Hello everybody!

I'm driving on a K5 1990. my front axle is GM 8.5" 10 bolt, and so is my rear axle.
Last week, while "offroading" my back-axle's gear, pinion, case and pinion's gears broke, and when i opened the cover i discovered a catastrophe.
now my questions are:

1. i counted 10 teethes on the pinion and 41 teethes on the gear - my the ratio is 1:4.10 right?

2. If so, then the front axle ratio is the same?

2. I'm riding on 33" tires, and I've been told that without a "Detroit Locker" the axle is to weak for me, is it true?

3. what's the best option for me? - buy a "Detroit locker" or replacing the axle, which will provide me a fair solution?

thanks in advance, Yarin.

 

Not a gear or axle expert but it sure sounds like 4.10 gears to me. And, yes, your front gears will be the same.

You should be fine running 33's on your axles as long as you don't get too crazy offroad. Spinning tires and sudden traction will tear up any set of gears/axles. What the locker will do is prevent the spinning tire, which will help prevent gears from exploding. It doesn't make the axle assembly stronger.

If your truck is also a DD, perhaps a better option is a selectable locker front and rear. They are a bit more $$$ but driving around town on a rainy night with a locker in the rear can be fun. Just takes a little getting used to.

 

by the way - why's the front axle is wider than the rear axle?
i know for sure that the back-axle is bolt 10 8.5", so what's the front axle? also 10 bolt on the cover

 

Your front axle is a GM Corporate 10-bolt as well.

As far as the reason why the front axle is wider than the rear, I am sure there is some good explanation somewhere, but this is how pretty much all GM solid front axle trucks are setup.

 

oh, so i'm not the only one with a wider front axle?
and is there a chance that the front is 7.5" and not 8.5"?

 

For your truck:
Front Axle:
GM Corporate 10-bolt (8.5-in. 1.28 Axle Dia. 30 Spline)
Rear Axle:
GM Corporate 10-bolt (8.5-in. 1.28 Axle Dia. 30 Spline)

 

ok. and what about changing the ratio to 4.88? the improvement is great or minor? plus will it effect the strength of the components involved?

 

Changing to a 488 is gonna make the axle even weaker the higher the number gets the small the teeth are. I have the same set of ten bolts I've had for like 9 years they have survived 2 k5s and one suburban running 38 inch tires and running a 400 engine. You just have to remember that you have ten bolts so you can't really beat the crap out of them. Your best bet is to upgrade to a 14 bolt rear if you have a lead foot those things are cheap and retardly strong. My 10 bolts are 373s and are running 33s under a s10 and I beat the hell out of that truck with no breakage yet 2 years later

 

ok so you're telling me to keep the 4.10s and with the detroit locker i'm planning to get i should be fine?

 

ok, i guess i was drunk when i counted the teethes, i made a mistake - i have 9 on the pinion, so the ratio of course is 4.56s.
and another thing - when removed the shaft to count the splines (28) - i realized that if the c clip will brake for any reason than nothing is holding the shaft, am i right? i i brake the shaft or the c clip off-roading the wheel will come right off??