NorCal FJs

FJ Cruisers of Northern California

Hi, today I went at the "Exploratorium" in S. Francisco (it was free today, not sure why).

It's a place for kids, but one thing was quit interesting: they had a couple of models of differentials one could play with and understand how it works.

Now, that was a relatively simple exhibit, I was wondering what is the way to understand what is inside a 4x4 system like the one the FJ uses, the locker, the central differential, what to do in the case of a failure on the trail, maintenance, fluids etc

bye!
Alessio

Views: 20

Reply to This

Replies to This Discussion

Bring an extra Third member tiwth you and you should be fine if one fails on the trail.. I beleve thats the best fix on the trail.. BUt I am sure GRM has had way more experience than I.. I believe he has done more than one on the trail during the trail teams days... LOL

Boss
True, one should bring so many spare parts... My friend that used to go illegally to cross the alps would close the car, go back home, and then go back the following week with the spare part :)
Believe it or not, I have only replaced one diff on the trail:


Took about an hour and a half. Its really easy once you have done it once. On my truck, I carry the stock diff from my 1986 toyota, which will bolt in place of my '07 FJ diff (I have a different drive-shaft flange, but it is very easy to make an adapter on a lathe so you can toss a $50 diff in the rear as a temporary solution).

Your center diff works just like the rear diff. only it transmits power front and rear vs. left and right.

The locker works by a small motor turning a shift fork, which slides a splined collar, which mechanically connects both axle shafts, so the differential action stops working.

I recommend reading http://www.gearinstalls.com/ for more information about Toyota diffs than you would ever want to know.

On another post, I put up what I carry with me on the trail, including spare fluids.
Thanks; I know how - in principle - differential works. I would like to see one open and put my hands in it :)

For example, AFAIK the FJ uses a "Torsen" central diff;I am not familiar on how it is made inside.

For the lockers, I'd really like how exactly the mechanism work; I am really curious if it is safe to engage it at high speeds (I do not want to start a flame, mine is "scientific" curiosity only)

The website you gave me has interesting info.

It'd be cool if a mechanic offered a "clinic" on how to tear apart a truck etc

Also, I would like to know when it is advised to use the central locker but staying in 4HI; for example, if the road is icy/snowy/muddy/sandy ??? Or not

Thank you
Alessio
Google 'Torsen' and you will see lots of pictures.

Lockers are safe to engage up to around 10 mph. They engage better at speed than when stopped.

Totally safe to use the center locker for icy, snow, mud, sand, etc. But I have found, on the road, the full time 4wd with the torsen diff does a better job at transferring power than locking the diff.


Find someone swapping gears in their rear axle, and I'll be more than happy to explain how to take apart an axle, and throw it back together. I am sure steve would film it too.
So, when should I use the center lock? You say the Torsen does a very good job, so when should I use it, if at all?
95% of the time, when you need the center diff locked, you also need low range.

I only use the center diff lock when on very low traction dirt roads.
hey that's funny...I'm sure GRM must of answer your question but I was just reading about the rear diff. on the sun visor of your car it said to use it when stopped on about 5-8 mph I believe. Look at it is a summary of it.
What Toyota recommends may be due to liability or so... I like to understand and open up things :)
What is the center diff locker you mentioned? Is that with the 6M trans?
Yes, the manual 6 speeds have a center diff lock since during normal (full time 4WD) driving they have a torsen center diff varying power front to back. The part time systems on our automatics are locked 50/50 when we are in 4WD.

RSS

Badge

Loading…

NorCal FJ Twitter Feed

The NorCal FJ Shop

The Black Bear Bag
Use it for school, as a bug-out bag, or for your spy gear that only you know about.

SHOP NOW!

NorCal FJ Network Status

© 2024   Created by NorCal FJs.   Powered by

Badges  |  Report an Issue  |  Terms of Service