Axle question

Do the front and rear axles have to be geared the same? I have a feeling
they do, but I wanted to ask anyway before I did anything.

I'm getting ready to do some major work to my jeep. It's a 2000 Sport with
the 4.0 and dreaded D35c. I want to swap in a Ford 8.8 with 4:10 gears in
the rear when I lift it (rubicon express 3.5 Superflex).

Thanks

Yes, they have to be close. I have heard of 4.10's and 4.11's in the
front going together...

Mike
86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
88 Cherokee 235 BFG AT's
Canadian Off Road Trips Photos: Non members can still view!
Aug./05 http://www.imagestation.com/album/in...?id=2120343242
(More Off Road album links at bottom of the view page)

"J.Valkyrie" wrote:
>
> Do the front and rear axles have to be geared the same? I have a feeling
> they do, but I wanted to ask anyway before I did anything.
>
> I'm getting ready to do some major work to my jeep. It's a 2000 Sport with
> the 4.0 and dreaded D35c. I want to swap in a Ford 8.8 with 4:10 gears in
> the rear when I lift it (rubicon express 3.5 Superflex).
>
> Thanks

If you want to use 4x4 they need to be the same. If it was a temporary
issue where you needed to drive it for a short time and NOT use 4x4 they can
be different. Probably best to remove the driveline if that was the case.
I know of one guy who drove a used wrangler for a few months, the dirt road
was getting rough so he put it into 4x4 only to find that it was undrivable.
The rear wheels kept trying to push the front wheels. Ended up finding out
that the previous owner did an axle sway with no reguard for what ratio was
being installed, and the rear end had a higher ratio than the front end.




"J.Valkyrie" > wrote in message
om...
> Do the front and rear axles have to be geared the same? I have a feeling
> they do, but I wanted to ask anyway before I did anything.
>
> I'm getting ready to do some major work to my jeep. It's a 2000 Sport with
> the 4.0 and dreaded D35c. I want to swap in a Ford 8.8 with 4:10 gears in
> the rear when I lift it (rubicon express 3.5 Superflex).
>
> Thanks
>

Though they are seldom exactly the same. In a Jeep, they come 3.73 and
3.74, 4.10 and 4.11, etc. They seldom match because the front and rear
ring gears are usually different diameters.

Rusted wrote:
> If you want to use 4x4 they need to be the same. If it was a temporary
> issue where you needed to drive it for a short time and NOT use 4x4 they can
> be different. Probably best to remove the driveline if that was the case.
> I know of one guy who drove a used wrangler for a few months, the dirt road
> was getting rough so he put it into 4x4 only to find that it was undrivable.
> The rear wheels kept trying to push the front wheels. Ended up finding out
> that the previous owner did an axle sway with no reguard for what ratio was
> being installed, and the rear end had a higher ratio than the front end.
>
>
>
>
> "J.Valkyrie" > wrote in message
> om...
>
>>Do the front and rear axles have to be geared the same? I have a feeling
>>they do, but I wanted to ask anyway before I did anything.
>>
>>I'm getting ready to do some major work to my jeep. It's a 2000 Sport with
>>the 4.0 and dreaded D35c. I want to swap in a Ford 8.8 with 4:10 gears in
>>the rear when I lift it (rubicon express 3.5 Superflex).
>>
>>Thanks
>>
>
>
>
>

--
Jerry Bransford
PP-ASEL N6TAY
See the Geezer Jeep at
http://members.cox.net/jerrypb/

That is the stock configuration for a Wrangler 4 cylinder, 5 speed. I have
noticed that it actually helps me pull out of skids, because the front is
geared higher than the back. When I step on the gas, the vehicle
straightens right out. :^)

Earle

"Mike Romain" > wrote in message
...
> Yes, they have to be close. I have heard of 4.10's and 4.11's in the
> front going together...
>
> Mike
> 86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
> 88 Cherokee 235 BFG AT's
> Canadian Off Road Trips Photos: Non members can still view!
> Aug./05 http://www.imagestation.com/album/in...?id=2120343242
> (More Off Road album links at bottom of the view page)
>
> "J.Valkyrie" wrote:
> >
> > Do the front and rear axles have to be geared the same? I have a
feeling
> > they do, but I wanted to ask anyway before I did anything.
> >
> > I'm getting ready to do some major work to my jeep. It's a 2000 Sport
with
> > the 4.0 and dreaded D35c. I want to swap in a Ford 8.8 with 4:10 gears
in
> > the rear when I lift it (rubicon express 3.5 Superflex).
> >
> > Thanks

Yes, they need to be geared the "same". The caveat is that "same" doens't
mean identical. The front willo mathematically work out to 4.11 where the
rear works out to 4.11. the difference is insignificant in this instance.
What you have to avoid is differences that are greater than the second
decimal place. Any variance in the second decimal place is okay, but I've
never seen the second place vary by more than 1 on any ratio that is
available. For example, you could put 4.11 in the front and 4.56 in the
rear, and this will cause trouble, but if you go with 4.10 for the rear,
then the front ratio will be 4.11. The ratio is arrived at by dividing the
tooth count on the ring gear by the tooth count on the pinion gear. If there
are 41 on the rear ring gear and 10 on the pinion, the ratio will be 4.1,
conversely the front ring gear will have 37 teeth and the pinion will have
9, this works out to 4.11.



"J.Valkyrie" > wrote in message
om...
> Do the front and rear axles have to be geared the same? I have a feeling
> they do, but I wanted to ask anyway before I did anything.
>
> I'm getting ready to do some major work to my jeep. It's a 2000 Sport with
> the 4.0 and dreaded D35c. I want to swap in a Ford 8.8 with 4:10 gears in
> the rear when I lift it (rubicon express 3.5 Superflex).
>
> Thanks
>