Hot Rods Ring and pinion pattern?

Opinions on my pattern please fellas?! Just set up this ford 9"

Thank you in advanced




Sent from my iPhone using The H.A.M.B. mobile app

 

First of all, check the backlash of the gear (hold the pinion still & shake the gear) to make sure it's within specs. Probably around .008" - .012", but check to see what it should be, according to the manufacturer. If it's not, set to the correct backlash and try it again.

If the backlash is OK, then the pinion is too close to the ring gear. Change the shim .003" to .005" to move it away from the gear, reset your backlash and try it again and see what it looks like. The contact on the drive side of the gear should be a little off the toe of the tooth and centered more on the tooth between the top & root of the gear tooth.

 

Thanks tagman, I will double check my backlash but I believe it was .009. If it is within spec I'll change my shims and get some better marking compound tomorrow and give you an update


Sent from my iPhone using H.A.M.B.

 

My backlash was correct, so I change the shims as you suggested. I'm hoping to have some better marking compound delivered today. This time around I tightened my backlash a bit.




Sent from my iPhone using The H.A.M.B. mobile app

 

Coast side doesn't look bad, but hard to tell on the drive side. How are you exerting a load on the gear as you turn the pinion? You can't really duplicate the "as driven" load, but you should put a good drag on the gear.

 

Shoot some red oxide primer on the ring gear in three or four places, let dry for five minutes, & read. Washes off with solvent or thinner ...

 

I was just trying to add drag with my hands. I will come up with a way tomorrow to add a good amount of drag and hit it with primer. Thank you for all the help guys.


Sent from my iPhone using H.A.M.B.

 

If the pinion preload is set, that's enough resistance to read the pattern.

 

I would tend to agree with that.
You can add a bit more drag by holding your hand and a rag around the pinion flange dust shield or the stem of the flange.. then put a long box wrench on one of the ring gear bolts, and work the carrier back and forth until you see a pattern.

 

The pinion preload is set to 15 pounds with the new bearings. I took a weight with the rope and wrapped it around the yoke to add more resistance. As I turn the ring gear it picks the weight up. All I could find is gray primer....nobody in town had actual marking compound. Thank you for holding my hand in this process!


Sent from my iPhone using The H.A.M.B. mobile app

 

After it dried more I seem to get a better marking!


Sent from my iPhone using The H.A.M.B. mobile app

 

Coast side looks good. Only one pic of the drive side and it's hard to see what you have. I'd also like to see a pic of the pinion drive side. The drive side, obviously, is the most important, since 99% of your heavy load & driving time is on that side. Shoot for a good pattern on the drive side and the best you can get on the coast. You have to pretty much accept whatever is on the coast side, since to change them independently would require a change in the cutting & processing of the gear set.

Pre-load on the pinion, is NOT the same as working load on the gear. The greater the load on the gear (from weight of the vehicle upon acceleration, etc). will tend to make the tooth bearing contact spread along the pitch line towards the heel of the tooth. The ideal pattern would be full tooth contact at the heaviest load to support the tooth strength of each member, without any heavy concentration (heavy, dark lines) of load at the top, root, toe or heel of the tooth. It would be very difficult to check the contact pattern under full load, so we try for a contact at the toe, centered on the tooth surface.

Just for your info and to let you know where I'm coming from, I spent 38+ years working for the world's premiere manufacturer of bevel gear equipment (The Gleason Works) and spent lots of time in customer's plants troubleshooting tooth development problems on new ratios.

 

Off the top of my head but 15 in lbs seems low for new bearings ?

 

Okay, here are just drive side pics




Sent from my iPhone using The H.A.M.B. mobile app

 

Not too bad, but I'd like to see it a little more to the toe, so that under load it'll have room to move back towards the heel.

 

Almost looks like the pinion needs to go back in just a tad.

 

Okay, the last time I added a shim I added two because they were suck together :doh:!!!!!! Sometimes I'm my worst enemy!! Removed one shim and reset back lash to .007.




Sent from my iPhone using The H.A.M.B. mobile app

 

Some questions about the gear set you are setting up. Is this a new gear set ,or are they used and if so how much?

The reason being that if setting up a used gear set then using the factory lash settings are not appropriate. You will need to set the lash a little more loosely to account for the wear on a used gear set.

 

Good point, fredeuce. I had assumed a new set.

 

This is a new set. It's a 3.50 gear set if that matters.


Sent from my iPhone using H.A.M.B.

 

I think I need to pull one more shim based on my last photos, right


Sent from my iPhone using H.A.M.B.

 

If the shims are around .003", I'd agree with you.

 

I removed the shim and found one that was .003 thinner. The backlash is .008. I hope this is good! Looks decent...I think


Sent from my iPhone using The H.A.M.B. mobile app

 

Looks to me like you nailed it, my friend. Congratulations on spending the time & effort to get it right. You should have a nice, quiet set of gears that last a long time.

 

You have been instructed correctly , you really need to load the ring gear as much as you can . This will change the pattern drastically.


Sent from my iPhone using H.A.M.B.

 

Only thing I'll add is that I hammer the side adjusters in place, don't rely on the torque of the bolts and that little keeper to stay the adjusters. I have a spanner wrench and smack it with a hammer to tighten the side adjusters. They have to be super tight to keep your pattern and BL.

 

Late to the game, but this video is the best explanation of R&P set up that I have seen. Pretty consistent with the advice TagMan was giving you. You're done, but maybe it'll help someone else.

 

Thank you so much guys! I'm going to have a beer and celebrate!


Sent from my iPhone using H.A.M.B.

 

I agree with the video, IF the gear set was developed, cut & processed correctly. To correctly develop tooth contact on each side of the tooth requires lots of time & effort: the cutting head may have to be re-shimmed and / or the cutting machine settings be adjusted. This all takes time. A good contact in the soft, cutting, requires taking into account pattern changes that will occur in the heat treatment or hardening process. Development reuires making cutting changes, hardening, lapping and test driving them in a car or test machine. If the contacts are not right, you try another change. and do it all over again. The process can take weeks and, if it's a small gear company or a foreign company, they may not have the right cutting blades, expertise, time or money to do it right, so they develop the drive side and ignore the coast.

Bottom line, all gears are not made the same, so do your homework, check into the reputation of the manufacturer and don't buy a set of gears based solely on price.

Just my 2¢

 

we used to buy a paste like dark yellow "paint" in an art supply store and used it for setting up gearsets. it was cheap back in the day and worked well . pete.