Gear Install HELP!

[Matt P]

I am rebuilding my diff. New bearings, seals etc. Also putting in Ford Racing 4:10s. I am not using a pinion depth tool, yet... I just started out with the factory 0.030 shim on the pinion and set back lash to spec. The marking pattern from the marking paste is a little high on the tooth, not hanging off, but on the upper portion of the tooth. Is this okay?

I have spent the last 8 hours just trying to get the teeth marking pattern to look dead on. If I bring the pinion out and reset the back lash I do not get any improvement in the pattern. I brought the pinion out 0.070 to the point it touched the center section and could not get the pattern to look better. I dropped the pinion shim down to .025 and reset the backlash and the pattern was about the same. I pretty much went from .025 to .070 pinion shims in .005 steps reseting the back lash every time and the marking pattern would not get any better. I lso tried running backlash very tight and this did not help either.

So do I stick with the 0.030 shim and the sort of high marking pattern?

 

[1/4MILEMUSTANG]

What are you setting your pinion preload at?

 

[Matt P]

What are you setting your pinion preload at?

At this point I am setting it around 18-22 inch pounds. I am reusing the original crush sleeve for mock up along with the original pinion bearings which I ground one a little so they slide on and off the pinion. I tap it out the crush sleeve a little every time to make it wider again. I wouldn't think pinion preload would effect the marking pattern? Eve preload was on the loose side I'd think the marking pattern would be lower on the tooth. Please tell me if it is otherwise?

What I am struggling with is that when I add shims to move the pinion deeper into the mesh the whole assembly gets very hard to turn, like I need to use a tool to turn it. So I reset back lash so spec and it turns freely, but the marking pattern is again a little high.

Thanks for responding...

 

[DE07GT]

On which gear is the marking high on? You don't need the crush sleeve when you set the pinion depth. You should tighten the pinion nut until there is no excess slack in the bearings.

 

[Matt P]

drive side on the top 1/3 heel side of the ring gear

coast side on the botton 1/3 toe side of the ring gear

I cant get it any more centered toe-heel on the drive gear no matter what I do.

My spacing between flank and face is pretty good.

I have seen that this is an accaptable pattern on a few websites. Maybe these ring and pinions just set up in a non standard but accaptable way?

 

[Matt P]

 

[Matt P]

 

[Matt P]

 

[Matt P]

Which one do you think looks the best?

 

[Matt P]

Amd another just cause

 

[Matt P]

And one more

 

[Matt P]

Last one I promise

 

[Matt P]

I'm thinking just stick with the factory pinion shim of 0.030 but get back lash in the .010 range?

 

[DE07GT]

Kinda hard to see in the pictures, but I'd just go with whatever you think is the most center. Looks like the ones with the pinion shims less than .030" are a little too shallow in the ring gear so I'd go with the greater amount of shims. It's easier when you see the paint in person. I used a Ratech pinion depth gauge and the 8.8 Master Housing Dimension to figure out and adjust mine. Checking it with paint showed the same result.
Spacing between the face and flank should be fine because it's determined by backlash and spec is .008-.012". I set mine up on the tight side because it's a manual trans car and backlash will increase with wear.

 

[Matt P]

Thanks.

I think .032 will be good!

Any one else have thoughts?

Kinda hard to see in the pictures, but I'd just go with whatever you think is the most center. Looks like the ones with the pinion shims less than .030" are a little too shallow in the ring gear so I'd go with the greater amount of shims. It's easier when you see the paint in person. I used a Ratech pinion depth gauge and the 8.8 Master Housing Dimension to figure out and adjust mine. Checking it with paint showed the same result.
Spacing between the face and flank should be fine because it's determined by backlash and spec is .008-.012". I set mine up on the tight side because it's a manual trans car and backlash will increase with wear.

 

[Matt P]

I think this is pretty good, what do you all think?

 

[fastback brian]

thats not gonna work.. do a pattern check on the coast side too..
the shim is typically set to the housing if you have ford cast gears. But them aluminum housings are know to get twisted and give you some out of whack gear patterns like that.... if the coast side is deep in the toe then it would need less back lash, if its already at .010 then the housing could be junk.. you sure that is a ford gear, it has ford casting numbers on it?

 

[Matt P]

Coast side was on the bottom 1/3 toe side of the ring gear.

Brand new FRPP gears out the box from Touysley.

How do you check for a twisted case? Run out of the ring rear was super good 0.002"

The car is mostly a street cruiser. It will never be tracked, drag strip a few times perhaps. My run sticky R compound road race tires on the street but never drag radials. Will stay NA for quite a while. May boost later but I cant see more then 500whp in a vert.

With all that said, as the car sits NA now and is a street cruiser, what issues could surface if I run it like above? Noise, premature wear, catastrophic failure? I guess I'd rather give it a try than drop the coin for a new case... unless its a severely bleak outlook for longevity.

I really appreciate you all taking the time to reply. MP

 

[fastback brian]

there are charts out there that give you direction on where to move the gears. if the gear pattern is so far out then the case can be out of spec.. look up "dana spicer gear pattern",, newer ford gears are hobb cut..

 

[Matt P]

Thanks Brian, Ive referenced various charts a bunch. Ive moved depth and back lash around quite alot. Check out this chart, look at the acceptable patterns, second down on the right, thats what I have...

So you want to install your own gears: A 'how to' 8.8 gear install - Ford Explorer Ranger Enthusiasts "Serious Explorations"®

I figure with the OE 0.030 pinion shim and BL set to spec 0.012-0.008 I can be no worse off than I was with the original 3.27 gears. The wear locations on the factory R&P look like the marking locations on the new R&P. If any one thinks I am crazy for giving this a shot please speak up.

Is their a way to measure the case to check for it being bent or warped?