Ok heres the deal . I have a 1993 GMC 4x4 1/2 ton short bed pickup with a automatic transmission and a 305 V8 motor in it .Its a ranch truck that we leave in Idaho for Ranch work and it seldom leaves the ranch . It looks like hell but runs circles around the other ranch trucks for getting into tight ,steep places . All along I been told it has a 700R automatic transmission in it . The transmission is getting weak and needs to warm up a bit before it starts working correctly . It has 134,000 miles on it . Motor has been changed and it runs like a top . I luv the truck and really want to keep it for ranch use ,but don't want to dump a bunch of money into a truck that old . I been looking around for a used transmission we can stick in it .
Now a guy told me the 700r is the wrong one for my truck . I am in Calif ,for now , and can't comfirm this ????? Anyone know the correct one ??
More than likely it "IS" a 700R4 transmission, that is what was pretty much the standard issue for that year.
You may have worn out disks and bands, but you may also have some other issues that are cheap to fix/check out.
I don't know what the oil looks like in the transmission, but when shops do an "Oil Change" they only change what is in the transmission pan and filter. There is still about eight to ten quarts of dirty, old oil in the Converter that needs to be changed out and it will break down and mess up the transmission's operations.
What you might do is a full flush with new transmission oil, it will take about an hour. You can do it yourself if you undo the cooler lines from the transmission to the Radiator. Put them into a five gallon bucket and start the engine. Let it idle until the oil starts to sputter, then shut the engine off. Refill with three quarts of AFT and restart the engine until the oil stream starts to sputter again and shut off and repeat. It will take about 14 to 20 quarts of oil before it turns a bright red again like what you are putting in. After you get the bright red oil, run it dry one more time, then remove the pan and replace the filter with a clean new one. That could be also plugged and the cold oil will not flow though it fast enough to make it operate until it is warm/hot.
After that, put the pan back on after tapping the holes in the pan where the bolts go though, they will be pulled up from the first install and will leak if you don't. Tap them back to flat using some steel to rest the lip of the pan on. Then refill the transmission until it is at the full level with the engine at idle.
There is also a computer control module that controls the shifting and it is located on the firewall of the engine compartment, you can trace the wires to it from the Transmission. It "May" be bad, but I doubt it.
Do the oil change first, it will cost about sixty bucks in oil and filter, if that don't work, then go for the $2,000.00 version later.
Good luck!
