I have noticed a trend among OEM transmission builders to add better air release properties to their ATF specifications. This is not necessarily anti-foam properties. The reasoning given is to reduce “pump whine” caused by implosion of air bubbles and pressure ripples. I am curious if any of BITOG commentators have experienced whine in newer transmissions and if so which ones?
AT Whine
- Thread starter DWC28
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My Nissan CVT has terrible whine and a FORD PS failure AAAAaaaHHHhhrrrrr! sound.
On the Nissan CVTs, doesn't that whine mean it's about to blow?
No idea but any time I had one whining it wasn't long for this world.
I am fairly sure there are several causes for transmission whine. I am curious as it seems the OEMs may be trying to solve a problem which they have not yet acknowledged and may never do so. It seems to be occurring in transmissions with smaller sumps and higher pressures. One solution has been to add baffling around the rotating parts so they do not contact the ATF (have you seen that?) Another is more anti-foam which as it is not soluble in ATF creates problems on its own. Also I may just be imagining it.
I am fairly sure there are several causes for transmission whine. I am curious as it seems the OEMs may be trying to solve a problem which they have not yet acknowledged and may never do so. It seems to be occurring in transmissions with smaller sumps and higher pressures. One solution has been to add baffling around the rotating parts so they do not contact the ATF (have you seen that?) Another is more anti-foam which as it is not soluble in ATF creates problems on its own. Also I may just be imagining it.
I've heard a number of transmissions that have planetary gear whine, also a number of transmissions that have loud pumps. Some have fluid noise. It seems like there is an acceptable range. One of my cars makes noise if the transmission is in manual mode.
Air entrapment in the fluid can cause pump whine. Mine is not to the loud siren level but still noticeable at lower rpms.
MolaKule
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Originally Posted By: DWC28
I am fairly sure there are several causes for transmission whine. I am curious as it seems the OEMs may be trying to solve a problem which they have not yet acknowledged and may never do so. It seems to be occurring in transmissions with smaller sumps and higher pressures. One solution has been to add baffling around the rotating parts so they do not contact the ATF (have you seen that?) Another is more anti-foam which as it is not soluble in ATF creates problems on its own. Also I may just be imagining it.
In my experience, most of the "zizz" like whine comes from the torque converter area and it has been due to pump wear, pump leakage, or pump bypassing.
My friends tranny shop did have a tranny one time that had a sort of modified "zizz" like whine and it turned out to be a crack in the flex plate near one of the attachment bolts.
I am fairly sure there are several causes for transmission whine. I am curious as it seems the OEMs may be trying to solve a problem which they have not yet acknowledged and may never do so. It seems to be occurring in transmissions with smaller sumps and higher pressures. One solution has been to add baffling around the rotating parts so they do not contact the ATF (have you seen that?) Another is more anti-foam which as it is not soluble in ATF creates problems on its own. Also I may just be imagining it.
In my experience, most of the "zizz" like whine comes from the torque converter area and it has been due to pump wear, pump leakage, or pump bypassing.
My friends tranny shop did have a tranny one time that had a sort of modified "zizz" like whine and it turned out to be a crack in the flex plate near one of the attachment bolts.
Originally Posted By: mclasser
A whining tranny usually means some bearing's shot. Definitely not a good thing.
Some trannies whine by design - not so much with passenger car ones(although Honda trannies sound different), but Voith bus ones have a distinctive whine to them and a whirr when the torque converter is in retarder mode.
A whining tranny usually means some bearing's shot. Definitely not a good thing.
Some trannies whine by design - not so much with passenger car ones(although Honda trannies sound different), but Voith bus ones have a distinctive whine to them and a whirr when the torque converter is in retarder mode.
AT545s whine like crazy!
One of the strong memories from my childhood is riding to school on the old GMC bus with some sort of gas engine and an AT545.
One of the strong memories from my childhood is riding to school on the old GMC bus with some sort of gas engine and an AT545.
Originally Posted By: Miller88
AT545s whine like crazy!
One of the strong memories from my childhood is riding to school on the old GMC bus with some sort of gas engine and an AT545.
Yes, me too. I remember when my school district changed from manual buses to the auto. They made a crazy amount of noise in 1st gear and during the 1-2 shift.
AT545s whine like crazy!
One of the strong memories from my childhood is riding to school on the old GMC bus with some sort of gas engine and an AT545.
Yes, me too. I remember when my school district changed from manual buses to the auto. They made a crazy amount of noise in 1st gear and during the 1-2 shift.
Originally Posted By: CBR.worm
Originally Posted By: Miller88
AT545s whine like crazy!
One of the strong memories from my childhood is riding to school on the old GMC bus with some sort of gas engine and an AT545.
Yes, me too. I remember when my school district changed from manual buses to the auto. They made a crazy amount of noise in 1st gear and during the 1-2 shift.
The HT747/748 used in front of a Detroit 6V-92TA also made those noises, you can even hear the 1-2 shift whirr above the blower. The newer Allisons don't make that much noise.
Originally Posted By: Miller88
AT545s whine like crazy!
One of the strong memories from my childhood is riding to school on the old GMC bus with some sort of gas engine and an AT545.
Yes, me too. I remember when my school district changed from manual buses to the auto. They made a crazy amount of noise in 1st gear and during the 1-2 shift.
The HT747/748 used in front of a Detroit 6V-92TA also made those noises, you can even hear the 1-2 shift whirr above the blower. The newer Allisons don't make that much noise.
I have a 2007 Kia Rondo V6 with a 5spd automatic trans and it whines like an old turnip truck with a granny gear. Kia replaced the first 2 transmissions b/c of it, the third does the same thing and has for the last 80k miles. I do a drain and fill on the ATF with Valvoline MaxLife Synthetic every 10k miles, just in case, but it still whines like crazy. I just tell my daughter to turn up the radio and ignore it
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