Are you refering to the shifter or the transmission? You need to check the fluid and see if it is low or burnt.
check your fuel filter and also your spark plugs.
It is GL-5 and the weight is 80/90 gear oil.
Chances are real good you will take out your pinion bearing, pinion gear, carrier bearings, and ring gear in really short time.
This engine does not have a timing belt, it is gear-driven. Possibly, you have broken gear teeth, causing the timing to be out of order.
What is the gear ratio for a 1985 CHEVROLET K10 pickup
4.10 ratio
It probably does not have one. An oil cooler was not standard equipment on a 1991 Caprice. But the Caprice 1991 made for the middle east has two separate oil cooling compartments in the radiator (one for engine oil , one for gear gear oil).
Change the gearbox oil and see if that helps. If it doesnt it will be the gear selection sensor.
the cam gear and the crank gear are dot to dot
Is your clutch bad or wearing out ?
You should NEVER have to adjust a new gear box. You have other front end problems that are worn out.
YES, as long as there the same GEAR RATIO.