Ring and Pinion Set

[Zach 1981 Flareside]

Is this a good ring and pinion set for my truck?  I want to change my Ford 9 inch from 2.75 to 3.25.  I worry a shop would sell me cheapest gears they can find for a higher price, so I want to get this on Amazon to cut out middle man.  I'm worried about the spline count.  This one says 28 spline, and I don't know what I need.  

It's the only option from Yukon for Ford 9 inch 3.25. Is Yukon a good fit for my truck?  That's what NPD sells.

I plan to have shop rebuild, they say it takes 4 - 6 hours, and costs $100 an hour.

Thanks! Zach

https://www.yukongear.com/productdetails.aspx?ProdID=10261

https://www.amazon.com/gp/product/B0078UBX60/ref=ox_sc_act_title_1?smid=ATVPDKIKX0DER&psc=1

[85lebaront2]

Ok, first item, a Ford 9" is probably one of the easiest rear ends to set up, it is a removable hog's head (heavy) but once removed is simple to work on. Pinion depth is set after the pinion bearings are installed and pre-loaded, basically once you have the pinion bearings set and the assembly finished, you never remove the bearings again, the pinion carrier is shimmed in or out to get the correct pattern.

The ring gear is started in hard contact with the pinion, then one side (the side the pinion is on) the bearing adjusting ring is turned in to set the pre-load, once this is set the backlash is checked, if it is in tolerance, a grease based dye is put on the gears and a pattern is rolled (both directions, drive and coast sides) if the pattern is good, you are done. Any older Ford service manual from 1957 on into the 80s on trucks will have the 9" setup and patterns. I have set up a number of these for myself and friends and much prefer them to the integral carrier style (8.8, 10.25).

Ford describes their gear sets as Hunting, Partial non-Hunting and non-Hunting. The description is based on the ring gear tooth count divided by the pinion tooth count, 35/10 = 3.50:1 so each pinion tooth hits the same 35 ring gear teeth, but if you change the pinion to 9 teeth then you get 35/9 = 3.88888888888889 or 3.89:1, this is a Hunting gear set as each pinion tooth ultimately hits ever ring gear tooth. A partial non-hunting set will run most of the teeth meshing at some point, but no all. 39/12 = 3.25 which is probably a partial non-hunting set. Hunting sets as long as they are not damaged can be reused as they do not have to be "timed" non-hunting sets have to be "timed" and new ones will come with painted on match marks.

An FYI, Roush-Fenway racing will sell "take-out" 9" rear sets from their race cars at a pretty reasonable price. This will have timing marks if needed and properly set up will probably last a very long time as they are certainly either Ford OEM or the best aftermarket gears available.

[Steve83]

Zach 1981 Flareside wrote

...cheapest gears they can find for a higher price, so I want to get this on Amazon...

That's NOT a particularly-good brand of gear.  It's more like a budget brand.

Zach 1981 Flareside wrote

I'm worried about the spline count.  This one says 28 spline...

The only splines on the R&P are where the yoke slips onto the pinion gear.  But that spec refers to the axleshafts in the side gears, which is irrelevant to R&P.

Zach 1981 Flareside wrote

Is Yukon a good fit for my truck?

I wouldn't use them, but the brand name has nothing to do with the fit.

How did you settle on that brand from Amazon?  There are MANY gear suppliers, and MANY brands of 9" gears.  Did you shop Currie, Summit, Jegs, ebay, BroncoGraveyard, BroncoHut, Drivetrain.com, Moser, Boyce, Reider, Richmond...

Zach 1981 Flareside wrote

I plan to have shop rebuild, they say it takes 4 - 6 hours, and costs $100 an hour.

They think it might take them 6 hours to set up some gears?  You could LEARN HOW to do the job in less than 6 hours!  And it's a very specialized job, requiring training.  It sounds like they don't know how, so they're charging enough to cover their @$$3$ in case you sue them.  You can pull the chunk yourself, and take it to a shop that knows what they're doing.  Or another option to consider: send it off as a core, and just buy a reman chunk with the ratio you want.

[emunder]

Actually Yukon is not a budget brand at all...they are really good gears. Steve have you run them & maybe had just a bad experience with a set? In the Jeep world this is one of the preferred set of gears. They are heat treated, set up easily, & durable as hell. Only way you are going to get a stronger set of gears is if you send them out & have them cryo-treated. They also run them in the King of The Hammers race so that ought to tell you something about their durability.

I rock crawl locked & aired down with my Yukon 5.13's & I have yet to ever have an issue with my ring & pinion sets & believe me...they go through some punishment. If they are set up & broken in correctly you should not have any issues what so ever unless you are just getting crazy with the skinny pedal lol. Used to be most of the top brands were made by Superior including the Yukons which were just rebranded but not sure if that's still the case. If I were putting a new set of gears in I would go with Yukon, Motive, or Superior.

[Steve83]

It's hard to find gears priced lower than Yukon, which is the definition of "budget".  I have a local friend who has been installing gears longer than I've been alive, and he doesn't recommend them.  I've only installed Ford gears (which are substantially better than Yukon), but only when I had to (like when I was working at the Ford dealership).  Now that I don't have to, I prefer to pay him, and he recommended used Ford gears over any new ones, so that's what's in my Bronco now.



All gears are heat-treated, and a lot of the Jeeps in those races BREAK DOWN.  That ought to tell you something about their choices for parts.  I'll stick with Ford/Dana/Spicer gears.

[Zach 1981 Flareside]

How do I determine how many splines I need.  I'm trying to figure out if this set would fit my truck.  Thanks! Zach

[PetesPonies]

There are no splines on a ring gear. Only splines are on the pinion where the yoke attaches. I've never seen that differ on street gears. Axle splines are irrelevant in your situation. A R&P can be carefully setup in about 2 hours. 6 hours is a hose job !!

[ArdWrknTrk]

X2!

I've had a Yukon 4.10 R&P for the last dozen years.
It's been great!  

I did take the time to break it in and changed the gear lube at 500 miles or so.

I've been noticing that there seems a bit of lash/clank when on and off the throttle, but I drive it hard.  

Maybe I just need to check the pinion in my 10.25".
If I have to go deeper I'll look at switching to more support of the later long pinion.