5.71 Motive IFS gear install
(23 low res pics loading)
DEC 21 2004

 
I marked and removed the carrier bearing caps...


 
I employed 2 tire irons to EASILY remove the carrier. 


 
The carrier bearing shims (washer plates)
are on the outside...each side measured 
about .111". 


 
The yoke was a tight fit onto the
pinion so I used the 10 ton press
and the pinion effortlessly dropped out.


 
This old bearing separator has been 
thru quite a bit and has removed many
a pinion bearing with Zero damage 
report. The bearing cages usually make
strong contact with the dish surface 
on the separators.....the key to no
damage is to modify the dish. I use a
worn down grinding wheel and it works 
great. I purchased my separator from
JC Whitney years ago.

Editor's note---I now use this fantastic
bearing separator OTC-1124. Go to USA WAREHOUSE
and type OTC-1124 in the search bar. 4-5-2008 ZUK


 
This is my IFS third and my wheelin' with
this rig is mainly camping and exploring 
so I am re-using the bearings....as long
as they check out good. I safely removed
the big pinion bearing and, as seen in the
pic, measured the factory pinion shim at 
.0995". It's nice to have vernier
micrometers......and even nicer to have a 
camera that will get as close as 1 inch.


 
This main pinion bearing to be 
transferred over to the 571 pinion.


 
The Motive ring gear appeared to 
have very good quality and had these
marking...V T571 IFS 40x7 M 10/00


 
I pressed the original pinion
bearing on with the .0995 shim.


 
This is the mini-kit I received from
Superior Gear. The only thing I really
needed from it was the crush sleeve 
and it was the correct fit...unlike
the pinion nut shown in the kit
which was way too big.


 
I re-assembled it without the crush and
used the old pinion nut and set the 
pre-load for about 10 in/lb. I made 
sure that I had lotsa gear oil on the
pinion bearings to give smooth accurate
readings. This "torque wrench" is 
another cheap investment and is available
from some bicycle shops for 40 smackeroos.


 
Lightly chisel around the ring to remove it.


 
18 alternating light taps with the chisel 
and hammer and the ring dropped off.


 
Sometime I wonder how flat my file really 
is...but I still run it around the ring 
gear to check/file the high spots.


 
I sometimes can line it up by eyeball and
use 2 of the bolts to pull it on all the way.


 
There was some carrier bearing pre-load 
I noted as I pulled the carrier out with 
the tire irons....it will need more 
during the final set but for the purposes
of checking the first pattern I will 
use just the .111" shims. Nobody seems 
to supply any carrier bearing shimming in
their kits but as it turns out, the 
shims used on Dana44/60 applications 
behind the big pinion bearing race are
the correct diameter for IFS Toyota carrier bearings.


 
The carrier dropped in nicely with a 
piece of wood and a hammer seating the 
bearings. Having a dial indicator with 
magnetic base is a cheap investment and
a must have for setting backlash. I 
think Harbor freight has the combo 
for 25 bucks or less.


 
Lucky me. The factory shim nailed it 
right on. I am noting in the pic how 
easy it is to wiggle the ring gear 
within the backlash range. That means 
the carrier bearing pre-load could be 
alot tighter. Tight CB pre-load keeps 
the ring from deflecting under heavy loads.


 
Close-up of the drive side.


 
The coast side....


 
See this casting right here.....


 
Well, due to the extreme thickness of the 
571 ratio, the teeth come very very close 
to scrapping. I measured less than .003" 
with my feeler gauges.


 
I had to take the carrier out again 
anyways to put the crush sleeve in so
it was a good opportunity to 'clearance' 
it some with the grinder. I also took 
the opportunity to also add 7 thou to 
the ring gear side on the carrier 
bearing shim and 3.5 thou on the 
other side. It was more difficult to 
get the carrier to seat down but it did
happen.


 
Might be my imagination but the carrier 
bearings look to be 'locked in place' 
and don't have a chance of moving......
at least compared to the stronger 8" 
rear 3rd which has raised towers that 
can flex a little. This would help 
the over-all strength of the smaller 
IFS ring/pinion set-up.....this is 
assuming the carrier bearings are
shimmed extra tight like mine are 
here. I believe that this 571 install
to be much stronger than the little 
axles that slide into the side-gears 
(27 spline and 1.075" diameter). If 
anything happens it's because the lower 
571 ratio will introduce 33% more 
torque or strain on the axles/CV's so 
now maybe a CV will explode. But then 
again, this is a 22RE with an automatic 
so maybe everything will last for years.
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