Great video Ash! It'll definitely help people. The difficult shifting (the crunch going into the next gear, and not wanting to shift when cold) are due to a combination of wear on the friction surfaces of the bronze synchronizer rings (you may call them baulk rings in the UK?), and on the conical shape of the hub that those friction surfaces are supposed to "brake" against. Without sufficient friction between those 2 surfaces, the hub and the gear it's part of, won't be slowed, in order to match the speed of the gear currently being used, and this causes the shift collar to not be able to slide. The result is the crutch as the collar's inside notches "crash" into the still-spinning "teeth" of the hub/gear unit, or the non-shifting, because the collar won't go over onto those teeth all. If you do a google search of syncroniser and hub images, you'll see some nice diagrams that show how everything is set up and how it moves to select a gear. The transmission builder specs a gear oil that matches the friction and braking ability of their synchro and hub design. Some transmissions take GL4 (like you see on your bottle of redline), some take GL-5 which is "more slippery" than GL4, some like Honda used to use 10w-30 engine oil, and they've now upgraded that to their own special sauce, which is still like 10w-30. Some, like Triumph and my vintage Mercedes coupe, actually run ATF (automatic transmission fluid) in their manual gear boxes! The Mercedes oil you purchased has an additive pack that helps the synchros to bite better, and that creates the best shifting, especially when cold. With such high mileage, and being crash-course-tested by delivery drivers, one can only imagine the bad shifting that your transmission has experienced. I'm sure your 2nd and 3rd gear synchros and hubs are very worn out. The MT90 was just way too slippery for the amount of wear in your transmission. GM makes a great product, and so does Amsoil, but since you've found the OE fluid works great, stick with it! Don't use the transmission as a brake for the vehicle, because that is very hard on synchros (and brakes are much cheaper then transmissions), and learn to "back shift" verses "down shift." You can also learn to load the shifter against the detent for the next gear, wait a moment with that pressure applied, blip the throttle, and then push into the next gear. It'll drop right in, because you've given the worn synchro a little extra time to slow the hub, and your throttle blip has helped match the rpm of the engine, to what the new rpm of the gearbox is. It's like learning to shift a manual trans without using the clutch. It'll really extend the life of that gearbox. Cheers my friend!
Happy new year mate, I hope you’re well. Awesome information from your engineering background very much appreciated Todd - especially the part about not engineer braking, I don’t use that much tbh, however I did when going through the mountains in Andorra to save cooking the brakes on some crazy gradients. Interesting regarding the difference in gear oils too, I think eventually it will need a recon transmission, but as I know about the vans issue with 2nd gear I’m very gentle in letting it drop into gear, rather than ramming it in. And you have brought back memories from when I was around 19-20 years old and my Renault 11’s clutch cable snapped and I got a replacement but didn’t really know what I was doing replacing it and had to drive around by blipping the gas to change gears without the clutch 🤣 fun times. I still popped it into gear without the clutch out of habit sometimes when it felt just right even when it was properly repaired 😁👍 Purely out of interest with your expertise, do you use any oil or fuel additives in your vehicles Todd?
@@beaulunaedvantures Happy New Year to all of you as well. You guys had an amazing 2024, and I'm looking forward to what you do this year! Regarding using the transmission as a brake. I think what I wrote wasn't clear. You are correct to have the transmission in a lower gear, when descending a long grade. The general rule being, whatever gear you used to climb the grade, you used to descend the grade. That doesn't hurt the transmission at all. What I was speaking about, is the use of the transmission to slow the vehicle down, by "down shifting" into a lower gear. For example, when approaching a corner, or a stop sign, or stop light. People who do that by "down shifting" are asking the synchros to "brake" the transmission internals, and that causes premature wear. The correct method of shifting, in that situation, is to "back shift" which requires the engine speed to be raised to what it's about it be in the lower gear, and that allows the syncro to do no "braking" work... it just applies some friction to the hub of the next gear, they both match speed, and then the shift collar slides easily. That method is the same method used if there was no clutch at all. Basically using the engine to match speeds, applying light force to the gear shift lever, and as the speeds match, the gear shift lever moves into the next gear. Since you have such good driving and shifting skill, I'll be you can get that transmission to last for years. Honestly, I wouldn't worry about it. The '05 CR-V that I purchased a year ago, has 279,000mi on it, and 3rd gear syncro is worn out from a combination of the previous own "speed shifting," Honda's lame transmission fluid, and the rev-hang that Honda has programmed into the computer, as a way to cheat emissions levels. I switched to the Amsoil, and shift into 3rd as if I had no clutch. No more crunch, and I can live with it. The only additive I use: A couple times a year, I'll dump a can of SeaFoam (white metal can with red lettering) into the fuel tank, usually when I fill up just before a big road trip. SeaFoam does a fantastic job of cleaning fuel injectors, intake ports, and the backs of the intake valves. On a car that's not been treated, the improvement in running is usually very noticeable.
Great video Ash! It'll definitely help people.
The difficult shifting (the crunch going into the next gear, and not wanting to shift when cold) are due to a combination of wear on the friction surfaces of the bronze synchronizer rings (you may call them baulk rings in the UK?), and on the conical shape of the hub that those friction surfaces are supposed to "brake" against. Without sufficient friction between those 2 surfaces, the hub and the gear it's part of, won't be slowed, in order to match the speed of the gear currently being used, and this causes the shift collar to not be able to slide. The result is the crutch as the collar's inside notches "crash" into the still-spinning "teeth" of the hub/gear unit, or the non-shifting, because the collar won't go over onto those teeth all. If you do a google search of syncroniser and hub images, you'll see some nice diagrams that show how everything is set up and how it moves to select a gear. The transmission builder specs a gear oil that matches the friction and braking ability of their synchro and hub design. Some transmissions take GL4 (like you see on your bottle of redline), some take GL-5 which is "more slippery" than GL4, some like Honda used to use 10w-30 engine oil, and they've now upgraded that to their own special sauce, which is still like 10w-30. Some, like Triumph and my vintage Mercedes coupe, actually run ATF (automatic transmission fluid) in their manual gear boxes!
The Mercedes oil you purchased has an additive pack that helps the synchros to bite better, and that creates the best shifting, especially when cold. With such high mileage, and being crash-course-tested by delivery drivers, one can only imagine the bad shifting that your transmission has experienced. I'm sure your 2nd and 3rd gear synchros and hubs are very worn out. The MT90 was just way too slippery for the amount of wear in your transmission. GM makes a great product, and so does Amsoil, but since you've found the OE fluid works great, stick with it! Don't use the transmission as a brake for the vehicle, because that is very hard on synchros (and brakes are much cheaper then transmissions), and learn to "back shift" verses "down shift." You can also learn to load the shifter against the detent for the next gear, wait a moment with that pressure applied, blip the throttle, and then push into the next gear. It'll drop right in, because you've given the worn synchro a little extra time to slow the hub, and your throttle blip has helped match the rpm of the engine, to what the new rpm of the gearbox is. It's like learning to shift a manual trans without using the clutch. It'll really extend the life of that gearbox.
Cheers my friend!
Happy new year mate, I hope you’re well. Awesome information from your engineering background very much appreciated Todd - especially the part about not engineer braking, I don’t use that much tbh, however I did when going through the mountains in Andorra to save cooking the brakes on some crazy gradients. Interesting regarding the difference in gear oils too, I think eventually it will need a recon transmission, but as I know about the vans issue with 2nd gear I’m very gentle in letting it drop into gear, rather than ramming it in.
And you have brought back memories from when I was around 19-20 years old and my Renault 11’s clutch cable snapped and I got a replacement but didn’t really know what I was doing replacing it and had to drive around by blipping the gas to change gears without the clutch 🤣 fun times. I still popped it into gear without the clutch out of habit sometimes when it felt just right even when it was properly repaired 😁👍
Purely out of interest with your expertise, do you use any oil or fuel additives in your vehicles Todd?
@@beaulunaedvantures Happy New Year to all of you as well. You guys had an amazing 2024, and I'm looking forward to what you do this year!
Regarding using the transmission as a brake. I think what I wrote wasn't clear. You are correct to have the transmission in a lower gear, when descending a long grade. The general rule being, whatever gear you used to climb the grade, you used to descend the grade. That doesn't hurt the transmission at all. What I was speaking about, is the use of the transmission to slow the vehicle down, by "down shifting" into a lower gear. For example, when approaching a corner, or a stop sign, or stop light. People who do that by "down shifting" are asking the synchros to "brake" the transmission internals, and that causes premature wear. The correct method of shifting, in that situation, is to "back shift" which requires the engine speed to be raised to what it's about it be in the lower gear, and that allows the syncro to do no "braking" work... it just applies some friction to the hub of the next gear, they both match speed, and then the shift collar slides easily. That method is the same method used if there was no clutch at all. Basically using the engine to match speeds, applying light force to the gear shift lever, and as the speeds match, the gear shift lever moves into the next gear.
Since you have such good driving and shifting skill, I'll be you can get that transmission to last for years. Honestly, I wouldn't worry about it. The '05 CR-V that I purchased a year ago, has 279,000mi on it, and 3rd gear syncro is worn out from a combination of the previous own "speed shifting," Honda's lame transmission fluid, and the rev-hang that Honda has programmed into the computer, as a way to cheat emissions levels. I switched to the Amsoil, and shift into 3rd as if I had no clutch. No more crunch, and I can live with it.
The only additive I use: A couple times a year, I'll dump a can of SeaFoam (white metal can with red lettering) into the fuel tank, usually when I fill up just before a big road trip. SeaFoam does a fantastic job of cleaning fuel injectors, intake ports, and the backs of the intake valves. On a car that's not been treated, the improvement in running is usually very noticeable.
wish we could get manual sprinters here in the US. Last longer than automatics.
I do enjoy driving the manual stick shift, nice when driving tight corners through mountains.