AWD Street Hardbody?

[lt1_performance]

Im getting bored with my camaro now and have been looking for something AWD to play around in. Id like to run a 4x4 Hardbody on the street with a turbo or something. Like a lowered street-beast. Kind of a Syclone/Typhoon sort of deal but Nissan of course. My question: Is there any way to run the 4wd full time on the street with-out hurting the transfer case, front axle, etc? I know generally peolple say not to drive locked in on dry winding roads or high speeds...but is anyone doing it with the Hardbody already?

[seang]

Not that I know of. Another member asked a similar question a while back but with the idea of making an all-Nissan "Syclone Killer" with a Skyline GT-R engine. The stock transfer case is 50/50 locked, and I'm not sure if there is any way of modifying it. It is not okay on a dry paved road locked in, I know that. Maybe in a perfectly straight line it would work out alright, but any turns would be very harsh. If you could adapt a tranfer case from a Syclone/Typhoon, Bravada, or AWD Astro van then it might work. There might be some AWD transfer cases on other Nissans, but I don't know specifically with the exception of the Skyline unit.

Say you did manage to do this. I would definitely recommend you use a heim joint center link (HooHaa makes one) with all that added stress on the front end. The stock front axle is an R180 which, while not outright weak, I have heard can break with enough torque or abuse. Also (if I remember correctly) you can install a R200 that is stronger. These trucks already have trouble holding an alignmet, so upgraded (possibly one-off custom) compression rods might be employed, but by now I'm just getting into guessing territory.

[Desert Rat]

You'd need some sort of AWD Tcase. This would be difficult since the Nissan case is a married design already and would need some sort of custom adapter plate at minimum to install something else.

Sean hit on some other points, though I don't think the diffs would really have any problem, the steering might be less than ideal.

[lt1_performance]

I have looked into the idea of taking the internal viscous coupler in a mid-90's Jeep and making it external to use on the stock transfer case. Seems to be unheard of from my research, that would solve alot if it will work...

**Edit** This is similar to what Im talking about. This is an external unit from a land rover.(pricey of course) The jeep unit consists of the center black drum thing.

[seang]

Then you would have the shifter and the ability to run 2wd if you wanted, something other AWD cars cannot do. I know the transfer is shift on the fly between 2hi and 4hi (it clicks in and out with ease even at speed as long as the hubs are locked); but that is with a 50/50 split, I'm not sure if that feature would be affected by the viscous coupler or not.

D21 does have equal length CV axles, which is good. I think there are steering dampeners available, too, to help with any possible torque steer. Not sure how much there would even be, honestly. I saw a video of a turbo Silverado launching in 4wd, and there was some torque steer for him.

Also, I have never heard of a D21 transfer case breaking. The stock 5sp (4wd version of the FS5W71C) on the other hand, is more likely to break if you thrash it. 240sx's and 2wd D21's and Frontiers also have this model, but I don't see fail stories like I have with the 4wd. I do know for sure that the 4wd 5sp transmissions have an oil fill plug that is an inch too low from the factory, and needs to be overfilled to avoid starving critical bearings of oil. 2wd and 240sx versions do not have this problem.

So that coupler would go with the front driveshaft? Are they reliable pieces?

[edited for info, see post below]

[Desert Rat]

The Nissan TX-10A is a chain driven case, not a gear driven one. I've torn several of them down for regearing.

[seang]

Thank you, DesertRat, I was hoping you would know. I like not guessing. I want to just say "Go buy a Syclone or a Typhoon," but it is not going to kill me to entertain an idea. Dammit now I'm late for my appointment.

[lt1_performance]

If my idea will work an easy solution for the shifter is just to take it off and leave it in 4hi. Then the viscous coupler still pulls the front wheels. The more you mash the gas, more the viscous coupler grabs. But still lets the front driveshaft turn at a different speed during cornering, thus full-time 4wd. As far as adapting the coupler, I was thinking of maching a flange to bolt to the stock front output flange, and another flange on the other side to bolt the driveshaft to. Have to shorten the driveshaft of course but no big deal. As far as the transmission goes, Whats the main cause of failure? Breakage or oil starvation? If its breakage how can I beef it up? For my project I want an XE V6 Hardbody, these transmissions and transfer cases any better?

[seang]

My guess is that the main cause of failure for the transmissions is that by the time an enthusiast discovers the overfill policy, a previous owner may have racked up a hundred thousand miles on low oil, promoting the eventual failure.

Smashing through the gears with monstrous torque is another culprit. A member of another website I frequent (but will not name because Nico is better) put a turbo on his ka24e 4x4 , and was running 350hp and over 360lbft of torque at the wheels (and that was the 2.4 liter) and he said he went through 3 transmissions. That thread is also old, so it may be more than 3 transmissions, I don't know there was never a recent update.

Not sure what transmission model the 4x4 v6 has.

Oh yeah, the gear ratios on the 4x4 transmissions are not really sporty. First gear is 3.92 where the first gear on 240sx and 2wd trucks is 3.2. Sure, you can throw more power at it, but when you race that Typhoon you will be maxing first gear before 25mph and will be in fourth by 60mph, almost a waste of all that turbo torque.

[lt1_performance]

Maybe a step-up in rear-end gear ratio maybe be in order at those speeds. Does anybody make stronger parts for the 4wd Hardbody transmission? Im still looking for a V6 Harbody cheap locally and I cant really find any at the moment, dont really wanna go with a 4cyl but may have to in all eventuality. And as far as lowering it, I dont see any kits to lower a 4x4 Hardbody, probably not enough demand. Thinking coil-overs in place of the shocks on the front and adjustable upper arms? Dont really wanna just crank down the torsion bars and throw everything off.

[seang]

I think the CV axles will be taking up space where the coilovers would go, but I definitely don't have any firsthand experience fabricating suspension stuff. If you can work a way around that, then it could proably work.

People have swapped independant rear suspension onto D21's from 240sx's using the whole rear subframe assembly. There is also the link setups or traction bars etc.... There are even Jaguar rear ends.

I'm not aware of any trans modifications, just a $90 rebuild kit with new bearings at least, synchros are extra charge. If you tear it apart while it is still good and unbroken, checking everything and replace any bad stuff, you might stand a better chance of having it last longer. 240sx guys don't seem to have any problems throwing 400+hp through their FS5W71C's, it's just these 4wd versions.

There is tons of axle info in the sticky at the top of this forum, earlier D21 4wd had a little bit taller ratios than later ones so you could maybe get some of those from an offroader who swapped in even lower gears.

I think 4wd v6 models might use a different model transmission than the 4wd 4cyl.

[lt1_performance]

Race coil-overs are not much bigger than regular shocks. I believe most are 2.5" dia. spring, while most shocks are around 1.5". I should be able to squeeze the extra .5" on each side in there even if I have to move the mounts a bit. I was thinking a link style rear, probably just a 4 bar to stop axle wrap.

After doing some research, the v6 models use a FS5R30A model transmission, same style as the 300zx's. It has a 4.061 first gear ratio, which is way too much in my opinion. These trannys any stronger?

[seang]

Speaking on behalf of 300zx transmissions, yes, fs5r30a is stonger than an fs5w71c. I'm not sure about the 4wd versions exactly, but I know that the z32 300zx fs5r30a is considered rugged. I don't think I recall hearing about any v6 model 4wd's blowing a transmission. About that first gear, maybe there are aftermarket gear sets that would fit, but they probably won't be cheap if there are, but I'm not sure. I know OSGiken used to make a race style gear set for the fs5w71c with taller low gears, not sure if those would fit the shorter 4wd transmissions or not.

[Desert Rat]

don't think the Z trans tailhousing interchanges with a truck transmission so you can bolt the Tcase on.

Coilovers on the arms could maybe be done, but you'd have to beef up both ends, as those shock mounts weren't designed to hold the weight of the vehicle. The upper might be strong enough, but the lower mount wont be. Also, with the addtional diameter of a coilover vs a shock, like Sean said, I think it'll interfere with your halfshaft.

Torsion bar lowering will only be good for 2 inches of drop, tops. lowering more than that using coilvers probably wouldn't net much more drop before you completely run out of suspension up travel. And you can't raise the axle up higher in the frame to acheive more drop because the axle will be in the oil pan.

v6 and 4 banger transmissions don't interchange.

[lt1_performance]

I think I saw a Hardbody running coil-overs on the front probably 2wd, anyone else see that? Oh and does the Hardbody have a solid front axle or that sliding thing in the middle?

[Desert Rat]

sliding thing in the middle? huh?

there's a diff mounted between the framerails with the pumpkin offset to the drivers side and an axle tube going to the frame rail on the right side. Then, equal length CV halfshafts bolt to the axle flanges and go to the outer hub/spindle.

[seang]

I think he meant the front driveshaft from the transfer case. Looks like it does slide, there is a boot on it, but I never had it apart.

[lt1_performance]

Yeah I did mean the driveshaft, sorry for the confusion. I cant find any 4x4 v6s around here, thinking of swapping a 2wd over. Alot of work but they are plentiful around here...

[rizzobc]

is there not some kind of AWD car that you can pull parts out of and fab a BAD A$$ AWD turbo beast . That would so cool stuff. I mean if you are putting this much work into it why not build a one off. You will the great suspention and the AWD and big power and, well you get my drift. just something to think about.

[lt1_performance]

The syclone/typhoon is really about the only awd truck that is similar. And not much chance of swapping anything over with the nissan drivetrain unless the transmission outputs are the same but I doubt it. The old NP203 is the most widely used full-time 4wd transfer case. A flange adapter and shaft coupling could work in theory with both the syclone/typhoon and NP203 transfer cases. Might be a good idea in comparision to the viscous coupler since the strenghth of that is seemingly unknown. This might also let me use a 2wd transmission if I make the adapter for that flange... More research is needed...searching.... but also this still doesnt make a 4wd V6 Harbody available, might just bide my time some more...

[rizzobc]

could you get the set up for the skyline. I know they do it for the 240s, but could you fab it work in the HB. That would be the Sh1t! I mean why not. You could drop as low as you wanted, put the suspention you want and you would smoke everybody! check into that dude!

[lt1_performance]

Skyline parts arent very available here, definitely not cost effective for what I wanna do. Not to say that it wouldnt be frickin sweet..

[lt1_performance]

I been researching the 2wd to 4wd transmission adapter, not finding much thats not full on custom tig welded ends on T56's. Which is cool but not exactly what Im looking for. Probably gonna stick with the 4wd unit for the time being. I still have a few questions I couldnt find: A FS5R30A 4wd transmission has a 30 spline outout shaft, is 2wd the same? Anyone have some good pics of the tail section of the 4wd transmission? Google turned up nothing... What is the diameter of the FS5R30A output shaft?
For the shaft coupler, I was thinking of using the front yoke splined sleeve thing from the FS5R30A 2wd (assuming it fit the 4wd shaft) and an old output shaft from a 27 spline GM transmission (th350,400,700r4,powerglide...about any of them) and machine the two to fit together and weld it solid. Thus a spline coupler! For the flange adaptor, flange on both sides, one for the nissan transmission and one for the syclone tansfer case, a big steel tube welded in the middle. Simple yet effective... Id like some feedback on what you think of the plan, it just might work!

[seang]

So it will be a divorced transfer case?

[lt1_performance]

Well not exactly, I think of a divorced transfer case as having a short driveshaft between the transmission and transfer case that runs externally. I would call my coupler more of an extension of the output shaft which will be encased in the adapter holding the two together. Maybe hard to picture but will be easier once I get my hands on one...

[seang]

I think I see what you are saying.

[lt1_performance]

Hopefully someone chimes in about if the 2wd and 4wd have the same output shaft spline and diameter...

[jvillstangman]

try a transmission and transfercase out of a 88 hb it has a divorced tf case

[lt1_performance]

Well I really need an awd transfer case so I can use it on the street... or the viscous coupler idea which could work with a regular transfer case

[lt1_performance]

Well ive made the first step into this project which is of course the project vehicle. Mine happens to be a '90 Hardbody, standard cab, KA24E, 5 speed but unfortunately its a 2wd! And I know everyone is like "Not a 2wd! It would be so much easier to start with a 4wd truck" Well if you think about it, I need an awd transfer case anyways, a 2wd 5 speed is stronger and could work with the tranfer case as a divorced unit. Of course I could mount the differential on a 2wd with a little fab work and maybe modify the 2wd front suspension to work or swap it out. Couple questions first to help with planning... Will the 4wd spindles work with 2wd ball joints? How hard is it going to be to match up a front diff ratio with the stock rear? Im gonna crawl up under it tomorrow to see about clearance for the diff...