Hey all. I seem to notice that when driving on the highway with my 91 740 at about 70 mph, the tachometer is reading about 3000 rpm and it will not shift into a higher gear. I assume that there are 4 gears in the transmission. I am currently getting about 20 mpg on the highway. Any idea on what speeds the gears shift?

 

It really depends on the weight that you have inside the vehicle. If your trunk is loaded with heavy things it might not shift as soon as it normally should. You could have transmission problems or might need to simply replace the transmission fluid and filter.

 

3000 at 70mph sounds like '4th' (really, overdrive) to me....

test: push the button on the shifter so the yellow up-arrow light is on (OD disabled), accelerate to a speed where the engine is going 3000rpm (likely about 40-45), maintain that steady speed, and push the button. it should shift to OD and the RPMs should drop. Or, go 55 or 60 normally, then push the button to disable OD, and the RPMs should shoot up.

 

Read the manual. When I had a 740 GLE the rear gear box would also shift as an overdrive.

I'd also check the plugs. The poor mileage could be credited towards NON-OEM plugs.

 

Most 91 740T's had a 3.73 rear end if equipped w/ the AW71L automatic. As mentioned, check the operation of the OD. 3K doesn't seem too steep but higher than some.

 

no US model turbo had the AW71L (L for locking) transmission. AFAIK, they are all just the AW71, which is the heavy duty version of the AW70 used on non turbos. turbos do have the taller rear end.

 

Right you are. I still was thinking of your 740 GLE which, once they went to 16V only in 89, had the AW72L. L's were used in Euro cars, but never made it over here.

AW lockup transmission type and numbers:
AW71L Volvo part #1208643 (Euro turbo applications 1990 on) B230FTI
AW71L " "1208417 (Euro) 86/87 B230K
AW71L " "1208371 (Euro) 85/87 B230K
AW70L " "1208563 (USA) 87- B230F
AW70L " "1208604 (USA/CAN/JAP/AUS) 89- B230F
AW70L " "1208652 (EURO) 89- B230F
AW72L " "1208666 (USA) 89-B234F/B230FTI/ rare & best
AW72L " "1208667 (EURO)89-B234F/230FTI/B204FTI rare & best
AW72L " "1208637 (USA) 89 B234F
AW72L " "1208638 (EURO) 89-B234F

Converter ratios:
AW70L 1.72:1
AW71L 1.72:1, 1.80:1
AW72L 2.40:1

Stall speed:
AW70L 2,000
AW71L 2,000start-2,700 stall, or 2,500
AW72L 2,500