T5 Gearbox Oil
Discussion
Yeah yeah, atf 
I put 75w90 millers full synth nanotech in mine
http://www.opieoils.co.uk/showproduct.aspx?Product...
I put 75w90 millers full synth nanotech in mine
http://www.opieoils.co.uk/showproduct.aspx?Product...
Edited by s p a c e m a n on Thursday 6th March 05:10
Read somewhere. ATF is a recommended must for the T5. There. are certain thrust faces on bearings in the T5, same as in automatic transmissions which benefit from from ATF. They do not get the same benefit if ordinary gear oil is used since these are thicker and dont have the same creep efficiency of lubrication to reduce wear and tear. ATF is there for a purpose. I will continue to use it.
I did a lot of reading on this subject when I first changed the gearbox oil on my car. It always resisted going into 1st gear from idling in neutral. What was recommended was a good quality A.T.F. Plus a bottle (around 200ml) of "Lubrizol". I put this in and I didn't notice any difference in the way the box behaved. I left that in for around 5000 miles then a couple of weeks ago I changed it again this time for Castrol VMX which is rated as an 80 weight oil but very runny even at cold temps. We use it a lot as it cures shifting problems in a lot of vehicles, especially the first cold shift from 1st to 2nd. Obviously I didn't put it in my box first off because it is not the recommended oil for it but it has made quite an improvement to the way it shifts and therefore my enjoyment of the car so I accept that if it shortens the life of the box then I will rebuild it. I have been using vmx for over 20 years and had nothing but good results. Don't know if that's any help to you but it is just what I have found "cheers"
Just read the blurb on the oil container. Castrol claim you can use VMX in gearboxes that are designed for ATF. 
mind you they are saying you "can" use it but whether or not it is as good for the internals as ATF is another thing.
(If the photo appears upside down its cos you guys are on the other side of the equator )
mind you they are saying you "can" use it but whether or not it is as good for the internals as ATF is another thing.(If the photo appears upside down its cos you guys are on the other side of the equator )
Edited by NZ fan on Thursday 6th March 05:25
The reason they recommend ATF for the T5 is because the baulk/synchro rings are made from a fiberous material, whereas traditionally they are made from brass.
If you don't use ATF, they will overheat and wear out prematurely, and you will be re-building your box.
This is from the T-5 Service manual from Tremec themselves.
2-4. APPROVED LUBRICANT. Most T5
transmission models use Dexron II automatic
transmission fluid. Refer the vehicle owner’s manual
or service manual for lubricant specifications.
CAUTION
Do not mix different bands or types of transmission
lubricant. DO NOT USE GEAR OIL IN THE T5
TRANSMISSION SINCE THIS MAY DAMAGE THE
BLOCKING RING MATERIAL.
By blocking material they mean the baulk/synchro ring material.
If you don't use ATF, they will overheat and wear out prematurely, and you will be re-building your box.
This is from the T-5 Service manual from Tremec themselves.
2-4. APPROVED LUBRICANT. Most T5
transmission models use Dexron II automatic
transmission fluid. Refer the vehicle owner’s manual
or service manual for lubricant specifications.
CAUTION
Do not mix different bands or types of transmission
lubricant. DO NOT USE GEAR OIL IN THE T5
TRANSMISSION SINCE THIS MAY DAMAGE THE
BLOCKING RING MATERIAL.
By blocking material they mean the baulk/synchro ring material.
Traditional mineral hypoid gear oils contain sulphur that attacks brass syncro rings, its also nearly always too heavy for the T5, especially our World Class T5 that uses needle roller bearings where plain bearings exist in the non-world class T5.
So any traditional mineral hypoid gear oil is a complete
in our boxes.
Mineral ATF is produced from a petroleum base containing a mix of substances including detergents, rust-preventatives, extreme pressure, anti scuff, viscosity modifiers, and seal conditioners. It normally contains a red pigment that's only added to differentiate it from other oils, this red pigment is nothing more than a dye it is not some special secret ingredient.
Without the red dye ATF would be amber in colour just like any other mineral oil.
The truth is a quality ATF is excellent oil, it has very good abilities to carry heat away and is extremely temperature stable, it also contains high levels of detergents, if added (in small amounts) to engine oil it can help free sticking hydraulic tappets & shift stubborn carbon deposits.
ATF must endure the extremely high pressures in an automatic gearbox which in turn generates very high temperatures, ATF can withstand temperatures around 200 - 300F for thousands of miles, its unlikely your T5 will ever get close to these temps even on the track.
ATF stays in grade over a very broad range of temperatures, as such it has many unexpected uses such as SU carburetor dash pots where high under bonnet temps will thin traditional engine oils causing overly rich conditions when the throttle butterfly is snapped open under hard acceleration, it's viscous stability also improves your old SU carb at the other end of the temp scale ie cold starts.
ATF is thin and cheap, making it perfect to fill your general oil can, you can even use it to make up your petrol/oil mix for your two stroke mower or chainsaw, because it's petroleum based it will mix well and remain perfectly suspended in petrol, it burns off in a very clean way reducing carbon deposits & plug fouling in your two stroke.
ATF makes an excellent hydraulic oil which is why its also used in power steering systems, it makes a very good motorcycle fork oil too. Automatic transmission fluid & power steering fluid are exactly the same product although better quality power steering fluids may also contain higher levels of seal conditioning additives.
In summary ATF is a very very flexible high quality lubricant that has many uses beyond your automatic gearbox or power steering system, and this is why Borg Warner specified if for their T5 gearboxes.
However, ATF is nowhere near as good at protecting gear sets as a traditional hypoid oil that contain special EP (extreme pressure) additives, but if the gears are properly hardened and their clearances correctly set you really don't need the EP qualities found in a traditional hypoid oil.
When Borg Warner designed the T5 it did so with ATF in mind from the outset because if the box could be made reliable on it (which it was) there were significant fuel economy benefits over traditional thick hypoid oils.
Borg Warner designed the T5 box to deliver a service life exceeding 100,000 miles using this ATF, giving both the required reliability while delivering those fuel economy benefits at the same time.
The light grade of ATF also delivered lighter shifts and the temperature stability gave a consistency of shift in a mix of climates that a traditional hypoid oil could never offer.
With all these advantages it's not hard see why Borg Warner designed the T5 to run on ATF.
Production figures of the T5 currently stand at well in excess of a million units, it is a totally proven transmission with literally hundreds of thousands of T5s completing millions of combined miles without issue, and all running on ATF!
The new breed of fully synthetic manual transmission fluids simply didn't exist when Borg Warner designed the T5, but that's largely irrelevant as the box was designed to use ATF and is proven totally reliable & long lived with it.
The bottom line is automatic transmission fluid has a much harder life in an automatic transmission than it ever will in your T5 manual transmission.
Ask not if a fully synthetic manual transmission fluid is better than ATF in your T5, but if you would you put a fully synthetic manual transmission fluid in your auto box.
Of course fully synthetic manual transmission fluids are perfectly safe in the T5, but why bother?
A mineral ATF is the oil this box was designed to use, mineral ATF is the proven lubricant in this box, mineral ATF is the oil you should use.
Its also worth noting that a synthetic ATF may well be too slippery for the synchro rings to work as designed, so your probably best off with a decent quality good old mineral ATF.
Regular changes are the key, you should be able to change your T5 oil with a good quality mineral ATF for less than £15 a time so there's really no excuses for not completing a change every 10,000 miles, which will ensure your T5 box gives reliable service for well in excess of 100,000 miles.
Keep to mineral ATF in your T5, sometimes the wheel doesn't need reinventing.
So any traditional mineral hypoid gear oil is a complete
in our boxes.Mineral ATF is produced from a petroleum base containing a mix of substances including detergents, rust-preventatives, extreme pressure, anti scuff, viscosity modifiers, and seal conditioners. It normally contains a red pigment that's only added to differentiate it from other oils, this red pigment is nothing more than a dye it is not some special secret ingredient.
Without the red dye ATF would be amber in colour just like any other mineral oil.
The truth is a quality ATF is excellent oil, it has very good abilities to carry heat away and is extremely temperature stable, it also contains high levels of detergents, if added (in small amounts) to engine oil it can help free sticking hydraulic tappets & shift stubborn carbon deposits.
ATF must endure the extremely high pressures in an automatic gearbox which in turn generates very high temperatures, ATF can withstand temperatures around 200 - 300F for thousands of miles, its unlikely your T5 will ever get close to these temps even on the track.
ATF stays in grade over a very broad range of temperatures, as such it has many unexpected uses such as SU carburetor dash pots where high under bonnet temps will thin traditional engine oils causing overly rich conditions when the throttle butterfly is snapped open under hard acceleration, it's viscous stability also improves your old SU carb at the other end of the temp scale ie cold starts.
ATF is thin and cheap, making it perfect to fill your general oil can, you can even use it to make up your petrol/oil mix for your two stroke mower or chainsaw, because it's petroleum based it will mix well and remain perfectly suspended in petrol, it burns off in a very clean way reducing carbon deposits & plug fouling in your two stroke.
ATF makes an excellent hydraulic oil which is why its also used in power steering systems, it makes a very good motorcycle fork oil too. Automatic transmission fluid & power steering fluid are exactly the same product although better quality power steering fluids may also contain higher levels of seal conditioning additives.
In summary ATF is a very very flexible high quality lubricant that has many uses beyond your automatic gearbox or power steering system, and this is why Borg Warner specified if for their T5 gearboxes.
However, ATF is nowhere near as good at protecting gear sets as a traditional hypoid oil that contain special EP (extreme pressure) additives, but if the gears are properly hardened and their clearances correctly set you really don't need the EP qualities found in a traditional hypoid oil.
When Borg Warner designed the T5 it did so with ATF in mind from the outset because if the box could be made reliable on it (which it was) there were significant fuel economy benefits over traditional thick hypoid oils.
Borg Warner designed the T5 box to deliver a service life exceeding 100,000 miles using this ATF, giving both the required reliability while delivering those fuel economy benefits at the same time.
The light grade of ATF also delivered lighter shifts and the temperature stability gave a consistency of shift in a mix of climates that a traditional hypoid oil could never offer.
With all these advantages it's not hard see why Borg Warner designed the T5 to run on ATF.
Production figures of the T5 currently stand at well in excess of a million units, it is a totally proven transmission with literally hundreds of thousands of T5s completing millions of combined miles without issue, and all running on ATF!
The new breed of fully synthetic manual transmission fluids simply didn't exist when Borg Warner designed the T5, but that's largely irrelevant as the box was designed to use ATF and is proven totally reliable & long lived with it.
The bottom line is automatic transmission fluid has a much harder life in an automatic transmission than it ever will in your T5 manual transmission.
Ask not if a fully synthetic manual transmission fluid is better than ATF in your T5, but if you would you put a fully synthetic manual transmission fluid in your auto box.
Of course fully synthetic manual transmission fluids are perfectly safe in the T5, but why bother?
A mineral ATF is the oil this box was designed to use, mineral ATF is the proven lubricant in this box, mineral ATF is the oil you should use.
Its also worth noting that a synthetic ATF may well be too slippery for the synchro rings to work as designed, so your probably best off with a decent quality good old mineral ATF.
Regular changes are the key, you should be able to change your T5 oil with a good quality mineral ATF for less than £15 a time so there's really no excuses for not completing a change every 10,000 miles, which will ensure your T5 box gives reliable service for well in excess of 100,000 miles.
Keep to mineral ATF in your T5, sometimes the wheel doesn't need reinventing.
Edited by ChimpOnGas on Thursday 6th March 10:03
AV8 said:
The reason they recommend ATF for the T5 is because the baulk/synchro rings are made from a fiberous material, whereas traditionally they are made from brass.
If you don't use ATF, they will overheat and wear out prematurely, and you will be re-building your box.
This is from the T-5 Service manual from Tremec themselves.
2-4. APPROVED LUBRICANT. Most T5
transmission models use Dexron II automatic
transmission fluid. Refer the vehicle owner’s manual
or service manual for lubricant specifications.
CAUTION
Do not mix different bands or types of transmission
lubricant. DO NOT USE GEAR OIL IN THE T5
TRANSMISSION SINCE THIS MAY DAMAGE THE
BLOCKING RING MATERIAL.
By blocking material they mean the baulk/synchro ring material.
Thanks that's what I read. Wise councel. If you don't use ATF, they will overheat and wear out prematurely, and you will be re-building your box.
This is from the T-5 Service manual from Tremec themselves.
2-4. APPROVED LUBRICANT. Most T5
transmission models use Dexron II automatic
transmission fluid. Refer the vehicle owner’s manual
or service manual for lubricant specifications.
CAUTION
Do not mix different bands or types of transmission
lubricant. DO NOT USE GEAR OIL IN THE T5
TRANSMISSION SINCE THIS MAY DAMAGE THE
BLOCKING RING MATERIAL.
By blocking material they mean the baulk/synchro ring material.
AV8 said:
The reason they recommend ATF for the T5 is because the baulk/synchro rings are made from a fiberous material, whereas traditionally they are made from brass.
If you don't use ATF, they will overheat and wear out prematurely, and you will be re-building your box.
This is from the T-5 Service manual from Tremec themselves.
2-4. APPROVED LUBRICANT. Most T5
transmission models use Dexron II automatic
transmission fluid. Refer the vehicle owner’s manual
or service manual for lubricant specifications.
CAUTION
Do not mix different bands or types of transmission
lubricant. DO NOT USE GEAR OIL IN THE T5
TRANSMISSION SINCE THIS MAY DAMAGE THE
BLOCKING RING MATERIAL.
By blocking material they mean the baulk/synchro ring material.
ATF all the way If you don't use ATF, they will overheat and wear out prematurely, and you will be re-building your box.
This is from the T-5 Service manual from Tremec themselves.
2-4. APPROVED LUBRICANT. Most T5
transmission models use Dexron II automatic
transmission fluid. Refer the vehicle owner’s manual
or service manual for lubricant specifications.
CAUTION
Do not mix different bands or types of transmission
lubricant. DO NOT USE GEAR OIL IN THE T5
TRANSMISSION SINCE THIS MAY DAMAGE THE
BLOCKING RING MATERIAL.
By blocking material they mean the baulk/synchro ring material.
I often hear of this rubbish about ATF not being man enough for the T5 give me a break 
any oil that can with stand what an Auto trans throws at it is good enough for me i.e heat and lots of shearing from wet multi plate clutches slipping etc 
Bare with me because I'm on my phone, so I'm not writing an essay 
Bernie at CTS says to use 75w90 gear oil, the head research blokey at Tremec has been quoted as saying that 'the only reason they spec'd ATF was cost, as a gearbox oil its rubbish.'
And ircc the last time Tremec updated their tech sheet advising oil and fitting was 1996, oil has moved on along since then.
I'm not saying its wrong to use atf, but imo it's not wrong to use gear oil either. Mine is filled up with 75w90nt because I forgot to but any fluid and that what my mate had in stock in his workshop as it's what most of the big boys run in their T5s on the cosworths. I'm sure it will be fine in my 4 litre 40k mile chim
Bernie at CTS says to use 75w90 gear oil, the head research blokey at Tremec has been quoted as saying that 'the only reason they spec'd ATF was cost, as a gearbox oil its rubbish.'
And ircc the last time Tremec updated their tech sheet advising oil and fitting was 1996, oil has moved on along since then.
I'm not saying its wrong to use atf, but imo it's not wrong to use gear oil either. Mine is filled up with 75w90nt because I forgot to but any fluid and that what my mate had in stock in his workshop as it's what most of the big boys run in their T5s on the cosworths. I'm sure it will be fine in my 4 litre 40k mile chim
Is ATF Dexron 111 ?I have this in my gearbox ,is it ok .
http://www.directcarparts.co.uk/product/67/xte/atf...
http://www.directcarparts.co.uk/product/67/xte/atf...
Gassing Station | Chimaera | Top of Page | What's New | My Stuff