its basically the same thing. an automatic tranny wont go in Overdrive until youre going at a generally constant speed. the same is true with a manual transmission- while driving on average roads (40-55 mph) you will not shift into the final gear until you are going at a constant speed.
Overdrive is a gear that turns the vehicle driveshaft faster than the engine and is used to improve fuel mileage (and also lower CO2 emissions). Typically 5 or greater in a manual or 4th gear or greater in an automatic is overdrive but there are exceptions. Because of CAFE (fuel economy standards) virtually all cars and small trucks have come factory with ovedrive since 1981.
In vehicles with a five-speed automatic transmission, keeping the gearshift in "D4" will cancel the fifth (or "overdrive") gear keeping the vehicle in fourth gear; this setting is recommended when towing trailers or boats to keep the transmission from overheating.
the synchronize in the transmission is bad, that why the jumping out of fifth gear
To switch back to automatic after being in the simulated manual mode, you need to shift past fifth gear. When you reach fifth gear, you can tap the shifter to the right twice and it will go back into automatic. Or, you can shift the car to neutral and then back to drive. I would suggest being stopped for this though.
I don't think there is room to put an overdrive in a Zuke, I've seen most of the aftermarket overdrive units and all the OD's I've seen would be way to big. There are transmissions with different fifth gear ratios, one trans has a higher fifth gear than the other. Guys with the 33" and bigger tires usually run the lower ratio fifth gear. You can ether swap the trans or swap the fifth gear in your trans if it has the lower ratio fifth gear in it. That might help, if I remember right its only about 300rpm difference.
i would think it's a syncronizer inside the transmission
There is no 5th gear overdrive, only 4th gear
If you have a digital display which tells you the gear the vehicle's in, the gear it's in can tell you if you're in an overdrive gear or not. However, you have to know your transmissions. For example, in a transmission such as the 4L60E or 46RH, only the fourth gear is the overdrive gear, so you know you're in overdrive when you're in that gear. The 6L80E has two overdrive gears, so you're in overdrive when you're in fifth or sixth gear. The other way involved a bit of mathematics, and probably isn't that practical to try doing while the vehicle is in motion. You would also need to know your transmission final drive ratio and your rear end gear ratio.
It sounds like the Cabriolet has a possible problem with the shifter forks. The transmission will need to be pulled apart to see what the problem is for sure.
it could be that the clutch isn't disengaging all the way
At the moment, my research shows that the GT's come with 3.31 gears from factory. There is an option for Premium GT's with Manual transmissions to swap the 3.31's with 3.55's. I know the manual trans is rated for better gas mileage, and had assumed that the auto's had different gearing. However, I've just found some information that discusses the specific ratios for each gear in each transmission. From that information, I gather that any gearing differences between the Auto and the Manual are caused by the transmission, not the rear end. All Ford literature that I find indicates that the 6 bangers, 4.6s and Shelby's come with 3.31 gears. Here are the transmission ratios as shown on Automotive.com: 44K 5-Speed Manual Transmission Manual five-speed transmission with shift lever on floor, 3.340:1 first gear ratio, 2.000:1 second gear ratio, 1.320:1 third gear ratio, 1.000:1 fourth gear ratio, 0.670:1 fifth gear ratio and 3.380:1 reverse gear ratio Tremec 3650; Standard transmission; Excludes: [44L] 4-Speed Automatic Transmission 44L 4-Speed Automatic Transmission Automatic five-speed transmission with lock-up, electronic control, shift lever on floor, 3.250:1 first gear ratio, 2.440:1 second gear ratio, 1.550:1 third gear ratio, 1.000:1 fourth gear ratio, 0.750:1 fifth gear ratio and 3.070:1 reverse gear ratio 5R55S; Automatic drive indicator on dashboard; Standard on Prem Conv for Fleet orders; Fuel consumption: EPA urban (mpg): 18, country/highway (mpg): 23 and combined (mpg): 20; Fuel economy EPA highway (mpg): 23 and EPA city (mpg): 18; Weights: curb weight (lbs) 3519; Excludes: [44K] 5-Speed Manual Transmission. See Related Links
that sounds pretty normal to me
When it is in 4th and 5th gear it sounds like its about to break down.[not that it is going to break down!!]