Slipping from 2H into 4H?!?!? HELP!!!!!

[tksuburban]

I'm having a problem I have an '87 V10 Suburban with a NP208 T-case, 700R4 and 10 bolt axles. The problem I'm having is that while driving I start to hear a real loud clicking noise come from the LF wheel. Almost like a bicycle freewheel. I'm almost positive that it's the crappy auto locking hubs trying to engage. But they shouldn't be if it's in 2H. So I think that my t-case is somehow working it's way into 4H trying to allow the hubs to engage. Is this something that can be fixed with an adjustemnt or do some hard parts need to be replaced? I've got new manual locking hubs that I'm going to be putting on but I don't want the front axle to always be engaged. And I need to know what to do. Any help would be appreciated.

 

[85mudblazin]

could also be your wheel bearings going out.
The manual hubs will alow you to disengage or engage the fron axle for 4wd.

 

[kevcarr59]

I have a '78 K5 that had the same problem a while back. I would also check a few other things before messing with the transfer case.

When I looked at the CV joint at the front of the transfer case, it was almost gone. 3 of the bearing cups had no neeedle bearings in them and they were almost ready to drop out. If you were to draw an imaginary line of 0 degrees on an axis, the other end of the shaft would turn about 20-25 degres. That's how much play was in it.

That was the first place I checked, but it wasn't the actual cause. Pulled the whole front shaft out but that was not it. Check the front stub shaft axle bearings in the steering knuckle. You can't grease those unless you use one of the neeedle bearing attachments for the grease gun. If it pops like you said, figure on a new stub shaft. Mine had completely tore the bearing apart and rubbed a place in the shaft where the bearing rode that was a about 1/8 inch of slop where it was supposed to be.

I don't know how much trouble you're gonna have finding that shaft. WARN has a replacement for my '78 at $128. from 4 wheel parts. I checked with Austin Drivetrain in Austin. They're a Dana/Spicer Dealer. Got the new shaft for $44 bucks plus tax.

Hope the info helps... If you need the number for Austin Drivetrain, let me know.. /forums/images/graemlins/thumb.gif /forums/images/graemlins/thumb.gif

 

[tksuburban]

It's not the wheel bearings because it's actually putting itself into 4H from 2H. It's like it's partially engaging. When I actually throw it into 4H everything goes back to normal. It's not a poping noise. It's when I first start off that I start to hear it and as I start putting the shifter into 4H, it starts to go away. When 4H is fully engaged it's gone.

 

[B_to_C]

had the same exact issue with my auto-hubs. Put the manual ones in and no more clicking /forums/images/graemlins/thumb.gif BTW I went cheap at first (MM hubs) broke those... went a little better (regular warn hubs) melted one of those.... now i'm on to WARN PREMIUM hubs, i ended up blowing up one of those too, BUT they are always replaced for free if you manage to break them. /forums/images/graemlins/deal.gif

 

[RustBuket]

Mine did that the other day...I just had to back up for quite a ways. What I do to make sure they unlock is back up for however long and then hang my head out the door while I drive slowly forward to check and see if the front shaft is spinning.... /forums/images/graemlins/rotfl.gif

 

[chevyorange]

hey guys, i'm new to this site but searched for my prob and found it exactly. i have an 81 pickup with the 208 and auto hubs. have been experiencing this incessant grinding/clicking sound while the truck jumps as if it's trying to engage into 4h while the stick is in 2h. i tried the backing up trick in an abandoned parking lot, must have been doing circles in reverse for 20 minutes. still no help. i though it was the case until a friend told me to check the hubs. this is my first 4x4 and it's all greek to me. he said that it was an easy swith to install manual lockers, is this so? and if so, exactly what do i need and how much $$ am i looking at?

any help would be appreciated.

 

[chevyorange]

i tore into my pickup this morning. pulled the hubs out, which was rediculously easy, and had no idea what to do. just messing around i turned the inside part of the hub inside the outer assembly and heard a sharp click. i decided that something had happened so i put them back in and discovered that the front shaft stopped turning. so you're probably having the same problem i am, the hub was rusted and not well greased and obviously worn. i'm going to replace with standard locking hubs and get rid of this automatic crap.
thanks guys for all your help
/forums/images/graemlins/peace.gif

 

[semper-k-five]

mine did the same thing....after you hear it clickin for a while when ur driving, get out and grab a hold of it!! it'll let you know it's burnin up...i replaced my auto's w/ some manuals and it's all good!