chipped pinion tooth in Ford 8.8...let it go or fix?

Just as the title says...my mysterious "grinding noise" in my driveline is a chipped pinion tooth. Ive been driving it around town on the weekends, it isnt getting any worse. I cleaned out the small bits inside the rear end and put in new fluid.

I dont see this rear end blowing up due to this chipped tooth. The noise is annoying (only when i decelerate)....everywhere i look it says these symptoms are due to a chipped pinion tooth or a high spot on the pinion

I think im just going to let it be, i can swap axles in the warmer weather and in the meantime look for a locked 8.25 or another 8.8

advice?

opinions?

I might just run it til it break, if not run it forever. many run ring/pinion with damaged teeths without a problem (if its not too severe damaged).

Id run it and in the mean time look for another 8.8 with the gearing you need...then swap the gear set into your 8.8 housing.

Sound like your pinion bearings might be had too. Could be what lead to the chip too.

It would depend upon how much you have invested! You didnt say what gears you have or whether you invested in a locker or not. The other thing would be the safety factor,it could grenade on you causing "almost" anything including an accident.Now we are talking about people not just equipment!!!!!

if its a trail rig..sure run it till it breaks.

i know a guy who totaled his jeep from a similar situation that your in. his rear end locked up when it was doing 70 down the interstate and caused him to loose control

You need to check the carrier bearings. If they have any kind of pitting I don't recommend continuing to drive it. If the bearings are good then take some 220 grit sandpaper and smooth out the sharp edges of the gear tooth where it is chipped and then thoroughly flush out the case and refill with good oil. Put a very strong magnet (like the kind found inside a computer hard drive) on the inside of the diff cover next to the ring gear. Do you have any idea why the tooth chipped? This can occur when the gears are not set up correctly or also if they are not broken in correctly. It is caused by excess heat making the teeth brittle.

well a few months ago my rear u-joint blew out and really F'd up my drivetrain....bent output shaft of NP242, and cracked the bellhousing on my AW4 tranny...im guessing the gear chip happened then...it was a major shock to the drivetrain. It is a factory 4.10 8.8 with slightly modified LSD so it locks better....i dont run on highways but she does she 50 MPH. finding 4.10 8.8s are tough, but I do want to keep the 8.8...guess i need to look for gears

what do you guys think about buying used gears?

Replace the gears and I have had a bad experience with used gears so I wouldn't... This would be the time to upgrade the front and rear though if you need deeper gears. And almost always can use deeper gears

wishihad1 said:

if its a trail rig..sure run it till it breaks.

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Yeah, go ahead and be the dick who makes your buddies wait around while your junk explodes on the trail. Excellent advice. :badpc:

benulis55 said:

what do you guys think about buying used gears?

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Used gears are just fine as long as you make sure they have no signs of overheating such as discoloration. Also make sure there are no pits in any of the contact surfaces on the ring and pinion. If your old gears show no signs of overheating and no cracks (check carefully with a magnifying glass, pay particular attention to the edges of the gear teeth and the holes where the ring gear bolts go through) then you should be O.K. to keep running them after you smooth out the sharp edges. You will have to remove the ring and pinion to properly inspect them. You'd have to do that anyway to inspect the pinion bearings. If all looks good you will probably be O.K. with the gears you have. That being said, now would be a good time to install some 4:56's