Gear Pattern

[gavin]

So I decided to take a journey into regearing a pair of axles myself.
I think I've done pretty damn good so far! haha.

Anywho, this is what the pattern currently looks like.

pinion a little low? It's pretty dang close to 2.524 which was the number engraved onto the head of the pinion.

also, measuring backlash; what's the best way to hold the pinion still and rotate the carrier, making sure the pinion doesn't move? I think backlash is currently around .015.

What should it be? Yukon's documentation states the "new 2-cut" should be .003-.006, and the "old 5-cut" should be .011-.016.

for the 8.8

edit: or is it too much backlash? Since it's pretty much dead-on center between heel and toe.

 

[storlied]

Nice dude, update when you're done about acceleration changes. That looks pretty close though, I was reading through gear swaps.. isn't the marking supposed to be in the middle, slightly outward?

 

[gavin]

Nice dude, update when you're done about acceleration changes. That looks pretty close though, I was reading through gear swaps.. isn't the marking supposed to be in the middle, slightly outward?

yeah it's pretty close, but I'll still be having to pull the pinion again since I've currently jacked up the roller bearing cage on 2 inner pinion bearings, so far. Plus I still need to grind down a tooth or 2 for pin removal.

But it looks to me like the pattern might be a hair bit high on the tooth.

I've done a bit of reading, plus looking through the book "Differentials - ID, restoration, and repair" by Randy Lyman and Jim Allen, plus looking through the Ford service manual.

 

[storlied]

Hm, sounds like something worth looking into. Did you go with 4.56? What exactly do you mean by grinding teeth? I've read about the center pin on the 8.8s how you gotta grind down the middle or buy a certain one for this application, is that what you meant?

 

[gavin]

Hm, sounds like something worth looking into. Did you go with 4.56? What exactly do you mean by grinding teeth? I've read about the center pin on the 8.8s how you gotta grind down the middle or buy a certain one for this application, is that what you meant?

the cross pin cannot be removed or installed, due to the height of the gears.
4.56 and numerically higher gearing requires either a notched cross-pin or clearancing the heel of a tooth or two. The notched cross-pin is installed in the carrier before the ring gear is.

down-sides to a notched cross-pin; if you need to replace spider or side gears, or need/want to replace the clutch packs for the L/S (or even replace the OEM L/S with a locker than can be installed inside a open or L/S carrier), you will have to pull the carrier and remove the ring gear from the carrier, to remove the cross-pin. Plus, the cross-pin is weakened due to a big notch in it. Although I have no clue how relevant that is. I read a (note: only one) thread on a Jeep forum where his notched cross pin was in pieces; although it's very possible it was due to the retaining bolt breaking or something else.

Otherwise, grind down the heel of a tooth or two, and you can retain the OEM cross pin, and still be able to remove it with the carrier still installed.
A possible downside to grinding, is dependent on where the contact pattern is for the gear set. Although a good pattern will most likely not be contacting much (if any) of the heel where it's ground.


On a side note; is this something to be concerned about?

 

[storlied]

Ah. I see what you're talking about.

Is that a chip? Hmm. As far as the chip is concerned, with how the spider gears are it doesn't seem like it's gonna effect much.. but the Fact that it chipped could be a sign of trouble later with the metal. Something got crazy in there.. I'd personally change them.. might be some fractures you can't see? On another note, you might be fine. Depends on the extent of the damage, if it causes any issues with the contact points of the gears or anything, plus if you find any cracks or anything else in that area.

Where's all the gear/diff experts at? Then again.. 4th of july weekend.

 

[gavin]

re-shimmed the whole carrier to get the correct carrier bearing preload.
checked pattern, way too much backlash.

moved the only small shim, .010, from the ring gear side to the other.

looks pretty close to me.

opinions?

maybe a hair less backlash?

pinion depth looks good since the contact is pretty centered between heel and toe.

 

[gavin]

ok so according to Yukon, the backlash should be .003-.006, not the .008-.015 (or whatever it is).

Per Yukon, backlash for the "Old 5-cut" gears is .008-.015, and the "New 2-cut" is .003-.006; and "most of the gears are the new 2-cut style."

In this case, my backlash is already at .005 which is the best it's gonna get.
Have had absolutely no luck getting any more than that.

 

[gavin]

loc-tited and torqued down ring gear bolts, installed pinion seal, replaced the bad inner pinion bearing, loc-tited and torqued down pinion nut, verified pinion bearing preload (about 15 in lbs), ground down a tooth for cross-pin removal, installed carrier and verified backlash is still within spec (0.005) per Yukon.

contact pattern looks good to me.

 

[gavin]

opinions?

 

[storlied]

For your first time, seems like you did this pretty well and problem free. Although I'm shocked not a single other person has made any type of comment.. I don't think there's really any other threads with good pics about gear setup. On the bright side, you just saved yourself hundreds of dollars.

 

[my pos mounty]

Its really tough to tell by the pics, but it kind of looks like you could move the carrier just a hair to the passenger side?? Could just be a bad angle, or bad lighting.

 

[Herbie 5.0]

your last pics are sweet. good job.as long as its all in spec i do alot of gears and it usually take anywhere from 2-4 pulls to get it right..theres only been 1 time ive set it up in a jeep D35 and it was dead on w/the first install..doubt that will ever happen again

 

[gavin]

For your first time, seems like you did this pretty well and problem free. Although I'm shocked not a single other person has made any type of comment.. I don't think there's really any other threads with good pics about gear setup. On the bright side, you just saved yourself hundreds of dollars.

ummm... well, no. Not really much savings for now. Although Young's Gear quoted me $1400 to regear both the 8.8 and D35 (bare axles, no labor on their part to remove D35 housing). And only labor for regear; doesn't include the price for the gears and install kits. I'm sure I could have found another shop that would have charged much less, though.
Although, in the end, I spent a good.... $800+ on tools just for this job. Add in a total of around $600-700 for gears and install kits... I didn't save much.
But it will help me down the line with my Bronco2.

Its really tough to tell by the pics, but it kind of looks like you could move the carrier just a hair to the passenger side?? Could just be a bad angle, or bad lighting.

passenger side... that would be the ring gear side? :
having a bit of a brain fart right now and can't remember which side the ring gear is on. In all honesty, the ring gear could move a tish towards the pinion to get closer to the middle of the backlash spec of .003-.006 (.005 right now).

your last pics are sweet. good job.as long as its all in spec i do alot of gears and it usually take anywhere from 2-4 pulls to get it right..theres only been 1 time ive set it up in a jeep D35 and it was dead on w/the first install..doubt that will ever happen again

well... I spent literally one whole day on just removing the pinion bearing races, then getting the pinion depth set. Kept screwing up my math 100 times over, so had to push the pinion out a multitude of times. Plus screwing up the roller bearing cage on 2 inner pinion bearings.

As for the D35... ugh. I literally spent... 4-5 hours yesterday just trying to get the effin pinion bearing races out. The housing doesn't have the "notches" in it to get a brass drive to pop the races out. Not to mention, atleast on mine, there was some sort of oil slinger between the inner bearing race and housing.
Ended up using a screw driver to pop the inner race out a little ways, after jacking up the oil slinger I fit a bearing/race/seal drive and popped the outer race out.
Then got a trusty balljoint/TRE remove fit into the housing and wedged up just enough onto the inner race to get it out.

yeah... not fun. At all.

 

[Herbie 5.0]

when i did it as a tech in CO. we were only allowed around 6hrs to set one up depending on axle. 90% of the time if a vehicle came in for a gear swap and you dropped it off the previous afternoon you would have it back at the end of the following day

 

[gavin]

when i did it as a tech in CO. we were only allowed around 6hrs to set one up depending on axle. 90% of the time if a vehicle came in for a gear swap and you dropped it off the previous afternoon you would have it back at the end of the following day

if I hadn't screwed up my math and measurements so many times with the pinion, I could see getting it done in a day.
Wouldn't be too hard pressed to see it done in 6 hrs.

 

[Herbie 5.0]

next time you do it..keep a note book marked L&R and write down what shims you use per side and subtract or add to your totals. it helps tremendously

 

[gavin]

next time you do it..keep a note book marked L&R and write down what shims you use per side and subtract or add to your totals. it helps tremendously

I did

 

[gavin]

ok, now I am thoroughly confused on the D35. I already got it tore down, and was working on installing the new gears, and here's where the confusion starts.

Everything I've read and looked at said the carrier shims go outside the bearings; between the housing and race. All fine and dandy, but when I pulled the old bearings off the carrier, there were shims between the bearings and carrier?!?!
According to the factory service manual the shims go between the housing and race; no shims between the bearings and carrier.

Next, apparently there's some sort of oil restrictor plate that goes around the inner pinion bearing race? Mine didn't have that; my Yukon master install kit has 2 of these plates. Looking at the Factory Service Manual, it shows the plate going between the race and the bearing? what? How would that work?

Thirdly... my install kit didn't appear to come with pinion shims? It has 2 sets of shims; they appear to be the same outer diameter, but one set has a much much larger inner diameter than the other. what?

I even verified that I have the correct install kit. It even comes with the correct 2 different axle shaft seals and 2 different axle shaft bearings.

wondering if, somehow, my master install kit got packaged incorrectly? Even though the appears to have everything, except an incorrect set of pinion shims? Atleast, I'm sure it's the right install kit. YK M35-IFS.

 

[4x4junkie]

I ran into issues with that stupid POS Yukon kit when I did my D35 some years ago. Seems they can't get their **** straight on it for some reason (I guess go figure... they seem to think this Dana axle was made by American Motors Corp., which hasn't been in existence for over 23 years now )

Mine had a wrong inner pinion bearing (I.D. was too small), and completely lacked any pinion slinger shims (only including shims that went behind the inner bearing race inside the housing). Fortunately I lucked out as I had to bring the pinion in a hair, which allowed me to reuse the original slinger shim, plus one added shim behind the race. My original bearings were like new as well.

As for shim locations, mine had none between the bearings and carrier, they were all between the bearings & housing. Any chance your carrier was swapped over from a Jeep rear D35?