AWD Transfer Case replacement

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Jan 31, 2004 | 10:37 PM

rkletke

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AWD Transfer Case replacement

I have a 91 AWD Aerostar 4.0 L that needs some work. 207k miles, original engine, tranny, everything. Now, I'm just guessing, but that pronounced vibration under the floorboards the other night at hwy speeds, the clunking as we slowed down, and the fact that the rear driveshaft literaly moved side to side by hand indicate that I might need a new transfer case! Oh yeah, all the silver colored oil around the rear seal pointed to something pretty well nuked inside the case!

Would you recommed a used, salvage unit, or a re-built unit? The vehicle still runs good, engine is strong, and tranny shifts good so we're not replacing right away.

Any suggestions about which part to pick, and any help on how hard it is to do is greatly appreciated. I've done most of the minor work on it, so am pretty familiar down there.

Thanks,

Robin

Feb 2, 2004 | 10:21 AM

aerocolorado

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I rebuilt my own around the same mileage but other than some chain stretching, everything else was in good order. If money is no object, a rebuilt unit runs around $950-1200, less labor. A used unit from a later model would likely be your most economical route unless you choose to rebuild your own. The silver colored oil suggests the clutch pack may be damaged and this will run up the rebuild costs considerably.

Removing and replacing the TC is fairly easy. Were I to do it again, I would rent a transmission jack - at least for the re-installation portion. There is a "paper" style gasket between the TC and transmission that should be replaced during installation. This does not come with the rebuild kit and is a dealer only item.

Feb 2, 2004 | 01:17 PM

rkletke

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Thanks for the info/advice. If I get a used part, would you recommend replacing the output seals on it, or do they not degrade if not being used?

Feb 2, 2004 | 02:20 PM

aerocolorado

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If your driveshaft has as much play as you indicate, replacing at least the rear seal would be warranted. If you are inquiring about replacing the seal on another unit, it would still be a good idea to replace both the front and rear before installation. Seals are inexpensive and simple to replace.

Feb 4, 2004 | 03:56 PM

rkletke

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Ok, its all done now (I don't really want to do it again!). I ended up with a salvage TC, bought new seals and had them installed since I don't have all the tools, and wrestled the darned thing back up under the van. This whole job would have been much easier with more clearance under the van, a good tranny jack (like aerocolorado said), and some help. If anybody out there does it themselves without the tools, make sure you've got strong shoulders and don't put your head between the TC and the floor!!!

All I need now is to find out where the little bit of oil is coming from. I think its escaping from either the TC/Tranny gasket, or the vent on the TC. Anyway, its running and my wife is again happy!

Thanks to all for helping.

Feb 5, 2004 | 10:26 AM

aerocolorado

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Ouch! I can relate having to wrestle that bugger into place, but only bashed a few fingers, not my entire head. Glad you are running again. I had a similar leak afterwards and then it has stopped. I think it is easy to overfill the case which allows it to escape via the vent. Wait a few weeks to see if the leak stops. Mine would only lose a few drips overnight during the time it was leaking.

Feb 10, 2004 | 02:57 AM

rkletke

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Ok, found the LEAK. The darned rear seal has come totally out of the TC! Last time I have a shop do it for me. I didn't think that these seals would just pop out like that. Anybody have a reason why that might happen?