Help needed with Gear pattern.

[Guest]

[Marlin]

I am trying to learn how to do this myself and I need some oversight.

-New FRPP 4.10
-New FRPP 31 spline trak lok
-Old housing from random 97 Mustang GT
-.033 Pinion spacer (Was in rearend)
-.015" backlash (Unable to reuse stock shims)

Not the final pinion bearing. I honed an old bearing for fitting and I need to pre-load the carrier barriers.

I have tried other combo but I get weird results. I tried this with less backlash and it looked strange.

So what do you think of this pattern.

[mmb]

If that was jsut one swipe and not multiple pattern checks you are just fine run it!

A trick to the pinion is to measure the old pinion and shim....   Then measure the new pinion and shim it so it is the same as the old....  That will put it in the same spot. 


Good Job 

[mj88stang]

15 thousandths backlash is kinda high, but the pattern doesn't look too bad. but you don't have the bearings you're going to be using in? so i'm sort of lost here as to why you did that.

[scienceguy]

You said 0.015" backlash...  and you're using new gears?  That's a little excessive for a brand new ring and pinion.  If this were a used R&P that was already worn in, that BL would be more in line.

What did it look like with a tighter setting?

Sometimes gears take a LOT of trial/error...  which would be a bit easier if you were dealing with a 9". 

Good Luck!

[mmb]

Nothing wrong with .015" especially if you are drag racing and putting a lot of rpm through the rear.

[scienceguy]

Nothing wrong with .015" especially if you are drag racing and putting a lot of rpm through the rear.

With the t-lok, I was under the -assumption- it was a street car. 
It is a bit on the loose end. 
He can try it and see what happens...

Good Luck!

[Lightnin McQueen]

The pattern looks ok. With .015" backlash the gearset could be noisy. If it were me I would try and get the lash around .008-.010". 

[mj88stang]

new gears, new bearings, i want  .008. but  .015 isnt the end of the world. but with new bearings  .015 is going to increase as the bearings get worn in.

[Marlin]

Gentleman thank you so much for your input. It has been very educational.

This is .010 backlash. This is also with final bearing and final assembly of the Pinion with same .033 shim.

[mmb]

That pattern is staggered and not going to work.   With that pattern the pinion needs to move out of ring gear (thiner shim)

If .015" backlash gave you a pretty pattern.... That is what I would run.   Have you checked runout of ring gear? Is .015" the max?

[Marlin]

This is .015 back lash with the .033 shim. What do you think?

The runout is less than .001 and .015 is the max backlash. I am not trying for .015 it just seems where I end up with the shims.

The difference between this pattern and the top pattern is this is the final bearing and I have established pinion bearing preload with the solid spacer.

Now I think it looks like my Pinion is too far away and I need more spacer. So if I increased the thickness of the pinion shim slightly do you think it is possible to reduce the amount of backlash and get a better pattern? I feel like I am chasing my tail.

This is the original pinion spacer and the same thickness of carrier bearing spacers on the ring gear side as the original one. The carrier is lightly wider then the removed one.

[Marlin]

Gentlemen I appreciate all the help. I decided to stop bring a pussy and went and tackled this thing. After torquing down the bearing caps I found it made an improvement in the pattern so after preloading the carrier bearings I was able to get a good pattern with .010 backlash. Now on to other projects.

Thanks.

[mmb]

Make sure you are checking patterns the way it will run in the car, preloaded on the bearings.

That was my next question, glad you got it figured out!

[Joel5.0]

Make sure you are checking patterns the way it will run in the car, preloaded on the bearings.

That was my next question, glad you got it figured out!

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