Change from 2:73 to 3:73

[yevgenievich]

In 89 f bodies got better axles for the 10 bolts and it remained same for 4th gens. 9 bolt was stronger in 3rd gens but not by much. 10 bolt can hold but it has a lot more chances at failure when paired with t56, 4.10 or higher gears and slicks.

 

[MikeB]

8.2 split?

8.2" 10-bolt carriers are 2.73 & down, and 3.08 & up.

 

[MikeB]

I just have to jump in again. Do not confuse 73-87 C10/R10 8.5" 10-bolts with the 7.5" & 7.625" 10-bolts used in S10 pickups and lots of passenger cars, including 1982-2002 Camaros and Firebirds. They are totally different animals.

For example, the 7.5" 10-bolts used wimpy 26-spline axles, whereas the 8.5" 10-bolt uses larger diameter 28 or 30 spline axles. The 8.5" also has larger bearings and 3" diameter axle tubes vs 2.5" diameter for the 7.5". However the 7.625" was a little stronger than the 7.5" because it used 28-spline axles and a larger pinion head bearing.

There is a also an 8.2" 10-bolt that was used in passenger cars beginning with the 1967 Camaro (except for high-perf engines, like 302 and 396). It was a little stronger than the 7.5", but not by much.

.

 

[bucket]

And again, the capabilities of a 10 bolt under a 2wd truck tend to be much greater than that of a 10 bolt under a 4x4 truck. Larger tires and more traction can really do a number on a stock 10 bolt.

 

[4WDKC]

Are these the goofy 9 bolt things they put in the Camaros and Fbirds? Or a for real 10 bolt? Also look what the GNX guys are doing with 10 bolts granted they have 30 spline axles but it's still the same housing.

the 82-02 fbodies had the 7.5 that was also in the s10s and g bodies, the rare exceptions being the aussie 9 bolt in the 3rd gen Irocs, the v6 4x4 manual tranny s10s and the Grand Nationals all had the 8.5" 10 bolt. The 2nd gen fbodies also had the 8.5" 10 bolt and while it is stronger than the 7.5 it is easily breakable especially in heavier vehicles.

 

[shiftpro]

Yeah I was bitching about my 3.73s thinking it was gonna be the end of the world once I put the 33" tires on it and how I needed to switch to 4.10s and all, but once I put the 33s on it I realized it's not so bad.

Once that rear end I put back together without shimming properly starts to go bad and needs to be replaced (been over a year and several thousand miles with no issue, so it may be a while) I probably will still go for 4.10s at that point, but for now there's no real noticeable loss of torque and if anything it just helps me cruise on the highway a little easier.

Long story short, the 3.73s are working out just fine with the 33s.

I'm glad your happy with your setup but I respectfully disagree my friend... regarding your current gear ratio vs lower.
I realize driving around town the difference seems negotiable, but hit highway speeds, headwinds, snowstorms, towing and passing
and then the obvious becomes... obvious.
But yes it's a lot of work and expense for seemingly little gain. Always depends ultimately what and how the truck is used.
Wish you the best of luck regardless my friend.

 

[Wildjoe330]

8.2" 10-bolt carriers are 2.73 & down, and 3.08 & up.

I must be a blessed guy I am changing my 14 bolt GM from 4.56 to 3.73 stock size tires for using around town. I have the ring pinion and Carrier just looking around to see whats needed before I open it up. I was just looking for a dial indicator and wondering if I could get away with not using it?

 

[Honky Kong jr]

I must be a blessed guy I am changing my 14 bolt GM from 4.56 to 3.73 stock size tires for using around town. I have the ring pinion and Carrier just looking around to see whats needed before I open it up. I was just looking for a dial indicator and wondering if I could get away with not using it?

You could but not advisable. You need it to set back lash. If it were a toy I'd do it by feel but being it's a road truck I'd use instruments to set it up. You will need a dial inch lb torque wrench as well a beam type works too dial is easier to read.

 

[Wildjoe330]

You could but not advisable. You need it to set back lash. If it were a toy I'd do it by feel but being it's a road truck I'd use instruments to set it up. You will need a dial inch lb torque wrench as well a beam type works too dial is easier to read.

Thanks HK that sounds good to me, so far I haven't found a loaner dial. My kit came with 8 shims that feels pretty good to me. The service shim seems to be .018 to .019 it was a temptation to just slap the original back in there.
I was looking for the service #'s on the pinion and can't figure it out what do you guys think?
4 on the face or 2 over on the tooth???

UPDATE: I found out that it could also be a zero on this one for the shim size.

You must be registered for see images attach

You must be registered for see images attach

 

[RecklessWOT]

I'm glad your happy with your setup but I respectfully disagree my friend... regarding your current gear ratio vs lower.
I realize driving around town the difference seems negotiable, but hit highway speeds, headwinds, snowstorms, towing and passing
and then the obvious becomes... obvious.
But yes it's a lot of work and expense for seemingly little gain. Always depends ultimately what and how the truck is used.
Wish you the best of luck regardless my friend.

Well I wouldn't say I'm happy with it, but I am no more unhappy with it now than I was before. Yeah I mean it has lost a little bit of oomph (which it never really had much of to begin with) but it's not terribly noticeable. I can still pass cars just fine and get out of my own way, it can even still spin tire a little (which I've only done once just to see if it still could, lol I'm already on borrowed time with that rear). I've towed a couple cars with it since then and it's not so bad. Definitely not ideal and I'd like to gear down eventually, but at this point I am in no rush to do so. Basically all I was saying is that it's not as big of a difference as I thought it would be going from 31s to 33s.

 

[MikeB]

Thanks HK that sounds good to me, so far I haven't found a loaner dial. My kit came with 8 shims that feels pretty good to me. The service shim seems to be .018 to .019 it was a temptation to just slap the original back in there.
I was looking for the service #'s on the pinion and can't figure it out what do you guys think?
4 on the face or 2 over on the tooth???

The only way to know for sure that pinion depth is correct is to read the drive and coast patterns. However, it's very hard to get a decent pattern on used gears. Checking the coast side pattern is usually the best way to go.

As for backlash, dial indicators with magnetic bases are dirt cheap. And very cheap insurance in the long run. And by all means, use a 0-60 in/lb torque wrench to check pinion bearing preload before you install the carrier. On my next R+P job, I plan to use a Yukon Gear crush sleeve eliminator kit. It consists of a spacer and set of shims.

Good tips on R+P setup here: https://www.ringpinion.com/TechnicalHelp/contentframe.aspx?filepath=~/content/parts/ringandpinions//four_critical_ring_and_pinion_settings.inc

 

[Keith Seymore]

And again, the capabilities of a 10 bolt under a 2wd truck tend to be much greater than that of a 10 bolt under a 4x4 truck. Larger tires and more traction can really do a number on a stock 10 bolt.

I've still got the original 8.5" ring gear 10 bolt in my Chevelle. Been racing it for 39 years, most of those 12.0's and quicker.

Presently has MW spool, axles and C clip eliminators. Best ET is 9.85 @ 136mph, at 3900 lbs (a little under 1000HP on motor).

K

 

[bucket]

I've still got the original 8.5" ring gear 10 bolt in my Chevelle. Been racing it for 39 years, most of those 12.0's and quicker.

Presently has MW spool, axles and C clip eliminators. Best ET is 9.85 @ 136mph, at 3900 lbs (a little under 1000HP on motor).

K

That's a very good example you've got there. I'm curious though, how long did you run the stock carrier and what were the power levels then?

And I'm betting that thing hooks pretty well too, doesn't it?

 

[Honky Kong jr]

I've still got the original 8.5" ring gear 10 bolt in my Chevelle. Been racing it for 39 years, most of those 12.0's and quicker.

Presently has MW spool, axles and C clip eliminators. Best ET is 9.85 @ 136mph, at 3900 lbs (a little under 1000HP on motor).

K

But 8.5s are junk .........cough cough.........28 spline or 30?

 

[bucket]

But 8.5s are junk .........cough cough.........28 spline or 30?

In a 4x4 used like it should offroad, yes.