Recently in my 99 jimmy 2d 4x4. When I first started it when cold(only conditions I can test) it feels like gears are slipping or binding when I try reversing out of my parking space. It feels like it takes alot more gas to move like it's in 4lo. The light for 2hi is on solid like normal. I didn't force it, I changed between 2hi and 4hi back and forth. 4 lo just blinks but I had it in park. Eventually I tried it again after playing with the buttons and it was normal. Then when I start moving forward it hesitated to shift or something. It just sounded like the engine was working but I wasn't moving much then it felt to have shifted gears and then drove fine

 

if only does it in reverse, ur rear diff is failing, e brake hanging, or front hub bearing collapsed and binding. u coulda broken a upper ball joint but u would c that right off.

 

Start easy E Brake

 

as for the e-brake, it doesnt work, and i no longer engage it because i havnt gotten around to diagnosing and fixing it. i have always used e-brakes in all of my cars, automatic or manual. but this one i noticed right away it doesnt very well, so i stopped using it. the ball joints were replaced less than 2k miles ago.

i feel like i should check my front left hub assembly first. i suspected bad wheel bearings for a while on my front right wheel, but i noticed after replacing that wheel hub assembly on the front right, that the noise i was assuming was the front right bearing never went away. as im driving and veering right/left to shift the weight from side to side to diagnose which wheel bearing is bad, the sound seemed to be prodominatly right, hense my replacing that side. but after replacing it seems like the sound is the same, and my ear is seemingly focusing more on the front left now.

i just got brand new snow tires on and there is noticably more road noise than before, and i dont know if the tires are just really loud or not, but the problem with the binding feeling in reverse is also new, so possibly a coincidence. so i still have my front right hub assembly i think i will throw it on the left since its an easy job, and just see what it does. before i dive into messing with my diff.

thanks for the info i hope im able to get this one figured out. 1 of 10 problems to fix! yay gm

 

just pick her up and shake er down and turn stuff first should be an easy find

 

What you described sure sounds like the sun shield giving up the ghost to me. Exact same thing happened to my dad's truck with the same 4L60E we have in these Blazers.

 

ive done a little more poking around online and it sounds like the sun shell to me also. this morning i went out to get in my truck and take it to my dads shop to swap a wheel hub assembly when i noticed i cant reverse out of my parking spot yet again. this time its worse then ever. i put it in reverse and knowing its having issues i am very gentle with it. i notice its not moving by itself at idle speed so i lightly give some gas and it just revs without gear noise or motion as if i was in neutral. so i let the truck idle a bit so it gets warm hoping maybe the transmission fluid will warm up and maybe that will help. im not an expert but i do take care of my vehicles and i try to baby them especially my daily driver. eventually the reverse felt like it wanted to move or at least that the transmission was engaged in reverse gear. it kind of felt like it was moving a tiny bit so i gave a little bit of gas, maybe a few hundred rpms at most and it didnt move any faster, eventually it rolled very very slowly, with engine sounding like its working to move it, but its not moving. as it slowly rolled i hear the clicking sounds like the gears are binding.

then finally after putting my foot out the cab and pushing myself i got it out of the parking spot and got to driving. driving through the parking lot at ~10mph i had some huge rpm fluctuations, around 500rpm up and down, similar to the ones ive been having on the freeway ~200rpm that i had diagnosed (transmission slippage) im awaiting a valve body repair at the shop for that currently.

then on the freeway i had it in cruise control ~55mph and there is a moderate hill for half a mile maybe, as i was going up that hill, it downshifted to 3rd like normal, good smooth feeling shift but then i noticed the rpm's kept climbing while my speed didnt really fluctuate, it was maintaining the speed (cruise control) yet my rpm's continued rising from around 2100-2200 all the way up over 3000 in a matter of 5-10 seconds? maybe faster. then i noticed the smell of transmission fluid in the cab so i pulled over. talked to my dad, decided to take a gentler route to the shop. i finally get to the shop and park it, i get out and stick my head between the fender and tire on the driver front and i smell a strong transmission fluid odor. does not smell burnt, but hot rather? as if it was hot and leaking?

sorry for the wall of text, hopefully someone has some insight on this.

 

Hate to say it but it sound like it is time for a tranny rebuild. Find a shop that know the 4L60E inside out. You tranning is slipping so bad it is overheating and causing the fluid to expand, thus coming out of the vent tube. Maybe not so much that is is causing it to burn, though.

Good news is you can get much better components, particularly the sun shell, than stock to build a rock solid tranny.

 

man i am totally flabbergasted.. i think i found the culprit to be loose transmission cooler lines. and looks to be an aftermarket radiator that i did not know about. we went to take the cooler lines off to look at the fittings because of a leak ive posted on these forums about. when we went to take the brass fitting off of the top cooler line it was basically no more than finger tight, and there is no rubber seal on the inside of the female end. the nut itself has the one on the inside of it though. but we tightened up the fittings top and bottom, both were very loose and leaking.i had been checking my trans fluid level for a while now but in my lack of experience i was checking the level when cold, not when hot. so i was basically just checking the fluid that was in the pan only. we checked it when hot and the dipstick was coming up dry. it was my personal fault for not checking the level correctly. i was thinking "oh that leak isnt very bad if its trans fluid cause i still have a good reading on the dipstick". well turns out i was running on 1 qt of fluid because it took us 4 quarts to get the hot reading to read right on the hot mark on the dipstick. now she seems to be running great. the real test will be here in about 20 minutes when i go start her up cold and see how she does. if she drives good on a cold start i found the problem to be low fluid!! ugh i feel super dumb, i should have acted on this leak more promptly. now i just hope i havnt done too much damage to it.

thanks for all of the help here, i learned a lot for sure and know a lot of symptoms and issues just from all your guys input.