97 Tahoe 6 lug to 8 lug conversion

[n8in8or]

In another thread of mine, I mentioned that the craptastic Motive Gear ring & pinion I installed in the 9.5" SF 14 bolt howled on decal. The conversation about that quickly escalated from "get Yukon or AAM gears" to "put a 10.5" FF 14 bolt and never look back". I had briefly explored swapping to 8 lug instead of sourcing the rarer 14 bolt SF, but it didn't sound feasible. Now I'm hearing some people say things that make it sound like it COULD be feasible....which would be really awesome, I LOVE the idea of an 8 lug Tahoe!

I thought there was enough merit to this conversation that it deserved its own thread so here it is. I am going to attempt to add the posts from the other thread so we can hopefully pick up where we left off. Thanks to @FellowTraveler, @Husker6.5 and @SmithvilleD for their contributions so far....maybe this just might work!

 

[n8in8or]

I don't have any drone, but I do have some gear howl. Don't buy Motive Gear ring and pinions.

Yukon or AAM.

IMHO: Dump that rear and go 10.5" FF and never look back.......

I second that. Find a 3.42 and you'll have the best of all aspects.

I don't hate the idea of a 10.5 FF, but converting one to 6 lug is a bit pricy. Wouldn't you know that Yukon gears have dropped in price since I did gears last summer....

It would be a lot easier/cheaper to convert the front to 8-lug, just swap out complete steering knuckles, since you're at a parts yard anyway. Disconnect the ABS plug, unbolt the brake hose, pop the upper and lower ball joints, tie rod end and Voila! You now have a set of complete 3500 spindles, backing plate, rotor, caliper brackets and calipers in 8 lug bolt pattern to match your new 10.5" FF 8 lug rear!

If you go that far, go all out, & pull the parts from a GMT800 6.0 gasser truck. You get the modern 2 piston disc brakes/bigger rotors (gotta ream knuckles to fit GMT400 balljoints & a different outer tierod end). You can weld, so welding in new spring perches & overload bumpers at the narrower GTM400 width isn't super difficult.

You'll end up doing gears in rear diff as most all the 6.0 trucks that got the AAM 10.5/14 bolt have 4.10's. I went with AAM gears to get the 3.73 ratio I wanted - the OEM's choose gears that are quiet. Newer rear has a wider track width (~2.5-3") that better matches the 9.25 IFS front track width.
View attachment 47532

Huh, when I looked into this last year it sounded impossible to go 8 lug in the front. I even looked at Pirate4x4 because they do all kinds of crazy stuff over there. I would love to have 8 lug front and rear, not only for added strength, but it would just plain look tough! I may have to look into this further. Thanks for the info.

2WD, right? The easy and cheap way is just pull the complete knuckles off of a 2500 diesel or 3500 gasser/diesel and swap them. Of course, I would install new ball joints and tie rod ends while I had it apart, new calipers, hardware and pads, but that's just me. Everything bolts in easy-peasey, no reaming, welding, etc.

Oh, there's the complication, nope my Tahoe is 4WD. I still have a hard time believing it's not doable, but without a roadmap I'm not super passionate about taking the time to try to figure it out.....at least not right now.

Which front differential is in your Tahoe? If it's the 9.5", it's still just a complete knuckle swap. If it is the 8.25", let me do a bit of research and get back to you, it is doable, just a question of what needs to be swapped out to do it. GM wasn't stupid, rolling down the assembly line everything was bolt on/in as the vehicle went by. It may be nothing more than a knuckle and CV shaft swap, but I have a feeling it may mean swapping the differential, too. In which case it would mean making sure the front driveshaft front U-joint yoke matches the differential's, ie: a shaft shop cutting off and welding on a new one. Still, pretty much a salvage yard wrenching project.

 

[n8in8or]

My Tahoe just has the 8.25 front diff. It would be well worth it to go to the 9.5" front diff I think (other than the added time of trying to wrestle one out at the junk yard, however if I found a truck with the engine already out of it, it may not be that bad actually).

Also, in the fall of 2014 I completely rebuilt the front end on my truck. Now I have a clunk developing in the front driver's side...I'm afraid I have something worn out again already. It would be really nice to not only fix again, but upgrade with better parts. I went with Moog problem solvers, but I don't think they're all that they're cracked up to be come to find out.

 

[Big T]

Should be following this thread on GMT 800 14 bolt FF with disc brakes swap:

http://www.thetruckstop.us/forum/threads/project-rear-disc-brakes.45238/

 

[n8in8or]

Should be following this thread on GMT 800 14 bolt FF with disc brakes swap:

http://www.thetruckstop.us/forum/threads/project-rear-disc-brakes.45238/

Watching now. Thanks for the heads-up.