229 xfer case destroyed?

[Thomas DeBusk]

My front axle hasn't been working reliably on my '83 Wag. My Wag is one of the few that has a vacuum front axle disconnect. Last week the shop found worn spots in the vacuum tubes at the firewall right in front of the driver. Front axle came back.

Until today.

Running down the highway at about 50 I flipped the underdash switch from 4WD to 2WD. No problem. Two miles later at 60 mph I hear/feel a medium drivetrain thunk from below. But no other immediate symptoms.

Three miles later after stopping at a stoplight, the Wag won't take off. I shift several times from Drive to Reverse and back. Nothing but a light grinding sound. Then I flip back to 4WD. It goes fine. When I park and get out a mile later, the Wag nearly rolls into the car in front of me as it makes that light grinding sound like when you shift into "Park" with the vehicle still moving. But I had put it in "Park" and it was stopped. I dived back in and got my foot on the brake. I parked it elsewhere, but had to roll it up against a snowbank to keep it from moving. "Park" didn't work.

Later, I drove 25 miles to my mechanic's garage with no trouble, I think in 2WD. Then, I went to get something to eat. When I left the restaurant, I flipped the dash switch to 2WD. No go with light grinding sound. Then I let it drop back to idle and engaged 4WD while in Drive. After a solid thunk, I could go. Down the street, I tried 2WD again. No go. Back to 4WD. It pulled fine.

What's the problem? Is this a bad viscous coupling? It seems like the back end isn't engaging. Apparently it's not the transmission. What else could it be? Some other problem with the xfer case? It doesn't seem like a rear differential problem, does it? I'm not getting any noises from there.

Another problem I've had with this xfer case is it can be a real pain to move the floor lever from high to low. Gets stuck in high. Moving the vehicle and relieving the pressure on the drivetrain usually does the trick, eventually. But today I never moved that lever.

Thoughts, anyone?

Thomas

[letank]

if i remember to shift to 4WD you need to be at a rolling stop, put in neutral and then engage the lever..... same to put back to 2WD

Michel
74 wag
85 Gwag

[Thomas DeBusk]

Don't think so. I know that's what it says on the lever housing, but I've shifted back and forth while moving plenty of times. Never at high speed under power from 2WD to 4Wd, but plenty of times at about-town speeds. My brother's '88 has the exact same xfer case and his housing doesn't say anything about stopping.

Michel, I think you're talking about other xfer cases, not this "full-time" case.

Aside from that, even if I were abusing the case, that would only explain HOW it got damaged, not WHAT got damaged.

Thomas

[shadowfax101]

That is the same thing mine did about two months ago. It would not go at all in 2W, but it would drive fine in 4W. Also mine would not stay in park while I was in 2W, but it would in 4W.

And Yes it turned out to be the VC. As far as the floor lever I have no idea if it is related or not, I hope so for your sake.

The shop that I took mine to found a new VC for around 900.00. The guy at my shop even told me that was crap and to try to find some other way arond. I went to crazy jeepman and got a good one for about 200.

[andy d]

uhhmn, the dash shift on the vac disco f/e should only be engaged at rolling speeds. thats why it is a 2 handed operation

[tuckers89GW]

Thomas,
If you have a front axle disconnect then you need to be stopped before shifting from 2wd to 4wd. only with the solid front axle can you shift on the fly. to shift into 4low then you need to be in 4hi and moving about 3-5 mph, shift into neutrual and pull up sharply. same back into 4hi. Several stop and turn off their engines when shifting into 4low. the little pin on the bottom of the 4wd shifter is to make sure you don't shift it while moving.(2 hand operation)

I'm not sure why it wouldn't move in 2wd. unless the front axle is disconnecting and allowing the t/c to remain engaged in 4wd. I don't know if this can happen because the front axle has to be engaged before it will shift the t/c into 4wd. if the t/c is still engaged and the front axle isn't. You will ruin your viscous coupling very quickly.
I'd start by making sure the t/c is actually ****ing out of 4hi by crawling under and checking the connecting rod from the vac motor. make sure its moved from each postition of the switch. Lube it up if it is sticking. That would be the first place I'd start.

[ February 19, 2003, 06:31 AM: Message edited by: tuckers89GW ]

[Thomas DeBusk]

This is very enlightening. I'm getting a difference of opinion here. Must I be completely stopped to shift from 2WD to 4WD? And vice versa?

Now that I think about it more, I doubt I've ever shifted from 2WD to 4WD going over 20-25 mph. But I have shifted from 4WD to 2WD going considerably faster. Like yesterday. Previous owner told me you could shift this thing on the fly. Hmmm.

Now as far as Mike's post goes, I'm suspecting that might be the problem. I know I had vacuum problems, and couldn't get 4WD for a while. And over the weekend I had some quirky behavior when I shifted to 4WD, but didn't seem to have the front axle working. I wonder if the front axle disengaged on the highway yesterday, but the xfer case was still in 4WD and the VC going bad was the thunk I heard/felt?

What does it do to the VC to have the front axle disconnected, but the xfer case still in 4WD?

And since I think I need a new VC, can anybody point me in the right direction? Incidentally, I think I need 2 as I need one for my J10 229 xfer case also.

I also wondered why my brother's Wag with 229 (1988) doesn't have the pin in the 2WD/4WD switch. Different front axle, huh?

Thomas

[xc_xtc]

Just curious, but i thought I could shift 2WD/4WD at any speed..... 85 GW (if mine would shift to 2WD)...

[shadowfax101]

On my Gwag I can shift on the fly, Mine does not require two hands. Some shifting controls need two hands some do not. I have been told that you could shift on the fly up to around 50mph. I will NEVER try that. I have heard that, but I am not sure I believe it. But an 85 can shift while moving.

As far as a new VC, it was cheaper for me to get a used T-case as a whole..

[LRRH]

it all depends on what type of front axle you have. the easiest way to tell is by your 2 to 4wd shifter. if it has the stupid little pull down knob below the box, then you need to come to a stop. you can change this by giving your front axle full vacuum and keeping it locked all the time, or by manually locking it via the shift fork.

[xc_xtc]

I have a whole other GW '87, but it's like 3900 Km away... :(

[Kimbrough]

Thomas -
double and triple check your vac hoses going to the t-case!
i had a crack in my vac lines on TOP of the t-case. They can be accessed from the trans cover inside the truck. I had the VERY SAME symptoms you describe. I fixed the lines and the t-case works fine. Apparently in 2wd, the t-case must have good vac in order to STAY in 2wd. Otherwise, the linkage will slowly creep towards 4wd(hi).
It winds up in a "neutral" position between 2 and 4wd. Thus, when you put it in park, it grinds and acts like its in neutral.
Check for leaks first - it might save you a ton of money!

[Serious Johnson]

Still doesn't explain why Thomas's rig will go in 4 but not 2. Please correct me if I'm wrong, but wouldn't it take a functioning VC to accomplish that? Only thing I can think of would be a busted rear R&P or prop shaft. Maybe there's something funky in the power flow of a 229 that I don't understand.

:-

[tuckers89GW]

serious,
I think the t/c isn't going into 2wd completely or if the front axle drops out of lock and the t/c stays in. most all the power will be transfered to the front and that is how v/c's get toasted. Kimbrough might have nailed it.

Read your owners manual on shifting into 4wd. I owned an '83 and it said to be stopped completely before shifting

[Wagoneer622]

Ditto on being stopped to shift on the 83, I had to do it on my 83, got sick of it, engaged axle permenentaly, never could re-route the lines right to get 4WD on the fly.

[mdill]

Hard to say what damage has been done by shifting on the fly over time,
the forces involved in trying to spin up the front drive shaft from 0 to 50
in zero time is pretty high I would at least have your mechanic pull the front
diffy cover to take a look at the engagment dogs, and change the fluid,
the transfer case is a tougher call as it is not a 1/2 job to pull open for a peeky
boo, at leaste change fluid in there, check the lines and if it works great if not
new case time ! I have the same 83 setup on my chero, I would swap that
crappy axle out if it was not my sacerficial (sp ?) winter driver.

Mike D.

[mechanic58]

Well, I have a 229 in my 89' wag currently and it seems to work just fine. I had to work on the vacuum servo, but other than that it works well. Although I do detect a tad bit of SLACK in the chain...it does have 190,000 miles on it. LOL. There's a trick to getting it to shift in and out of low range. You have to "relax" the drive train in order for this to happen smoothly. If you're in low and want to shift back to high, make sure you're not in a bind and put it in nuetral and then try it...if it still acts stuck, click to reverse and then back to nuetral again. It should slip right into high or low....whichever you're trying to select. Your other problem, the grinding and soforth sounds to me like your vacuum shifter servo may be going bad or maybe your vacuum shift linkage is fouled up...mud or a stick or something...dunno. Just a suggestion. Good luck. BTW, my 229 is going to be removed and replaced by a 208 very soon. It will be for sale.

[tuckers89GW]

mechanic58, on an '89 the front axle is a solid axle. doesn't have a disconnect in the front pumkin. that is the only reason why you can't shift the '83-'84 with 229 on the fly.

[Thomas DeBusk]

Wish I'd posted this question a long time ago, but, then, I guess I didn't have this problem before.

Too bad I don't get great gas mileage to go with my disconnected front axle.

Now I understand why the little pin is on the bottom of the 2WD/4WD selector. I'm trying to recall shifting into 4WD at speed. I really don't think I've done it at more than 20-25 mph. But I wouldn't be surprised to find out that's what's toasted the VC. On the other hand, I sure hope it's a vacuum or servo problem. I found a new VC for $900. No such thing as a rebuild. What is it about these things? Seems like a local tranny shop found one for $2-300.

Thomas

[tuckers89GW]

You can get the entire t/c for 1K from these guys.
Transfercases (http://www.transfercases.com/order.htm). Seems you can get them cheaper, but not sure where.

[scotty]

yikes! :eek:

all kinds of bad things can happen when shifting the disco frontend on the fly,not the least of which is breaking spider gears,and the resulting metal chunks also destroying your R&P and bearings in true "snow ball effect" fassion. not to mention what coulld happrn to the t case if the axle does not engage.

the reason you must be stopped to shift the disco axle is the inner,disconnected shaft is spinning BACKWARDS-opposite of the way the outer shafts that are still connected to the wheels via their full time drive flanges.

shifting the axle while this is going on very viloently engages the coupler as the 2 shafts line up,then starts it spining the correct way.when this happens,the diff itself and front drivesahft will start spinning as well. the extra effort it takes to spin the diff and driveshaft make the shockload on the axlesshafts,coupler and spider gears that much worse. end result can be broken spider gears,broken axleshafts,and stripped splines on the shafts and/or coupler.

i would advise against sifting from 4 to 2 at speed as well. as the couplers slide apart,the diff and front shaft will stop spinning,and the inner shaft will start spinning backwards as power spins thru the stationary diff. while you dont have the same shockload as you do when engaging the axle,the spider gears will very suddenly start spining very fast,so there is some stress there as well.

IMO the vaccum disco axle is a cool deal. people who have trouble with them typically dont understand how they work and how to trouble shoot their vaccum systems.

i have my disco axle in my daily driven xj hooked up to its own seperate vaccum switch. i can connect and disconnect it seperately from the transfer case.

this can be cool for a daily driven rig cause you can keep the axle disconnected in the summer months,so the front shaft isnt spinning. you can also disconnect the front end in 4lo,in case you ever need the extra "grunt" of low range,but are on dry pavement so you dont need 4 wheeles pulling.

it can be really cool for a trail rig cause you can add a locker or spool to the front end,and be able to disconnect 1 side and be able to turn with a flip of the switch. it sure beats jumping in and out to lock/unlock the hubs.

in my xj,i can shift in and out of 4wd at any speed i want-ive done so at 65 mph on the highway. the important thing is that ive had the forsight to have flipped the axle switch to lock it in BEFORE i started moving.

if you dont really feel a need for the benefits youd get from adding a sepearte switch to the front end,you can simply route a vaccum line to the port that keeps it locked,and it will be much like any later GW that had a full time front end. the shift motor itself doesnt go bad all that often. usually when people have a prollem with it, its due to a vaccum issue(lack thereof ;) ).

on the v/c it is quite common for a rig to not move in 2wd and have to be shifted into 4wd when a v/c goes out. it has to do with the way a 229 creates 2wd,the mechanism somehow lets power spin thru the diff,but not to the front output. its been awhile since ive been inside one o them,so i cant remember it exactly. putting it in 4wd adds the front output back ino the equasion ao that power cannot spin thru the broken center diff assembly.

hope that helps anyway smile.gif

[ February 21, 2003, 07:10 AM: Message edited by: scotty ]

[Bob Barry]

One possibility is that the repaired front axle vacuum lines were reversed.

The way it is supposed to work is that the vacuum MUST engage the front axle before it will send vacuum to the vacuum shift motor on the transfer-case to engage 4wd.

If those vacuum-lines are reversed, then the vacuum-motor on the front axle would engage the front shaft and THEN engage 2wd rather than 4wd. Then, when you shift to 2wd, the front axle disengages, but the vacuum is now shifting the transfer-case into 4wd, which is why it doesn't go when the lever is in the 2wd position. And which is also why the lever won't go into 4Lo.

That's one possibility.

But definitely pull the front cover and see what is damaged in that front housing.

[shadowfax101]

I would see if anyone has a used one on here they might want to sell. I got a good one from Crazy-jeepman for about 200.00 and I had that put it. A lot cheaper than 900 for a VC..