1991 4.3 tbi 5lm60 tranny can be teplaced with??

[Jonf]

I have a 91 GMC Sierra with 150,000 miles on it. My late father bought it new and left it to me when he passed., so its more sentimental a reason that I'm keeping the thing although it does run good and always starts up. It has the
4.3 tbi and what I believe is a 5lm60 5 speed manual tranny.
Over the course of about a year and getting worse , it's developed a bearing howling noise and a tight vibration that both go away when I press down the clutch. Imput shaft bearing ? Any bearing that needs replaced in that thing, from what I've read, is beyond my mechanical desires and abilities. It's still drivable but for how long I'm not sure. Looking for economacle suggestions/solutions, compatibility lists, websites, and any other knowledge you folks would be willing to share. (the local pull your own yard has a sale going on untill the 15th, any tranny $150)
TIA!!

 

[fancyTBI]

I understand the reasoning for taking a gamble on a used transmission ($150 for something as important as that is potentially a great deal!) but would be hesitant to do so myself. Your best bet is to get yours rebuilt.

For what it’s worth my dad replaced the original getrag 5-speed in his ‘92 4.3 equipped C1500 with a later NV3500. Last I priced a rebuilt NV3500 they were about $1,800.

 

[Jonf]

I understand the reasoning for taking a gamble on a used transmission ($150 for something as important as that is potentially a great deal!) but would be hesitant to do so myself. Your best bet is to get yours rebuilt.

For what it’s worth my dad replaced the original getrag 5-speed in his ‘92 4.3 equipped C1500 with a later NV3500. Last I priced a rebuilt NV3500 they were about $1,800.

Thanks for the info!
Yea, I'm not too excited about going used, as it would be a crap-shoot at best. Id go with a crate transmissionor factory rebuilt if they were available. And didn't think having it rebuilt was a good idea either I just haven't had much luck finding any info on the 5lm and when i do find something or someone that knows a little bit, its always how hard they are to work on or how expencive the parts are.
As for the nv3500 swap your fatherr did, do you recall what, if any, issues he ran into along the way? Slave cylinder, clutch flywheel, drive shaft,or anything electrical? I watched a YouTube video of a guy saying he tried I believe the same senerio and it didn't work for him. He was shooting for more of a plug n play, bolt rite up type of outcome, where ya don't have to change anything. He said the NV shaft was ¼" too long or something was not allowing the thing to bolt up to the bell housing by a quarter inch. He was a inexperienced young guy that didnt seem to have alot of car smarts, so I wasn't convinced it wouldnt work, just not much info out there.
Anyway buddy, your reply gave me a ray of hope on my delima and I do appreciate the heck out of it! Tell your dad I said thanks also! After all, they are truley special people as im sure you know .

 

[fancyTBI]

Thanks for the info!
Yea, I'm not too excited about going used, as it would be a crap-shoot at best. Id go with a crate transmissionor factory rebuilt if they were available. And didn't think having it rebuilt was a good idea either I just haven't had much luck finding any info on the 5lm and when i do find something or someone that knows a little bit, its always how hard they are to work on or how expencive the parts are.
As for the nv3500 swap your fatherr did, do you recall what, if any, issues he ran into along the way? Slave cylinder, clutch flywheel, drive shaft,or anything electrical? I watched a YouTube video of a guy saying he tried I believe the same senerio and it didn't work for him. He was shooting for more of a plug n play, bolt rite up type of outcome, where ya don't have to change anything. He said the NV shaft was ¼" too long or something was not allowing the thing to bolt up to the bell housing by a quarter inch. He was a inexperienced young guy that didnt seem to have alot of car smarts, so I wasn't convinced it wouldnt work, just not much info out there.
Anyway buddy, your reply gave me a ray of hope on my delima and I do appreciate the heck out of it! Tell your dad I said thanks also! After all, they are truley special people as im sure you know .

As far as I know he had no issues. I just got off the phone with him and he said he didn’t make any changes. Bolted right in and away he went. He did this over the 4th of July weekend in ‘02.

 

[Erik the Awful]

Any bearing that needs replaced in that thing, from what I've read, is beyond my mechanical desires and abilities.

Manual transmissions are fairly easy to rebuild, so long as you have the tools. The first "heavy" job I ever did was rebuild the transmission in my RX-7. I had to borrow a super-deep socket for the nut holding the gears on the output shaft. Nowadays I have a welder, so I can make my own sockets if needed.

But it also depends on whether you can have the truck down while you fumble your way through your first transmission build. You might be better off installing a junkyard transmission and rebuilding yours on your own time to have as a spare.