Trunk Monkey
Moderator
Gotcha, so normal 100 front locker install. Didn't know if with the Harrop there was some grinding or clearance issues I hadn't heard of.
I think I broke my front diff what are my options? (1 Viewer)
- Thread starter sdnative
- Start date
This site may earn a commission from merchant affiliate
links, including eBay, Amazon, Skimlinks, and others.
Gotcha, so normal 100 front locker install. Didn't know if with the Harrop there was some grinding or clearance issues I hadn't heard of.
Yessir, just a funky front, nothing specific to Harrops.
The front units for Tacoma, 4Runner, GX and FJC do require a wee bit of grinding on the housing to clear the magnetic actuator.
See page 15 of the attached instructions for details.
I was going up a sandy / rocky section in the local desert when I lost traction. The truck slid left into a rock while the front wheels were spinning trying to get traction. I was very light on the throttle, RPM was around 1200, ATRAC was active. Tire started bouncing then apparently gripped and I heard a pop. At first I thought the tire had thrown a rock up against the skidplate. As I backed down and turned around I could feel a slight bind every 5 feet or so. I drove it maybe 50' to a flat section then pulled the drive flanges and front driveshaft and limped it home in 2wd. I haven't pulled it apart yet, but pretty sure it's the diff. I am guessing I broke a tooth off the ring gear.
This is in my 2003 LC.
So... what are my options?
Is it just a matter of pulling the third and replacing the ring & pinion? Does the housing or other components typically get damaged when the gear breaks?
I have a factory locked rear axle (from a 99 so 4.30 ratio) I was going to swap in. I was planning on regearing that to 4.10 as I didn't want to mess with the factory front. Now that the front needs repair I could regear that to 4.30. I feel that the 4.30 ratio would be a good match to the 33" tires, but not sure how common replacement gears are in that ratio.
I may put in a locker while I am in there. Does anyone make a reasonably priced e-locker for the front? I really don't care for the ARB.
Would love to get some opinions.
This is the obstacle, except it wasn't nearly that rough. Most of the deeper sections were filled in with sand. I was going up towards where the jeep is sitting.
(This is an image I found on the web, I was not with this vehicle/group)
sdnative-
Sounds like the ring gear might be missing 3 teeth. I can get the 430 Nitros and a nice Harrop . Can post pics of the damage too on this thread.
Will answer your email now.
Ken
hoser
SILVER Star
@gearinstalls.com Obviously, the 100 has a reputation of destroying front diffs, whether 2 or 4 pinion. Some believe the addition of a front locker reduces the chances of stripping the gears by virtue of reducing deflection between the R&P. Any chance you could give a professional opinion on which locker design would do best at "reducing deflection" between the R&P? If you have any other ideas about strengthening the front diff, i.e. solid pinion spacer, we are all ears!
Hi hoser-
It's just my opinion but it probably has more to do with the configuration.....the front is an 8" high pinion. The FJ80's are also 8" high pinions and they also occasionally bust a front ring gear.
High pinions are known to be stronger going forward. Nobody ever really thinks about the backward part. The logic is we're going forward 99% of the time....and 1% going in reverse. So who cares about reverse when it's only 1%?
I contend that the breakage or latent damage happened while in reverse gear(coast side of the ring). I think the greatest strains happen while in reverse....at least on the typical trail rigs.
A full case center carrier might help a little bit for ring deflections but the important parameters of pinion depth and carrier bearing preload can prevent most of the failures. Washer plates are used to set the CBPL on the front 100 series and it is important to get a washer plate that has to really be pounded in place to get some real CBPL.....pounded with a gentle hammer.
Pinion bearing preload is not as critical.....just the usual 10~12 in/lb of start torque.....a solid collar keeps it from loosening up with time.
As far as which locker design works best for minimum deflections........The big 3.....Harrop....ARB.....TJM.....are full cased and have very rigid cases. They might reduce deflections somewhat. The inside guts of all 3 are very strong and they won't blow up like a factory 2 pinion might.....all 3 are Australian made....those Aussies sure make good lockers
But really, this topic really can't be fully exploited with no Marywanna......or at least a good bottle of wine.
ZUK
It's just my opinion but it probably has more to do with the configuration.....the front is an 8" high pinion. The FJ80's are also 8" high pinions and they also occasionally bust a front ring gear.
High pinions are known to be stronger going forward. Nobody ever really thinks about the backward part. The logic is we're going forward 99% of the time....and 1% going in reverse. So who cares about reverse when it's only 1%?
I contend that the breakage or latent damage happened while in reverse gear(coast side of the ring). I think the greatest strains happen while in reverse....at least on the typical trail rigs.
A full case center carrier might help a little bit for ring deflections but the important parameters of pinion depth and carrier bearing preload can prevent most of the failures. Washer plates are used to set the CBPL on the front 100 series and it is important to get a washer plate that has to really be pounded in place to get some real CBPL.....pounded with a gentle hammer.
Pinion bearing preload is not as critical.....just the usual 10~12 in/lb of start torque.....a solid collar keeps it from loosening up with time.
As far as which locker design works best for minimum deflections........The big 3.....Harrop....ARB.....TJM.....are full cased and have very rigid cases. They might reduce deflections somewhat. The inside guts of all 3 are very strong and they won't blow up like a factory 2 pinion might.....all 3 are Australian made....those Aussies sure make good lockers
But really, this topic really can't be fully exploited with no Marywanna......or at least a good bottle of wine.
ZUK
hoser
SILVER Star
Good answer! I'm going to contact your the next time I pass through AZ! 
Ken rocks...Good answer! I'm going to contact your the next time I pass through AZ!
Good answer! I'm going to contact your the next time I pass through AZ!
sdnative,
Just a heads up that I received the Nitro 430 gears/Nitro master kit/solid collar.....and looking forward to seeing you in May sometime
Ken
