ZF6 Oil
09-10-2017, 11:29 PM
#2
Race Director
In the transmission?
I wouldn't use motor oil in the transmission... I used Pennzoil Synchromesh, works great.
In the engine, whatever Synthetic 5W30 is fine. I use Supertech Full Synthetic from Walmart in my C4, because well, it's old and I don't think it's worth the extra $10 for Mobil 1 for it.
I wouldn't use motor oil in the transmission... I used Pennzoil Synchromesh, works great.
In the engine, whatever Synthetic 5W30 is fine. I use Supertech Full Synthetic from Walmart in my C4, because well, it's old and I don't think it's worth the extra $10 for Mobil 1 for it.
09-11-2017, 12:10 AM
#3
Pro
Thread Starter
Thanks, I tried finding that also at a few autoparts stores but couldn't find it but I just looked it up at and looks like a few other stores in my area carry it. Going to return the Royal Purple I bought and pick a few quarts of the Pennzoil up.
09-11-2017, 10:15 AM
#5
Race Director
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One of the recommended lubricants for the ZF6 is the Castrol Motorsports TWS 10w-60 full synthetic motor oil available at BMW dealers. It's been in my ZF for 15 years.
09-11-2017, 11:43 AM
#6
Melting Slicks
I used this stuff, like many others on the forum, just did the fluid change last week!
https://www.summitracing.com/parts/p...0aAqusEALw_wcB
Pic of the old stuff, was down about half a quart I think
https://www.summitracing.com/parts/p...0aAqusEALw_wcB
Pic of the old stuff, was down about half a quart I think
09-11-2017, 11:59 AM
#7
Drifting
GM sells a synthetic manual trans oil that works well. 10W60 motor oil has been found to to cause problems by some forum members (see past threads)
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dizwiz24 (10-09-2019)
09-11-2017, 09:54 PM
#8
Safety Car
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2023 C4 of the Year Finalist- Modified
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Old thread with positive experiences - https://www.corvetteforum.com/forums...ranny-wow.html
09-12-2017, 03:33 PM
#9
Team Owner
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Co-winner 2020 C4 of the Year - Modified
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St. Jude Donor '09-'10-'11-'12-'13-'14-'15-'16-'17-'18-'19-'20
When I first bought The Ghost I changed to the TWS and I was OK with it because I could not compare with any other. Later on, I kept reading about Amsoil Synchromesh, gave it a chance and I was very pleased with the results. The ZF shifts smoothly with Amsoil and has never gone back to TWS.
I just did another trip (only 5,700 miles) with new Amsoil and all was great.
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vettespecial (10-11-2019)
09-13-2017, 07:14 AM
#10
Melting Slicks
When I first bought The Ghost I changed to the TWS and I was OK with it because I could not compare with any other. Later on, I kept reading about Amsoil Synchromesh, gave it a chance and I was very pleased with the results. The ZF shifts smoothly with Amsoil and has never gone back to TWS.
I just did another trip (only 5,700 miles) with new Amsoil and all was great.
09-13-2017, 10:18 AM
#11
Le Mans Master
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Tale of an inherent ZF flaw and resulting lubrication failure:
After my ZF locked up as I was doing about 70 on the interstate, I got a new ZF from Bill Boudreau (ZF doc), and some sage advice:
Bill told me this wasn't an un-common failure for the ZF. Up to that point, I had been using the GM recommended fill. which was a mineral oil base lube (non-synthetic), as I understand it to be (at that time).
The issue, as Bill explained it, is the too small size of the oil galleries, especially those feeding the reverse gear.
Its that reverse gear, or rather the lack of lubrication, that is the real issue. That gear too is synchromeshed with the others (read: engaged to the output shaft), and when not being used, it spins freely on its shaft.
Being a rather small (low) gear, it not only spins freely on its shaft, but at very high speed (especially when in 6th gear). As result, the oil film between the gear and its shaft is put to the extreme test, and with some oils that film has sometimes broken down, and then metal to metal contact begins to occur.
The metal on metal heat then becomes sufficient that the gear begins galling to the shaft and (effectively) tries to engage. (It is pre-told by a sudden dragging felt as tho the brakes had been applied. It is intermittent at first, but quickly becoming more severe; accompanied with some deep guttural groaning sound - felt as well as heard - coming from the transmission.
Within moments of the first indication of trouble, the galling is sufficient to weld the gear to the shaft! The result is essentially having two gears engaged at the same time (reverse and whatever), and the output shaft locks, "freezing" the differential pinion gear in place, and thus the rear wheels freeze in position and the car skids to a stop! (Not fun - especially on the expressway, I can tell you!)
For a price, as part of a special ZF prep package, Bill said he enlarges those galleries. But! if I didn't opt for the upgrade, I should be sure to use synthetic oil which may be sufficient to avoid a lubrication failure.
The ZF is a German design, and the recommendation was the Castrol TWS 10W-60* synthetic (from my local BMW dealer). It seemed to work fine - or at least my ZF never again locked up afterward.
Then Castrol discontinued that TWS. What to do?
Frankly, there are several good synthetic gear oil sources; AMSoil synthetic Synchromesh Gear Oil, Mobil 1 synthetic gear oil, Redline synthetic Heavy Shockproof...to mention some of the popular ones. And, some (most of these mentioned) not only provide protection from that inherent reverse gear issue, but improve the ease/smoothness of shifts across the entire (transmission) temperature range.
I'm using the Redline Heavy Shockproof in my ZF, upon recommendation by a renown ZR-1 mechanic. And, like some others, I immediately felt a difference in the shifting - a bit smoother...I think.
The point is to avoid a possible catastrophe. Use a good synthetic gear oil. In the 12 years since my "lockup" mishap, I've not had further issues with any of (3) ZFs...knock on wood!
After my ZF locked up as I was doing about 70 on the interstate, I got a new ZF from Bill Boudreau (ZF doc), and some sage advice:
Bill told me this wasn't an un-common failure for the ZF. Up to that point, I had been using the GM recommended fill. which was a mineral oil base lube (non-synthetic), as I understand it to be (at that time).
The issue, as Bill explained it, is the too small size of the oil galleries, especially those feeding the reverse gear.
Its that reverse gear, or rather the lack of lubrication, that is the real issue. That gear too is synchromeshed with the others (read: engaged to the output shaft), and when not being used, it spins freely on its shaft.
Being a rather small (low) gear, it not only spins freely on its shaft, but at very high speed (especially when in 6th gear). As result, the oil film between the gear and its shaft is put to the extreme test, and with some oils that film has sometimes broken down, and then metal to metal contact begins to occur.
The metal on metal heat then becomes sufficient that the gear begins galling to the shaft and (effectively) tries to engage. (It is pre-told by a sudden dragging felt as tho the brakes had been applied. It is intermittent at first, but quickly becoming more severe; accompanied with some deep guttural groaning sound - felt as well as heard - coming from the transmission.
Within moments of the first indication of trouble, the galling is sufficient to weld the gear to the shaft! The result is essentially having two gears engaged at the same time (reverse and whatever), and the output shaft locks, "freezing" the differential pinion gear in place, and thus the rear wheels freeze in position and the car skids to a stop! (Not fun - especially on the expressway, I can tell you!)
For a price, as part of a special ZF prep package, Bill said he enlarges those galleries. But! if I didn't opt for the upgrade, I should be sure to use synthetic oil which may be sufficient to avoid a lubrication failure.
The ZF is a German design, and the recommendation was the Castrol TWS 10W-60* synthetic (from my local BMW dealer). It seemed to work fine - or at least my ZF never again locked up afterward.
Then Castrol discontinued that TWS. What to do?
Frankly, there are several good synthetic gear oil sources; AMSoil synthetic Synchromesh Gear Oil, Mobil 1 synthetic gear oil, Redline synthetic Heavy Shockproof...to mention some of the popular ones. And, some (most of these mentioned) not only provide protection from that inherent reverse gear issue, but improve the ease/smoothness of shifts across the entire (transmission) temperature range.
I'm using the Redline Heavy Shockproof in my ZF, upon recommendation by a renown ZR-1 mechanic. And, like some others, I immediately felt a difference in the shifting - a bit smoother...I think.
The point is to avoid a possible catastrophe. Use a good synthetic gear oil. In the 12 years since my "lockup" mishap, I've not had further issues with any of (3) ZFs...knock on wood!
09-13-2017, 12:09 PM
#13
Melting Slicks
Member Since: Jan 2014
Location: Downers Grove Illinois
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Tale of an inherent ZF flaw and resulting lubrication failure:
After my ZF locked up as I was doing about 70 on the interstate, I got a new ZF from Bill Boudreau (ZF doc), and some sage advice:
Bill told me this wasn't an un-common failure for the ZF. Up to that point, I had been using the GM recommended fill. which was a mineral oil base lube (non-synthetic), as I understand it to be (at that time).
The issue, as Bill explained it, is the too small size of the oil galleries, especially those feeding the reverse gear.
Its that reverse gear, or rather the lack of lubrication, that is the real issue. That gear too is synchromeshed with the others (read: engaged to the output shaft), and when not being used, it spins freely on its shaft.
Being a rather small (low) gear, it not only spins freely on its shaft, but at very high speed (especially when in 6th gear). As result, the oil film between the gear and its shaft is put to the extreme test, and with some oils that film has sometimes broken down, and then metal to metal contact begins to occur.
The metal on metal heat then becomes sufficient that the gear begins galling to the shaft and (effectively) tries to engage. (It is pre-told by a sudden dragging felt as tho the brakes had been applied. It is intermittent at first, but quickly becoming more severe; accompanied with some deep guttural groaning sound - felt as well as heard - coming from the transmission.
Within moments of the first indication of trouble, the galling is sufficient to weld the gear to the shaft! The result is essentially having two gears engaged at the same time (reverse and whatever), and the output shaft locks, "freezing" the differential pinion gear in place, and thus the rear wheels freeze in position and the car skids to a stop! (Not fun - especially on the expressway, I can tell you!)
For a price, as part of a special ZF prep package, Bill said he enlarges those galleries. But! if I didn't opt for the upgrade, I should be sure to use synthetic oil which may be sufficient to avoid a lubrication failure.
The ZF is a German design, and the recommendation was the Castrol TWS 10W-60* synthetic (from my local BMW dealer). It seemed to work fine - or at least my ZF never again locked up afterward.
Then Castrol discontinued that TWS. What to do?
Frankly, there are several good synthetic gear oil sources; AMSoil synthetic Synchromesh Gear Oil, Mobil 1 synthetic gear oil, Redline synthetic Heavy Shockproof...to mention some of the popular ones. And, some (most of these mentioned) not only provide protection from that inherent reverse gear issue, but improve the ease/smoothness of shifts across the entire (transmission) temperature range.
I'm using the Redline Heavy Shockproof in my ZF, upon recommendation by a renown ZR-1 mechanic. And, like some others, I immediately felt a difference in the shifting - a bit smoother...I think.
The point is to avoid a possible catastrophe. Use a good synthetic gear oil. In the 12 years since my "lockup" mishap, I've not had further issues with any of (3) ZFs...knock on wood!
After my ZF locked up as I was doing about 70 on the interstate, I got a new ZF from Bill Boudreau (ZF doc), and some sage advice:
Bill told me this wasn't an un-common failure for the ZF. Up to that point, I had been using the GM recommended fill. which was a mineral oil base lube (non-synthetic), as I understand it to be (at that time).
The issue, as Bill explained it, is the too small size of the oil galleries, especially those feeding the reverse gear.
Its that reverse gear, or rather the lack of lubrication, that is the real issue. That gear too is synchromeshed with the others (read: engaged to the output shaft), and when not being used, it spins freely on its shaft.
Being a rather small (low) gear, it not only spins freely on its shaft, but at very high speed (especially when in 6th gear). As result, the oil film between the gear and its shaft is put to the extreme test, and with some oils that film has sometimes broken down, and then metal to metal contact begins to occur.
The metal on metal heat then becomes sufficient that the gear begins galling to the shaft and (effectively) tries to engage. (It is pre-told by a sudden dragging felt as tho the brakes had been applied. It is intermittent at first, but quickly becoming more severe; accompanied with some deep guttural groaning sound - felt as well as heard - coming from the transmission.
Within moments of the first indication of trouble, the galling is sufficient to weld the gear to the shaft! The result is essentially having two gears engaged at the same time (reverse and whatever), and the output shaft locks, "freezing" the differential pinion gear in place, and thus the rear wheels freeze in position and the car skids to a stop! (Not fun - especially on the expressway, I can tell you!)
For a price, as part of a special ZF prep package, Bill said he enlarges those galleries. But! if I didn't opt for the upgrade, I should be sure to use synthetic oil which may be sufficient to avoid a lubrication failure.
The ZF is a German design, and the recommendation was the Castrol TWS 10W-60* synthetic (from my local BMW dealer). It seemed to work fine - or at least my ZF never again locked up afterward.
Then Castrol discontinued that TWS. What to do?
Frankly, there are several good synthetic gear oil sources; AMSoil synthetic Synchromesh Gear Oil, Mobil 1 synthetic gear oil, Redline synthetic Heavy Shockproof...to mention some of the popular ones. And, some (most of these mentioned) not only provide protection from that inherent reverse gear issue, but improve the ease/smoothness of shifts across the entire (transmission) temperature range.
I'm using the Redline Heavy Shockproof in my ZF, upon recommendation by a renown ZR-1 mechanic. And, like some others, I immediately felt a difference in the shifting - a bit smoother...I think.
The point is to avoid a possible catastrophe. Use a good synthetic gear oil. In the 12 years since my "lockup" mishap, I've not had further issues with any of (3) ZFs...knock on wood!
09-13-2017, 12:54 PM
#14
Instructor
Anyone on the qualities of the Royal purple?
Also, I though that GM syncromesh semi-synthetic is highly recommended.....isn't it?.., or is it the full synthetic GM man. trans. fluid??
I too will be having mine changed soon and am following this thread closely. I really don't want to make a fine shifting trans. with albeit old fluid shift worse with new fluid.
Also, I though that GM syncromesh semi-synthetic is highly recommended.....isn't it?.., or is it the full synthetic GM man. trans. fluid??
I too will be having mine changed soon and am following this thread closely. I really don't want to make a fine shifting trans. with albeit old fluid shift worse with new fluid.
Last edited by SR71!; 09-13-2017 at 01:00 PM.
10-08-2019, 10:59 AM
#15
Tale of an inherent ZF flaw and resulting lubrication failure
The ZF is a German design, and the recommendation was the Castrol TWS 10W-60* synthetic (from my local BMW dealer). It seemed to work fine - or at least my ZF never again locked up afterward.
Then Castrol discontinued that TWS. What to do?
The ZF is a German design, and the recommendation was the Castrol TWS 10W-60* synthetic (from my local BMW dealer). It seemed to work fine - or at least my ZF never again locked up afterward.
Then Castrol discontinued that TWS. What to do?
10-09-2019, 02:15 PM
#16
Melting Slicks
Royal Purple makes a Synchromesh oil, some CF users say it is good in the ZF6. Any synchromesh 5w30 oil will work in the ZF6, which one you use depends on how long you want to leave it in. Pennzoil and Valvoline synchromesh are good but will not last as long as the synthetic products from RP and Amsoil.
10-11-2019, 03:27 AM
#17
Instructor
When I first bought The Ghost I changed to the TWS and I was OK with it because I could not compare with any other. Later on, I kept reading about Amsoil Synchromesh, gave it a chance and I was very pleased with the results. The ZF shifts smoothly with Amsoil and has never gone back to TWS.
I just did another trip (only 5,700 miles) with new Amsoil and all was great.
10-11-2019, 08:07 AM
#18
Tale of an inherent ZF flaw and resulting lubrication failure:
After my ZF locked up as I was doing about 70 on the interstate, I got a new ZF from Bill Boudreau (ZF doc), and some sage advice:
Bill told me this wasn't an un-common failure for the ZF. Up to that point, I had been using the GM recommended fill. which was a mineral oil base lube (non-synthetic), as I understand it to be (at that time).
The issue, as Bill explained it, is the too small size of the oil galleries, especially those feeding the reverse gear.
Its that reverse gear, or rather the lack of lubrication, that is the real issue. That gear too is synchromeshed with the others (read: engaged to the output shaft), and when not being used, it spins freely on its shaft.
Being a rather small (low) gear, it not only spins freely on its shaft, but at very high speed (especially when in 6th gear). As result, the oil film between the gear and its shaft is put to the extreme test, and with some oils that film has sometimes broken down, and then metal to metal contact begins to occur.
The metal on metal heat then becomes sufficient that the gear begins galling to the shaft and (effectively) tries to engage. (It is pre-told by a sudden dragging felt as tho the brakes had been applied. It is intermittent at first, but quickly becoming more severe; accompanied with some deep guttural groaning sound - felt as well as heard - coming from the transmission.
Within moments of the first indication of trouble, the galling is sufficient to weld the gear to the shaft! The result is essentially having two gears engaged at the same time (reverse and whatever), and the output shaft locks, "freezing" the differential pinion gear in place, and thus the rear wheels freeze in position and the car skids to a stop! (Not fun - especially on the expressway, I can tell you!)
For a price, as part of a special ZF prep package, Bill said he enlarges those galleries. But! if I didn't opt for the upgrade, I should be sure to use synthetic oil which may be sufficient to avoid a lubrication failure.
The ZF is a German design, and the recommendation was the Castrol TWS 10W-60* synthetic (from my local BMW dealer). It seemed to work fine - or at least my ZF never again locked up afterward.
Then Castrol discontinued that TWS. What to do?
Frankly, there are several good synthetic gear oil sources; AMSoil synthetic Synchromesh Gear Oil, Mobil 1 synthetic gear oil, Redline synthetic Heavy Shockproof...to mention some of the popular ones. And, some (most of these mentioned) not only provide protection from that inherent reverse gear issue, but improve the ease/smoothness of shifts across the entire (transmission) temperature range.
I'm using the Redline Heavy Shockproof in my ZF, upon recommendation by a renown ZR-1 mechanic. And, like some others, I immediately felt a difference in the shifting - a bit smoother...I think.
The point is to avoid a possible catastrophe. Use a good synthetic gear oil. In the 12 years since my "lockup" mishap, I've not had further issues with any of (3) ZFs...knock on wood!
After my ZF locked up as I was doing about 70 on the interstate, I got a new ZF from Bill Boudreau (ZF doc), and some sage advice:
Bill told me this wasn't an un-common failure for the ZF. Up to that point, I had been using the GM recommended fill. which was a mineral oil base lube (non-synthetic), as I understand it to be (at that time).
The issue, as Bill explained it, is the too small size of the oil galleries, especially those feeding the reverse gear.
Its that reverse gear, or rather the lack of lubrication, that is the real issue. That gear too is synchromeshed with the others (read: engaged to the output shaft), and when not being used, it spins freely on its shaft.
Being a rather small (low) gear, it not only spins freely on its shaft, but at very high speed (especially when in 6th gear). As result, the oil film between the gear and its shaft is put to the extreme test, and with some oils that film has sometimes broken down, and then metal to metal contact begins to occur.
The metal on metal heat then becomes sufficient that the gear begins galling to the shaft and (effectively) tries to engage. (It is pre-told by a sudden dragging felt as tho the brakes had been applied. It is intermittent at first, but quickly becoming more severe; accompanied with some deep guttural groaning sound - felt as well as heard - coming from the transmission.
Within moments of the first indication of trouble, the galling is sufficient to weld the gear to the shaft! The result is essentially having two gears engaged at the same time (reverse and whatever), and the output shaft locks, "freezing" the differential pinion gear in place, and thus the rear wheels freeze in position and the car skids to a stop! (Not fun - especially on the expressway, I can tell you!)
For a price, as part of a special ZF prep package, Bill said he enlarges those galleries. But! if I didn't opt for the upgrade, I should be sure to use synthetic oil which may be sufficient to avoid a lubrication failure.
The ZF is a German design, and the recommendation was the Castrol TWS 10W-60* synthetic (from my local BMW dealer). It seemed to work fine - or at least my ZF never again locked up afterward.
Then Castrol discontinued that TWS. What to do?
Frankly, there are several good synthetic gear oil sources; AMSoil synthetic Synchromesh Gear Oil, Mobil 1 synthetic gear oil, Redline synthetic Heavy Shockproof...to mention some of the popular ones. And, some (most of these mentioned) not only provide protection from that inherent reverse gear issue, but improve the ease/smoothness of shifts across the entire (transmission) temperature range.
I'm using the Redline Heavy Shockproof in my ZF, upon recommendation by a renown ZR-1 mechanic. And, like some others, I immediately felt a difference in the shifting - a bit smoother...I think.
The point is to avoid a possible catastrophe. Use a good synthetic gear oil. In the 12 years since my "lockup" mishap, I've not had further issues with any of (3) ZFs...knock on wood!
Regards,
John
