8 3/4 gear setup

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pishta

pishta

I know I'm right....
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What do you set first, the pinion depth or the carrier offset? 489 case using OEM crush sleeve. with a conical pinion gear shape, seems you could have quite a time finding the sweet spot for the pattern. I set carrier offset before but the pinion was not disturbed for carrier bearing replacement only.
 
You set pinion depth first but with out the crush sleeve. just install the pinion with the bearings,races and yoke, just tighten the pinion nut to remove all the play. Without a set up bearing it is difficult, start with a shim around .030 to .035. Then check the gear pattern with the Back lash at .008-.010. I would suggest making or buying a 489 set up bearing that slides on and off so you can change the pinion depth until you get it right. When your satisfied, then install the pinion with the crush sleeve and tighten to the correct preload. 14-19 inch pounds.
 
SGBARRACUDA said:
You may want to consider a crush sleeve eliminator.
Click to expand...
On a 3rd member like the 8.75, do you have to take the carrier out for every shim change while setting up or are the shims so thin that they dont affect the pattern you worked to get?
 
I swear up and down that I was going to learn how to do this and was never going have someone set up my gears again. In the end last time I folded! LOL and paid the $175 and didn't look back... :(
I tried to justify it to myself by saying I didn't have the right tools or knowledge. I guess I never will at this rate...
Although I was able to get the gears and the setup for the price most just want for the gears. But that's just stupid justification..
 
pishta said:
On a 3rd member like the 8.75, do you have to take the carrier out for every shim change while setting up or are the shims so thin that they dont affect the pattern you worked to get?
Click to expand...
When your trying for a good pattern between pinion and ring gear, yes the carrier has to be removed to add or subtract shims behind the pinion large bearing. This is why I suggest a set up bearing that slides on and off to change the shim stack. Other wise you have to use a puller to remove the bearing and a press to install it. Plus you run the risk of ruining the large bearing. It is possible to shim the pinion deeper or shallower by using shims behind the race in the case.
 
If you are only replacing the carrier bearings as you say, and have no need to remove the pinion, all you do is check backlash first, remove the carrier, replace the bearings, re install the carrier and re set the backlash to what it was before. Honestly f you want you can run a pattern afterwards, but if it is a used gearset and was quiet before, just reset the backlash and it should be the same. Used gearsets may have less to than perfect patterns.
 
d55dave said:
If you are only replacing the carrier bearings as you say, and have no need to remove the pinion, all you do is check backlash first, remove the carrier, replace the bearings, re install the carrier and re set the backlash to what it was before. Honestly f you want you can run a pattern afterwards, but if it is a used gearset and was quiet before, just reset the backlash and it should be the same. Used gearsets may have less to than perfect patterns.
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I'm guessing you didn't read the whole thread? He is installing a used set of 4.56 gears.
 
SGBARRACUDA said:
I'm guessing you didn't read the whole thread? He is installing a used set of 4.56 gears.
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No, they are NOS. No markings on them to tell me they are US, Richmond or ?
<<They are US GEAR per the part number>>>
 
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SGBARRACUDA said:
...I would suggest making or buying a 489 set up bearing that slides on and off so you can change the pinion depth until you get it right...
Click to expand...
Ok, I do have an old bearing and race that I can clearance. That sounds like a great idea. I dont like the sound of pressing and pulling a bearing until I can get a good pattern.
 
Look on the back of the pinion gear for an etched number. Like .047 or something like that or 3.067.
Very first set of 4.56 gears we had set up in a 489 housing split the crush sleeve like a laser cut. Been using a crush sleeve Eliminator ever since then.
 
Jadaharabi said:
Look on the back of the pinion gear for an etched number. Like .047 or something like that or 3.067.
Very first set of 4.56 gears we had set up in a 489 housing split the crush sleeve like a laser cut. Been using a crush sleeve Eliminator ever since then.
Click to expand...

It says in scribe 73 and 2.767" ? I also was able to polish the inside of a good used Timken pinion bearing so it just slides on to the hilt so I can use that as a setup bearing..
 
pishta said:
It says in scribe 73 and 2.767" ? I also was able to polish the inside of a good used Timken pinion bearing so it just slides on to the hilt so I can use that as a setup bearing..
Click to expand...

Are you ready for my idea?
Take a pushrod or straight edge an mount it catty-cornered across the cap area.
It would be underneath the cap on one side of the carrier and the other would be underneath the cap on the other side of carrier so that the straight edge is above the back of the pinion.
Then take a caliper and measure from the back of the pinion to the bottom side of the pushrod or flat Edge.
Then you would add Shims in order to bring it up to that number that is scribed in the back of the pinion.
This is how aftermarket gears are set up. OEM not so much.
Anyway it won't hurt to try it.
 
Jadaharabi said:
Are you ready for my idea?
Take a pushrod or straight edge an mount it catty-cornered across the cap area.
It would be underneath the cap on one side of the carrier and the other would be underneath the cap on the other side of carrier so that the straight edge is above the back of the pinion.
Then take a caliper and measure from the back of the pinion to the bottom side of the pushrod or flat Edge.
Then you would add Shims in order to bring it up to that number that is scribed in the back of the pinion.
This is how aftermarket gears are set up. OEM not so much.
Anyway it won't hurt to try it.
Click to expand...
I think your onto something. I measured from cap line to pinion top and got 2.607. to get it to 2.767 Id need to sink it another .160? How would I do that? bearing is flush against pinion gears. Mind you I didnt torque it down but thats what Im reading when its just sitting in there with a few turns. Id imagine a few hundred lbs of torque on that nut would cinch it up a few thou...
 
With this tool. I have the same tool as in this video. If you ever plan to do it again, invest in this tool.
 
pishta said:
I think your onto something. I measured from cap line to pinion top and got 2.607. to get it to 2.767 Id need to sink it another .160? How would I do that? bearing is flush against pinion gears. Mind you I didnt torque it down but thats what Im reading when its just sitting in there with a few turns. Id imagine a few hundred lbs of torque on that nut would cinch it up a few thou...
Click to expand...

Did you happen to put shims under the big inner bearing race?
 
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