Kieran
05-07-2005, 12:11 PM
My new purchase has the beginnings of the dreaded 4th gear transmission shudder - I already knew this, and having read some of the postings on here, I'm not about to yank the gearbox out and start panicing.... Why? Well...
One of the cars I've considered purchasing in the past is the Toyota Soarer, which is known for shuddering transmission problems - Mainly when the 'box is filled with Dexron rather than the Toyota Type-IV fluid.... Now, as you know, Mitsubishi USA share transmisison technology with Chrysler.... Have a read of this......
'The friction characteristics of DEXRON are different from 7176. It is a "grabbier" fluid. The Chrysler transmission has an electronic system which continuously senses the behavior of the transmission and regulates shifts accordingly. If DEXRON is used, the clutches inside the transmission will "grab", and the electronic controls, which sample the operation of the transmission about 140-180 times a second, will let up on the clutches. The clutches will then slip excessively, the transmission will try to tighten up on them, and due to the characteristics of DEXRON, they will again grab. This will occur at the 140-180 times per second rate, and the transmission will have a shuddering feel to the shifting. This is also very hard on the clutches, and they will have a short life.
General Motors has two new rigorous tests that evaluate an ATF’s anti-shudder capabilities and sprag clutch wear. The key issue here is torque converter shudder protection. Shudder is merely what happens when two pieces side-by-side inside the transmission rub together but rotate at slightly different speeds. Without protection from the ATF, the two pieces may “stick-slip” causing a shudder or vibration. Not all ATF’s provide that protection successfully. '[/SIZE]
Interesting, eh? Well, as we know, the INVECS will tolerate Dexron-III. However, several members have tried amsoil ATF (which meets the SP-II standard) and report that it's much better.
So, when I have a weekend free, I shall flush out the Dex-III and get hold of some Amsoil, and see if it will prove to be a cheaper solution to the shudder o'doom. /Hmmm
One of the cars I've considered purchasing in the past is the Toyota Soarer, which is known for shuddering transmission problems - Mainly when the 'box is filled with Dexron rather than the Toyota Type-IV fluid.... Now, as you know, Mitsubishi USA share transmisison technology with Chrysler.... Have a read of this......
'The friction characteristics of DEXRON are different from 7176. It is a "grabbier" fluid. The Chrysler transmission has an electronic system which continuously senses the behavior of the transmission and regulates shifts accordingly. If DEXRON is used, the clutches inside the transmission will "grab", and the electronic controls, which sample the operation of the transmission about 140-180 times a second, will let up on the clutches. The clutches will then slip excessively, the transmission will try to tighten up on them, and due to the characteristics of DEXRON, they will again grab. This will occur at the 140-180 times per second rate, and the transmission will have a shuddering feel to the shifting. This is also very hard on the clutches, and they will have a short life.
General Motors has two new rigorous tests that evaluate an ATF’s anti-shudder capabilities and sprag clutch wear. The key issue here is torque converter shudder protection. Shudder is merely what happens when two pieces side-by-side inside the transmission rub together but rotate at slightly different speeds. Without protection from the ATF, the two pieces may “stick-slip” causing a shudder or vibration. Not all ATF’s provide that protection successfully. '[/SIZE]
Interesting, eh? Well, as we know, the INVECS will tolerate Dexron-III. However, several members have tried amsoil ATF (which meets the SP-II standard) and report that it's much better.
So, when I have a weekend free, I shall flush out the Dex-III and get hold of some Amsoil, and see if it will prove to be a cheaper solution to the shudder o'doom. /Hmmm