2nd gear mysterious grinding - fixed??
04-25-2016, 12:18 AM
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2nd gear mysterious grinding - fixed??
Hi all YT. It has been quite a while.
I just finished an auto-to-manual swap on a 4x4 93 4Runner with a swapped 3.4L. The transmission is behaving a little weird, and I would like to know what you gurus think. I've tried several things to solve the issue and I will summarize in detail all I've done. It's a little extensive, so bare with me. Thank you!
While installing the transmission (from a 88 4Runner), my heart stopped for about a day when I noticed that the transmission was filled with WATER! It was mixed with some oil, which means the transmission wasn't fully dry and soaked in water all this time. A guy suggested to drain, put clean oil, drive for about a week or so and then change the oil again. Back then I had no idea these transmissions dont like GL-5 oil, and so I'm sure that's what went in. Finished the swap and went for a test ride. Surprisingly, the transmission ran great. The best improvement after a 3.4 swap. However, shifting felt rough and it was sometimes hard. I could feel through the shift stick rough metal-to-metal rub when engaging gears. I started thinking that this is the way these transmissions work, and so I got used to it. It didn't seemed that bad. Eventually 2nd gear became very tricky to engage. 80% of the time, it would not fully engage, causing it to grind pretty badly. Another 15% it will almost enter, but it will grind like 2 or 3 "clicks" before fully engaging, and the other 5% it will shift normally. After two grinds, I was traumatized. The shifter actually popped out from 2nd gear a couple of times. I thought it could be the collar not fully engaging, so I tried holding down the shifter in position whenever I need 2nd gear (just a little bit of pressure, ensuring it doesn't pop out when letting go of the clutch). This is when the transmission will sometimes click a couple of times before fully engaging. Another thing that has also helped is to hold down the clutch, shift into 2nd gear, shift back to neutral and then again to 2nd gear. This has worked 100% of the time. Haven't tried proper double clutching.
In 4 days I had already done 250miles on the first batch of oil. Transmission ran perfect but with the 2nd gear grinding and the ocasional rough shifting. After reading about a million threads here and 4Crawler's complete website for the 12th time, I decided to order some Redline's MT-90 GL-4. Unlucky/lucky enough, only after I had drained the transmission oil (it was poop-brown colored) did I noticed that the delivered oil was actually Redline 75W90 GL-5 oil. I needed the truck, so I filled her with the Redline GL-5 oil. Shifting was still rough. 2nd gear still grinds as before. Alternate shifting methods also continued to work the same way. After a quick email to the supplier, they apologized and sent me a new batch of MT-90 oil free of charge. I got the oil and changed the tranny oil within 1 week (yesterday). The used oil looked brown-transparent, and I noticed A LOT of metal particles in it. I stuck a toothbrush inside the transmission drain plug and also saw more particles. They felt sharp. I didn't notice any particles on the first oil change, but I didn't look carefully either. I filled the transmission with MT-90, drained the transfer case too and filled it with the used Redline 75W90. I now wonder if that was a good idea...
Yotatech users would describe MT90 as the holy grail of transmission oils. I thought it was a bunch of BS. Boy, was I wrong! I can only use their same adjective: it feels like butter. There was no more rough shifting in any gear, even when shifting into reverse. I cant explain how nervous and anxious I get every time I move that shift stick into 2nd gear and then slowly let go of the clutch, waiting for the horrible grinding noise. Heart stops, brain mutes all outside noise, ears and right hand sensitivity is heightened while I firmly grip the shift stick, waiting for the worst. Consequently, I had developed the habit of skipping 2nd gear to avoid any more damage, only engaging it when strictly necessary. However, without performing any of the techniques from above, no 2nd gear grinding in all three attempts!!! Wohoo!!
I had already order new seats and sockets from Marlin Crawler, thinking those could also be bad and cause 2nd gear to not fully engage. I plan on changing them anyways because I have no idea on the status of the current ones. I also think is a little too early to proclaim victory on the 2nd gear grinding issue, because I'm not sure how much actual damage did the water caused, I don't know the reason for the metal particles found and the fact that I have no idea how much abuse this transmission went through before me. I did always hear these things are indestructible.
Summarizing, no grinding as of yet (will get some city driving tomorrow) and shifting is much smoother after switching from Redline 75W90 GL-5 to MT-90 GL-4. However, I want to know what are your thoughts on this. I'm not new to Toyotas, but I am fairly new to manual transmissions. How much should I be concerned over this grinding issue? How much grinding is "too much"? Could the GL-5 oil have caused this? Could the GL-4 have actually fixed this? Is it normal to see metal particles on transmission oil changes? And how much is considered "normal"? What should I expect from having left the transmission filled with water for about a month? What are the possible causes for grinding in one particular gear when shifting normally? And why on earth would it not grind when I "double shift"? Thanks in advance!
I just finished an auto-to-manual swap on a 4x4 93 4Runner with a swapped 3.4L. The transmission is behaving a little weird, and I would like to know what you gurus think. I've tried several things to solve the issue and I will summarize in detail all I've done. It's a little extensive, so bare with me. Thank you!
While installing the transmission (from a 88 4Runner), my heart stopped for about a day when I noticed that the transmission was filled with WATER! It was mixed with some oil, which means the transmission wasn't fully dry and soaked in water all this time. A guy suggested to drain, put clean oil, drive for about a week or so and then change the oil again. Back then I had no idea these transmissions dont like GL-5 oil, and so I'm sure that's what went in. Finished the swap and went for a test ride. Surprisingly, the transmission ran great. The best improvement after a 3.4 swap. However, shifting felt rough and it was sometimes hard. I could feel through the shift stick rough metal-to-metal rub when engaging gears. I started thinking that this is the way these transmissions work, and so I got used to it. It didn't seemed that bad. Eventually 2nd gear became very tricky to engage. 80% of the time, it would not fully engage, causing it to grind pretty badly. Another 15% it will almost enter, but it will grind like 2 or 3 "clicks" before fully engaging, and the other 5% it will shift normally. After two grinds, I was traumatized. The shifter actually popped out from 2nd gear a couple of times. I thought it could be the collar not fully engaging, so I tried holding down the shifter in position whenever I need 2nd gear (just a little bit of pressure, ensuring it doesn't pop out when letting go of the clutch). This is when the transmission will sometimes click a couple of times before fully engaging. Another thing that has also helped is to hold down the clutch, shift into 2nd gear, shift back to neutral and then again to 2nd gear. This has worked 100% of the time. Haven't tried proper double clutching.
In 4 days I had already done 250miles on the first batch of oil. Transmission ran perfect but with the 2nd gear grinding and the ocasional rough shifting. After reading about a million threads here and 4Crawler's complete website for the 12th time, I decided to order some Redline's MT-90 GL-4. Unlucky/lucky enough, only after I had drained the transmission oil (it was poop-brown colored) did I noticed that the delivered oil was actually Redline 75W90 GL-5 oil. I needed the truck, so I filled her with the Redline GL-5 oil. Shifting was still rough. 2nd gear still grinds as before. Alternate shifting methods also continued to work the same way. After a quick email to the supplier, they apologized and sent me a new batch of MT-90 oil free of charge. I got the oil and changed the tranny oil within 1 week (yesterday). The used oil looked brown-transparent, and I noticed A LOT of metal particles in it. I stuck a toothbrush inside the transmission drain plug and also saw more particles. They felt sharp. I didn't notice any particles on the first oil change, but I didn't look carefully either. I filled the transmission with MT-90, drained the transfer case too and filled it with the used Redline 75W90. I now wonder if that was a good idea...
Yotatech users would describe MT90 as the holy grail of transmission oils. I thought it was a bunch of BS. Boy, was I wrong! I can only use their same adjective: it feels like butter. There was no more rough shifting in any gear, even when shifting into reverse. I cant explain how nervous and anxious I get every time I move that shift stick into 2nd gear and then slowly let go of the clutch, waiting for the horrible grinding noise. Heart stops, brain mutes all outside noise, ears and right hand sensitivity is heightened while I firmly grip the shift stick, waiting for the worst. Consequently, I had developed the habit of skipping 2nd gear to avoid any more damage, only engaging it when strictly necessary. However, without performing any of the techniques from above, no 2nd gear grinding in all three attempts!!! Wohoo!!
I had already order new seats and sockets from Marlin Crawler, thinking those could also be bad and cause 2nd gear to not fully engage. I plan on changing them anyways because I have no idea on the status of the current ones. I also think is a little too early to proclaim victory on the 2nd gear grinding issue, because I'm not sure how much actual damage did the water caused, I don't know the reason for the metal particles found and the fact that I have no idea how much abuse this transmission went through before me. I did always hear these things are indestructible.
Summarizing, no grinding as of yet (will get some city driving tomorrow) and shifting is much smoother after switching from Redline 75W90 GL-5 to MT-90 GL-4. However, I want to know what are your thoughts on this. I'm not new to Toyotas, but I am fairly new to manual transmissions. How much should I be concerned over this grinding issue? How much grinding is "too much"? Could the GL-5 oil have caused this? Could the GL-4 have actually fixed this? Is it normal to see metal particles on transmission oil changes? And how much is considered "normal"? What should I expect from having left the transmission filled with water for about a month? What are the possible causes for grinding in one particular gear when shifting normally? And why on earth would it not grind when I "double shift"? Thanks in advance!
04-25-2016, 01:16 PM
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GL-4 vs GL-5 has all to do with the synchronizers, the little brass clutches that get the gears running the same speed before they slide into mesh. GL-5 is much slicker so the synchros don't work as well. GL-5 is necessary for the differentials, because the hypoid ring and pinion mesh almost like worm gears, and there is a lot of sliding contact going on. The transfer case doesn't care much one way or the other.
Some synchros can actually be damaged by GL-5, but Toyota doesn't say not to use it, so I doubt you've hurt anything by using it.
If the synchros and balk rings are working properly, GL-5 should not cause grinding, but may cause hard shifting since the gears get to the same speed very slowly.
"Double shifting", better known as double clutching, is a method of matching gear speeds with the throttle without the use of synchronizers. Used to be SOP on older truck transmissions - anything before the mid 1950's for sure, and much later for bigger over-the-road rigs. It's pretty easy to master for upshifting, not so easy for downshifting (you have to burp the throttle just the right amount between gears when downshifting).
I wouldn't worry much as long as shifting remains smooth with the GL-4. Time enough to tear the transmission apart when other symptoms appear.
Some synchros can actually be damaged by GL-5, but Toyota doesn't say not to use it, so I doubt you've hurt anything by using it.
If the synchros and balk rings are working properly, GL-5 should not cause grinding, but may cause hard shifting since the gears get to the same speed very slowly.
"Double shifting", better known as double clutching, is a method of matching gear speeds with the throttle without the use of synchronizers. Used to be SOP on older truck transmissions - anything before the mid 1950's for sure, and much later for bigger over-the-road rigs. It's pretty easy to master for upshifting, not so easy for downshifting (you have to burp the throttle just the right amount between gears when downshifting).
I wouldn't worry much as long as shifting remains smooth with the GL-4. Time enough to tear the transmission apart when other symptoms appear.
04-25-2016, 01:36 PM
#3
I'm glad you got it running better. But just the thought of what the inside of that thing looks like makes me wanna 
Metal particles as you describe them = bad news
Basically if there's anything but a very fine powder, there's some pretty substantial damage going on. As big or bigger than a grain of sand, or sharp to the touch, not good.
If I were you I'd be planning on swapping it out again in the near future. How near? That's the question. I'd bet you don't get another 50K out of it. 100K at best. But who knows? They definitely ARE NOT indestructible though.
Metal particles as you describe them = bad news
Basically if there's anything but a very fine powder, there's some pretty substantial damage going on. As big or bigger than a grain of sand, or sharp to the touch, not good.
If I were you I'd be planning on swapping it out again in the near future. How near? That's the question. I'd bet you don't get another 50K out of it. 100K at best. But who knows? They definitely ARE NOT indestructible though.
Last edited by MudHippy; 04-25-2016 at 03:21 PM.
04-25-2016, 10:25 PM
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GL-4 vs GL-5 has all to do with the synchronizers, the little brass clutches that get the gears running the same speed before they slide into mesh. GL-5 is much slicker so the synchros don't work as well. GL-5 is necessary for the differentials, because the hypoid ring and pinion mesh almost like worm gears, and there is a lot of sliding contact going on. The transfer case doesn't care much one way or the other.
Some synchros can actually be damaged by GL-5, but Toyota doesn't say not to use it, so I doubt you've hurt anything by using it.
If the synchros and balk rings are working properly, GL-5 should not cause grinding, but may cause hard shifting since the gears get to the same speed very slowly.
"Double shifting", better known as double clutching, is a method of matching gear speeds with the throttle without the use of synchronizers. Used to be SOP on older truck transmissions - anything before the mid 1950's for sure, and much later for bigger over-the-road rigs. It's pretty easy to master for upshifting, not so easy for downshifting (you have to burp the throttle just the right amount between gears when downshifting).
I wouldn't worry much as long as shifting remains smooth with the GL-4. Time enough to tear the transmission apart when other symptoms appear.
Some synchros can actually be damaged by GL-5, but Toyota doesn't say not to use it, so I doubt you've hurt anything by using it.
If the synchros and balk rings are working properly, GL-5 should not cause grinding, but may cause hard shifting since the gears get to the same speed very slowly.
"Double shifting", better known as double clutching, is a method of matching gear speeds with the throttle without the use of synchronizers. Used to be SOP on older truck transmissions - anything before the mid 1950's for sure, and much later for bigger over-the-road rigs. It's pretty easy to master for upshifting, not so easy for downshifting (you have to burp the throttle just the right amount between gears when downshifting).
I wouldn't worry much as long as shifting remains smooth with the GL-4. Time enough to tear the transmission apart when other symptoms appear.
I'm glad you got it running better. But just the thought of what the inside of that thing looks like makes me wanna
Metal particles as you describe them = bad news
Basically if there's anything but a very fine powder, there's some pretty substantial damage going on. As big or bigger than a grain of sand, or sharp to the touch, not good.
If I were you I'd be planning on swapping it out again in the near future. How near? That's the question. I'd bet you don't get another 50K out of it. 100K at best. But who knows? They definitely ARE NOT indestructible though.
Metal particles as you describe them = bad news
Basically if there's anything but a very fine powder, there's some pretty substantial damage going on. As big or bigger than a grain of sand, or sharp to the touch, not good.
If I were you I'd be planning on swapping it out again in the near future. How near? That's the question. I'd bet you don't get another 50K out of it. 100K at best. But who knows? They definitely ARE NOT indestructible though.
Not for the faint of heart nor for weak stomachs:
Draining water from transmission
Draining water from transfer case
04-27-2016, 10:36 AM
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I will try to take some pics of the particles found on the tranny.
In the mean time, any thoughts on the water found inside? How much damage could this have caused?
In the mean time, any thoughts on the water found inside? How much damage could this have caused?
