recently my 1994 GMC x-cab 350ci auto-4 spd 216000 miles, started making loud clanking noises when i shifted into reverse. then it began the proceeding day to do the same loud noise in neutral, and once driven even in park. what puzzles me is that in drive it shifts and drives fine with no noises. to better explain the noise and some of what is happening it sounds as when a uni-bearing in a drive shaft clanks and the drive shaft does sometimes attempt to rotate very fast back and forth while in park, neutral and reverse. but sometimes its only heard coming from the torque converter area of the tranny while in park. this sound resembles the noise of bad lower crank bearings. when driving in reverse it is as though something is binding up the engine making it strain or fight like a wore out drive shaft uni-joint. but the uni-joints do not have wear or play in them to cause the binding. any ideas? thanx.

 

Check your tranny fluid before starting it, then start it and see if the fluid level drops on the dip stick like it is supposed too.

 

thanx for the quick response. i checked the fluid level cold and it was way above the "cold" mark into the part of the dipstick where it forms a "z" like pattern. then i started it up and the level dropped to the "full hot" level after a few minutes warm up. on initial start up no noise, but again once i put it in reverse the noise began and continued in neutral and park. then after a few minutes the noise went away. when placed in drive all "noises" discontinued. the oil is a tad bit on the darker side, so i feel it does need to be replaced, but i worry that some bearing clutch plates etc or converter problem may exist. yet i do know that the torqe convertor always turns in the same direction. so the convertor operation in forward leads me to believe it maybe an internal tranny problem?

i consider myself a giant parts changer, not a mechanic.

ive had a 71 455 buick race build blueprint/balanced with hi-lift cam and JE pistons etc to 462 ci and t-400 trannys pro-built w/bearings and x-clutch plates for the torque/power. all i did was attach the parts after a real mechanic did the details, and i shoehorned it into a 1987 buick regal by myself.

 

Well its hard to tell. Maybe put the rear on some jack stands and have someone start it and change gears to see if you can tell where the noise is coming from.

 

noise pretty much has gone away 'cept sometimes in reverse. but the "locking up and jerk-clank" is no longer present. just changed fluid & filter. but it had chunks of what apper to be seals gaskits or clutch plate material in the pan. dunno. are there any replacement such as a turbo 350/400 or older 700r4 long tail that will just bolt in. ya i do know that the passing gear link will present some prbs. but i'd really like to someday shoehorn the thing into my s-10 w/5 or 6 speed tranny. but i see all the x-tra challanges as far as hydr clutch linkage etc from my jtr manuel. and i only want a sleeper w cold a/c. i'd even trash the PC for a carb. even if it loses HP and burn more fuel.

 

Any of those tranny's will work. The next year(95) they started putting in the 4l60E. Im not sure though. So I think you would be happy with a 700R4. Wont have to mess with the comp or nothing.

 

just bought a replacement tranny outtah a cash for clunkers at $500 100,000 miles "1994 chevy 4l60E" the same "E" tranny as in my 1994 GMC. the truck was driven into the scrap yard. and is in better shape interior and cosmetically then my truck. i wish i could have just traded the entire truck and swapped serial numbers.

so far we have all but the top 2 trans/engine bolts removed. it appears that the only way to access them is to lift the engine off their mounts and move the whole thing fwd just a tad. these newer vehicles are a pain in the *** to work on. you have to drop the freakin exhaust just to get to the convertor dust pan, and even to change the tranny filter you have to remove the damn trans mount bracket. ppl used to think i was nuts. just to work on a carbed street/race buick 455 and my brother's buick 350 powered regal trans. i'd just pull the entire engine tranny out as one and table mount them back together after stall convertor or rebuild....then re-install it and hook up accesseries & a few wires. i lived in arkansas back then, there is NO inspection sticker emission laws that are enforced, so all emissions were stripped off and true 4" collector headers w/ 3" dual exaust short tail pipes cut off @ the rear axle turned down or even open headers were no probs even for the streets.. sounded like a few harleys. and that would be my story if i were stopped for noise. why are harley's allowed to run open pipes? and my car ran on 110-116 octane sunoco or VP fuel from the pumps. "lotsa Big Block ski boats around there"....here i can get an inspection sticker w/no troubles but if its too loud the cops will ticket you. thanx for the info and post. thats one reason i will do my best to get a vacuum distributor/if older heads are nesscery/ new alum. intake and a 600cfm carb and get rid of all computer related items when i swap the engine into my 1993 x-cab S-10...and a maual tranny like the one in there already....don't care if it drops the HP from whatever to 200HP and burns double the fuel. i get free gas anyway from my company.

un-related i have a 1977 GMC step side w/a stock 500c.i. cadillac+turbo 400 from a Cadillac Hearse. it runs like a scolded ape. the problem im having is appling for a lost title. since it was traded to one person w/no title ever registered, then driven from Georgia to Arkansas then i traded a dodge dakota straight up for it, and i now live in Louisiana. ive ran the serial numbers online and nothing comes up. ive tried Louisiana DMV, Georgia DMV, Florida DMV, and even Carolina DMV...and no one can help me to gain a title. i do know it is not stolen because ive asked the state police to run a search for the VIN numbers on the door panel. it doens't even show "ANY" vehicle matching those VIN numbers. i don't know who was the orig nor second so on owners that may have registered it. any sugggestions?

 

I would find another junkyard with a 77 GMC in it and swap out serial numbers as you suggested above. That's exactly what my uncle had to do when trying to get a title on his 83 Chevy.