Selec-trac noob questions... bear with me...

[slackin']

Im trying to learn all I can through the tech section and search, but I have some questions I can't seem to find the answers to. so please bear with me.

So this is my first FSJ... actually my first 4wd.
3 of my cars are AWD which is different (to me at least).

anyway, so I have an 84 j10 with selec-trac. I understand the H-L transfer case lever and the 2w-4w switch... but what is up with the manual locking hubs. what do they do? when would I engage them? does it lock the diff?

I appologize in advance for SUCH a noob question. perhaps that is why I couldn't find the answer.

[sungoesdown]

i am new to all of this stuff also, i dont think you are supposed to have manual hubs. i have an 83 j10 with selectrac, the lever, and the switch and i dont have manual hubs. thats what the switch does, vacuum operates the front diff

[Chevelleguy]

Look for the round tag, about 2" in diameter, held on with a screw in the center of it on the back of case, to the left of the rear shaft. This will have the model number on it.

[slackin']

thanks for the replies.
I totally understood what you are saying clark.

but... is the 2w-4w switch under the dash and the locking hubs seperate systems?
should I have both? or is it either one or the other?
Im confused because as Sungoesdown mentioned... from my reading Im not sure I should have both.

Im in the middle of a brake overhaul this weekend... so once I get that all set I'll scrape the TC and see what's up.
thanks again!

[slackin']

BTT.
Where did clarkgriswald go? he's like a shadow... one minute here, then his posts are gone.

I cleaned the TC and found the badge. it is a 229. actually a 229AM... whatever that means. at first I thought it was a time stamp.

so is this what I should have. I have never seen a j10 without locking hubs so Im still confused. I flipped the 2w-4w switch and heard the vacuum doing something but still no 4wd. I was going to lock the hubs and see but clark (the post is now missing) said I could damage the TC if the hubs did not jive with the TC.

anyone???
basically, I just need to know what the operating procedure is to get my truck in 4wd.

this thing is a major POS, so who knows.

[FSJ Guy]

With a 229, you want to lock your hubs whenever you are NOT in 2WD. Or, even better yet, simply lock the hubs and leave them that way.

Re-check all your vac lines and make sure your vacuum shift motor (on the t-case side of things) works.

Amazingly enough, the Chilton's manual gives a good pictorial of how the linkage goes together and works.

[710 Burner]

DO NOT flip the switch to 4WD and drive the vehicle without locking the hubs. Your vehicle DID NOT come from the factory with manual hubs. Driving even a short distance without the hubs locked while in 4WD could be fatal to a 229's high range. As stated earlier, you may want to lock the hubs and keep them that way as a precaution. Otherwise make sure to lock them FIRST before attempting to put the vehicle in 4WD. You should have a light on your dash to indicate when you have activated 4WD. Assuming it works, it may not come on until you remove the load from the drivetrain, i.e., placing selector in reverse then drive, removing foot from throttle at road speed, shifting to N while in motion, etc.

[slackin']

thanks guys for the info.

does this mean I have a parttime or fulltime 4wd?

I promise my questions will end soon (on this topic anyway).

[J4GRAND]

229 is a part-time 4wd system that's why you have the option of 2wd or 4wd.

[Lindel]

It is a part time case, but with the option of full time 4 hi operation. The 229 has a viscous coupler that allows street operation.

So, you could lock the hubs, stick it in 4 hi and forget it.

[slackin']

So, you could lock the hubs, stick it in 4 hi and forget it.

that's bold!
I can see my gas milage now.

thanks guys for the input. I'll be out tonight in the driveway testing this all out for the first time.

[Lindel]

Trust me, your mileage won't change much at all!

[710 Burner]

Trust me, your mileage won't change much at all!

My front axle is such a drag, I don't think it changes any. AAMOF, I was towing a 2500lb box up hill against the OK wind Saturday and kept thinking "maybe I should flip the switch and see if it has more power that way".

[GWChris]

Really, the 229 is full time 4WD. You can leave it that way all the time, dry or wet.

From the factory (without locking hubs), there is almost no difference between running in 2WD or 4WD. In 2WD the front axle and driveshaft are driven by the road at the same speed they would be anyway if you were in 4WD. About the only difference is it will have some additional friction when in a turn, as the VC is trying to drive both shafts at the same speed - but if you are on a highway going stright, there is NO difference.

So in theory, if you are in 2WD and unlock the front hubs, you would lose some friction and have better mileage, but I don't know how much of an improvement. And if you were to forget and shift into 4WD that way, you'd toast the VC pretty quick.

On the other hand, I love the 229, as it always has traction on nasty roads. If I want mileage, I'll drive the Hyundai.

[shimniok]

Tcases...

You know how in your axle there is a differential that allows one wheel to turn at a different speed than the other?

Well, there's a differential inside some transfer cases that allows one driveshaft to turn at a different speed than the other (like when going around corners while in 4wd).

Some transfer cases can be shifted into 2wd and 4wd. Some are full time 4wd (similar or identical to many AWD systems, like in my WRX)

Well, anyway, the NP208 in some J-trucks and Cherokees (and the rare Wagoneer/GW) is a 2wd/4wd tcase WITHOUT a center differential. The front and rear driveshafts are mechanically connected. Those types of transfer cases (called Part Time) can and probably should have manual locking hubs. That way the front wheels spin free of the front axle.

Meanwhile, NP228 and NP229 cases are 2wd/4wd and have a center differential. Actually the NP228 does. The 229 has a viscous coupler, like a limited slip differential. These should NOT have hubs because in 4wd the vehicle will either not go anywhere or burn up a lot of energy into the viscous coupler.

Finally the NP219 is a 4wd tcase only. It has a viscous coupler limited slip mechanism. It can't have hubs because it is always in 4wd of course.

Michael