Author Topic: differential question? (Read 2715 times)

jpmxer · « **on:** Feb 11, 2008, 06:15:06 PM »

on my 4 runner i noticed the driveshaft turns almost a half of a turn before it engages. what causes this?

Duffil · « **Reply #1 on:** Feb 11, 2008, 07:49:55 PM »

do you have a detroit in it, is it factory or what?

93tonkatoy · « **Reply #2 on:** Feb 11, 2008, 10:02:55 PM »

It all depends. are you referring to the front or rear? if the front, do you have add or auto locking hubs? If it's the rear, do you hear "gear whine" varying with your speed on the road? With a little more info, it would be easier to pick out the problem. Year, axle, setup (gear ratio, stock/ aftermarket), open diff/ locker (type) would help.

79coyotefrg · « **Reply #3 on:** Feb 12, 2008, 06:32:54 AM »

sounds like extremely bad contact pattern/backlash

jpmxer · « **Reply #4 on:** Feb 12, 2008, 07:06:38 AM »

this is in the rear diff. i have 529's with a detroit. i do hear some whining but i thought that was coming from the transmission.

Duffil · « **Reply #5 on:** Feb 12, 2008, 07:32:03 AM »

its the detroit. everyone i know with a detroit has that. try parking on a hill, when you let the clutch out with no ebrake, it will roll back like a foot.

jpmxer · « **Reply #6 on:** Feb 12, 2008, 07:50:13 AM »

exactly. that is how i noticed it. no big deal then?

Fearofrunner · « **Reply #7 on:** Feb 12, 2008, 07:59:43 AM »

I think it's the 5.29s, i've got an aussie and it does the same thing. Even with the t-case e-brake on it rolls forward/backards a bit.

79coyotefrg · « **Reply #8 on:** Feb 12, 2008, 11:50:28 AM »

who set up yalls differentials

DTB · « **Reply #9 on:** Feb 12, 2008, 11:54:11 AM »

Quote from: Duffil on Feb 12, 2008, 07:32:03 AM

its the detroit. everyone i know with a detroit has that. try parking on a hill, when you let the clutch out with no ebrake, it will roll back like a foot.

Mine doesnt...its tight like a tiger...

Quote from: 79coyotefrg on Feb 12, 2008, 11:50:28 AM

who set up yalls differentials

Fontucky Fab! They had a two-fer deal

twistedtoy92 · « **Reply #10 on:** Feb 12, 2008, 11:59:15 AM »

haha! yeah, shouldnt do that....... excessive BACKLASH

79coyotefrg · « **Reply #11 on:** Feb 12, 2008, 12:27:48 PM »

i set my own up with .006 of backlash and my pinion doesnt move maybe 10 degrees, if that

Fearofrunner · « **Reply #12 on:** Feb 12, 2008, 01:44:52 PM »

ya but you got 4.37 gears, the guy that did my gears had his dad and the other owner of their diesel shop (that do alot of gears for big rigs and small rigs) look over his work and said it was excellent. The yellow marking grease showed good and even lines across the ring. I've also beat on these gears and DD my truck and it's as smooth and as quite as it was with the factory set 4.10s.

Just my two cents YALL...

Duffil · « **Reply #13 on:** Feb 12, 2008, 02:13:43 PM »

I set up my own. I had .007" backlash, but the detroit makes it act like that. There are several pro setup diffs around here I know of that are the same as mine.

twistedtoy92 · « **Reply #14 on:** Feb 13, 2008, 10:11:19 AM »

must be the detroit

Steve_925 · « **Reply #15 on:** Feb 13, 2008, 01:40:35 PM »

thats a relief. i have 5.29s with a detroit and it does that too. never really worried about though cuz there were no other problems with it

*ROKTOY* · « **Reply #16 on:** Feb 13, 2008, 03:02:57 PM »

Its the Detroit for sure.

twistedtoy92 · « **Reply #17 on:** Feb 14, 2008, 09:22:14 AM »

i havent ever ran a detroit....i'd like to though!! only lockrite and lincoln

mountain28 · « **Reply #18 on:** Feb 15, 2008, 03:53:20 PM »

i have the same problem but mine is stock with 355,000, is that bad gears? i drive it every day and it will snach in any gear.

twistedtoy92 · « **Reply #19 on:** Feb 19, 2008, 08:44:56 AM »

snach in any gear???

skyscraper · « **Reply #20 on:** Feb 19, 2008, 12:38:55 PM »

Quote from: Fearofrunner on Feb 12, 2008, 07:59:43 AM

I think it's the 5.29s, i've got an aussie and it does the same thing. Even with the t-case e-brake on it rolls forward/backards a bit.

In the setup manual for the aussie, it states that "excessive backlash is normal for these types of lockers"
Its the locker not the gears.

bluetoy84 · « **Reply #21 on:** Feb 20, 2008, 11:54:27 AM »

Quote from: toyguy86 on Feb 13, 2008, 03:02:57 PM

Its the Detroit for sure.

Agreed. Detroits (and lunchbox lockers) have excessive backlash. I like them for a front diff, but too much slop for a rear.

I've always ran welded rear diffs, but I traded for a detroit and swapped it in my rear diff. After about two months I put my welded diff back in because I did not like all the slop in the detoit. Seems to me that the extra backlash would be harder on the gears and shafts. When you roll back on a hill and dump the clutch the backlash allows the shaft to slip enough for it to ramp up to speed and then engage violently.

I'll stick with my welded diff in the rear and leave the detroit for a front. Just my $.02.

DTB · « **Reply #22 on:** Feb 20, 2008, 12:04:33 PM »

If they are set up right backlash is negligible

bluetoy84 · « **Reply #23 on:** Feb 20, 2008, 12:26:00 PM »

Quote from: DirToyBoy on Feb 20, 2008, 12:04:33 PM

If they are set up right backlash is negligible

You must be referring to a lunchbox locker (lock-right,aussie,etc.)

The backlash I was referring to is internal on a detroit (full case) locker. If there is a "correct" way to set up a detroit please explain.

skyscraper · « **Reply #24 on:** Feb 20, 2008, 08:41:18 PM »

Quote from: DirToyBoy on Feb 20, 2008, 12:04:33 PM

If they are set up right backlash is negligible

He is not talking about backlash on the gears. Thats different then the backlash in the locker. I can turn my aussie inside the carrier a good 1/8 turn or so.

Rocksurfer · « **Reply #25 on:** Feb 20, 2008, 08:56:50 PM »

My Detroit did have some excessive backlash in it too, it was professionally setup. My welded diff didn't have this so I vote for the locker, if I remember correctly it also stated this issue in the instructions/owners manual.

skyscraper · « **Reply #26 on:** Feb 20, 2008, 09:25:06 PM »

I measured mine and it is what its supposed to be(6-10 thou or something, dont remember). I can actually move the locker inside with my hand.

jpmxer [OP]

jpmxer [OP]

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