Any idea what the markings on the pinion gear mean? Just got this from Dr. Diff...
Marking on new pinion gear..
- Thread starter Miranthis
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ValiantRacing
Well-Known Member
2.77 should be your pinon depth
Where is that measured from on a 489 case?
I was told to use the pattern to set the depth, using the old pinion's shim as a start (trial and error). Then once depth was set, set the preload on pinion, then finally the back lash
You measure from the center of the carrier bearing .
Usually,,,the bearing caps will not be perfectly centered .
I always mic them and see how close it is .
Usually,,,it’s around 10 thousandths or so off .
I literally just did my 489 carrier last week,,,it was right at .007 off centered .
I just added that to my shims,,,,I think I put .036 under the pinion .
It worked out really nice,,,,very good readings .
The gear is a new 3.55,,,,my pinion bearing preload was at the max,,,,,but I didn’t want to waste another crush sleeve to get it perfect .
Tommy
Usually,,,the bearing caps will not be perfectly centered .
I always mic them and see how close it is .
Usually,,,it’s around 10 thousandths or so off .
I literally just did my 489 carrier last week,,,it was right at .007 off centered .
I just added that to my shims,,,,I think I put .036 under the pinion .
It worked out really nice,,,,very good readings .
The gear is a new 3.55,,,,my pinion bearing preload was at the max,,,,,but I didn’t want to waste another crush sleeve to get it perfect .
Tommy
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Inertia
Well-Known Member
Old post with depth tool
www.forabodiesonly.com
Pinion depth setting
Instead of buying a $300 pinion depth tool couldn’t I just use a piece of machined flat stock mounted to the saddles with a threaded hole with fine threaded rod and measure the distance to the top of the pinion . then shim accordingly? I could test it on a factory mounted pinion to verify that...
www.forabodiesonly.com
ValiantRacing
Well-Known Member
Like said above its measure from the center, but i quite doing it that way years ago because the pattern would never come out right, so i aways start with a .30 shim, unless your doing something like 5.13s and then you need more shim.
I am swapping out an open 2.76 for a new SG 3.23. The old pinion had a .34 shim and i am using that as a starting point for set up this weekend. I think i will try the "trial and error" depth method and see how it goes.
Inertia
Well-Known Member
You don't need to use the crush sleeve for set-up.
Do all your trial and error stuff leaving the sleeve out, just snug the pinion brgs, do all you're fiddling, then when shims and pattern established,- do final assembly with the single crush sleeve.
Or add a shim to used crush sleeve and re-crush to torq.
I didn’t,,,,,it was just a little too snug after my impact gun finally got the sleeve to crush down .
The preload was at max,,,,19 inch pounds ,,,,I usually try to keep it closer to 15 .
I always use the crush sleeve as the last thing I do .
Tommy
The preload was at max,,,,19 inch pounds ,,,,I usually try to keep it closer to 15 .
I always use the crush sleeve as the last thing I do .
Tommy
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Before I did the trial and error pattern method, I thought I would use my calipers and a straightedge to try to use the pinion depth, or at least check it as it stands with the same shim the prior pinion had.
Putting my straightedge across the two bearing cap mounts (L and R just above the pinion and zeroing out the height of my straightedge) I measured from the bearing cap mount down to the top of the pinion gear. That gave me 2.7625. The question is whether the Bearing cap mount is on the center line. If it is, then 2.7625 is my depth. If it's not, then I need to add or subtract the difference from 2.7625 to get the current depth.
To see if I could figure that out, I measured the ID of the bearing raceway with the cap installed and tight. Compared that to the OD of the bearing race and they are nearly the same as it an interference not a slip fit. Then measured the distance from the tops of the bearing cap mounts to the bottom of the raceway opening. This measurement should be one half of the ID of the raceway opening. If it IS then the cap mounts are "on the centerline". If it is NOT, then the difference (+ or -) must be added or subtracted from the depth measurement to get the "to the centerline of the bearing" measurement. I am going to do the measurements again tonight with a newer and more reliable straightedge. but assuming it do get it to the marked 2.770 depth, that should yield a good starting, if not final, pattern.
Putting my straightedge across the two bearing cap mounts (L and R just above the pinion and zeroing out the height of my straightedge) I measured from the bearing cap mount down to the top of the pinion gear. That gave me 2.7625. The question is whether the Bearing cap mount is on the center line. If it is, then 2.7625 is my depth. If it's not, then I need to add or subtract the difference from 2.7625 to get the current depth.
To see if I could figure that out, I measured the ID of the bearing raceway with the cap installed and tight. Compared that to the OD of the bearing race and they are nearly the same as it an interference not a slip fit. Then measured the distance from the tops of the bearing cap mounts to the bottom of the raceway opening. This measurement should be one half of the ID of the raceway opening. If it IS then the cap mounts are "on the centerline". If it is NOT, then the difference (+ or -) must be added or subtracted from the depth measurement to get the "to the centerline of the bearing" measurement. I am going to do the measurements again tonight with a newer and more reliable straightedge. but assuming it do get it to the marked 2.770 depth, that should yield a good starting, if not final, pattern.
RustyRatRod
Caput villa stultus
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Icetech
Well-Known Member
oh come on.. i wish i had that tool when i did mine.. i figured they were a lot more expensive i think i had the carrier in and out like 10 times...Ratech 10007 Ratech Pinion Depth Setting Tools | Summit Racing
Free Shipping - Ratech Pinion Depth Setting Tools with qualifying orders of $109. Shop Pinion Depth Gauges at Summit Racing.www.summitracing.com
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