newest 720 sas

[godzirra]

This will be my first post here so lets see how it goes..

Any comments, questions, opinions, advice is welcome

 

I bought it bone stock, 165,000 original everything... $1200

 

I drove this way for about a year, put a 3" suspension lift from 4x4parts.com (they may be the only place for Nissan aftermarket, but they still screwed me out of $260) which consisted of assist. leafs and some upper control arms that look EXACTLY like the stock ones.

 

Of course I got tires of the 3" and started researching more "extreme" options...

 

here we have a d44 out of a 1979 IH Scout (if anyone is looking for good SAS axles, Scouts have a good width to them that works well with 720s).

The axle has been turned to spring over, holds 4" lift Jeep CJ leaf springs (rigid as hell), with custom made hangers (square tubing, 3/8" steel plate, etc. etc.)

 

 

And this is all that was in the way (u-joints on most of the IFS were slinging oil, torsion bars maxed out, rides rough as a 3 horse wagon - I figure if I am going to ride rough, its going to be worth it).

 

 

End of day 1.

 

Sometimes, it helps to have a fork-lift...

 

All welds to the frame are reinforced by at least two grade 8 bolts per seam (took a lot of drilling but I like staying OFF the ground).

 

I added about 3" of shackle length in the front, made a drag-link, chased down some braided banjo lines and was ready to roll, on 36x14.5 TSLs

 

Now for gears, I have a Toyo V6 rear 1-Ton with 5.29s (the thing is bullet proof). (BY THE WAY: NOTE TO ANYONE DOING A YOTA/NISSAN AXLE SWAP, V6 AXLES WILL NOT DIRECTLY BOLT UP!!! ask me how I know. I had at least 5 local guys say "oh yeah, don't worry it will bolt right up" --NO!. You have to match the pinion flange to driveshaft flange, and perches just like any other scenario.

 

Front axle will eventually be Dana 5.38 gear (having too much fun in 2wd right now), by my math that's about a 1.7% rotational difference, so as long as I don't run 75mph down the freeway in 4wd, I'm good.

 

I have since this picture, raised the back to level with the front (CJ/Nissan leaf spring bastard pack) ditched the TSLs for some 37"MTR Military surplus Humvee tires (awesome), added a steering stabilizer, and Skyjacker M95 shocks. Still needs a front DS though (I am going to attempt to mate a K10 Chevy 1310 U-joint shaft to my current Nissan front shaft).

 

It is now sitting at a comfy 52" from the bottom of the headlight to the ground (2" below the Georgia lift limit, which no one pays attention to anyway).

 

I will eventually add some newer photos, hopefully some of it doing what I built it to do..

 

again, all comments, questions, advice, are welcome

 

 

[datzenmike]

Looks like an '80? sure that lil L20B will power it?

[godzirra]

I was concerned about that at first, it is indeed an L20B, a 33 year-old L20B, I run it at about an average of 50-55 (that's the point I feel safe with the steering being manual). I get about 3000rpm -maybe a little less, too busy watching the road at those speeds :)  it does not LIKE hills, it won't eat up a 1 mile 30 degree climb, but it also won't stall, choke, or let the tach drop. gear ratio helps, a LOT.

 

I am fairly impressed so far, I think I might have hit the happy power-band area with the gears and tires (I ran that equation probably 15 times).

I also run nothing but ethanol-free 93% through it, keep the carb. conditioned, keep the valves timed, removed any and all backpressure systems from the exhaust (bye-bye muffler/cat converter), re-plumbed the entire coolant system: radiator, water-pump, reservoir, hoses, etc. (not that it helps a lot with power).

 

Haven't had a REAL challenge for it yet, mostly around town, on the hwy stuff.

[godzirra]

newer picture

[datzenmike]

I was only foolin'. I ran 4.11s and 33s in my 620.... had little choice, but it would go 60MPH probably more. Would slow on any hills and if there was a head wind. Figured to get another set of 4.375s which would have helped. Anyway I used Toyota front top leaves re-arched to fit on top of Ford F-150 rear leafs. Did the same on the rears. Friggin' stiff, so much so I didn't need a sway bar. It wouldn't articulate worth shit but then I drove it mostly on the street.

 

The 720 looks bawss with the SAS.

[godzirra]

Yeah I have come to never underestimate the capability of a well built Japanese 4 cyl, no matter what you slap onto em, they are hard to hurt. I will admit though, I get scared at 60mph without power steering, roll bar (and maybe even p.s.) is definitely in the future.

 

I was considering the same, going with Nissan gears and keeping the stock rear axle, but I practically stole the Yota V6 rear at $100, $120 for gears, and an alcohol-driven mechanic to put them in at $100.

 

oh lord, I know my CJ springs are stiff under such a light truck, but as far as I know 620s are the same weight if not lighter and with f150 springs!

Lucky for me there is more mud than rocks in Georgia.

 

I greatly appreciate the compliments, I will admit it turned out pretty well for a 19yr old with a sawzall and a gas welder that probably belonged to Methuselah...and access to AutoCAD..

[datzenmike]

The L and the Z series have MASSIVE main bearings and 5 of them, hell some other Nissan fours have only 3!. They were totally over designed for their day. As long as you keep them full of oil and water you can not hurt them. Here's an example.

 

The KA24E motor makes about 150 HP which is over 50% more than the L20B. Yup the KA main bearing is the one on the right. KA turbos make upwards of 300 hp on those bearings. What would an L20B hold???

 

[godzirra]

Wow, I haven't had the chance to really get into a KA (my older brother has a dual-ported one I found for him, in a '88 D21, 153,000mi for $1700 - THAT thing can get up and go something serious).
 
But I am very happy with the good 'ol l20b and all its 100hp glory (this was/is my daily driver and first truck in one).
I have been wondering about a relatively simple way to squeeze just a couple horses more out of it, without completely re-engineering the carb/intake/exhaust setup (if there is such a way).

[K_trip]

- removed -

[heretic]

YEAH WHAT K_trip said.!!!! 

 

AND this 720 is badass

[godzirra]

I appreciate all the compliments guys, I worked very hard at it so I am glad I'm not the only one who likes how it turned out :)

 

However, if anyone has dealt with bump-steer, wandering or flighty steering, or anything similar (particularly with larger tires) I would really like to hear about it.

 

Stats on the steering are: heim joints all the way around - no ball joints, solid tie rod, angled draglink (the DL does not connect to the TR, it connects at the steering arm on the hub), and of course a 33 year-old manual steering box.

 

My primary thoughts are that the gear box is worn and should be replaced with power steering (the pump, gear, hoses, and reservoir total $500-$600 all together at the local parts store).

 

Just wanting to know some thoughts, get some advice before I start throwing money at it again.

 

(and yes, I would love to be able to find a parts truck, but around where I am when you say "Datsun" people start talking about their aunt's dog).

[datzenmike]

I have been wondering about a relatively simple way to squeeze just a couple horses more out of it, without completely re-engineering the carb/intake/exhaust setup (if there is such a way).

.

A 32/36 Weber carb swap.

[poor-mans-720]

I have a SAS 720 too. I love the beast. It sits on 37" super swampers. I had some really bad steering issues when i first did my swap. Sadly, I threw a steering stabilizer on it. It will run 80 mph (yes, I know it is 80MPH, I have a GPS speedo.) and i swear, it is like a normal truck, One finger steering. and the other arm hanging out the window.... As far as PS goes. toyota IFS truck setup is what i run. Was very easy to fab up.

Can see some pics of mine in this incredibly too long thread... lol. I am digging how straight your rig is. Sexy...

As far as front DS I made a square tubing one, and that thing is freaking bomb proof... And as far as balance goes, I can do 60 in 4wd high and then i feel a slight shake.

 

http://community.ratsun.net/topic/37709-82-720-kc-build-thread/page-14

[godzirra]

Nope, mine is white knuckles most of the time. In fact I took it on about a 15min. ride out of town tonight, on the way back going about 50 I hit this pot-hole/bump/dip in the road that sent the whole passenger side off the shoulder and reciprocated into the other lane to correct (since it was an empty county road with 2mi. worth of foresight and no one around).

 

I put a MOOG stabilizer between the tie-rod and axle housing, it helped but I would be out of my mind to push past 60 the way it drives now on anything but glass-smooth pavement. I don't know if its just because MOOG is a cheap-ish name brand or what.

 

Also how do you have yours aligned? And do you run a dropped pitman arm on it? I will look into the Toyota PS stuff as well.

 

I don't expect the thing to drive like a Cadillac by a long shot, but there is a fine line between driving safely and wondering why you didn't install a roll bar while you are careening sideways down the hwy at 50mph. 

And everyone local says "Oh that's just part of the monster you built." Ironically, everyone who has said that has also refused to go for a ride in it...hmmmm....

[poor-mans-720]

Thats insane. My truck drives so smooth, I mean, it drives better the the stock IFS ever did. no tracking, no bumpsteer, no feedback, nothing but normal.

I know what you mean about white knuckle. before my steering stabilizer, I had death wobble.... Maybe that is an understatement. I had, truck shook so violently, you shit your pants uncontrollably. And that was in 1st gear, at less then 10mph....

I took a tape measure to it. Measured the front of the tires, and the back of the tires. 1/8-1/4" in on the front.

It sounds like you have play, somewhere in your steering system. Have some on rock your steering wheel back and forth, very slightly, and look at each joint to see if there is ANY play. heim joints are notorious for this... bolt too small, bottom of the collar not sitting flat, bolt moving around in steering arm... Check every nut and bolt, and make sure everything is tight.

nope, no drop pitman. That is a normal one. yea, people always say that. But i have built at least 10 different rigs, and every single one of them would do freeway speeds without an issue.

[poor-mans-720]

check them front shackles too... looks like there is no brace between the two strips... got better pics of the steering components?

[godzirra]

Shackles are open for now but definitely a priority. I am planning to slap some rolled steel bars in between them, front and back at the earliest convenience.

 

I DID have the very earliest occurrences of death wobble (not near as bad as YOURs it sounds) but at about 25mph with the IFS, and recently serviced ball-joints like 4 months earlier, if you hit a good crack in the road the truck would go into automatic full-body-massage mode until you slow down to about 12mph. It makes me wonder if the steering gear isn't worn out, when I first took notice (after sas) of the steering slack, there was maybe a whole 1/8th of a steering wheel turn before the pitman arm would move (trucks so high I can clearly see the pitman arm while stretching my arm up through the drivers window). So I tightened down that little set screw at the top of the gear box and that helped, A LOT though still chases rabbits and I have already had to re-tighten the thing (and yes the locking nut was tight).

 

I will also try to get some better pics of steering up soon

[poor-mans-720]

yea, I would weld up them shackles. First thing. I bet, with them being shackled in the front like that, that it is a big problem I have never seen shackles like that, for the front. seems like there would just be a lot of play for them. mhmmm... Did this with IFS too?? that means, pre-existing issue. maybe the steering box, shaft? and it is a manual box?

are all your steering bars lined up correctly, drag link not crossing over your tie rod? Id just focus on the Heims, making sure there is no play in any of them. That is what caused my death wobble.

[datzenmike]

Nope, mine is white knuckles most of the time. In fact I took it on about a 15min. ride out of town tonight, on the way back going about 50 I hit this pot-hole/bump/dip in the road that sent the whole passenger side off the shoulder and reciprocated into the other lane to correct (since it was an empty county road with 2mi. worth of foresight and no one around).

 

I put a MOOG stabilizer between the tie-rod and axle housing, it helped but I would be out of my mind to push past 60 the way it drives now on anything but glass-smooth pavement. I don't know if its just because MOOG is a cheap-ish name brand or what.

 

Also how do you have yours aligned? And do you run a dropped pitman arm on it? I will look into the Toyota PS stuff as well.

 

I don't expect the thing to drive like a Cadillac by a long shot, but there is a fine line between driving safely and wondering why you didn't install a roll bar while you are careening sideways down the hwy at 50mph. 

And everyone local says "Oh that's just part of the monster you built." Ironically, everyone who has said that has also refused to go for a ride in it...hmmmm....

.

This isn't normal by any means. My SAS was very stable. Alignment is my guess. Toe out makes it hunt and search driving down the highway.

[]2eDeYe]

Welcome aboard. Nice truck :)

 

The problem with hiem joints is that the want to roll before they transmit motion, especially if they aren't in line with one another. A buddy has them on his Jeep and you can watch the drag link roll before the tires move. This could be part of the issue with the loose steering, but I think there are other issues as well.

The bump steer is likely caused by the angled draglink. You want the draglink to be parallel with the tie rod. With it angled it will push the truck all over the road as it rotates up when the suspension compresses. You should be able to high steer that Scout axle pretty easily with some flat top knuckles, which brings up the next issue.

The Scout Dana 44 has 0 degrees caster. This leads to wandering as the wheels don't want to track well. You should have at least -5 to -7 degrees of caster in order to have the tires track correctly. You can shim the axle or get adjustable ball joints, but the best solution is to rotate the knuckles, this will allow you to set the caster and  pinion angle to their optimum position.

This link explains the caster issue in simple terms.
http://www.jeepfan.com/tech/adjusting-castor/

 

This link explains how to set up the Scout Dana 44 by turning the knuckles to correct the caster and pinion angle.
http://www.jeeptech.com/convaxle/ihscout/d44f.html

 

I too have the Toyota IFS power steering box and love it. I used a modified Marlin Crawler mount kit. I run it with a stock Nissan KA power steering system, this required changing some of the line fittings at the box. I used one ton tie rods on the drag link and tie rod.

 

 

A properly set up frontend will not need any stabilizers. I have none and my truck drives straight down the highway, with no bump steer or wandering, with one hand resting on the steering wheel. If the suspension was a little softer, it would be a Cadillac ride.

 

Here is a link to my project thread if you want to see how I went about it. I think the axle swap starts on page 12 or so.
http://community.ratsun.net/topic/35996-1978-620-king-cab-4x4/?hl=%201978%20%20620%20%204x4

 

 

[godzirra]

I will try the toe-in adjustment first (I always like to start with the least expensive option). If that does not work I can always snatch out the front axle and go to work on caster angle adjustment, it doesn't seem too hard, just grind off welds and beat it into submission.

 

datzenmike, just out of curiosity, what was your caster angle?

 

power steering is definitely an upgrade I am interested in, Toyota pumps are always an option, but I found one of the threads on here with someone using a Sentra PS pump/reservoir combo (thus alleviating the need for a separate reservoir) to a standard PS Nissan gearbox and it does not look very complicated, and Sentras are very easily found in the junk yards around here. Also I hear that some IH and Ford pumps have a built-on reservoir. I am not really worried about hoses/fittings since one of the local places in town here makes hydro hoses by demand.

 

thanks for all the input

[]2eDeYe]

Ford steering pumps are notorious leakers, the GM style Saginaw pumps are pretty reliable. Both will require custom hoses to run a metric steering box. Toyota pump shouldn't be to hard to mount on an L series. Remember that the Sentra pump is optimized for a rack and pinion setup. It might not be an issue, just something to keep in mind. Separate reservoirs help keep the hydraulic fluid cool in my experience.   

 

I've been to every hydraulic shop in the Everett area (Naval Port with quite a few hydraulic shops) and not a single one had fittings for a Nissan or Toyota steering box. I ended up building my own by soldering Toyota fittings to my Nissan lines. Worked out well and was almost free with a bit of junkyard scrounging. :)

 

Cut off the old end and sleeve the Toyota fitting and hardline line onto the Nissan hardline after cutting off the Nissan fitting.

 

 

[datzenmike]

My caster is what ever the early '80s Toyota truck had.

 

As for toe adjustment, don't just go at it and adjust it. It could be fine. Park with the wheels straight ahead. Get out front of the truck and eye the driver's front tire. Sight down the outside sidewalls of it. Is it lined up with the rear tire on that side? If not turn the steering until they are on exactly the same line. Now go over to the passenger side and take a look. Are you seeing tread? if so the front tires are toe out. If seeing just to the outside of the rear tire it's toe in. This is a very rough test to check for toe out. The amount of toe in will require you to make some measurements.

[godzirra]

The toe was set about 1/4" OUT when I first measured this afternoon. so I decided to set it in just slightly (1/4" IN) by tightening the heim joints on the tie rod, as is normal. Took about 1.5 hours (I also straightened up the relationship between the wheels and the steering wheel so that when the steering wheel is at 0 degrees the wheels are straight). Took it for a test drive, marginally better, not safe at 55+mph still.

 

I wish I had a camera that was worth a crap so I could video the driving experience, but in description, I can be going say 35mph and move the steering wheel at least a whole1/8th of a turn in each direction and the truck does not respond! This lack of control increases exponentially with speed as the faster I go, the more distance is covered in what ever direction I happen to travel at the time.

 I am thinking this is the issue more so than caster angle or anything else (though I am certainly not disregarding the advice on the topics, the toe DID help, a little, haven't messed with caster angle because that solution requires almost complete destruction of the front axle.)

 

My conclusion is a mechanical failure SOMEWHERE, either in the steering gearbox (damaged possibly because it IS 33 years-old and the truck had cases of death wobble about 8 mo. prior to the axle swap), OR in that rubber P.O.S. thingy (yes its a technical term) that connects the steering column to the steering gear. There is no U-joint in this column, just a big thick rubber washer with bolts through it.

 

I also would like to think that power steering would solve a lot of the problems, for instance at about 45-50mph if I hit a decent bump, no matter how hard I brace for impact (I'm not a small fella) the tires still force the steering wheel. I don't know if any of you guys have run ex-military MTR DuraWalls, but those suckers have some ass behind them, we are talking 50lb a piece w/o a wheel.

 

Just trying to get all the ideas out there, and thank you very much to all who have responded, I appreciate all the input and advice A LOT!

[godzirra]

BTW, local salvage yard has a '85 Nissan PS pump for $35... I am assuming it would mount differently as it would be on a KA24E instead of an L20B, but I could always make my own mounting bracket.