djbeatz87

recently purchased a 91 Suburban 2500 back in december. Had the transmission serviced in January. Truck ran and drove great...until a few weeks ago. I had been driving the truck to and from work all week no problem whatsoever. Even that day, I had drove the truck to work and home several times with no issues. I parked it, went in to work. Came back out 2 hours later to go home and the the truck would not reverse. So I turned it off, waited a couple minutes hoping maybe I was just imagining things. I turned the truck on. Motor runs fine, but the transmission wont engage. There is no movement whatsoever in the drivetrain. What could it be? Im on a budget so any trans work I would be doing myself. this is just a standard 91 3/4 ton burb from what I can tell. It has the 4l80e I have determined from the 17 bolt pan. Any clues? Is this common? Where do I start? Help Please! This is my dream rig and I hate to see it sitting after only 6 months

Joe In NY

Please understand, but, there is fluid in the transmission correct? It didn't leak out or anything. And is it at the correct level and is it the right fluid?

cleveland63b

does it go forward?

djbeatz87

I havent done any maintenance on this vehicle yet. My parents were driving it until theirs was repaired a couple months ago. I have done some checking since last night. here is what I have observed. And sorry but I am a newbie when it comes to servicing my own vehicles, but I am very mechanically inclined and I do my research as much as possible.

ANYWAY, upon checking the trans dipstick I discovered it was dry! ugh! not a drop on it. I do not see any apparent leaks although there is fresh fluid on the tip of the breather hose? I believe its a breather hose. black rubber hose coming out of the top of the transmission at the rear where it meets the transfer case. Anyway, I filled with fluid, and when i attempted to shift into gear, no response still. after a min, the vehicle acted like it wanted to go forward, but seemed like it was in a higher gear maybe? seemed sluggish and hesitant to accelerate. No odd noises. Motor is in great shape sounds great. but shifting the column doesnt seem to affect it like normal....doesnt lower rpms or engage at all. So I turned it off for fear of making it worse? and had it towed back to my house. now that its home, i turn it on, and back to no response.

djbeatz87

sorry i should add the whole story i suppose...Had been driving all day no hard shifting, no overheating, no problems at all, drove like i imagine a new one would. 2 hours later when I originally started it after work, it would go forward, but when I attempted to shift into reverse, it still wanted to go forward, no matter which position the column was in. So i turned it off. waited a second. turned back on. no response from any location on the column. checked and discovered dry dipstick. filled with fluid and truck would seem to want to go forward, no reverse, but like it was in 2nd or 3rd maybe... turned it off. towed it home. turned it back on. no response again.

djbeatz87

I should also add that Ill be doing any repairs myself. No matter how technical or involved or tools necessary. I believe in learning everything I can about maintaining and repairing the vehicles i drive.

Joe In NY

Ah. There we go. Well. I dont know if I can help you much. But I started and then you provided good info for the more knowledgeable to help.

I would check all the trans-lines to make sure of no leaks. But I am not at all familiar with a breather hose for transmission...

djbeatz87

I was not aware of a breather line either. Anyone know what it might be? long black rubber hose starts at the top of the rear of the transmission where it meets the transfer case. the other end of the hose seems to have a black plastic tip thats melted. Any clue what that is? Again Im a newbie but Im ready to learn everything I can about my truck...Been wanting this exact setup for years.

91 Suburban Silverado 2500 with the 4L80E I have determined... not sure if any other work has been done to it. Looks like new components under the hood like its had the engine replaced/rebuilt. other than that, Im learning as I go. Im able and willing to post any pics if it would help. Thanks everyone.

Joe In NY

post pics

73shark

I suspect the black rubber hose is a extension of the transmission vent. These are common on 4 wheel drive vehicles to get the vent above any possible water incursion when fording streams. The differential vents usually also have these extension tubes on them.