[Ozbrick: I caught this interesting thread midstream...]

 Hi Neil,

 These POS AISIN automatic transmission that Volvo is using do not last long. I have seen some fail at 5K miles and I have seen some go as
 far as 150K miles. It is the pull of a straw if you get one that is a keeper. The Volvo Mechanic I use has replaced so many that he can quote you
 off the top of his head what type of transmission you need and how much it will cost to replace!

 What I do know is that AISIN makes a middle of the road automatic. It is not a high quality transmission then it is not entirely a piece of junk
 either. However, I feel that it is not a transmission I would expect to see in a $40K car. I would expect to see one in a $12K to $20Kcar (Jeep
 Cherokee Classic, Toyota Camry, GEO Prism just to name a few).

 The clue to the problem is the transmission fluid burning at low mileage. Automatic transmission fluid can not handle temperatures over 90deg
 C for long periods of time (of course this will very on the automatic fluid you are using). So something somewhere is causing the transmission
 fluid to over heat, burn, not lubricate and not work well as a hydraulic fluid.

 I have narrowed it down to either something in the transmission itself or the radiator is not large enough to cool the fluid.

 The Transmission itself:

 Here I can only guess at what might be a source of over heating the oil. Several ideas have been thrown out on the table from fellow Engineers.
 First idea is the toque converter is too small for the engine and the car. This idea came from looking at diagrams and cut away of Aisin front
 wheel drive transmissions. Second idea is that the transmission was design for a lighter/smaller car. The 40 series uses the same basic
 transmission as the 70 series and I have not heard to date any complaints about transmission problems in the 40 series. And the third idea has
 to do with the design of the gear shifting mechanism. I had a chat with a no nothing Factory Rep who B- S'ed me to believe that the
 Electro-shifting design uses the toque converter lockup as a fuel saving featured when shifting gears. This can lead to rough shifting. My
 interpretation of the Factory Rep comments is the Volvo/Aisin designed a POS for a transmission and us Volvo customers are getting the
 shaft.

 Also these AISIN Automatics do not have any means of filtering out particles in the oil that can accumulate from normal wear on the mechanical
 parts. So any metal particles that are created from bearing break-in and gear meshing will stay in the transmission oil. These metal particles
 can act like sand on the existing bearings hence wearing them down faster until something breaks over time. What I did to solve this is to install
 an external paper filter that you can get from any good auto part store. Just attached it to the car's frame and feed the oil cooler lines in one
 side and out the other side.

 Cooling the Oil

 You can change the cooling ability of the radiator by adding a transmission oil cooler. I installed one on my 99XC with an after-market
 transmission oil cooler. The type of transmission oil cooler that you would use for towing a trailer. This would get you the best bang for the buck.
 Cooler oil will last longer hence keeping the transmission working better longer.

 Good Luck,

 Steven---
                                         Re: POS AISIN Transmissions[XC][2000]   [post reply]
                                   Scott Massey -- Wednesday, 14 November 2001, at 7:15 a.m.

 Good post but the Jeep Cherokee uses the AW4 transmission which is IMHO the most reliable transmission ever built :-). It is very similar to
 the AW71 used on the 740t which is also a very strong transmission. You may be thinking of the Grand Cherokee (the more expensive one)
 that uses a POS Chrysler transmission.

 For my XC I have been flushing 12 quarts of Redline synthetic ATF every year. It costs about $70 a case but the car shifts better than new. No
 more clunk from first to second.
                                         Re: POS AISIN Transmissions[XC][2000]   [post reply]
                                      Steven--- -- Thursday, 15 November 2001, at 9:14 a.m.

 Hi Scott,

 You and I agree that the AW4 is one of the best transmissions on the market. The new Jeep Liberty is using it! I owned 2 Jeep Cherokees and
 ran both of them into the ground. I had over 150K miles on both with never a transmission problem. I wish I could say the same about my 99XC.

 However, Aisin does make the AW4. The A stands for Aisin and the W stands for Warner. If my memory serves me correctly AMC needed a
 transmission for the new Jeep Cherokee (1984 it was new, 16 year run for a truck design, not bad!)and got Aisin and Warner to design one.
 So it was a joint effort between Aisin, Warner and AMC. Aisin is still making them and has adapted the design for other vehicles like the Ford
 AWD V8 Explorer and some Toyota rear wheel drive sedans. The Jeep Grand Cherokee uses a Borg/Warner automatic that is a POS.
 Chrysler does not design nor manufactures their transmissions. Some are Borg/Warner transmission and Mitsubishi makes some
 transmission for Chrysler as well. With the take over by Damler I would expect to see more German technology show up in Chrysler cars in the
 near future.

 So when I bought my 99XC I new I was buying an Aisin transmission (I did my homework). However I did not know that the basic design has
 problems. I have a friend who works at New United Motor Manufacturing (NUMMI). NUMMI manufactures on one assembly 320,000 Toyota
 Corolla and GEO Prisms each year. These cars use Aisin transmission similar to the Volvo 70 series car
 (http://www.aisin-aw.co.jp/eng/frameset.html). My friend told me that NUMMI rejects quite a few AISIN transmissions due to manufacturing
 quality problems. So it is tough for me to tell if these POS Aisin transmission are a Volvo problem or Aisin problem.

 I flush my fluid every 10Kmiles. It still shifts badly (it slams between 3rd and 4th). I know I am in for a replacement at 60Kmiles. The paper filter I
 added always contains a large amount of metal (between 3 to 4 grams) every time I do the change. Something inside is slowly grinding away. I
 suspect something is not right with the shifting mechanism that causes the shift from 3rd to 4th gears. As for what it is I can only guess. When it
 finally dies I am planning to tear apart the transmission to see what got screwed up.

 I would expect some metal from break-in period. At 16Kmiles I had the transmission flushed so I would expect the metal particles to be a very
 small amount from that time onward. All I can say is that Volvo is off my list of cars to buy and especially is off my list of cars to recommend!

 Good Luck,

 Steven---