On a recent road trip I had been driving for about 2 hours and stopped for a few minutes. As I started back onto the road the transmission would not shift into overdrive. This transmission was replaced by the dealer some 35K miles ago. I changed the fluid some 15K miles ago. The color, smell and level of the fluid were normal. I pulled over, selected "3" on the shifter and proceded on to the next rest stop. After about 30 minutes, I got back on the road and with the shifter in "D" again, everything worked normally. Two days later I'm on the road again, this time about 20 minutes and when I stopped at a toll booth and began to pull away, the car seemed like it was trying to start in high gear. Once again I stopped, selected "3" and took off fine. This time I manually shifted to "D" at about 3K rpm. It went into overdrive and shifted up and down as my speed dictated. The problem continued at each toll booth, traffic light, etc. I made it home and parked the car for about 2 hours. When I drove it, everything seemed back to normal. I thought there might be some temperature considerations, but, the temp gauge never fluctuated from it "normal operating temperature" position. I am about to change the ATF to Castrol Synthetic. How do ATF change intervals differ between synthetic and Mercon III? Heeeeeelp! Thank you.

Hello there, Let me give you some food for thought.

Have you ever heard of Amsoil before? If you have not you should look into it. I have a 1995 Volvo 850 GLT Sedan and have been using the Amsoil Product throughout the entire vehicle. I originally started using the product about 2 years ago in my 4 WD vehicle and was impressed with the results. Now I even sell the Amsoil Products.

The Amsoil Synthetic products out perform all synthetics, sythetic blends and regular base motor oils that are currently on the market. Amsoil was the first Company to do full synthetics, they started in 1972.

The Amsoil 100% sythetic Universal ATF Fluid exceeds the performance requirements for domestic and foreign automatic transmission fluids. It provides auto. transmissions, power steering units and hydralic equipment with an excellent lubricating protection along with better performance over a wider temperature range. Provides low temperature protection and is forulated with excellent wear protection to last for extended drain intervals.

It meets or exceeds the following specifications: GM; DextronII,Dextron III, Ford; Mercon V, Chrysler ATF+ thru ATF+4, Allison; C-3, C-4, Caterpiller; TO-2, TO-3, Voith Commercial; Opel & GM Strasbourg.

This product will extend your drain intervals by 3 times and depending on the persons driving habits sometimes even longer.

It's worth the look and the Money. If your interested in learning more I'll be glad to help you out and that goes for anyone even slightly interested. Give me an email at rpiescik@attbi.com.

Talk to you soon.

First off, changing the fluid will have no bearing on your problem. Start by checking the PNP switch (www.volvospeed.com > repairs & maintenance > bay 13)
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RussB in Ct. - '96 855T- '91 940T - '93 850GLT (R.I.P. 6-16-02)

Thanks everyone for the advice, and especially you at Bay 13. You are a Godsend!
The dealer just happens to have one in stock. As soon as I get it in my hot little hand, I'll be at it! Thanks again!

hear hear!!