Trans gearing question

[Old Rusty m1008]

Ok so I finally got my title and got my truck registered and took it on its maiden voyage as a former military truck I know these things are geared really low as they have a ton of torque. It does not really appear when driving that these trucks spend any real time in first gear its almost immediately into second then they shift into third about 15-23 mph and it tops out about 55 mph with the truck screaming... the truck cruises at 40 with no problem... is that normal for these trucks ? I know we have all three gears as ive put it manually into first and second and they seem to work..

 

[epartsman]

This is normal. The trucks have 4:56 gears for off road use. You have several options. You can change over to 3:73 ratio with some modification. You can go with a lift kit and larger tires. You can do a 700r4 or a 4L80 trans swap. All of which is discussed in detail in the forums here. Welcome to SS!

 

[cliffyp]

For typical driving that sounds normal. If you really get down on the throttle those shift points should be higher. You can also manually shift if you have a need to raise the shift points for a specific application.

 

[TVOLLMER]

I have recently installed a 700r4 and have come to appreciate hearing myself think. The best mod I have ever done. The low gears and lower 1st gear in the 700r4 are very helpful when towing like I do. And with the over drive i can cruise at 65 with no issues and less road noise then with the stock turbo400 at 55.

 

[Keith_J]

If the vacuum regulator on the injection pump has failed, you will get sluggish shifting regardless of throttle.

To diagnose, get a vacuum gauge, vacuum line and a T fitting. Install the vacuum gauge on the top line off the vacuum regulator on the injection pump. Test drive, vacuum should be proportional to throttle position with 18" at idle and no throttle. It should drop to 3-4" at wide open throttle.