H3 Damn... another transfer case failure???? no 4 wheel low when I need it.

[jakesz28]

I believe it is. Been checking old threads to get the numbers.

 

[Bigunit]

The 4:1 TC is #BW 4494/NR6.

 

[Bigunit]

Part # for the 3.7L 4:1 TC is #24247592. The part # for the V8 TC is different and the 2 cases are NOT the same, so make sure you get the right case based on the engine size.

 

[jakesz28]

Is that the GM part number? and is it on the transfer case? That's good to know that the v8 is a different TC. Thanks

 

[backcountryislife]

Well...


My 4:1 showed up today,

so we should be able to get the old one out & rob some parts for you soon. Unfortunately, the steel case for the diff showed up looking very aluminum-ish:huh:.... so not sure if we can make it all happen yet or not.

If we pull the front diff, and put in the T-case, the truck will still be able to move around in RWD right? I just know my mech isn't going to want to have it blocking his garage till we get the new diff carrier.

 

[reaper]

I don't think you can pull the front diff and roll it! But I could be wrong... I'd leave it on to roll your truck in and out of the garage.

Hey, should we take apart your new tcase in the meantime, just for fun?

How can we be sure you don't have the plastic shift fork in there?

 

[backcountryislife]

I don't think you can pull the front diff and roll it! But I could be wrong... I'd leave it on to roll your truck in and out of the garage.

Hey, should we take apart your new tcase in the meantime, just for fun?

How can we be sure you don't have the plastic shift fork in there?

It's a stock 07... pretty sure I've got the plastic shift fork. OH... the new one... yeah, umm... NO!!:wink:


Only issue is that once we start work, it's holding up his garage completely... I guess we could swap the T-case ourselves, then deal with the diff later. If he does the work though, he's going to need to do it all at once.

Right now it still drives, so I could swing your way & we could swap the T-case there??? Trying to figure out a good way to do this, Zach's supplier made a mistake, I'm sure we'll get it figured out pretty quick here, but I'd like to pull the t-case & get that done sooner.

 

[reaper]

Right now it still drives, so I could swing your way & we could swap the T-case there???

Sure! We could do that, but mine doesn't drive so we'd be working in the street (the garage is slanted). Or just wait. I'm a little booked between now and... oh crap, it's a long time, we need to just make it HAPPEN! I guess we just need to decide: party down here or party up there? If you have the fluids, I think we could do it all in one shot at either location, but I think my gasket will need to dry off before we mount it. I don't know how gasket compound works, do you? Ideally we could do both trucks in a day, but we probably need to plan on just getting yours done the first day. We could get your truck done in one day without too much effort for sure.

 

[backcountryislife]

I've never waited more than 1/2 hr for permatex to set, it's not like it's a crankcase where there's pressure. On our 2 strokes we give it an hour, then pull the rope. Should be MORE than long enough to put it in & get stuff re-attached.


Only issue with doing mine, is we're doing redundant work to do the diff & T-case separately... so sucks to do one without the other being here.

 

[reaper]

More Pics! Still stuck though.

By now I've taken the whole damn thing apart. Here's the carnage:


Now, to assemble it again... REALLY not that hard. This starts at about page 175 of the manual if you are playing along. The manual is slightly out of order: you have to install the high/low planetary carrier first, and then teh ring gear and retaining ring. Here's a pic of that that looks like:



From there, you can easily add in the main shaft (including a bearing in there...), the shift fork (this is what was PLASTIC in the 2006 FYI), and the shift cam:


As you're installing it, you're working in high gear. Next, add in the oil pump and it looks like the following. Now you can turn the shift cam counterclockwise which raises the fork on the gears on the right into low gear. (In the middle is neutral.) The following pic is low gear:



And here is where I'm stuck. At this point, the gears grind for me. Which of course is what I saw on the vehicle. Page 174 talks about a mainshaft support bearing that I don't seem to be able to locate. Perhaps that's missing from in the high/low gear carrier? If I lift the shift fork up ever so slightly, I'm in low gear and happy. But in the default position, she grinds. Note that when I take everything apart there isn't signs of wear, it all looks new under there. But it seems like something is missing or doesn't QUITE fit right.

 

[MaxPF]

Try putting the rear case half in place to properly support the shift fork rail and output shaft. It's possible just a bit of deflection in the shift rail isn't letting the fork pull the coupler completely up. It doesn't look like you can put the shift fork in backwards on this case. I'm guessing you ruled out cam wear? Another possibility is a missing thrust washer that doesn't put the rotary shifter shaft in the proper position. Also, is it possible that the planetary isn't fully seated? I am not familiar with the parts stackup in a BW case. I'm much more familiar with NP/NVG/Magna cases, although they are very similar designs.

 

[reaper]

parts list!

Thanks Max: Yeah, everything is seated properly, there's just VERY little difference between 4low and 4-neutral.

I took the half as-is in the last picture into the dealer this morning, and they recommended replacing the following parts. Crap, these parts are pricy!!! I listed them out along with the dealer price and online price (does anyone else have recommendations for part vendors-- I got these prices from gmpartshouse.com.)

Part#	Name	Dealer price	Online price
88996561	Hub (unique to 4494)	170	125
15580249	Ring Gear retainer	9	7
19178136	Shift Fork	53	39
89059542	front output Shaft (mine is bent!)	140	104
89059520	Bearing (front output shaft)	43	32
88996628	Shift cam LEVER (only the end of the shift cam)	77	57
		520	402 including shipping

I'll probably get some of these parts from backcoutryislife when we swap out his tcase, but might want to put new parts in for some of these. Thoughts/opinions/part sources anyone?

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POST UPDATE: While the dealer recommended trying out replacing all those parts... it was just the Hub gear that needed replacing, not because it was "worn out", but because it was the WRONG FREAKING GEAR. Good thing I only ordered that.
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[MaxPF]

Might want to try drivetrain.com and anaheim gear.

 

[reaper]

Might want to try drivetrain.com and anaheim gear.

Thanks Max. I just ordered the hub from hummerpartsonline.com, which seemed to be the cheapest overall. $131.21 for the hub and the ring gear's retaining ring. With that and some stolen/borrowed parts from other tcases (thanks backcountryislife) I think we'll be good to go on the cheap, but *done right*.

I took it over to my friend at Medved and we looked at it over lunch, I decided that the hub is the offending piece, either that or the main shaft, as when it's in the correct position the teeth aren't in quite the right position. Now that I've figured that out I'll have to post some more pics. So maybe the %&*ers who rebuilt it last year put in the wrong hub gear... we'll find out when the new part comes.

I think the moral of the story so far is to rebuild the case yourself if this happens to you. That way you know it's done right, it's relatively simple to see that things are fitting together and working as they should when it's apart on your workbench. Parts are always less scary when you take the "majik" out of them and know how they work.

 

[reaper]

The Culprit

Ok, here's really REALLY why.

The hub on the left is the hub that was in there... I assume that the tranny shop rebuilt it using the hub from a non-adv. tcase. The hub on the right is the correct size, it's specific to the adv. tcase. You can see that the wrong hub would KINDA work for a little while as long as everything was put in a certain way, the teeth would just barely grab, but would slip right out. But the distance of those teeth is the distance that the gears were off. The pic says it all, they put in the wrong freaking hub gear!



The correct gear, on the right, is about a half an inch smaller since the adv. tcase has a bigger hi/low gearset.

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EDIT:
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Never mind... the hub on the right is for the 4493 tcase, I ordered the wrong freaking part thanks to my local dealer. I shoul dhave checked on the part numbers he told me. Although the length of the hub seems to be what the length of the 4494 part should be. I'm so confused....

 

[backcountryislife]

so, now knowing what they did, can you go back to them & have them pay for the parts???

Hoping mine shows up here eventually so we can get both of them done!!! I'm gonna drag your azz up spring creek before the snow one way or the other!!!!

 

[reaper]

so, now knowing what they did, can you go back to them & have them pay for the parts???

Hoping mine shows up here eventually so we can get both of them done!!! I'm gonna drag your azz up spring creek before the snow one way or the other!!!!

They did refund all my money.... I'm not entirely sure if they left the wrong hub in there or put in a new wrong hub. But I did get every penny back from them. A-Affordable Transmission in Denver (3485 South Zuni Street) is the shop to avoid. They should have at least seen the mechanics not working while it was apart... the mechanics of a tcase are pretty simple and you can mechanically shift the gears with it opened to diagnose.

 

[reaper]

Crap.

Crap crap crap crap crap.

The hub I ordered was for the freaking 4493, not the 4494. So that wasn't REALLY the issue although it appeared to be. It does appear to me that the freaking hub isn't the right length, or I'm missing another part. So I'm returning that hub and ordered the following today. I got this from hummerpartsonline.com, which seems to be the best price by far. For a $100 part, they beat gmpartshouse.com by $20. This might change on a part by part basis, but they do seem to be a bit cheaper in the end, even though their handling charges are silly.
My order:
*89060050
PAD (shift fork pad, x2) - should help, should be replaced, not the issue though.
$3.16

*89059529
HUB - this is the hub I replaced earlier. Will return the old one.
$81.52

*12334624
BEARING - from that main shaft. Should replace it.
$15.92

*89059521
WASHER - in case mine is missing/different.
$13.56

*89059519
BEARING - the main one in the tcase. Mine isn't that smooth, should probably replace it.

 

[backcountryislife]

We'll have my standard T-case to reference off of in a couple days, but I'm wondering how much help that's going to be anyhow.

 

[cdarveaux]

What is the V8's 4:1 (NR6) part number?

 

[4speedfunk]

V8's are different??? I thought a 4:1 was a 4:1, regardless of the motor.

 

[06 H3]

They are not different mechanically. The rear half of the case has a different part # because there is a heat shield riveted on for the crossover exhaust the H3 alpha has. Other then a heat shield its exactly the same