see what broke off and fell off the bike. Finding nothing I rode on, getting used to rather loud klunks when I shifted.
kinterridge
Member
+1 on the Redline, I've been using the Shockproof version for about 5 years in my R100S, it really smooths out the shifting and most, if not all false neutrals have disappeared. Preloading shifter does work, I had to do that years prior.
beemeruss
Member
In 1972 I bought a nearly new '70 R75/5. The period ride tests of the day described the shifting action, though normal, as the transmission case being smacked by a Louisville Slugger! I must have gotten used to it as I have never owned nor ridden a BMW newer than a '78. A slight blip of the throttle for downshifts and preloading the shifter for upshifts comes with practice. No double clutching required....
Russ '78 R80/7 '78 R100RS '76 R90/6 (lawn sculpture)
dennisdarrow
#4869 Earned Lifetime mem
An excellent description. One has to follow the history of that action through the various modes of operation. Actually, the same engineers were left over and hired after their excellent designs of howitzer breech closing actions and operations while even being able to function during the sub-freezing wastes of Stalingrad. Several other design engineers were employed to use the fork action left over from the ME2 landing gear and seat comfort being adapted from waiting benches at the infirmary left over from Dachau...............So much history evolves even from the pots and pans with the BMW manufacturing mark............
Which version Red Line..?
Not to totally hijack the thread, but I'm curious what version of the Red Line 75W-90 gear oil you guys are using and the differences in their offerings...theres the NS that jhall mentions, and then the 'shockproof' versions come in lightweight and super lightweight, and then there's the 75W-90 GL-5, and then there's the heavy shockproof.....
I've always used Lucas 75W-90 gear oil in my bikes, and have certainly never had any issues, but curious if there really is a felt improvement when using the Red Line stuff. I've been having just the slightest gear slippage in second these days (clutch adjustment is in spec), and have never really loved the airheads clunky shift feel. If the Red Line really makes any difference, I'm all ears....
ECJ
Not to totally hijack the thread, but I'm curious what version of the Red Line 75W-90 gear oil you guys are using and the differences in their offerings...theres the NS that jhall mentions, and then the 'shockproof' versions come in lightweight and super lightweight, and then there's the 75W-90 GL-5, and then there's the heavy shockproof.....
I've always used Lucas 75W-90 gear oil in my bikes, and have certainly never had any issues, but curious if there really is a felt improvement when using the Red Line stuff. I've been having just the slightest gear slippage in second these days (clutch adjustment is in spec), and have never really loved the airheads clunky shift feel. If the Red Line really makes any difference, I'm all ears....
ECJ
jad01
New member
I've been using the V-twin transmission oil in my two airheads for a number of years. I started using it in my /7 in an attempt to ease shifting between 2nd/3rd gear. I can attest that it definitely quiets things down and smooths shifts (even once warmed up). I was having a problem with the RS popping out of first gear when pulling away from a stop (not fully engaging, I think); switching from 80W90 gear oil to the V-twin gear oil eliminated that behavior.
I monitor the condition of the oil and look for metal on the drain plug when I change it- no issues so far. The transmissions have never been apart on either bike (to my knowledge). 90K miles on the RS and 110K on the /7... so far so good. I'm guessing I've put ~30K miles combined on the bikes since switching over to the V-twin oil. One day maybe I'll pull the transmissions and have them serviced while there are still a few folks out there who can do so... that will give an opportunity to see how the bushings and other internals held up. I seem to recall Paul (?) writing about the importance of gear oil rating (GL-4, 5 etc.) as it applies to the bushings. The heavy shockproof (on which the V-twin oil is based) says it exceeds GL-5, but... there is no rating listed on the V-twin oil that I can find.
In any event, I like it and will keep using it until I see a problem.
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jhall
BMWMOA #24809
RedLine 57304 Or 57104
I have been using RedLine MT90 GL4 in classic car (BW T85 3speed/OD, and BW T-10 4-speed) transmissions for about 20 years, and they love it. The MT90 has been popular in 50s-80s vintage muscle cars for at least 20 years now. I was fist told of it by a race car driver, now in his 80s, who's been racing since high school. In instantly noticed difference the first time I tried it; very smooth shifts, hot or cold.
I am in new territory with RedLine in an Airhead, about 1000 miles now. Because Airheads call for GL5, I chose #57104, which is 75W140NS with GL5 level protection; NS stands for Non Slip, which supposedly works best in gearboxes, per info on their web site. I'd also feel comfortable with 58304, 75W90NS, with same properties but lighter weight. I chose 75W140, thinking its thicker cling property may help quieten the Airhead hot noise, in neutral. As expected, it shifts smoothly, hot or cold. If it stiffens up when temps drop into the 20s-30s next winter, I may try 75W90NS, but I could not ask for better in the current temps here, 40 and up.
I have no experience with the non NS version 85W140 GL5 or 75W90 GL5, but may try it someday just for comparison with the NS. I also have no experience with their 'Shock Proof' line, but would read their specs and, if it appears applicable for Airhead, would not hesitate to try it. Just read the fine print, and insure it says no harm to yellow metals.
The RedLine web site is very helpful, so you could also just go there, read the specs carefully, and make your own choice. If you chose a non NS version, or 'Shock Proof' version, please come back here and advise us of the results. Anything RedLine is FAR superior to Dino oil IMHO, so you can't go wrong.
I have been using RedLine MT90 GL4 in classic car (BW T85 3speed/OD, and BW T-10 4-speed) transmissions for about 20 years, and they love it. The MT90 has been popular in 50s-80s vintage muscle cars for at least 20 years now. I was fist told of it by a race car driver, now in his 80s, who's been racing since high school. In instantly noticed difference the first time I tried it; very smooth shifts, hot or cold.
I am in new territory with RedLine in an Airhead, about 1000 miles now. Because Airheads call for GL5, I chose #57104, which is 75W140NS with GL5 level protection; NS stands for Non Slip, which supposedly works best in gearboxes, per info on their web site. I'd also feel comfortable with 58304, 75W90NS, with same properties but lighter weight. I chose 75W140, thinking its thicker cling property may help quieten the Airhead hot noise, in neutral. As expected, it shifts smoothly, hot or cold. If it stiffens up when temps drop into the 20s-30s next winter, I may try 75W90NS, but I could not ask for better in the current temps here, 40 and up.
I have no experience with the non NS version 85W140 GL5 or 75W90 GL5, but may try it someday just for comparison with the NS. I also have no experience with their 'Shock Proof' line, but would read their specs and, if it appears applicable for Airhead, would not hesitate to try it. Just read the fine print, and insure it says no harm to yellow metals.
The RedLine web site is very helpful, so you could also just go there, read the specs carefully, and make your own choice. If you chose a non NS version, or 'Shock Proof' version, please come back here and advise us of the results. Anything RedLine is FAR superior to Dino oil IMHO, so you can't go wrong.
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Snowbum mentions the use of something like 75w140 as a gear lubricant. But he thinks they might be OK in extreme conditions such as pulling a trailer or chair. If things stiffen up when cold, I think that's telling you something. I would worry about cavitation and the fluid not flowing well enough to protect the meshing surfaces and bearings. I can't find anything on it from Oak, but I'm pretty sure he stuck by the OEM recommendations of a good quality 80w90 GL5 gear oil.
jhall
BMWMOA #24809
Looks Excellent
This one looks like an excellent choice. Per the RedLine web site, it is same fluid as their Heavy Shock Proof oil (but likely with different additives), which has cling property of 75W250 yet has 'low fluid friction like 75W90'. As mentioned, they make something for just about every occasion. I would not hesitate to try this one also. Thanks!I've been using the V-twin transmission oil in my two airheads for a number of years. I started using it in my /7 in an attempt to ease shifting between 2nd/3rd gear. I can attest that it definitely quiets things down and smooths shifts (even once warmed up). I was having a problem with the RS popping out of first gear when pulling away from a stop (not fully engaging, I think); switching from 80W90 gear oil to the V-twin gear oil eliminated that behavior.
I monitor the condition of the oil and look for metal on the drain plug when I change it- no issues so far. The transmissions have never been apart on either bike (to my knowledge). 90K miles on the RS and 110K on the /7... so far so good. I'm guessing I've put ~30K miles combined on the bikes since switching over to the V-twin oil. One day maybe I'll pull the transmissions and have them serviced while there are still a few folks out there who can do so... that will give an opportunity to see how the bushings and other internals held up. I seem to recall Paul (?) writing about the importance of gear oil rating (GL-4, 5 etc.) as it applies to the bushings. The heavy shockproof (on which the V-twin oil is based) says it exceeds GL-5, but... there is no rating listed on the V-twin oil that I can find.
In any event, I like it and will keep using it until I see a problem.
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jhall
BMWMOA #24809
Needs An Update
Sounds like he needs to familiarize himself with later technology in lubrication. LOL
pauls1150
MOA #24991, south of Los Angeles
Not necessarily, Kurt - the mutigrade synthetic (like 75W90 or 75W140) flows a LOT more easily than a straight petroleum 140W would.
Mutt never mentioned what the mileage is on his bike... maybe it needs to be re-shimmed? The master mechanic (Jed) at Marty's re-shimmed my 2nd /5, and from then on, it was SWEET!
Mutt never mentioned what the mileage is on his bike... maybe it needs to be re-shimmed? The master mechanic (Jed) at Marty's re-shimmed my 2nd /5, and from then on, it was SWEET!
How so? The base or "winter" value is 75W versus the recommended gear oil at 80W. Can the 75W flow that much better?? I'm just concerned about the additives that give the oil the 140 weight at the upper temperature. For me, I'll just stick with the OEM recommended lubricant.
jhall
BMWMOA #24809
It's amazing how far lube technology has came. Don't need an engineer degree, just read the info on RedLine's web site. I would not even consider 140 wt dino oil, as it would pour like molasses. But there's a world of difference between dino oil and quality synthetic. The RedLine 75W140 pours like dino 90 wt. Will see how it works, down the road. According to many, I can only expect 60,000 to 80,000 miles out of the gearbox before rebuild anyway. The same people highly recommend dino oil. With 40,000 now on this Airhead, I am half way there. Time will tell how the RedLine works out.
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