bruzer

Is it just me or has anyone else had trouble with the stock gears breaking in there IFS diff's? I have broken my second ring gear. Does anyone know of someone who makes a stronger ring gear for thie IFS? I know I am ready for a SAS, but just wanted to know if anyone has had as much trouble as me. If so, it might help put my woman at ease since she seems to think I am a little hard on my runner.

dcg9381

I haven't run IFS hard, but I can say that I've broken stock R&Ps when I allowed my axles to hop. If your suspension is hopping, it's massively hard on the driveline.

If you're keeping IFS, you cold see if you could get the stock gears cryo'd... Otherwise you're looking at doing SAS as you've mentioned.

dijlop

havent personall broken rly anything thus far, but then again havent wheeled enough yet to say im lucky. have heard of the r&p's being somewhat of a weak link though. most certainly quote me to the wifey. hehehe.

yotasavg

???.........you don't have an ifs gear set to break.........lol

i've got stock 4.88's too. never had any issues. hope i didn't just jinx it!

snap-on

sounds like a bent houseing to me

most people grande a front CV long before the diff blows.....

ShortyzKustomz

My friend went through 2 on his IFS too, And he never wheeled it hardcore, I havent had probs with mine though, My friend is SAS'd now though

Jay351

Are you ever going hard on the truck in reverse?
That might cause the problems... or so I have heard.

89-4Runner

X2, who is setting up your gears, how are you breaking them?

MudHippy

It took me all of about 6 months to figure out how to chew the ring and pinion gear gears out of a 7.5" differential. Those were the 4.10s I bought it with. Put another 4.10 r&p which lasted about 2 months. I'm now on my 3rd set of ring and pinion gears for the IFS. Swapped some 4.30s this time. They have held up MUCH better for whatever reason(I do have my theory), even chewed the side gears out with them and cracked a CV. They've got a small chip or 2 knocked off of 'em, not on the wear surfaces luckily, and are running just fine to this day. A YEAR later, TWICE as long as the longer lasting set of 4.10s.

I've always chalked it up to running big ass 35x12.5 tires. But, I'll take your word for it that you can do it with the 33s.

Just wanted to add I've broken ALL mine in a forward gear, never reverse. I think it's because the front gears are stronger in reverse, IIRC. And that I've never had a hint of trouble from my 8" in the rear. I've even "downgraded" to the 4cyl 2 pinion 3rd member (came from the factory with the 4.30s) which has been given as much abuse as I can muster.

MudHippy

How the...wha? There's no housing to bend. There's only 1 axle tube, and tucked away as it is, bending it would be VERY hard to do.

yotasavg

lol! that's what i was thinking!

bruzer

Bent housing wouldn't be likely, the first housing was the factory set up with 4.56's. the second housing was set up by a guy that I really don't know with 4.88s and that unit/diff blew out the diff so the gears are still good in that one. The 3rd unit/diff was from a 95' with the factory 4.88s and the lasted about one wheel'n trip and one trip to the sand dunes.

mudbutt

I've never blown the front diff, it is stock with 4.56 gears. I have blown many rear diffs due to excessive power and "case spreading". I don't stay on the power when the front is spinning in the air though. At the dunes I have not noticed any times when the front is really loaded.

I have though about getting a supra rear and modifing it to work in the front end to get a 8". Or trying a LC100 diff because they are reverse rotation(highpinion) and take the same gears as the LC80 front diff. I have not gone this route yet because I have not had any failures, I feel I will loose a CV soon bu no noise yet.

InternetRoadkill

I imagine that the breakage is due to the 7.5" ring size. It's not as strong as the 8".

Flash319

Would the fact that it is a 3rd member style diff not make "bent housing" unheard of? The gears are sitting in a carrier so you can't have a flex situation like you would in say a chev axel where the housing is holding everthing in alignment. 3rd member is a cast member, don't think it could bend just break.

tc

No locker in the front right? That dramatically increases the shock loading when the (inevitable) front tire looses contact.

My next guess would be the gear setup. As mentioned above, it's only a 7.5" ring gear - there's not a whole lot of beef there to absorb any installation issues.

bigtrucknwheels

Knock On Wood, my front diff takes the heat just fine, knocking again! 4.10 factory gears. Our old truck was a standard cab 90, and my step dad beat the s#!t out of it and never broke a diff. i dont know what you guys are doing to these things!

bruzer

No locker, open diff. As far as installation issue's, there yota gears so I don't think its a install issue.


Lots of rock crawling and dune running.

I am starting to think the gears don't like my 33x12.50's

GV27

Well, it's not like ya just slap 'em in there.....install is more important to strength than the parts themselves. Not that the gear iteslf isn't important.....

www.gearinstalls.com

bruzer

I didn't just slap them in there, there the factory gears from when yota built the diff assembly. All factory, case has never been open to my knowledge.