Problem: My 1993 940 transmission filter keeps getting clogged up. This is the 5th time in 3 months. I've flushed it using the techniques on this site. I installed an in-line filter 3 weeks ago and have had two in line filters clog up since. Once I replace the in-line and/or regular tranny filter, it runs pretty well until the next time it clogs up. When I remove the pan the oil is dirty, but when I remove the filter, bright red fluid runs out of the tranny.

History of vehicle: Bought it used on Ebay last year. After driving it home to NC from PA, found out it had a head gasket leak and engine oil was in the coolant. I had this fixed. I noticed the transmission fluid was a tan color. I learned that the radiator was broken inside and the oil/coolant mixture that was in my radiator got into the tranny. What is weird is that the transmission ran great even with that crap in it. The trouble started 3 months after replacing the radiator and flushing out the transmission. I replaced the tranny filter and it had what looked like old oily pasty powdery substance clogging it. This filter lasted about 3 weeks and clogged again. Now it clogs every week or two. The last two in line filters I used were for trannys but looked like a fuel filter. I'm getting a screw-on type that is easier to replace.

Questions: Is it possible that the black goo that eventually clogs the filter is left over residue from the cross-contamination from the head gasket and radiator problem? Should I get a professional transmission flush or will this ruin my transmission?

Once I change out the fluid and filters the car runs great except that it has to run about 2/10 of a mile before it will go into 2nd gear when it first starts. Could this be caused by residue in the valve body? Any help would be appreciated.

Thank you for all the responses. A phone call to a tranny shop solved the mystery. When I cracked open the in-line filter that just clogged, I noticed fibers clogging it. A mechanic asked me if I'd noticed fibers in the fluid. When I told him I had he said that when the water got in the transmission it dissolved the water soluble adhesive that holds the clutch material on and that is what is clogging the filter.

What is the opinion out there of getting a tranny from a salvage yard and having it put on versus having the tranny rebuilt? I can get a used tranny for $300 locally and have a mechanic friend of mine put it on for a few hundred dollars or spend $1800 for a rebuilt one. Please give me some opinions/advice on which is better. Money is tight so I'm leaning towards the used one. Also, what is a fair price for removing my old tranny and installing the salvaged one if I go that route?

Thanks.

You can feel completely comfortable going the used tranny route -- that's what I'd do. These AW units are legendary for their durability.

Jeff Pierce
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'93 945 Turbo ( one kickass family car ! ), '92 Mercedes 190E (my daily driver), '53 Willys-Overland Pickup (my snow-plow truck/conversation piece -- sold to a loving home), '85 Jeep CJ-7 w/ Fisher plow

you may be on the right path and close to the fix. all a full flush will do
can be accomplished by you. simply open up top trans line @ radiator, put
a 3/8" (or whatever size rubber hose) on radiator and zip tie it off. get a
clear 1 gallon plastic jug (milk, ect...) and have assistant start car, as the
gallon of old ATF is pumping out pour the 4 new quarts into the trans dipstick
tube. one gallon out, 1 new gallon in. REPEAT 3-4 times and you should'nt even
have to check fluid level. that process accomplishes the exact thing a PRO
flush does. I do not see where any additives are needed or are likely to help.

I have never had any of my volvos do the delayed 1>2 upshift thing you describe.
You may have a roasted transmission. I just described the flush to save you
about $80.00

good luck, post back with FIX
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Kevin P Walsh, Casper WY. '91 945 SE turbo 165,000 miles / paid for

You've obviously got major internal contamination. Make sure the new radiator is not leaking into the tranny cooler (you don't have to keep topping it off, do you?). If that's OK, then I suspect that the old coolant may have dissolved some clutch/band material which is now liberating itself into the tranny fluid. I'd keep changing the in-line filter for a while and see what it looks like: it may be that this process stops and you'll be fine. It may also be an indicator that you need another tranny.

Check the kickdown cable adjustment for the delayed 1:2 shift.

Thanks for the reply Steve. There is no leakage from the radiator since I fixed it. I did replace the kickdown cable last month. Would the kickdown cable being out of adjustment cause the 1-2 shift delay only when the car is cold? Also, how do you feel about professional transmission flushes. I'm getting mixed info from different mechanics. Some say do it and others say it could make things worse. Is there a product I could buy to help clean the tranny out or would this make it worse?

Thanks!

Bottom line is, new fluid will not hurt the tranny. If it stops working after a professional flush, it was living on borrowed time anyway. There are 2 types of pro flushes; one is a complete fluid change, out with the old, in with the new, if you or the tranny guy are worried about the internal state of the tranny (I would be) go w/regular fluid, not synthetic, because of the cost.

The other type is really a thorough filtering of the old fluid, the machine is hooked up to the tranny lines and the old fluid is filtered to death (5 or 10 microns I think, maybe less), it ends up looking like new fluid (remember, old oil does not lose its lubricating ability, it just gets dirty). The downside is, some of the additives may be played out, I have not heard enough on that to have an opinion. I had this done at 120K and it worked great, no problems. Check around for the best prices and compare them to a complete fluid change. I'd go with whichever is cheaper considering the tranny being questionable.
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Bob Kraushaar '94 945T, '91 940T(retired), '88 240, '84 242Ti, '94 F-150, '88 300TE, '89 560 SL, '68 Shelby GT-500 KR