Hi all,

I dropped off my rear carrier for some work today. Hopefully it only requires resetting of the backlash and adjusting some thing to hold the ring gear tighter. But, if the tech gets in there and decides I need new gears, I have some questions. I am pretty sure I have the 4.30 gears and the tech likes to use Richmond gears. Looks like they only have 4.10 and 4.88 for my truck. What could I expect from going from 4.30 to 4.88 and keeping the same tire size? Would I be happy with that? Would the spedo be off much? I probably would NOT want to go down huh? Thanks!

P.S. I realize I'd have to regear the front too...

 

Only thing that would bother me is if I did a lot of highway commuting. Other than that, you'd be pretty happy with the extra "power" from the gears.

 

Your RPMs will be very high and yes your speedo will be off. I really did not like driving my 4.88s with 285/75s due to the high RPMs at highway speeds. Around town and on the trail (low speeds) they were awesome but I had a 75 mile daily commute. I now have 4.88s with 315/75s and it now drives a lot closer to stock.

Don't let the techs personal preference for gears force you into a bad gear ratio. If I were you I would stick with your stock 4.30s.

 

Thanks to both of you. I was unaware that Precision made 4.30 gears for the third gen. I was aware that they seem to be pretty good based on some other posts I read. I don't think the tech would make me regear just because his preferred supplier does not carry my ratio. I just havn't actually talked to him yet because Pops dropped off the carrier with him today since his work schedule is a little more flexible than mine.

 

I've searched diligently for after-market 4:30's to no avail. Could you tell me how you know for sure that Precision has them? They aren't listed on their website.

 

Sorry, I was incorrect (it has been a while since I looked there). The set I saw was for the 4 cyl 8" diff. You are correct that PG does not have 4.30s for the 8" V6. My previous post is edited.

 

Damn. Oh well, I really would like to have access to some new ones. The junkyard supply is dwindling as we speak. I have some from an automatic 4 cyl I managed to nab up.

 

I think I read 4cyl gears will work with shims is that correct? I am guess that they must not be as strong as the V6 gears...

 

if the tech is in there and is insiting on changing the gears (might as well do it), go with 4.56's. yukon/motive/precisions are good. slightly lower than stock and since you've got the 75's and not the oem 70's...that should bring you back to stock. i've got the same setup as bighead...although i havent ridden on anything but my 35's on 4.88's..i'd imagine it'd be buzzy at cruising speeds over 65...

 

Oh yeah...anything over 65-70 mph with 4.88s and 285s had the RPMs a bit higher than I liked. It was pretty gutless at those speeds...I had to have great conditions for me to pass another vehicle at highway speeds.