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Originally Posted by kwerks
(Post 7717124)
Here is what I use and it solved my rough shifts
Mobil 1 Synthetic Gear Lube LS 75W-140 http://www.mobiloil.com/USA-English/...75W-140LS.aspx http://www.mobil.com/USA-English/Lub...LS_75W-140.asp Dave |
Originally Posted by dgeesaman
(Post 7741775)
That lube is for limited slip truck axles, not for hypoid differentials or synchromesh transmissions. It might work ok, but I would not recommend it.
Dave Seems to work really well..I had mazda factory oil in there before and shifts required a lot of effort...switched to this and its very smooth now... |
I don't doubt your results - it's just that using a gear oil like that with friction modifiers is a shot in the dark as far as results go, and it may not be chemically compatible with your synchros over time.
In theory, friction modifier additive may help many synchromesh shifting issues. Dave |
Also forgot to add that it runs many times cooler. Don't know why but when the factory oil was in there the tranny would heat up so much that the shift knob would reach 120F!!! (i used the mini laser thermo reader from micro temp so its + - 3-5F) With this new oil the shift knob never heats up. I'll be using it all track season so I'll report back on how it goes.
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Originally Posted by dgeesaman
(Post 7741771)
My recommendation is Amsoil MTG GL-4 oil or Redline MT-90. You can get the Amsoil from any Amsoil rep. Redline is on some store shelves.
I recommend these because the friction coefficient maximizes synchronizer response. I would not use them in the diff though - something like an Amsoil Severe Gear or Redline Shockproof is best for the diff. IMHO, if you're going to go to the trouble and cost of putting in synthetic gear lubes then it makes no sense to put the same thing in both the diff and tranny. The diff and tranny have much different lubrcation needs, and for not much extra cost you can put the best in both. Dave |
Originally Posted by kwerks
(Post 7743399)
Also forgot to add that it runs many times cooler. Don't know why but when the factory oil was in there the tranny would heat up so much that the shift knob would reach 120F!!! (i used the mini laser thermo reader from micro temp so its + - 3-5F) With this new oil the shift knob never heats up. I'll be using it all track season so I'll report back on how it goes.
I imagine you'd see similar results with any synthetic compared to stock dino oil. Dave |
hate to bring this thread back up but I just changed my gear oil to the Neo synthetic and my 2nd gear crunches now. I do not know what was in the box before. What sucks is that I just had the tranny out for a 5th gear sync change. Anyone know of a good friction modifier to get me going for a while before I drop the trans again for a rebuild?
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^ Im having similar issues..
I just changed to Neo and have the 2nd gear crunch when not FULLY warmed up. Would make any difference to change the fluid again? I read that the second change might help out in smoothness. |
You could put an axle friction modifier. No idea how much though - I would start small and add little more at a time until it gets about right.
Dave |
Originally Posted by Aeka GSR
(Post 8073670)
hate to bring this thread back up but I just changed my gear oil to the Neo synthetic and my 2nd gear crunches now. I do not know what was in the box before. What sucks is that I just had the tranny out for a 5th gear sync change. Anyone know of a good friction modifier to get me going for a while before I drop the trans again for a rebuild?
I got the same result changing to Neo, but in 4th gear. Before that I ran redline MT90 for years - no grinding whatsoever but it was very slow to take 2nd even when warm. I just bought some Amsoil MTG to give that a try. FWIW my trans has 130K miles on it, not recently rebuilt. |
let me know how it goes. I'm frustrated because mine only has 52k miles. These transmissions go to shit too quickly. I've had a turbo Integra GSR that i beat the ever living shit out of from 53k miles (when i put the turbo on) to 120k miles and the trans never gave me crap.
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Well I got the Amsoil MTG in and tested it back-to-back with Neo. Engagement is even quicker/easier than Neo, but the grinding into 4th is also a bit worse. Seems thinner than both Neo and MT90.
This stuff would be great if my trans wasn't so old and tired. In it's current condition, it might even grind 4th with MT90, it's been over a year since I switched to Neo. Maybe I'll try royal purple at some point. |
Digdug, your tranny sounds perfect to try out friction modifier. :)
Dave |
Originally Posted by Aeka GSR
(Post 8078240)
let me know how it goes. I'm frustrated because mine only has 52k miles. These transmissions go to shit too quickly. I've had a turbo Integra GSR that i beat the ever living shit out of from 53k miles (when i put the turbo on) to 120k miles and the trans never gave me crap.
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Originally Posted by dgeesaman
(Post 8079914)
Digdug, your tranny sounds perfect to try out friction modifier. :)
Dave I might as well give it a try. Which friction modifier do you recommend? Any idea how much to add at first? I read that there are modifiers out there to both increase and decrease friction - to help with grinding, would I want to increase friction? Obviously the FM is used to address grinding, but how does it also affect engagement speed, as I've gotten noticeably different results with different oils? |
Synchros are brakes. If you're getting grinding it's because they don't have enough friction to 'stop' the rotating parts. So you'd want some kind to add friction.
I have no idea which one to try first. Probably an aftermarket brand, since OEMs tend not to tell you anything useful about their fluids. I'm going to google that idea at lunch today. Dave |
ill call my supplier today to see what kind of modifiers they have and what they actually do.
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I've been reading up on friction modifiers for synchros.
Lots of people using GM synchromesh w/ FM on all kinds of cars and claiming miracle results. Of course it's not a 75w90 which some have pointed out. There is a Motorcraft synth 75w90 GL4 with friction modifier which is supposedly made by Fuchs. It's much more expensive but it's a real 75w90 unlike GMSFM. I read about this on miata.net, the 6-speed owners apparently get grinding issues. I read that you can get the GM friction modifier additive by itself from Chrysler, maybe I can try mixing some of that in with the Amsoil. It's part #4874464. |
damn it, i totally forgot to call my supplier. Hopefully I will remember on Monday.
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Originally Posted by DigDug
(Post 8082482)
I've been reading up on friction modifiers for synchros.
Lots of people using GM synchromesh w/ FM on all kinds of cars and claiming miracle results. Of course it's not a 75w90 which some have pointed out. There is a Motorcraft synth 75w90 GL4 with friction modifier which is supposedly made by Fuchs. It's much more expensive but it's a real 75w90 unlike GMSFM. I read about this on miata.net, the 6-speed owners apparently get grinding issues. I read that you can get the GM friction modifier additive by itself from Chrysler, maybe I can try mixing some of that in with the Amsoil. It's part #4874464. |
I am around 6,000 to 17,000 dollar transmissions in my line of work, our builder tells us to mix in a friction modifier if we can't get hold of the oil he wants us to use. Now if i can remember to call (im a retard) ill find out what the modifier is that we use. 3rd times a charm, right??
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Originally Posted by Aeka GSR
(Post 8097395)
I am around 6,000 to 17,000 dollar transmissions in my line of work, our builder tells us to mix in a friction modifier if we can't get hold of the oil he wants us to use. Now if i can remember to call (im a retard) ill find out what the modifier is that we use. 3rd times a charm, right??
I'd like to hear what you guys use. Turns out that Chrysler part # was wrong, and the only modifier I can find separate from Chrysler and Ford is the LSD additive. I haven't looked into it any further. What kind of transmissions do you work with? |
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Originally Posted by DigDug
(Post 8097455)
I'd like to hear what you guys use. Turns out that Chrysler part # was wrong, and the only modifier I can find separate from Chrysler and Ford is the LSD additive. I haven't looked into it any further.
What kind of transmissions do you work with? |
Dave |
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