Yukon ring and Pinion Gears
#11
I broke down and purchased a 3.70:1 Yukon ring and pinion set. They do look a little nicer finished than other brands I've installed in that Yukon polished the bearing surfaces on the pinion gear. Still a lot of machining burs on the ring gear. And no spec anywhere for pinion depth. Instructions say use trial and error method and has a litany of pictures with acceptable contact patterns. At least that's not as difficult on a 9" Ford. But, I like to know when I select a final shim I am close to what the gear mfg. wants for the pinion depth. The Motive Performance Gears (which I now believe are also US Gear) gives pinion depth specs and state the final pinion depth mush be plus or minus 0.002" of that spec. OEM gears also have pinion depth specs. Removes trial and error.

A little disappointed at this point. I don't know yet if I will use this Yukon gear set or return it. Have to digest it a little more. It was a bit pricey for what I got.
Reply
#12
I guess this is good news and bad news all in one post. I tried to find an answer for you and stumbled across this:

https://www.yukongear.com/downloads/manu...g_tool.pdf

It contains some calculations that will hopefully allow you to calculate the required pinion depth. Not sure if it will or will not for help you.

What's funny is the instructions has a disclaimer indicating the pinion depth setting is the responsibility of the manufacturers. Are you sure you don't have the settings? Sometimes they are right on the gears themselves.
Reply
#13
Apparently Yukon has changed something. The only number markings on the ring gear were 37 and 10 indicating 37 tooth ring gear and 10 tooth pinion for a 3.70:1 ratio. There were also on both the ring gear and pinion gear the number 244 to indicate a matched set. Pinion depths for 9 inch differentials are small numbers typically in the range of 1.020"-1.030" so 244 couldn't be for pinion depth.

The instructions that came with this gear set were completely different from what you found at Yukon's website. The instructions with this gear set said for all 9" Ford rear ends start with a 0.022" shim, set the backlash between 0.006"-0.010", and then trial and error with shims and backlash adjustments to get the correct pattern. I guess that's okay. But the mfg. lap the gears so why not provide the pinion depth.

After closely comparing these Yukon gears to the Motive Performance series 3.89:1 gears I have, the Motive Performance gears are at least completely deburred. I'll probably go back with the 3.89:1 Motive gears I have. They were quite and setup very easily. I just wanted a slightly different ratio. Did Yukon change manufacturers recently to reduce cost? I don't know.
Reply
#14
Yes very disappointing and I could imagine very frustrating for you at this point. The instructions I posted were for a pinion depth tool kit but it gave some Ford specs that I thought might be useful to you.

I have noted the pinion depth for an original Ford 9 inch rear to be 1.044 measured at the center of the axle. Not sure if it will help you but maybe it will give you a base line for a starting point with .022 shim recommended by Yukon.

You may also consider using the same shim set up you had with the 3.89 Motive gears as a starting point then set your backlash and see how the pattern looks.

I did some research online to see if others were having the same issue of where the mfg. pinion depth spec is located on the Yukun gears and seems others are asking the same question. Most of the responses to the question were to call Yukon. Go figure...
Reply
#15
I suspect Yukon made this change to eliminate returns due to noise when customers stated the gears were setup per their specs.

I always thought when the mfg lapped the gears they also determined the optimum pinion depth during the process. Who knows anymore with aftermarket parts.

In the process I did find out USA Gear (not US Gear) is owned by Yukon. They sell their lesser quality gears through the USA Gear brand.
Reply
#16
Interesting...let me know what you gear set-up you will go with. You mentioned you may stick with the 3.89's.

I will be going through the same ordeal is just a short time. I made more progress today with the cowl work. Much easier when you can just buy the cowl or patch panel.


Attached Files Image(s)
       
Reply
#17
Nice work. I wish I had more than a 2 car garage to work in. I've never been one to want to replace an entire panel when just a small patch needs to be replaced. My thought is leave as much of the original sheet metal there as possible. I'm old enough to remember when replacement panels were not available if the dealer didn't sell them. We use to make patch panels from doner fenders, quarters, etc.. Then good old body filler and glazing putty as needed to finish it. I don't understand why today so many jump to replacing an entire panel when a patch is all that is needed.

My plan is to recheck contact pattern and bearing preloads as I disassemble it. Hopefully I'll find something obvious wrong like the rear pinion bearing went bad. I might pull the pinion housing first to check the pinion bearings before going on to anything else. If everything looks good I am leaning towards reinstalling the 3.89 gears. I'll let you know what happens.
Reply


Possibly Related Threads…
Thread Author Replies Views Last Post
  3.25 rear gears vs 3.55 ? rindel 4 12,622 07-06-2016, 12:40 PM
Last Post: 1969_Mach1
  flywheel ring gear for 1969 351w automatic rindel 3 12,155 06-07-2015, 10:50 PM
Last Post: rindel

Forum Jump:


Users browsing this thread: 1 Guest(s)
[-]
Latest Threads
What's One More Iron In The Fire!
Last Post: fram lee666
03-18-2024 06:21 PM
» Replies: 125
» Views: 238050
"Jacobra"
Last Post: JTS71 Mach1
06-30-2023 11:13 PM
» Replies: 86
» Views: 150851
My old Queensland Ambulance
Last Post: JTS71 Mach1
06-30-2023 11:08 PM
» Replies: 5
» Views: 1685
New member from San Jose, CA
Last Post: JTS71 Mach1
05-09-2023 08:39 AM
» Replies: 12
» Views: 3956
Saving Seatbelts
Last Post: Jim
02-19-2023 10:23 PM
» Replies: 2
» Views: 9109
Sourcing new wheels
Last Post: JTS71 Mach1
01-25-2023 02:34 PM
» Replies: 1
» Views: 1995
Shaker Air Filter
Last Post: JTS71 Mach1
01-08-2023 02:24 AM
» Replies: 3
» Views: 1466
1971 Mach 1 parting out interior parts -...
Last Post: ylwhrse
12-22-2022 01:38 PM
» Replies: 0
» Views: 640
Painting
Last Post: Rare Pony
12-14-2022 06:24 PM
» Replies: 2
» Views: 1964
WELCOME ALL NEW MEMBERS INTRODUCE YOURSE...
Last Post: JTS71 Mach1
08-31-2022 01:36 PM
» Replies: 82
» Views: 157019
1970 mach 1 matching numbers
Last Post: Kstweeter
08-31-2022 10:31 AM
» Replies: 1
» Views: 1086
Brake booster/servo hose length
Last Post: JTS71 Mach1
08-23-2022 09:40 AM
» Replies: 7
» Views: 2993
New Member
Last Post: JTS71 Mach1
08-20-2022 11:18 AM
» Replies: 2
» Views: 1498
smooth window operation on 70 Mach
Last Post: CUSTOMMISER
08-15-2022 12:10 PM
» Replies: 2
» Views: 1472
Blinkers on solid
Last Post: busted21
08-09-2022 03:58 AM
» Replies: 14
» Views: 8715
Blinkers on solid when lights on.
Last Post: JTS71 Mach1
08-08-2022 12:06 PM
» Replies: 1
» Views: 1719
351 cj running hot
Last Post: busted21
08-08-2022 12:13 AM
» Replies: 5
» Views: 3403
Major Winter projects
Last Post: JTS71 Mach1
07-09-2022 05:12 AM
» Replies: 49
» Views: 21262
Happy Fathers Day!!!
Last Post: JTS71 Mach1
06-20-2022 02:34 AM
» Replies: 0
» Views: 1682
1969 Raven Black 390 Looking For
Last Post: mason1958
06-11-2022 09:48 AM
» Replies: 10
» Views: 15079

>