What causes difficult cold shifting in manual transmissions and by cold shifting I don't mean freezing ambient temperatures which logically would make the gearbox oil thicker/more viscous and hence make it more difficult to shift gears. Rather I am referring to median ambient temps around 25 deg celcuis and a cold engine/gearbox that's difficult to shift for the first few minutes and then once the engine nears operating temps shifting returns to normal.
What causes difficult cold shifting in manual transmissions?
- Thread starter MountainBloke
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Same thing, just less effect when the temp is higher. Synchros don't like matching speeds with molasses between them.
It's basically what you said. Oil viscosity varies with temp. Remember "cold" to a car is different than "cold" to a human.
It also could be indicative of a gearbox overdue for a fluid change, or a gearbox with an inferior or outright improper fluid. A simple fluid change drastically improved both my Vibe (90k) and my Impreza (130k), both with unknown maintenance histories.
It also could be indicative of a gearbox overdue for a fluid change, or a gearbox with an inferior or outright improper fluid. A simple fluid change drastically improved both my Vibe (90k) and my Impreza (130k), both with unknown maintenance histories.
You could try a thinner oil. Many manual transmissions work best using ATF which is really thin
Originally Posted by SubieRubyRoo
Synchros don't like matching speeds with molasses between them.
This pretty much sums it up!
Synchros don't like matching speeds with molasses between them.
This pretty much sums it up!
Originally Posted by SubieRubyRoo
Same thing, just less effect when the temp is higher. Synchros don't like matching speeds with molasses between them.
The gears rotation dragging in that thick lube make the synchros matching chore a tough job. Those big gears with a lot of rotational inertia (SECOND) are going to take a bit of time!
Same thing, just less effect when the temp is higher. Synchros don't like matching speeds with molasses between them.
The gears rotation dragging in that thick lube make the synchros matching chore a tough job. Those big gears with a lot of rotational inertia (SECOND) are going to take a bit of time!
Originally Posted by MountainBloke
What causes difficult cold shifting in manual transmissions and by cold shifting I don't mean freezing ambient temperatures which logically would make the gearbox oil thicker/more viscous and hence make it more difficult to shift gears. Rather I am referring to median ambient temps around 25 deg celcuis and a cold engine/gearbox that's difficult to shift for the first few minutes and then once the engine nears operating temps shifting returns to normal.
I bought a 2000 Honda Civic with a super notchy stick. Even the Mrs. complained. I contacted Red Line, and they recommended a lube to me. I think it was MT-1. The difference was substantial, and we were both very happy. Just a thought!
What causes difficult cold shifting in manual transmissions and by cold shifting I don't mean freezing ambient temperatures which logically would make the gearbox oil thicker/more viscous and hence make it more difficult to shift gears. Rather I am referring to median ambient temps around 25 deg celcuis and a cold engine/gearbox that's difficult to shift for the first few minutes and then once the engine nears operating temps shifting returns to normal.
I bought a 2000 Honda Civic with a super notchy stick. Even the Mrs. complained. I contacted Red Line, and they recommended a lube to me. I think it was MT-1. The difference was substantial, and we were both very happy. Just a thought!
I had one older vehicle that had gotten moisture in the fluid. Warm shifting was no issue but below freezing, VERY stiff.
Fresh fluid took care of the issue.
Fresh fluid took care of the issue.
Can difficult cold shifting have any other sources other than viscosity?
Why would I suddenly develop it out of the blue with fresh Honda MTF that's only run on 3000 miles?
Why would I suddenly develop it out of the blue with fresh Honda MTF that's only run on 3000 miles?
Originally Posted by MountainBloke
Can difficult cold shifting have any other sources other than viscosity?
Why would I suddenly develop it out of the blue with fresh Honda MTF that's only run on 3000 miles?
Anyone have any ideas, one day it suddenly started, wasn't cold outside around 77 degrees, difficult to shift into first, after the first few shifts it was fine. Now it takes a few minutes till its normal to shift, same difficulty in all gears, no grating but I have to force the gears in which doesn't feel great.
Can difficult cold shifting have any other sources other than viscosity?
Why would I suddenly develop it out of the blue with fresh Honda MTF that's only run on 3000 miles?
Anyone have any ideas, one day it suddenly started, wasn't cold outside around 77 degrees, difficult to shift into first, after the first few shifts it was fine. Now it takes a few minutes till its normal to shift, same difficulty in all gears, no grating but I have to force the gears in which doesn't feel great.
Well, for one, when a new manual transmission lubricant is introduced into the 'box - it does not immediately "take"; it can take 500 miles to be fully-in-place, within the synchro's, and only at that time it fully reveals to the driver what the shift-feel is. That Honda lubricant, now, reveals its true character.
BUT: I provide a graphic, from Volkswagen, many years ago - commenting on the choice of a manual transmission lubricant. It talks about shift-feel, and that the quality of an oil to protect some of the elements inside of the box - in a superior way - does NOT correlate with the shift feel.
I don't know why ALL of the gears feel this way to you. Usually, it is the 1st to 2nd shift (other than shifting into first) - that feels stickiest. If this is the case, either start in first, and shift really slowly to second at hardly above a walking-pace... and this is 'real easy for the gearbox; do this for the first few shifts of the day. Or, if you park the car so there is a small down-gradient when you drive-off... start in 2nd gear... don't rev it up much at all ('real little, in fact, if you can manage it) for your start -- and let out the clutch really slowly... You will not add much additional wear to your clutch if you do this just the first few times of the day. Re the other gears, just shift-up slowly at lower rpm's... and similarly if you have to shift down while the 'box is cold... do so at 'real low speeds (lower than the normal downshift speed) - again for the first few shifts of the day.
I have long accepted that a manual box has to "nursed" to operating temp. In cold climate areas.... for daily drivers, I would never run a manual... in an extremely cold place. Other than that - I just accept this as a fact related to driving a manual... and I make adjustments in my driving, to suit.
I really do like manuals... but I 'kind of think, in my mind - that I am driving a Ferrari... (I say this 'cause when most Ferrari's were manual 5 speeds... the Ferrari clubs would counsel owners to either start in second, or start in first and then shift to third... until their gearboxes warmed up). So, I do this with my "Mazdarati" hehe.
BUT: I provide a graphic, from Volkswagen, many years ago - commenting on the choice of a manual transmission lubricant. It talks about shift-feel, and that the quality of an oil to protect some of the elements inside of the box - in a superior way - does NOT correlate with the shift feel.
I don't know why ALL of the gears feel this way to you. Usually, it is the 1st to 2nd shift (other than shifting into first) - that feels stickiest. If this is the case, either start in first, and shift really slowly to second at hardly above a walking-pace... and this is 'real easy for the gearbox; do this for the first few shifts of the day. Or, if you park the car so there is a small down-gradient when you drive-off... start in 2nd gear... don't rev it up much at all ('real little, in fact, if you can manage it) for your start -- and let out the clutch really slowly... You will not add much additional wear to your clutch if you do this just the first few times of the day. Re the other gears, just shift-up slowly at lower rpm's... and similarly if you have to shift down while the 'box is cold... do so at 'real low speeds (lower than the normal downshift speed) - again for the first few shifts of the day.
I have long accepted that a manual box has to "nursed" to operating temp. In cold climate areas.... for daily drivers, I would never run a manual... in an extremely cold place. Other than that - I just accept this as a fact related to driving a manual... and I make adjustments in my driving, to suit.
I really do like manuals... but I 'kind of think, in my mind - that I am driving a Ferrari... (I say this 'cause when most Ferrari's were manual 5 speeds... the Ferrari clubs would counsel owners to either start in second, or start in first and then shift to third... until their gearboxes warmed up). So, I do this with my "Mazdarati" hehe.
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I would have thought difficult cold shifting in warm ambient temps would display itself soon after new oil has been filled if it was ever going to be an issue. The difficult shifting in my case disappears literally 5mins after starting the vehicle and once the vehicle is moving it's pretty much gone, shifting to 3rd and higher once moving isn't an issue, it's only 1st/2nd/reverse that is difficult. Though before the first pull-off when you are standing still idling all the gears are very difficult to shift into, which they never used to be.
Change out the fluid. It will shift better. It still won't be the same when warm but it will shift better.
Had the same problem with a 2006 Nissan Spec-V with the 6 speed manual. A red line fluid swap smoothed out the synchro crunch. Whatever they had from the factory wasn't ideal and a lot of others had better luck with Redline.
Originally Posted by Dave1027
You could try a thinner oil. Many manual transmissions work best using ATF which is really thin
Thanks god that we know gradiations like 75w 75w80 these days...
I wouldn put ATF in any MT or Transfer case....go to VOA/UOA section and have a look at add pack of any ATF vs GL4 or GL5 fluid...
You could try a thinner oil. Many manual transmissions work best using ATF which is really thin
Thanks god that we know gradiations like 75w 75w80 these days...
I wouldn put ATF in any MT or Transfer case....go to VOA/UOA section and have a look at add pack of any ATF vs GL4 or GL5 fluid...
sometimes it's not thick oil from viscosity - I ran into this just moving to my first syn lube in an MT. The syncros had a hard time "grabbing" 2nd just because it had friction characteristics which seemed to make it harder for them to do their job.
In addition to the excellent suggestion to grab 2nd earlier when cold, another recommendation: double-clutch when it's cold.
In addition to the excellent suggestion to grab 2nd earlier when cold, another recommendation: double-clutch when it's cold.
I have to rev match (but about 500rpms high for some reason)
Originally Posted by MountainBloke
Can difficult cold shifting have any other sources other than viscosity?
Why would I suddenly develop it out of the blue with fresh Honda MTF that's only run on 3000 miles?
Failing clutch hydraulics can cause only partial disengagement, which would increase shifting difficulty, particularly when the gear lube is also not up to operating temp.
Can difficult cold shifting have any other sources other than viscosity?
Why would I suddenly develop it out of the blue with fresh Honda MTF that's only run on 3000 miles?
Failing clutch hydraulics can cause only partial disengagement, which would increase shifting difficulty, particularly when the gear lube is also not up to operating temp.
Originally Posted by Dave1027
You could try a thinner oil. Many manual transmissions work best using ATF which is really thin
Chrysler manual gearboxes in the sixties use ATF.
You could try a thinner oil. Many manual transmissions work best using ATF which is really thin
Chrysler manual gearboxes in the sixties use ATF.
I think it have to do with type of fluid . My 03 cobra t56 was very notchy going to second when cold . After switch to Mobil 1 atf . It's smooth into second gear in cold
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