I have been daily drivin my blazer a couple of weeks at a time since I finished it in August last year, and I'm finally getting fed up with the noise its making. I think its the t-case but I'm not sure. It makes kind of a whirring, grinding noise, that you can sort of feel in the floorboards on decel or anytime the drivetrain is in a kind of free spin mode (running 70, letting off the gas, makes horrendous noise). I thought it was the rear end at first, but I pulled the cover off and everything looks nice and new, no shavings, backlash ok, etc. It only does it from about 40mph and up, but its starting to make a bit of noise below that. Anybody have any ideas? I'm tempted to just pull the t-case and rebuild it since I have no idea how it was treated by the previous owner. Any help would be greatly appreciated!
CK5
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Noisy np208?
- Thread starter BadassBlaze
- Start date
i have a feeling its your pinion angle on the driveshaft. very common problem, but to do ti right could get expensive.
look up CV rear driveshafts and or a slip yoke elimination, or swap in a 241 that has the SYE conversion with the cv shaft already.
there are caddilac CVs that came from older eldorados? with the th400, it should be a slip yoke cv that will work good for you. i think its 1350 too, not sure.
just have that shaft cut down and put the right yoke on the pinion and i think that can help out alot.
when you have a cv rear driveshaft the pinion is to be pointed at the tcase output then drop it down 2 degrees.
without the cv you should have your tcase output and pinion nearly parallel to each other.
look up CV rear driveshafts and or a slip yoke elimination, or swap in a 241 that has the SYE conversion with the cv shaft already.
there are caddilac CVs that came from older eldorados? with the th400, it should be a slip yoke cv that will work good for you. i think its 1350 too, not sure.
just have that shaft cut down and put the right yoke on the pinion and i think that can help out alot.
when you have a cv rear driveshaft the pinion is to be pointed at the tcase output then drop it down 2 degrees.
without the cv you should have your tcase output and pinion nearly parallel to each other.
resurrected_jimmy
1/2 ton status
Check the driveshaft slip yokes and u-joints for wear. The 208 is not a hard T-case to pull apart and inspect. You may find its cheaper to get a used unit than to rebuild yours if price is a concern.
MuddinK5
Registered Member
i dont know if this will be any help at all, but i had a 208 in my k5 and it started making a awful noise. at cruising speed it was very faint, but when i put it in 4wd it was a tremendous grinding whining sound like it was about to explode noise. i kept driving it offroad like that because i wheel fairly close to home and 1 day it stopped pulling period no 4wd or 2wd, so i dropped it out and inspected it (i don't know why i inspected it lol i don't even know what i'm looking for) because a friend told me maybe the chain broke but it wasn't. i just put another tcase in it and called it a day. so to this day i never knew what happened to it
. i hope you can figure yours out.
OK THIS IS THE END OF MY USELESS POST LOL
. i hope you can figure yours out.OK THIS IS THE END OF MY USELESS POST LOL
I really want to rebuild it that way I know its good and fresh. I'm scared of buying a used one and it having problems. Its not really that much for a rebuild kit, and its worth the peace of mind to me. I replaced the u-joints in August. Why would it be the slip yokes? Also, not sure if this matters, but with my shackle flip my pinion is almost pointed straight at the tcase
resurrected_jimmy
1/2 ton status
A worn out or binding slip yoke will make all kind of noise and throw the vibration all through the drive train making it hard to pinpoint the source of the noise.
If you have your rear diff pointed at the T-case without a CV shaft I am betting on the shaft for the source of the noise.
There used to be a drive shaft shop on, I believe S. College, once you drop over the hill on University into Bryan. I bought lots of parts from them when I was there. I cant remember the name of the place right now.
Worn shift fork bads will cause an NP 208 to howl as well.
If you have your rear diff pointed at the T-case without a CV shaft I am betting on the shaft for the source of the noise.
There used to be a drive shaft shop on, I believe S. College, once you drop over the hill on University into Bryan. I bought lots of parts from them when I was there. I cant remember the name of the place right now.
Worn shift fork bads will cause an NP 208 to howl as well.
Bryan Drivetrain used them when I was going to college in college station a few years ago.
I'll check it out once I get it running again... Think it blew a fusible link this morning, no power to anything right now 
vortec
1/2 ton status
the whine reminds me of mine when i shift into 2hi but the hubs don't disengage immediately (backing up isn't always an option). but i have no grinding. maybe your chain or bearings are wearing out.
There's a shop at University and Poplar (iirc) that used to have some good drivetrain parts sitting around. My friend got a 208 off them for $50 and it ran beautifully. The salvage yards north of Bryan (year the vineyards iirc) have a massive amount of good stuff too. i can't promise any of that still exists...i haven't been there since graduating college in 2003.
There's a shop at University and Poplar (iirc) that used to have some good drivetrain parts sitting around. My friend got a 208 off them for $50 and it ran beautifully. The salvage yards north of Bryan (year the vineyards iirc) have a massive amount of good stuff too. i can't promise any of that still exists...i haven't been there since graduating college in 2003.
mwwebmstr
Registered Member
I had a similar whirring, turned out my rear axle lost a seal and was running dry. Eventually blew it up!
