2_point8_boy

I found this when I opened my diff to change the fluid and inspect it this morning.

https://www.thirdgen.org/techbb2/sho...hreadid=207712

TekViper

few too many neutral slams i take? how the **** did u do that.

you said u rebuilt it once already? why did u have to rebuild it originally and what was wrong?

Project: 85 2.8 bird

you're using that nylon gear set from the 4cyl aren't you?

2_point8_boy

I rebuilt it once, about a year ago, because the front pinion bearing went bad. It chewed itself to death so badly that the bearing cage didn't even exist when I got it apart. No nuetral slams or hard burnouts or anything. I think when I put it back together I misadjusted the pinion depth and it just chewed the teeth off. Nylon gears...seriously. Do you think that Nylon gears can stand up to the manly power of the mighty 2.8??? -insert evil laugh here-

TekViper

setting the pinion depth the the ring gear is hard, likely you screwed up there

Gumby

You should do a quick check while it still together. wipe off the ring as mich as you can and smear some grease on it and see the patters th pinion gear makes.

Should be nie and even inthe middle. Looks like its adjusted so it on the far edge, from the broken pieces.

Matt

Doward

Yeah, looks that way... damn, I hope the turbo doesn't eat MY rear end!

2_point8_boy

yeah, I looked at the patteren on the gear and it is that the pinion is too far away from the ring gear. Kinda weird too because i remember cecking and re-checking it when I assembled it to begin with and it was fine. I just don't know what happened.

Anyone got any tips or know how to get the pinion depth right the first time. When i rebuilt it last time I was forced to use the ol' guess and check meathod. Assemble parts minus crush sleeve, check pattern, disassemble and adjust accordingly. Once the pattern is good, you take the front bearing out, pop in the crush sleeve, and tighten it down to 25 inch/lbs and hope to heaven that you got it right.

Ever since I rebuilt it to begin with(rush job without access to proper tools, plus the fact that everyone said that only professionals can do it) it whined like a mo' foe. i figure, if only pros can do it, then how did the first person to do it themselves figure it out? If you have tips or have done it and are willing to share, please let me know. I am going to drive the car like it is until I either get all the replacment parts(full rebuild kit and new ring/pinion set) or all the teeth come off and it just doesn't move anymore.

PLEASE HARE YOUR KNOWLEDGE ON THIS SUBJECT.

RBob

iTrader: (1)

When I looked at the pics the drive side pattern appeared high to the outside. Thought maybe the lighting was off, now I see that it was what I saw.

Couple things. If you re-used the original gears when you replaced the pinion bearing then no shim changes required. Just put is back together with the same shims it came with.

For the new gears. . . Find the pinion shim that was originally used for that housing (your current one). The shims are matched to the housing more then to the gears. Then just set the backlash to a reasonable measurement and do a pattern check. If the pattern is off a little shouldn't need to move it more then a couple of thou.

When you tightened the pinion nut to 25 inch/lbs, that was drag (pre-load), correct? Good.

RBob.

TekViper

check the contact pattern on the teeh while it is under load. put the yellow marker paste on the gear and lower the car and drive it back 20ft and forward 20ft slowly. doesnt matter if the cover is off and its out of oil.

2_point8_boy

I used a new ring and pinion the first time, and when I removed the original one, it didn't have a shim behind the bearing. the only shims that existed in the entire rear end were the carrier shims. Kinda makes it hard to reuse the old ones.

The 25 in/lbs. was the bearing preload. Also, the backlash was right on the mark before I installed the rear back into the car(took the entire rear axel out because I actually had to use a press to get the original pinion out).

I was looking at pinion depth tools online last night: $300 for the damn thing. i guess the ol' guess and check meathod is the way to go. I'll get it right this time. Now that I know more about what i'm doing, it should go a lot quicker and easier.

Thanks for all the help guys. Keep the tips comin'!!!