Can anyone clear up the record for good on the history of the transmissions that were put into the 850. Volvo tells me one thing, and an independent specialist another.

Is it true that an Aisin-Warner box went into the earliest models, and that it was replaced by a Borg-Warner?

(If it is true...)

What were the reasons for change/failures? What are the model designations of the two different trannies? Can a later model tranny be put into the earlier model-year cars?

Answers to any of these questions would be appreciated, as I am currently email corresponding with someone looking at big tranny costs who needs the issue clarified.

Michael:

The l850 uses an Aisin Warner AW 50-42 transmission. There are differences between early and late models in that the sensors which supply ground speed signals for the speedometer are different. The transmissions will interchange but the speedometer,odometer, cruise and fuel consumption monitor will not work without some modifications. If you require more detail, I can supply it.

Thanks Ken,

I have some information from Volvo which was written around (my guess) 1992-93, which states that the tranny on the original GLT is the AW-42. (Of course, that didn't tell me if the tranny was to change in later years, hence the original question. You & John have sorted me out there, ta.)

I guess the AW-42 that they (volvo) talk about and your AW 50-42 are the same thing. What's the '50' nomenclature?.

Any further info on the trannies and year variations is appreciated, I will put it up at my site for anyone who is interested, and it will certainly help this guy in Hawaii to get his bearings.

Now that I know that the 850 tranny was always Aisin - Warner, the thing that I want to know is why the apparent variation in reliability between earlier and later models?

Kino's survey reports 1993, 74%, with 50 people responding; 1994, 21%, 113 people; 1995, 33%, 101; 1996, 12%, 76; 1997, 17%, 28 and 1998 13%, 66. The 1993 result is particularly unnerving. (though it depends on how you see the numbers: 37, 23, 33, 9, 4 and 9 are the roughly raw numbers of respondents saying they had tranny failure, making all three first years look pretty bad...)

Just my 2c worth, but there may be a lot of factors causing the unreliability (seen in Kino's survey) for the AW-42. A few possible causes:

* Difference in time elapsed between years surveyed;

* individual variation in the way the transmission is used/car driven;

* Variations in maintenance. (As more people/dealerships/whatever became/become aware that it is important to change ATF, boxes are less prone to failure? Anyone know about TSB's on ATF changes/when they were released?)

* might the probs have anything to do with the mods that you speak of? On the surface the mods, being just sensors, sound too trivial to do that, but the fact that they were done might imply some more significant modifications to the AW-42 during its' life on the 850? Or am I totally up the wrong tree and was it pretty much the same box all the time???

And (sorry for the 61 questions) I wonder whether the 960's AW-30's were prone to such failure as well? (or was that RWD?)

I'll kill this rant before it goes on any longer! Thanks for your help

Michael;

I can't tell you what the 50 represents on the model no. As to what changes might have been made internally between early and late models, I can"t say. The only obvious change that I am aware of is the change in location of the ground speed sensor, from near the drive axle to much higher on the housing. The casting on the later models changed to accomodate this. As to the survey results; perhaps the higher rate of failure for the early 850 can be attributed to the fact that they are older and likely to have more use and mileage. How many of the failures were actually PNP seitch failures? I installed motor and trans. from a 1998 into my 1994 850 without any problems other than the speedo. I am currently working on an adaptor to solve that problem.hope this is of some help.

It's Asian Warner (NOT Borg Warner, never although I believe the companies are "related"). Volvo has used AW trannies since (at least) the 70s in their RWD auto trans cars and ALL FWDs still use AWs with the exception of the S80 (GM).

If your going to replace your trans with a reman, not used, I'd suggest buying it from a Volvo dealer and using the same year trans as they list it for, NOT trying to put a newer type trans in an older 850. It's alot of work and you (or whoever) won't want to do it twice. All Volvo parts have a 1 year/unlimited mileage warranty in the US, don't know about elsewhere but you should ask.

thanks John,

I presume that the guy in question would get the same work/parts guarantee in Hawaii. I'll pass on the info on the AW.

thanks/regards