I was suffering from what I thought was too much shifting notchiness, esp. when cold. I had the dealer change the transaxle oil and it made a significant improvement, both cold and hot.

Now hot is like butter and cold is much easier. Don't know if the improvement was due to a lighter viscosity or the simple fact that the oil was more than 4 years old (no one could tell me definitively what was in there as compared to what they put in).

So, if notchiness is plaguing you, you might give this try. Be forwarned...it is an expensive service (around $400).

 

$ 400 to change the diff oil? OMG...what do they use, liquid gold?

I don't know the spec off hand for AM lube in the transaxle, but I do those in all my other vehicles for about $ 30 worth of oil and if I have to put a friction modifier in there another $ 15. I was under the car last week changing out the exhaust and it didn't look very hard to do....

 

Castrol synthetic gear oil. Only available from AM (supposedly) and it's $55/qt and takes 4 quarts. So half the service is just materials.

 

That's the Aston Kool-Aid. I run into the same thing from BMW on their motorcycles. Typically Redline, Royal Purple or Amsoil will make a 75w90 gear oil with Limited Slip modifiers in it that meets the Spec (typically API GL5) for around $ 18 a quart and performs equal to or better than Castrol. Most the ones I do take about 20 minutes once the car is off the ground, so I think there is definitely some room to improve on that $ 400 price tag.

 

Duane good thoughts buddy....the premium brands always try to charge an arm and a leg on fluid services. I've used Redline, Amsoil and Royal purp. ....good stuff.

 

Lots of discussion on this in the past... Royal purple works great on the older 4.3L. Some prefer to use other ones, just make sure you use one with LSD friction modifiers. Royal Purple 75w-90 comes with them, I believe Redline you can get with or without so double check.

Also, shifter cable adjustment procedure is also supposed to help but a bit more complicated and costs more. The fluid is the easiest bandaid solution for the V8 vantage transmissions. V12s do not seem to be plagued by the same issues.

After having driven my buddies 06 back to back after the RSC ltw flywheel & clutch setup, I realized the real cause of the notchy shifting is the actual clutch mechanism itself. It never fully disengages it appears for some reason. After the upgraded clutch disc was installed, shifting was completely different, it was unlike any vantage I had driven (driven quite a few).

If you need to replace the clutch, replace with RSC one, with that said, engagement point is alot sharper and you lose that buttery smooth engagement point (some like it, some hate it). But with that said, the shifting becomes MUCH better with the upgraded clutch disc (You do not have to upgrade the flywheel if you don't want to, it does not make that much of a difference compared to LTW flywheel on other cars for some reason.

Hope that helps,
007

 

Way around the price is to get Castrol SynGear 75W90 and add the Kendall LSD additive (ordered from Aston or anywhere else online)..

I've posted all this before, here it is again..correct fluid used by Aston in the UK is "Castrol BOT270A" for the manual gearbox..are dealership inquired Castrol about this being why pay for marked up oil from Aston when we could order from Castrol on are account..Castrol informed us "BOT" is a UK term and cannot supply us in N.A with the oil, we would have to order from Aston in the UK..but Castrol informed us that there SynGear 75W90 is the same less an additive for the LSD clutchs..Aston came out with a S.B informing dealers that 75W90 can be used if the LSD Kendall additive was added.. http://kendalloil.carshopinc.com/pro...09162/505-7478 ..Only 1 bottle is required...I have also put in R.P 75W90 in few client cars, they supplied so I put..R.P already has the additive so no Kendall bottle is needed

 

Does anybody have a write on on changing the transaxle oil?

 

it's pretty straightforth..no write up really required, but here:

1: jack up vehicle and support with stands for safety.
2: remove lower tray shield (either plastic or metal type, depends on model) bolts/screws bolts the trays are 13mm heads and/or T30 heads, depends on models and years..
3. remove the 22mm fill plug at RH side of transaxle, just in front of the RH half shaft
4. remove the 14mm female(need allen bit/key) at rear bottom section of transaxle differential to drain oil, yes you need something to catch the oil..so get ready.
5. remove the filter at the LH lower rear side of the differenital, be advised some oil with exit, there are 2 x 8mm bolts retaining a plastic plate..remove the bolts and wiggle out the plate that is actuallt the filter screen..do not pry to hard for it will snap..wiggle wiggle, and the rubber-ring will release. Clean the filter screen with parts/brake cleaner. If seal is undamaged, refit..otherwise replace the o-ring and then refit screen and secure 2 x 8mm bolts..there 8mm so don't go crazy..no torque spec, just secure...
6.refit back the drain plug, replace washer gasket if out of round and torque plug secured, spec is 49Nm.
7.fill transaxle with gear oil, requires 4.5L...4L in tranaxle and 0.5L in cooler..don't believe you will need anymore than 4L..when the oil starts to seep out the filler hole, you are done filling..fit the fill plug, replace washer if required..secure fill plug..spec is same as lower plug 49Nm.
8. clean up all the leaked/spilled oil and refit the undertray
9. remove jack stands and your ready to burn rubber!!