Fluids Capacities & Discrepancies
 

I'm wondering if anyone else has come across this? Ok so I was looking for some definitive info on the fluid used in the Graziano AM803T transaxle on my 2006 Vantage as I'm about to swap the oil. There was some helpful info on this forum regarding different brands and Rich had posted a link to a tech doc that supported my decision to go with Amsoil SVG - which I've used successfully for many years in BMW's. However as I searched for info on the correct capacity I came across a myriad of contradictory information - not from the forum - but from Aston Martin official documents.

All of the documents I referenced contained conflicting specs in regard to either the types of fluids or the various fluids' capacities in the vehicle. My Aston Martin Workshop Manual even offers a differential fluid capacity of 2 liters for an 80w140 - that to the best of my knowledge is not even for this model? I've got three different recommended Power Steering fluids for the same Vantage vehicle from different AM publications???. It is possible that MY changes are the reason for brand (type) recommendation changes but capacity differences - in the same parts?? Even MY changes would not explain why in one case Aston Martin has different capacities published within the same Workshop Service Manual (Issue 8) for the same vehicle - just in different sections.

Some differences are inconsequential such as the windscreen washer fluid capacity differences but for others, differences are not insignificant - i.e. CHF11s specified in one owner manual for the PS fluid cannot be mixed with the other two types recommended in the 2 other manuals. In two of the docs AML have a 3 liter difference in the recommended V8V capacity for coolant and in another a half liter difference in trans-axle fluid capacity - which is considerable and accounts to around 10% under-filled.


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Aston Martin Owners Manual MY2006


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Aston Martin Owners Manual MY2007


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Aston Martin Owners Manual MY2011


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AM WSS 2011 Issue 8


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AM WSS 2011 Issue 8
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You can't trust any manual as it says in fine print subject to change. Real world is all you can rely on. Fluid specifications are correct just need to drain and refill to the level. Transmission will only hold so much until it self levels in the fill hole. BTW is closer to 4 jugs than 5.

I couldn't find the term "subject to change" Can you post this fine print from either the Aston Martin WSS or the Owner Manual?

Basically you are saying capacity specs are unnecessary. ?? A tranny will only hold so much - somewhat correct when cold and prior to the air bubbles dissipating up through the transaxle breather- that is why the procedure tells you to fill then drive then top up. Even in this car if you've drained it correctly you won't fill the cooler lines till the car is running so you'll be down a half liter immediately. Less critical on a manual but still essential having the exact fluid amount is absolutely critical in automatic & sequential transmissions. BTW in my part of the world the term "jug" in automotive shops is slang for a 3.78 liter container with handle.

Capacity specifications are for a dry unit. If one was to swap out fluid the cooler and cavities have said fluid, you cannot over fill it. You are making an easy thing very difficult to yourself to comprehend a basic drain and refill. Stick with the BOT 70 Castrol. Guess the automotive world to the North has an exact amount for a jug? It's a slang term, didn't realize it has an exact quantity.

Capacity specs are always for a dry unit - still doesn't explain why the different specs have different capacities.

I've done too many of these to fill via liter bottles and have puddles all over my floor. I fill via a pressure line with shut-off valve - no mess - but the quantity is crucial for several reasons. I've done more tranny drains and refills than I'd care to remember so I think I know what I'm doing - My point was that Aston specs are all over the place. Offering fluid not in the vehicle, a 3 liter discrepancy in the cooling system & completely different specs for PS fluid + more.

In regard to my AMv8v transaxle - Thanks for the tip but I'll go with the Amsoil SVG since the Bot 270 was a fix for the sequential only and the Amsoil SVG is superior to anything else for this purpose.

Lastly if you think you can't over fill a tranny or transaxle then you haven't done enough of them nor know enough about them. If you add too much transmission fluid, you will notice that it may foam, and that can bring about erratic gear shifting. Some other problems that may arise include oil starvation and transmission damage. an overfilled manual transmission results in fluid-leak from the top breather vent and shifting the gear becomes a problem when the clutch is depressed. All transmissions, auto or manual, have some ways to relieve excess pressure. Adding too much transmission fluid can also cause early failure and damage of parts as result of excess pressure. The pressure in shift from low to maximum in this condition making some parts of your vehicle completely unstable. When you try to change the gears more so on the 3-4 and 2-3 as well as the reverse gears this condition can become even worse. The pressure can result in friction and easily push out snap rings, break parts, etc. Causing sudden failures and/or serious damage. Modern vehicles have transmissions that include a pressure valve which regulates pressure after the pump. However, as previously mentioned excess pressure can result to pre-mature wearing out of some parts – the valve included, thus causing it to fail. Failure of the valve can in turn create pressure related problems in other engine components. Which is why pros and the sort rely on published vehicle specs when performing service.

So yes, adding too much transmission fluid can lead to pre-mature failure of the car’s system over time, and may most likely void any warranty in effect, if reason for the failure is found to be the presence of excess fluid.

Similarly under filling a transmission (especially automatics) is a common occurrence I see on home DIY'ers who then bring the car to the dealer cause it isn't shifting properly. Typical cause - not following the drain and fill procedure and deviating from the correct fluid capacity.

The correct amount of transmission fluid (auto or manual) is crucial to correct operation and longevity. So much so that today on many vehicles the drain and refill and top off correction can ONLY occur when the fluid is at a specific temperature read by tranny temp sensors to ensure the correct volume is installed.

The only tranny's that couldn't be overfilled had open drain holes on the side but they've long since disappeared due to EPA concerns.

Edit: lastly for anyone else reading this thread I plan on installing 4.5 liters of new transaxle fluid after a full pressure drain. Why that amount - the specs are so conflicting from 4.3L to 5.0L - after the test drive I will hoist the car up again and measure and top off. No it's not complicated - the only complication being the specs offered by Aston Martin.