Low geared t-case/high geared axle?

Thanks for the post Lynn,

Rich finding replacement gears isn't a problem I have extra gears if he needs them plus I know he has a stockpile of d-300 in his shop.

 

To date this particular component failure (tc gears) has only occurred 1 time.
Perhaps the occurrance was only a fluke like a defective forging or something.
Repeated failure of the same components under similar conditions is understood to be a weak link.
It is here that we strive to develope a complete and synchronous system.
Comprehending the ideal synchronous system; all components succomb to failure at the same time.
Example: The engine will throw a connecting rod, the clutch will slip, the transmission will explode, the transfer case developes a major crack, the axle shafts twist and the tires slip all at the same instant of time.

We all know that when push comes to shove something has to give !
One needs to have a fail safe to prevent expensive component failure.

Partly what I was inferring by the M715 reference is that Willys Motors had a fail safe built into their formula.
For all Jeeps the standard fail safe was realized as tire slippage.
Technically it is referred to as the co-efficient of friction.
Example: The CJ-3B was limited to climbing up a 51.5% slope.
Why ? Because the co-efficient of friction was approximated at point .6%.
See: http://www.film.queensu.ca/CJ3B/Photos/Engineering/CJ3BGradeability.JPG

Running large and sticky tires a normally low co-efficient of friction is drastically increased.
Like I say... given a 1% or greater co-efficient of friction a Jeep can potentially climb a 100% grade.
At 100% grade (45* angle) the force of gravity = I G. = No Go No Mo.
You need to determine your fail safe as something that is cheap and easy to replace.

That said do you drive this Jeep on the interstate ?
If so what is your preferred cruise speed ?
That speed can dramatically effect your choice of the optimum final drive ratio.
As you know increasing the final drive ratio will proportionately decrease the transfer case stress.
Your model 60 axles can surely take on more of the drivetrains stress.

 

O.K. scratch that; apparently this gear breakage has happened to many others.

 

This rig won’t see the interstate, possibly some back roads until I finish my grocery getter.

I was thinking tire spin (rockers = year to break in, still not a sticky) or the 1310-1350 combination u-joint would be the fail safe.

 

If road speed is a no issue then you should load more of the mechanical force onto the rear gears.
As I recall Dana made a 5.86 to fit the D60.
Of course the front axle model will also effect the ratio decision.

 

7.17 are the lowest aftermarket gears for a 60 that I know of.

I could run a 5.13 thick gear and still use my 4.10 carrier.

 

Gears came in last night.



I decided to go with USA standard gear because of the price, $50 less a set then yukon. Standard gear is yukon except they don’t do the final lapping with a fine grit compound that helps with break-in and run quieter and cooler. I won’t hear gear noise, if any, over the V8, and larger tires (won’t be at higher speeds as well).

Yukon/ USA Standard Gears are manufactured by Punjab Bevel Gears in Ghaziabad, India.

I’m excited about installing my first set of gears. The only draw back is the axles are mounted. The rear 60ff won’t be bad just slide out the shafts but I just finished buttoning of the front 60 so everything will be coming off again.

 

5:13's ?

 

Yes, 5.13's

You mentioned going 5.13's as well, I paid $155 a set.

 

what about set up kits ?

 

The place I got the gears sells the set up kits as well if your interested.

What I need I'll get locally.

 

Last weekend I finally had a chance to setup my rear 60. The numbers worked for me for this particular gear set and with a few adjustments I was good to go.

I swapped out the 4.10s for 5.13s. The case split is numerically 4.10 and down so I had a choice of finding a new case, thick cut gears, or spacer ring. I chose the spacer ring as the less expensive and quickest to my door step.

Spacer ring







I checked the BL in 4 spots and pattern in 2 spots. BL is .007, pinion preload 10 inch lbs.

 

Looks good. Periodically pull the cover and check the ring gear bolt torque. You did use red threadlocker and longer ring gear bolts right?


Sent from my iPhone using Tapatalk

 

Thanks, and yes used red. The longer ring gear bolts were included with the spacer.