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Im planning on building something with AWD. The requirements Im shooting for are
-3200 lbs or less weight (my Nova is 2800 currently)
-readily available front limited slip
-fit 275/60-15s on all 4
-800wtq setup
For the transfer case, I am going to use BW4472. It is the transfer case
that Syclone/Typhoons use, but is also exactly the same in old Astro AWD vans,
Bravadas, and supposedly some S10 Blazers(I haven't seen one yet). They are easy and cheap on eBay. There are evidently four variations, two variants have 27 spline rear output and two have 32 spline output. There are two input pilot ring diameters also, only about 1/2" difference for some reason.
The BW4472 AWD cases are full-time with no switches, and split 1/3 front, 2/3 back. The transfer cases are easy to find, but the correct factory transmission to xfer case adapter is tougher. Early years had an adapter to a 700R4, which is four bolt to the transmission, and happen to be the same bolt pattern to TH350. Later years are 6 bolt to a 4l60e, pretty much worthless unless you actually plan on using a 4l60e. The th350 and 4l80e adapters use the early 4 bolt factory adapter. They are a total pain in the *** to find. Xfer cases falling out of trees, but the adapters were all thrown in the trash evidently. You can find them on car-part.com if you're willing to call yards and have them ship you one..who knows if they know what they're even looking at. I got lucky and go the correct one for $50 shipped.
Im using a TH350 for mine so I got an extension piece from Advanced Adapters part no 50-8506. My TH350 was a regular run of the mill 6" extension car transmission. I had to cut 1.5" off the output shaft, just used an angle grinder on it without removing the trans guts to get to it.
Im not 100% what vehicle to use, but I know the GM 7.2" IFS that comes in so many vehicles (I think Astro/Bravada/Syclone/TBSS) has no limited slip available. There is some random person that supposedly made some, but there is not much info. So thats out.
I have a 64 Nova that just dynoed 740/810 so Im considering using that. I think a solid axle Cherokee XJ Dana 30 front axle might be good. Its driver side input, which would match the BW4472, and limited slips are all over. They are narrow, maybe 1" wider than the Nova WMS distance. Its a solid axle but uses coils that are in about the same spot as the stock Nova front end, so it would be relatively simple to put under there. It would have to sit about 4" higher than stock at least. Even being solid axle it would still probably be better than the stock Nova suspension/steering.
The other option I have been thinking about is getting an old Cherokee XJ and replace the engine/trans/xfer case with a turbo 5.3/th350/BW4472. They are super light so would be right at 3200 lbs probably with an L33.
Finally, the BW4472 mostly seems to come with a CV joint front driveshaft. It seems like a weak point and is expensive to replace so I want to run a u-joint so I can use a stock XJ front driveshaft. I found a flange yoke that works, fits perfectly Spicer 2-2-939. Evidently its made for a Ford 8.8 flange.
EDIT: For future reference, the part numbers of the GM adapters (goes between 700r4 and xfer case)
15654083
15683749
15661062
15623497
Last edited by Hank Peabody; 12-02-2015 at 09:14 PM.
those dana 30s out of any jeep are the biggest piles of **** ever created by man, if anything go with an aftermaket dana 44 with a high pinion. even then I wouldnt trust it at 800rwtq.
Yep consider a hi pinion 9" with Dana 60 outers. By the time you put all that money into a Dana 30 or 60 for a few grand more you could build a 609 that will hold the power
I have a high pinion D30 out of a 1990 Cherokee currently. I'll probably use it gently and upgrade it if it looks like its a problem. Ive been running on a GM 7.5 rear at between 600-800rwtq the last six years, only have ran 6.20s, but its held up great so far, so I figure sending a little of that to a D30 with its 7.2" gear might work ok especially since its 3.07 geared (rear is 3.08) and its all street driving. Thanks for the advice and ideas, I'll keep it all in mind.
D30's got a bad wrap....but Ive NEVER busted one. Ive also never jumped my Jeep, and I know when to get out of the darn skinny pedal.
I had a 4.6 stroker in an XJ, turning through a high pinion D30 with 4.88s and 35" tires. Air down, they would wrap halfway around a rock while pulling the jeep along. In 4 low...thats some decent torque. Never busted it. I built it right, re-inforced the housing in some spots, and never busted it.
In a street application, if its hooking hard on that front axle, you might have issues. But Im betting it would survive more than you might think.
Obviously..given the budget a 9" is the way to go here haha. Just saying. My D30s never exploded. Ive own a bunch.
Thanks for the info. I figure it will probably be fine. Offroad with giant tires and 4.11-4.88 gears is a lot different then on-road with a 3.07 gear. 200hp Lincolns in the 70s came with Ford 9" rears, it doesn't mean 9" rears are weak.
I got the axle in, trailing arms mounts on, used cherokee steering parts and QA1 coil-overs. Now I just need to get the engine/trans/xfer case in, shafts shortened and it should be ready to go. I locked out the vacuum disconnect for now, Im going to put in Motive shafts and a Lock Rite after I try it out in 3wd mode for a few miles.
Thanks! For the suspension I just used coil overs and mounted the brackets upside down. All of the steering/track arm is standard Cherokee stuff, it really seems like it will improve the driving. The stock stuff is so terrible with that elliptical bolt crap for alignment that I never could quite get right.
-more available LSD for solid axle
-seemed easier, but turned out to not be probably
-the faster diesel trucks seem to work better with solid vs ifs, I could be wrong
-anything is an improvement on the stock **** in these cars
9 out of 10 people would choose IFS over solid axle even in an old car, I understand why, I just did this 100% for straight-line acceleration so didn't see a reason for IFS.
Once I change the axles/joints to Motives and put the Lock Rite in, I think the stock carrier will be the weak point. If that goes or the Lock Rite sucks Im going to put a True Trac in and that will replace the carrier at least.
Many of you have probably seen this car already with its infamous chained driveway burnout, but this was posted a couple days ago. The build uses some of the same AWD parts. Also, further inspiration for the OP.
Thanks for posting that, I hadnt seen that new video. I guess that is an open diff in the front so 3wd for the most part? Super nice car for sure. My main goal is to get 0-60 to low 2 second range on the street. The fastest Ive ever seen in any of my cars or bikes is 3.0-3.1 with my Vbox on the street. Im hoping with real 4wd and 275 MT DR on all 4 I can finally use 1st gear.
I have the engine/trans/xfer case in and mounted. I dropped the prop shaft off this afternoon, just need 1" taken off. I have a driveshaft that luckily fits. It should be on the road in about two weeks.
12-02-2015, 06:37 PM
AWD ruminations, BW4472 Typhoon/Astro insanity 
