Ring gear backlash question

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Pin_Head said:
I will save a washer for you. The Inner Harbor is sure nice now, but it was a dive back then. I worked at Monument and N. Wolfe St. You din't want to hang around there after dark. I still have fond memories of the fresh oysters and soft shell crab sandwiches with Utz potato chips washed down with a Natty Boh at the Northeast market.
Click to expand...

Yeah, inner harbor is nice, unfortunately the rest of the city is still in pretty rough shape. Back when I was in a band, we used to play shows in Dundalk - another area that wasn't a great idea to be in at night (and we'd be stumbling around drunk at 2AM). I'm a little older, and a little less invincible now! I don't stray too far from the harbor, Canton, and Fell's Point.

@Pin_Head I have one more question for you: I was told by a buddy that simply adjusting the gear backlash on the ring hear back to within spec would screw up the contact pattern, and lead to gear whine. He said I'm better off leaving it slightly "out" at 0.011 than to dial it back in and risk messing up the contact pattern. His words were: "If you're not rebuilding it, get the pinion tightened down and run it, don't mess with the backlash." What is your take on this? If I'm just trying to tighten things up (but not go through a full dis-assembly/rebuild) do you think there would be more harm in dialing the backlash in, or leaving it where it is.

I'm sure the short answer is that I'm splitting hairs and it would probably be fine either way, but, I'm curious as to your more educated opinion (or anyone else willing to chime in).
 
I have adjusted the backlash back to spec on used R&Ps and it didn't make them noisy.

Eat Bertha's muscles.
 
Cool, sounds like I'll dial them back in that .003 then! I'm hoping to mess with this some more this weekend.
 
Have you actually run a pattern? U will most likely have to go and adjust pinion depth to achieve an acceptable pattern, my procedure when I set them up at the shop

Get pinion preload close, using a torque meter,

Set back lash,

Run pattern,

Adjust pinion depth, to achieve proper tooth contact on coast and drive side,

Verify/ adjust pinion preload again,

Install seal,

Lock tight and stake nut after
torquing,
 
In order to adjust pinion depth (and not preload) I would need to pull the pinion entirely, correct? The plan was not to do an entire, ground-up rebuild (particularly since this is the front diff) but rather just tighten it up and run it. Don't have the tools, time, or knowledge to go much farther!
 
I think that you can safely skip resetting the pinion depth. Assuming that the depth was fine when it left the factory, which was probably correct because it was not noisey, wear will only decrease the depth by about .001. At the time the Toyota shims varied by only .004, so you would need to devise some custom shims under the inner race to gain .001. A .001 inch change in pinion depth does not make a significant change in the pattern in my experience.

As I said at the beginning of the thread, you probably could skip all of this and just run it as is because it is on the front.
 
@Pin_Head - Spot on with the suggestion to set it up without the thin shim. Proof positive that I'll only need to remove a small amount of material in order to get the preload back within spec. With the thin shim out, the pinion was tough to turn by hand. Impossible to turn without seriously damaging the inch-pound torque wrench!

Didn't get around to sanding down the washer today, but that's definitely the next step. Thanks for the good advice!

IMG_1910.webp
 
Pin_Head said:
You don't really want to tighten it that much.

Carry on.
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I know - the plan is to get it to the 10-11in/lb range it should be. This was just to ensure that removing material was the way to go - I wanted to make sure I didn't have a bigger issue afoot before I started sanding.
 
Ok, so, per @Pin_Head's instruction, I spent today sanding my preload washer on a piece of flat glass with some 220 grit sandpaper and mineral spirits as a cutting agent. I only cut from the non-tapered side. I'm still not clear on what the taper does, but it seemed wise not to mess with it:

Sanding the preload Shim.webp

I ordered a couple of fresh 0.25mm shims from Toyota as well. It turns out the shim currently in the differential was a thicker, 0.45mm shim. It took a couple tries - first I cut the washer from ~2.98mm to about 2.88mm. Preload ended up too low with the 0.45mm shim, and much too high with a 0.25mm shim. I cut the washer further, to about 2.79mm. Some testing determined I was REALLY close if I did away with the 0.45mm shim, and replaced it with two 0.25mm shims. It was still a little two low. Third time was the charm - cut the washer to 2.77mm, reinstalled with the two new 0.25mm shims, and viola:

Correct Preload 7.8 to 11.6in-lb.webp


At long last I'm getting measurement of around 9in-lb of preload, smack in the middle of the 7.8 - 11.6 in-lb tollerance. The nut is torqued to 150ft. lbs. There is no discernible play in the pinion. I'm going to call this set.

Once I track down a replacement dial indicator, I'll see what I can do about backlash.

Thanks, @Pin_Head for all the help!
 
Ok @Pin_Head, here is the latest from an idiot working on a differential. First, this is what happens when your torque wrench doesn't work:

image.webp


So I fixed it with what I had on hand, this grade 8 bolt, so I'm now "that" PO. Think this will cause enough problems that I should order the Toyota bolt, or will this about cover it::hillbilly:

image.webp


Lastly, I managed to adjust the backlash from 0.011 to 0.007, back within specs, but this involved tightening one side 3 notches, and none on the other:

image.webp


Is this ok, or do you need to adjust each side evenly?

Anyway, everything appears to be in spec, just want to make sure I'm not royally screwing the pooch!
 
How much preload force did you put on the side adjusters ? I made a set of tools to adjust mine and loaded them pretty hard to minimize deflection on the ring gear , it does help but some think it's no big deal ....

I'd prefer a metric bolt vs using an sae but it's just my preference - the 8x1.25 has a better pitch than 5/16-18 sae and seems to hold the load better .
Sarge
 
Weber Sarge said:
How much preload force did you put on the side adjusters ? I made a set of tools to adjust mine and loaded them pretty hard to minimize deflection on the ring gear , it does help but some think it's no big deal ....

I'd prefer a metric bolt vs using an sae but it's just my preference - the 8x1.25 has a better pitch than 5/16-18 sae and seems to hold the load better .
Sarge
Click to expand...

@Weber Sarge, it is a grade 8 metric Bolt (8x1.25, propper length, within mm) just the wrong head. My bigger concern is clearance when the gears are reinstalled in the housing - plus now I'll need two wrenches if I'm ever in here again. A little :hillbilly: but I'm assuming it will work.

My "adjuster" tool was very low-tech. In fact, it was the same bar-stock rod with two bolts through it I used to hole the pinion flange in place a few posts back. As such, I didn't measure the preload on the adjusters. I was already close to within specs for the backlash. I simply tightened/loosened the adjusters slightly in order to bring the ring gear backlash back within the 0.004 - 0.008 specs. By loosening one side, and tightening the other, I was able to get it to about 0.009. By leaving one side as it was, and only tightening the other (3 notches) I was able to get it even closer, 0.007 (which is also right within tolerance). My bigger concern is that the adjustment seemed to be most effective by moving just one side 3 notches (the blue dot, above, was the original position). On the other side, I didn't move the adjuster at all (picture below).

I did MOVE the other adjuster, but I had to loosen it, not tighten it. I found leaving it in place (and fairly snug), and adjusting the other side only (tighter), got me a tighter backlash measurement (the difference between 0.009 and 0.007).

My concern is, now I've *technically* loaded the one bearing more, while leaving the other carrier bearing the same as it was. Might be splitting hairs again - just wasn't sure if the two sides should be adjusted evenly. That said, I would have had to LOOSEN the side I didn't touch to improve the backlash, so my guess is I'm overthinking it...

IMG_1985[1].webp
 
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