Adventures of a RWD(2WD) FZJ80

[kenton]

I just put my front driveshaft back on and locked my front hubs after a summer and 6.5k miles of 2-wheelin' it.
I have essentially a stock '97 FZJ80. Stock tires, suspension etc. I did the CDL wire mod, and advanced timing. In this form, I get 15 mpg in mostly city traffic.
This summer I installed the front manual hub locks, unlocked them, removed the front driveshaft, and engaged the central diff lock.

Positive changes: gas mileage improved 10%, to 16-17 mpg (more variable than in 4WD mode). It felt 'sportier', esp. with PWR button pressed. Steering was pleasingly lighter. I could 'peel out' in low-traction conditions! Finally, my front axle was back in part-time mode where God intended Birfields to be (hee hee, I know that last one is flame bait).

Negative changes: I lost ABS, and I had two orange lights on my dash, as a constant reminder. My wife really disliked always being told that she had no ABS, and it occured to me that it could possibly be illegal to intentionally disable ABS in some states. I also noticed the reduced traction in inclement weather. Also there is the (minor) hassle of removal and installation. NOTE: interestingly, with no driveshaft, I would get the driveline 'clunk' that some people have mentioned, when approaching a stop for example. With the driveshaft in, no clunk.

All in all, if I could find some way to keep ABS I would probably be willing to remove/install the driveshaft every year (installed for winter, removed for the remaining three months heh heh). I definitely enjoyed the satisfaction of knowing that my front axle seals were almost 7k miles further distant from needing another rebuild. The savings in gas and the ability to drive further between fill-ups was also appreciated. However, I don't think I could forgive myself, or even handle the doubt that would be created, if an accident occured while ABS was deactivated and someone was hurt.

Kenton

p.s. an interesting side-note: in the course of the experiment, I had an oil change at a Quiki Lube. *The lube guys never mentioned the missing driveshaft*. Wow, it gives me an idea for a contest: see who can get the most messed-up vehicle through the Quicki lube without comment. Transmission fluid in the oil pan? Replace grease zerks with BNC connectors? No diff cover (for domestic-style diffs)? Will they notice anything?

 

[NorCalDoug]

So let me get this straight...you perform an unneccesary modification to your truck to get a 10% gain in fuel economy...spending probably more in $$$ to do the work than the 10% will likely save and now you're concerned about its reliability?
https://forum.ih8mud.com/showthread.php?t=27181


sir, your logic eludes me.

 

[kenton]

So let me get this straight...you perform an unneccesary modification to your truck to get a 10% gain in fuel economy...spending probably more in $$$ to do the work than the 10% will likely save and now you're concerned about its reliability?
https://forum.ih8mud.com/showthread.php?t=27181


sir, your logic eludes me.

Well, not sure what you got, but it wasn't straight. Lets skip the probably's and likely's, and just calculate it, shall we? Here's my logic and assumptions for recouping the $75 hub cost in approx. one year:
hub: 12k mi/yr * 1/16 gal/mi * $2/gal = $1500/yr gas cost
plate: 12k mi/yr * 1/15 gal/mi * $2/gal = $1600/yr gas cost,
therefore $100/yr gas savings with hubs.
I think that's pretty direct logic, and not very elusive, don't you think? Pure profit after the first year.
Plus, there's the concept of no miles being put on the front axle, delaying maintenance-repair. Here's my math and assumptions for that:
12k mi/yr * 1 repair/60k mi * ($300 & 16 hrs)/repair = ($60 & 3 hrs)/yr savings. The 3 hrs savings is pretty small, and partially compensated by the time to R&R the driveshaft.

One can always quibble on the exact values, but roughly speaking, we're talking about > $100 in savings per year.

Regarding reliability-- I don't see any appreciable difference in locking hub reliability vs. the plate. Please correct me if I'm wrong.

But, as I stated, despite the savings I'm leaning towards keeping the Full-time 4WD.

Regards,
Kenton

 

[LandCruiserPhil]

If you dont mind the way it drives and handles in 2WD hub are the way to. Even if you subtract the MPG savings the wear on the front end and front drive line makes hubs worth it. Plus when was the last time you saw an 80 sliding around

 

[RWD]

Why drag me into this ........ LOL

 

[kenton]

Why drag me into this ........ LOL

Cuz like Phil says we like the way you can swing yer ass-end around. And yer brother "F" is boring. On the other hand (axle), yer sister "A" is basically a wanna-be "4", but we of course all love her anyway.

heh heh ... whoo-ee, ok, time for me to go to bed...

Kenton

 

[Doc]

If you want to do donuts, just lock the rear diff and stomp on the gas. Simple as that.

 

[MoJ]

OK - not to bash your optimism but....

$100 cost avoidance a year? $8.33 a month? $.27 a day?

Throw in the fact that you may only run in 2WD for 75% of the year and your down to a wimpy 20 cents a day.

Jeeesh, just eat out one less time a month. Bring a coke from home each day instead of buying one from the vending machine. Make one of your kids go without dinner each week.

Hardly seems worth the trouble.

My 20 cents.

Jason

 

[alia176]

Kenton,

Good experiment. Mind PMing me, where you got the hubs? I need a set!

MoJ,

I think the biggest noticeable improvement in MPG would be on long driving vacations. I think Robbie felt the biggest gain in that dept when his wife made a couple of long hauls.

However, what's more important to me is the fact that you can isolate the birfs after you break them! Just unlock the hubs, remove the DS and head home!

Ali

 

[MoJ]

Long trips? OK - make that 21 cents a day.

 

[ginericLC]

I didn't do the lockouts on my 94 but I get about the same mileage as you do without the hubs. Stock stock rig, even the Michelin tires. 197k on it and I get 15-16 almost all the time and on the highway I've pulled as much as 18 mpg. I attribute it to switching to synthetic lubes in the drivetrain. Wonder if I could do better if I tried hubs. My 91 has hubs and I noticed no increase in mileage by running unlocked and without a driveshaft. But I didn't expect it would. My eventual goal is to build a 35-37" tired 80 that gets 20 mpg. I will be successful!

 

[mabrodis]

Even if no mpg saving at all it's still worth it IMO. Driving in only RWD definetly changes the feel of the vehicle, it feels much less tank-ish and more rallycar-ish. And yes having the front disconnected, and rear locker in is darn fun on snow!!

I haven't pulled my front driveshaft in a long time, too much hassle, and I never know when I'll need 4wd (in winter it snows and summer I wheel...). I can just unlock the hubs and lock the CDL and still have the 2wd experience with very little effort. Sure I'm still spinning everything, and not gaining anything, but it's fun. Practical? Not at all, but since when is lifting a vehicle then smashing it against rocks practical for any of us?

 

[NorCalDoug]

So for saving that $0.27 per day, you lose your ABS -- which you state may be illegal (I wouldn't know about the legality of it), but if your insurance company found out about it, they could charge more (based on the fact that I get a discount for having ABS, I can only assume that if I didn't have it I'd lose the discount). And factor in having to deal with the idiot light being on all the time? I wouldn't do it.

I won't even factor in the "wife is annoyed" factor. I don't know you or your wife so I don't know what kind of grief you'd get (if any), but I know that I wouldn't consider a quater a day savings worth irritating the wife...Wait, I just reread your other post -- the one where you state that your wife thinks the 80 is maybe not such a great purchase -- so it does sound like she's getting annoyed...

Dude -- it's your truck and you can and should do what ever you like to it. But to me, it doesn't seem worth doing for the savings you describe. Not for 27 cents a day.

Please don't take this the wrong way -- I am not trying to bash what you did. It's just that I don't agree that the savings provided by what you did is worth the benefits

Me? I've just accepted the fact that I will be "grabbing my ankles" whenever I need to fill up the tank and that driving slower is better for my driving record (I've picked up more than my fair share of speeding tickets in my life).

 

[Chuck_FJ60]

It's not something I would purposely do to the wife's 80. Since she drives the kids around, I wanted a tank, AWD & ABS to keep everyone safe. She hated it when her previous SC'd Previa (RWD) unexpectedly fishtailed in the rain as she turned & accelerated. Just my opinion...

 

[reffug]

Me? I've just accepted the fact that I will be "grabbing my ankles" whenever I need to fill up the tank and that driving slower is better for my driving record (I've picked up more than my fair share of speeding tickets in my life).

I can completely relate to this sentiment (TRY HAVING A 70 GALLON TANK) I totally accept the fact that I will be "grabbing my ankles" but as much time as my wife and my two children spend in this vehicle without me being the driver, I would never considering compromising there safety over $$. If $ had s***e to do with it I wouldn't own the LC.

LANDCRUISER CAUSE EVERTHING ELSE JUST SUCKS!

 

[kenton]

... as much time as my wife and my two children spend in this vehicle without me being the driver, I would never considering compromising there safety over $$. ...

LANDCRUISER CAUSE EVERTHING ELSE JUST SUCKS!

Reffug, just because you wouldn't consider compromising your family's safety over money, doesn't mean you don't do it all the time. Did you know that among unintentional injuries, MOTOR VEHICLE occupant injury is the #1 cause, killing 15,000 children every year? I assume that you allow your family to spend as much time as they do in the car at least in part because it is convenient and saves you money, just like I do. Because they'd be much safer to never or almost never go anywhere, although it might cost you alot of money to bring schooling and entertainment to them.

I guess what I'm saying is: absolutist statements and sloganeering aren't constructive additions to a discussion of possible mod's to our 80's. And it is mildly offensive to me to get the implication that I'm somehow exceptionally endangering my family when I openly discuss the pro's and con's.

Kenton

 

[NorCalDoug]

Negative changes: I lost ABS, and I had two orange lights on my dash, as a constant reminder. My wife really disliked always being told that she had no ABS, and it occured to me that it could possibly be illegal to intentionally disable ABS in some states. I also noticed the reduced traction in inclement weather. Also there is the (minor) hassle of removal and installation. NOTE: interestingly, with no driveshaft, I would get the driveline 'clunk' that some people have mentioned, when approaching a stop for example. With the driveshaft in, no clunk.

All in all, if I could find some way to keep ABS I would probably be willing to remove/install the driveshaft every year (installed for winter, removed for the remaining three months heh heh). I definitely enjoyed the satisfaction of knowing that my front axle seals were almost 7k miles further distant from needing another rebuild. The savings in gas and the ability to drive further between fill-ups was also appreciated. However, I don't think I could forgive myself, or even handle the doubt that would be created, if an accident occured while ABS was deactivated and someone was hurt.

So are you or are you not concerned about safety?

 

[robbie]

So who says ABS braking systems are safe, I personally think they do not work that well one the 93-94 model years. They work much better in the 95-97, then 10 fold better on the 100 series. So IMHO, the debate on if you need ABS or not is just personal wants. If it is snowy or ice I have my center locked up for better traction and handling, and it has no ABS on.
For 2x with the drive shaft out, I am and will do this for the saving I have seen. I currently spend about 30k miles a year in my truck, with about 70 % in 2 wheel drive, my truck currently weigh about 7k lbs. The big trip I took for a wedding to Napa valley was a long way. all in all we did 3000 miles there and back. worse milages was on the way out, 11 mpg at 90-95 ffrom salt lake to reno, best milage was 16.5 going from carson to green river utah on HW 50(lonelest HW in america) 60-65 mph. Spent about 500 dollars in gas for this trip (still cheaper than 4 airline tickets and rental). If I had the front drive line in, it would of cost more, but I do not know how much. My truck handles fine in all weather, very much like the FJ60-62. We even went through south tahoe in a snow storm, ice on road. I was more cautious, never felt unsafe (all the weight i have over or behind rear axle). My personal daily drive is 25 miles one way, hilly. I get 14-15 on average witht he drive line out, drive line in I get 11.5-12.5. May not seem like much, the handling is good, still better in AWD, but braking is better with out the ABS for most of the time. I do wish there was a factory switch that would let you select this.
any how I will run in 2x and reap the small benifts it give me, As for safety, I am jsut as safe as the next guy, it is a matter of driveing habits not gadets on the vechicle that make you safe.
Eric 20mpg is possiable, put a 5 speed in, part time system, keep the vechicle as low as possiable and carry no weight, never go over 60mph, stay on the flat land. later robbie
Happy T-day to all

 

[NorCalDoug]

So who says ABS braking systems are safe

The National Highway Traffic Safety Administration (NHTSA) for one
NHTSA Report on ABS

I fully agree that there are times that ABS is not the most desireable -- such as when braking on rough corregated roads. But in most driving condition, I think having ABS is much better than not having it. I haven't driving an 80 with the front unlocked and driveshaft removed, so I can't speak to the seat-of-the-pants feel of not having ABS in your set up.

To each their own. But I think if a person starts making modifications like this, they need to fully be aware of what they're doing and what the consequences will be. I think some people are aware...and some are not.

 

[e9999]

I must say that I was intrigued by the idea of the freewheeling hubs, but the idea that the axle seals may be damaged if the thing moves lengthwise if kind of a serious downer....

E