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Pinion gear set up help

southernspeed

southernspeed

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I'm doing my diff gears and the instructions say to preload the pinion bearing by 13-15 in-lbs. My smallest torque wrench only goes as low a 40in-lbs.
Would I be right in thinking that 15in-lbs on the pinion shaft is really just getting rid of the free play? no percieveable drag at all?:xmas:
 
Pretty much. But if you have not done it before i would suggest you find someone to at least be there with you and give some pointers.

I have set up many gears and the hardest thing is pinoin depth in most cases. Not because it is difficult per say but it requires many steps to get it correct.

I would say the easiest is backlash. I can get it to between .005 and .010 usually without my gauges. You just learn to tell when it is correct.

When you think you have it set correct for pinoin depth and backlash then post up some pics of your pattern and we can tell you if it is good.
 
Thanks. Bit late to get some help in...I'm starting to re-assemble. I'm a motorcycle mechanic by trade so I'm hoping I'll be ok. I know it's going to be in and out a lot. It's a bit of a steep learning curve but that's what it's all about eh!!:thumb:
 
Well no one said it would be easy!! I just did a 1st dry run using the original pinion shims as suggested in the instructions (Yukon Gear) and it locked up solid! I only had 2 12thou shims in there! Out of time and knees hurt too much so I'll resume this tomorrow!:grin:
 
Thanks. Don't suppose you fancy a red eye to England?!!! lol.

I'll get there but it always takes ages when you're doing something for the first time and double checking everything.
Am I right in thinking that the contact pattern is 'almost solely' determind by pinion depth and moving the carrier to adjust back lash won't effect the pattern much?
Thanks for your help, much appreciated.
 
You are correct. The pattern is what will tell you how well you did with choosing the pinion shims.

The backlash can affect the pattern if it is way out, as in .100. You can check your BL before running the pattern if you want to. I usually dont unless the pattern looks way out.

BTW. What axle is this. 10 Bolt D44, D60....
 
It's a '78 12blt rear. Then it'll be the front 10blt next!

Thanks, see how it goes tomorrow.:waytogo:
 
Use the old inner pinion bearing to press on and off when setting up the gears. We have slip on bearings, which make everyhitng go much easier, and faster. As for the Pinion torque, cant help ya there, I do it by feel.

What kind of bikes do you work on?
 
pattern opinions please!!

I've had the pinion in and out more times than I've eaten Turkey over the last week and this is about the best I've got it.
With 8thou less shims the pattern was clearly too far away. With 5thou more than I have at the moment it was again VERY clear that the pinion was too close but this pattern looks good to me on coast but drive is a bit vaige.
It's a bit hard to tell in the pics but any input would be gratefully received!
This is with 5 1/2 thou backlash. Bit tight but shouldn't make a lot of difference to the pattern I wouldn't have thought.

pinion 001 copy.JPG

pinion 003 copy.JPG

pinion 007 copy.JPG

pinion 008 copy.JPG

pinion 011 copy.JPG
 
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The coast side looks good
The Drive side looks like the pattern is a little close on the toe side.

I would try increasing the backlash to about .007 or .008. If that does not make it better you should remove about .003 from the pinion shims and reset the backlash.

Overall you are doing a great job for having never done this before.
 
Hey Happy Birthday!:grin:

It's been interesting doing it but I'm now at the 'worried' stage. It's close but how close does it have to be?!!
Am I going to trash the gears if it's not spot on? Judging the patterns without having done it before is tough as they're a bit vaige.
I'll do as you suggest tomorrow and see how we go. Seems a bit strange that one side can be good but the other is off?!
If you don't mind I'll throw this back at you tomorrow for some more 'wisdom'. (as long as the Navy and your wife allow you some CK5 time tomorrow!!)
Thanks again for your help.:waytogo:
 
I know setting up gears is a PITA. Overall yours look good and you could leave them there without worrying about it.

You can have the gears off a little as far as pinion depth and not have any issues unless you run a high HP/Torque motor.
On the other hand if your BL is too tight or loose you gears will not last long at all.

  • Too tight and they will not get enough lube
  • Too loose and the ring and pinion will beat each other to death everytime you press or let go of the gas.
 
That's good to know anyway, thanks. I'll have another crack at the pattern tomorrow and try to get it better. And try to get the pinion gear pre-load right with the crush washer in this time.

And then there's just the front to do!!:haha:
Thanks again.
 
prepare ahead for the crush sleve. It is a bitch to do. Takes something like 300-400Ft/Lbs to crush it.

I will tell you to put some gear oil on the sleve. it makes it easier and will stop it from crushing crooked........ask me how i know.:D
 
Ok all back together, just hope I did it all right!!

Re set the pinion depth one more time and messed with the backlash a few times ending up with 7thou and these patterns.
Crushing the sleeve wasn't a problem but judging preload when you've got the seal on there too was tricky. Think (hope) I stayed on the looser side of tolerance.
Now all I got to do is the front!
I put a Lock-right in the back while I was at it too! click click click!!
HAPPY NEW TO YOU ALL!!

pinion1 002 copy.JPG

pinion1 005 copy.JPG

pinion1 009 copy.JPG

pinion1 011 copy.JPG
 
84_Chevy_K10 said:
Good job man.

Hmm, those gears look familiar. :D
Click to expand...
Thanks Tim. But I'm sure it said on the box that the vendor was going to fit them too! Imagine my dissappointment when I opened the box and you weren't there!!:haha:
 
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