Well the question is has anyone here ever had first hand experience with a different gear ratio in the front dif than what your rear dif had? Is this dangerous...what could happen...what should I avoid should I decide to do this?

I need to decide if I can install Superior Axle's 4.10 ring & pinion in the M226 now or not. It will be 8 to 12 months before they release gears for the M205, I've called them twice now and was told the same both times. This means if I swap now the front will be at 3.36 ratio for up to a year while my rear dif will be at the 4.10 ratio. I can't not wheel for a friggin year! I'm putting the ARB locker in now (since my rear blew up), so if I decide to regear later I'll be paying again for the labor ($250 wasted), it is no extra cost doing it now, but I have to have incompatible gear ratio front to back. Superior told me all I need is a ring and pinion (29 spline for an 05) plus the spacer = $269...then I'll be crusin with 4.10's.

Well, what would ya'll recommend...

i've heard 1% difference max

its dangerous since its a 4wd system, not an AWD system which has a center differential....the front will be spinning at a different speed than the rear, which is ok if you dont have traction...but too much gas and hit a spot of good traction, and bam, there goes driveline parts

Yea i would say off road you might get away with it but on more grippy terrain you might run into problems. I'd say don't chance it unless you have to $$$ to spend. In that case F-it, run the different gears untill it breaks or the new gears come out. You got the Titan diff up front so you might get away with it.

i say dont do it, i cant forsee any benefit to it.

what should you avoid should you decide to do it? id avoid using 4wd at all

any kind of front/rear traction will bind up the driveline

Too much difference, you will bind up your drive shaft/transfer case and cause all sorts of possible damage.

I have heard that for off-road, 10% difference is max....I think. Maybe it's 5%. But you wouldn't want to run it high speed on the road like that. The gears need to be the same front and rear.

I should say that I'm definitely no expert on gears though.

Yeah that is the same feedback I getting on TheNewX as well. SteeevO, owner of Rugged Rocks Off Road, who's opinion I have the highest regard for posted the following. "Usually the rule of thumb is to not have gear ratios Fr & Rr more than 3% different.
anything more will be disastrous. My advice is to re-gear both axles at the same time."

yea what i said. he he. Good luck with the regearing.

I definitely trust steeevo from rugged rocks. I think 3% would be max at worst case.

I would even go closer as Baf said at 1% if you can.

With the issues the next gens have, even if you are changing out the xterra gears and or diffs, too much difference and you'll find the next weakest link in the drivetrain.

If you CAN't re-gear the front...you're stuck...unless you don't USE the front end....or run different sized TIRES front and rear.

:D

(Your swap is going to raise your rear rpm by about 18%, that's too much of a difference even off road.)

BTW - (Example - made up #'s) - If you were currently cruising along at ~ 2,500 RPM, and you drop in the 4.10's, for the same speed, you'd now be cruising at ~ 3,050 RPM...about 550 RPM higher than before.

Now - That generally means you'll be making the engine use more revs at any given speed....hurting mpg...but improving ooomph.

:D


So - If putting a 4.10 in the rear RAISES the RPM by ~ 18% in BACK...

...You COULD swap on a set of SMALLER FRONT TIRES, say 18% smaller than the REAR TIRES, to compensate....and have the front and rear RATIOS now "work".

Of course, you'd need another spare for the other size, etc...and you would have more nose down rake/less front clearance, etc....

So - MECHANICALLY, it would be doable, but practically, you may not be happy.

:wink-big:

Penksi61 had installed an M226 (with 3.36 gears) in his Fronty while the front diff was stock (3.69 gears, IIRC). Anyway, the transfer case did not like the different gear ratios. When he tested it out, he had a lot of trouble trying to get the truck to switch out of 4LO. He ended up installing the 3.36 gears in the front, so he could wheel again.

I echo everyone else that said to keep the front and rear diff gear ratios the same. 4.10s would be bada$$.

Penksi61 had installed an M226 (with 3.36 gears) in his Fronty while the front diff was stock (3.69 gears, IIRC). Anyway, the transfer case did not like the different gear ratios. When he tested it out, he had a lot of trouble trying to get the truck to switch out of 4LO. He ended up installing the 3.36 gears in the front, so he could wheel again.

I echo everyone else that said to keep the front and rear diff gear ratios the same. 4.10s would be bada$$.

Ted actually i bought a new front diff from the dealer with the 3.69's :)

2% is max for difference in ratio , im running 1.7% difference on the 1st gen SAS

To go with my new ARB air locker, I ordered new 4.56 gears today for my M226.

Now the wait begins for Superior Axle to release a 4.56 gear set for the Titan M205 front dif (target date is 6 months), and ARB to release the locker (target date is 4 months).

No wheeling for me until that time.

Sad to hear that amount of down time for you but it will be well worth it in the long run.