Houston, we have a problem

[83gt351w]

So back in 97/98 I had a "friend" install the gears in my 8.8. He had been doing many 9"s so I figured what the heck. After the install, I only had about 5 miles on the new gears when the car got parked for 15+ years. I recently watched a video on the install, and didn't remember the guy doing any of that preload, backlash, etc., stuff. So before buttoning up the rear, i decided to check the backlash. Crap.

[Jerry peachuer]

Think you want under 10 closer to 8

Fixing it yourself ?

[83gt351w]

Sure am. Studied up on the subject extensively. And I have access to a great diff guy. Now, from what I've read, I just shim the drivers side to make up the difference. I might add, there were zero shims.

[83gt351w]

My course of action, is just continuous reading, and studying on the subject. This things got me all sorts of stressed out. One issue after another. Welcome to loving cars, I guess.

[Jerry peachuer]

Sounds like your covered not to mention a guy to bounce it off

I have one suggestion that makes all the difference for mock up

The bearing on the pinion backside take a dremel of some type and bore out the bearing so it slips on and off pinion rather than being pressed on or off cause you have to damage them to remove them

Understand this bearing will NOT be used in your final assembly it's just a removeable bearing to set your depth up/down of pinion engagement
I think there's usually a 27-30 shim under them and to set side to side you also have to set up/down for proper engagement

So again this bearing is just a tool not to be used for assembly it doesn't take much effort to hollow out the center like .002 or so and this will let you slide shims on and off with ease then when you find your numbers you put the right shim under it and press it on and the rest should be in any DVD or you axle guy

A old timer guy showed me this and it's worth the cost of the bearing to have it for a mock up tool for 300 dollars plus worth of components that could be destroyed on your first outing

I see a dial indicator so I know you know what .001 is and that is more than half of it other than paste and some guys wiggle it and call it a day
Good luck

[Jerry peachuer]

Bad shoe productions(DVD) does a awesome job on the axle not to mention he includes all the tolerances once you can read a dial indicator it's a matter of moving it left right up down

A piece of lined paper is .003 thick your out of spec by approx 6 pieces of paper to put it in a visual aid so it don't take much to not have a good engagement of your gear set but it's not difficult to correct you add or take away a shim

[83gt351w]

I've watched a few off those videos. They're great. Being that the backlash was so off, it makes me question the preload. My BIL is bringing one of those inch pound bar wrenches next week so we can check it. But, we were both leaning towards not trusting anything now. I guess I can replace the pinion flange with one of those upgraded ones and a seal while I'm at it.

Love the mock up bearing idea. I'm guessing it's reusing the crush collar for a mock up as well, until you're ready for the final install.

[Jerry peachuer]

Correct on the crush and pinion nut

I had extra shims from other axles that were handy to change them in and out for adjustability

Also make sure main caps are pointed correctly that hold your trac loc in

Inch pound is neeeed to measure break away torque for preload so good note there

[JACook]

I do the mock-up and check pinion depth without a crush collar. Doesn't need to be there until final assembly.

[Jerry peachuer]

True it does nothing on the backside for depth so I would agree but as for mock up it's a good practice so you have a progressive order of re assembly

Makes you focus

[83gt351w]

Now if I understand everything correctly, Fords master pinion shim is .003" if I press off the pinion bearing, that's what I should expect to find? Once I make my mock up bearing, install the pinion, and pinion flange?

And if I read it right, install the carrier, use marking compound, and depending on the markings, the pinion has to come out, or go in further. To me, the pinion seems like the tricky part.

On a side note, I'm going to rebuild the trac lok, as it's a rear of unknown miles. To be honest, that part looks like a breeze. Pull the disc out, measure them, soak new ones, slap them in, curse at the S clip.

[Jerry peachuer]

Should be closer to .03 not .003
The paste is visual aid for pattern for pattern wear

The bearing I mentioned is the only part you can't put on and take off without destroying so buy 1 hone out the center so it presses on and off with little effort so you can change shims with ease and when you find the one you throw it on and press bearing on it

The crush sleeve is another one time shot thing if you over do it it then that should be replaced

I had a fear swap done in a car a long time ago and it was 400 I had the gear I felt a bit taken so I grab a DVD and I already owned the tools and had a old timer walk me through some of it it's not bad if you can read the tools your using properly and if you orientate the components properly and if your not in a hurry

It really is that simple moving shims equally left right up down and reading your tools

Which takes me back to my first comment (I see a dial indicator)

The old timer guy works on semi trucks and does his axles and everything else with the trucks he wiggles it and calls it a day lol he worries about temp not lash in axles though and he has great success but goes against the gran of tolerances rather feel

[OX1]

If backlash was that far off, what makes you think pinion depth and/or the resulting pattern will be right when you get correct backlash.
Can try it I guess and see what pattern looks like with correct backlash, but I'd be skeptical right off the bat.........

[83gt351w]

Reading directly from Ford's site, they seem very confident that if you're using their gears, the master pinion shim, of around .03" is going to turn out to be the correct one. I think at this point, I can't trust anything the guy did. A crush collar is cheap, and so is a new pinion bearing. Through my BIL, less than 20 bucks, I'm guessing.

I have access to a press at work, so it's tear down time.

Talking to my diff guy, those new crush collar replacements, that are a shim pack instead of a crush collar, are around 50 bucks, and only really convenient if you're laying on your back under the car. An actual crush collar is a much cheaper route, being that the rear is on a work bench.

[83gt351w]

If backlash was that far off, what makes you think pinion depth and/or the resulting pattern will be right when you get correct backlash.
Can try it I guess and see what pattern looks like with correct backlash, but I'd be skeptical right off the bat.........

if you can get your pattern centered, front to rear, I think it would indicate correct pinion depth. Then it's a matter of adjusting the backlash to end up with the correct pattern.

[Jerry peachuer]

I had a .03 and I had a .028
For pinion shim but ox-1 comment about skeptical is well stated but I feel if your not trying to do anything special or exotic for preload and such

Trying to start with a .03 shim is a good starting point

The machine process will define exactly what you need on the end if housing is cut too deep you will need bigger shim if it's not deep enough you will need smaller shim

Your main caps can be plus or minus on the depth which will change it as well

Your posi unit is NOT adjustable it's set on your caps and will not move up down only side to side with shimming

You literally have to shim up or down on the pinion with proper shim this is the only up down adjustment

You must now what the tolerance .001 thousands is to understand allowable tolerances we won't go with anything close or than .001 because there is a acceptable limits of allowed deviations in machining

Understand take a piece of paper and divide it 3 times the thickness that's .001

So as far as paste this will be the only tool that will SHOW you your end results like a track in the mud if you shim too much you will bury your pinion on your ring gear and you will think you have good backlash

This isn't true because side to side is and up down is not meshing properly

It's just math and shims and paste

If your diff guy put it together with no shims and he has sucees with other axles I'm afraid to say he is trying to destroy your stuff or he is a good talker and without knowing the subject it's really easy to listen or misunderstand what is being said and take it minimal it is hard to describe how to do something but watching is another thing

bad shoe production DVD does a great job showing you without the special dealer only tools

These axles are set at a factory in a production volume by aunt Susan on the assembly line so special tools are out there so aunt Susan (this is kinda of a joke) but there are aunts moms sisters and such on assembly lines installing your gearsets of course with special tools and instructions

My point is you don't need a diff guy he may be holding you back as far as your research goes and your studying and such get a DVD and see if you want to tackle it
1) you will see what's involved and it's on your own time in your house
2) it's only 20 -25 bucks and if you get a good one it's worth the info and then some

Just my opinion

[PaceFever79]

Cool thread, good info

[83gt351w]

Okay, since this thing has to be gone through all the way, I decided it was a good time to check the trak loc. Easy to come apart, tap out the S spring, and simply rotate the spider gear, and they'll slide right out.

Next, I removed the large spider gears where the clutch packs are located. A standard working posi track, on an 8.8, is .640-.645.

A high performance clutch pack will measure .655". An upgrade is in order, as I was bordering on a one tire fire.

[83gt351w]

Finally got the pinion bearing pressed off today. Managed to take it off quite easily. Should make for a good mock up bearing. I did measure the pinion shim, and think I found the problem with the enormous backlash.

[homer302]

Good luck with this. I appreciate what you are trying to do for sure. There are two ways to do something, a wrong way and a right way. I get it. And if you are already taking everything apart, why not go the extra steps.
That being said, I don't know who assembled these for Ford back in the day. They were sending them down the line as fast as they could be screwed together. They went in F150s, Mustangs, Cougar, Thunderbird, Lincoln Town Cars, Mark VIII, LTD, Fairmonts...Heaven knows what else. I find it hard to believe there was really that much labor put in their assembly and setup. There is an IDEAL and there is also a safe range. I imagine some cars had noisy rear ends and some had quiet ones. As long as it isn't too tight, it will not burn up. I am just saying maybe you shouldn't stress SO much.
again, Good Luck!

[Domino]

I am looking forward to seeing how this comes out.

Sent from my SGH-T399 using Tapatalk

[83gt351w]

Here's a follow up

http://vb.foureyedpride.com/showthre...-tooth-contact