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Where can I find the gear ratio on an "obs"...

Avery4jc

Avery4jc

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So I'm starting to think that somewhere along the lines there's been a screw-up... from the get-go I thought the tow rig had 4.10's because of some paperwork I read while we bought it but I did some math and it looks like it might have 3.73's...

It's hard to tell with these online calculators because I think the TC lock-up (or not locking up) is throwing it off depending on how fast I'm going...

I'm doing about 2150rpm @ 70 and about 1500 @ 50 (I've recorded others but those are all I can remember right now)... on www.4lo.com that works out to 31.5" tall tires if I have 3.73's but like 35's if I have 4.10's so I think something's up b/c my tires are about 31ish inches tall...

I have the Vin # but they don't put that kind of info. encoded in the vins do they? Anyways short of counting the teeth is it on a sticker anywhere?
 
RPO code decal in the glove box.

[SIZE=+1]GT4 : AXLE REAR, 3.73 RATIO[/SIZE] [SIZE=+1]GT5 : AXLE REAR, 4.10 RATIO[/SIZE]
 
GT4 w/ a G80 ewwww...

Well not like it really matters, I've been blown away at how well it tows but I was just currious about that original paperwork @ the lot we picked it up from... they listed some basic features related to towing and one was axle ratio, someone messed up along the lines somewhere... now I need to change my sig :)
 
if in doubt, just do the drive test. have a buddy count the driveline revo's as you drive 1 tire revo.
 
No I'm sure they're 3.73's... thats what the RPO code says and thats what the gear calculators say at a couple different speed vs. RPM....
 
I know, with 31ish inch tall tires I can't really hurt it but I've just heard/read so many horror G80 stories :) It still works though, when we were stuck in the sand this past summer it was lockin' up both back tires...
 
Avery4jc said:
I know, with 31ish inch tall tires I can't really hurt it but I've just heard/read so many horror G80 stories :) It still works though, when we were stuck in the sand this past summer it was lockin' up both back tires...
Click to expand...
yeah, but for a tow rig/occasional wheeler, you'll be fine. I've powerbraked my truck on the road in front of the house a few times just because, and I aint been able to break it. Both locked up, and countless time on slipery boat ramps, I've made it out in 2wd.
 
I wish my sister would get the friggin' pics off of her camera so I could show you guys a trip I took a couple weekends back...it was a "church retreat" but really it was just some people from church who spend the weekend in this sweet little valley with minimal houses (just so you're not sleepin' outside) but to get there you have to dive UP, yeah I said UP not through, a river... beneath the water its solid rock so I was having some serious fun out there with no weight in the bed and the big block you could punch it and drive sideways down the river and the G80 locked up every time...
 
Avery4jc said:
I wish my sister would get the friggin' pics off of her camera so I could show you guys a trip I took a couple weekends back...it was a "church retreat" but really it was just some people from church who spend the weekend in this sweet little valley with minimal houses (just so you're not sleepin' outside) but to get there you have to dive UP, yeah I said UP not through, a river... beneath the water its solid rock so I was having some serious fun out there with no weight in the bed and the big block you could punch it and drive sideways down the river and the G80 locked up every time...
Click to expand...
like i said, its not that bad
 
a g80 in a 14ff is a lot stronger that the ones in 10b's. i believe it is the 10b's that give them the gov-bomb name.
 
So are G80's like "in-house" built limited slips? Or are they bought from another producer?
 
avery what kinda mpg you seeing in the 2000?

the g80 in your 14ff should be fine.... especially for just a stock DD/tow rig if you had 42s and wheeled it that would be a diff story but like has been said 10 bolt g80s are the ones to run away from like an atom bomb
 
Thanks Masiony...


Cajun: It varies quite a bit depending on how heavy my right foot is but on average I'm at about 13-14 unloaded and as little as 7-8 with a full load pulling hills (10k pounds)...
Why? It just rolled 86k, is it time for some tune-up work? I've been kicking around the idea of getting a custom tune based off of data I record by Justin over on GMFS...

I need to keep a piece of paper in the truck and actually calculate the mpg over a couple tanks... I haven't done it in a while...
 
im just curious as a truck like yours is EXACTLY what my next truck will be and i was just wondering what to expect mpg wise from the 454... ill be happy with 13-14mpg because i only get 9-11 now. a custom tune is where its at imo whether it be nelson or westers, i think ima get a westers for the next truck, i wouldnt ever recommend a w4m tune to any one like the one i have on my 97
 
Yeah I love the "obs" crew cabs...the back seat is huge...
The only thing I'd like is if it was 4wd but other than that its been an absolutely incredible truck...especially with the big block, when we're not towing it doesn't even break a sweat. We had it pegged at 80mph+ on the trip from Cali to Texas and it never ran hot and was consistent the entire trip, not a single issue.

Plus if you only tow a couple times a year its hard to justify a $50k new diesel (it'd be nice but not worth it imo)...
 
oh damn i never even realized yours was 2wd! yea mine will def be 4wd... and im gonna go out on a limb and say that OBS crew cab short beds are my favorite trucks on the road to date:bow:
 
yep it was originally purchased for my mom to drive for a couple months and then my sister was supposed to take it out to Texas for college... well she can't drive to save her life so my mom was stuck with it for about a year, then when I came out I sort of took it since she was tired of driving it around (its a pretty hefty truck for a mom by herself) and she got an '07 Santa Fe'...

I pushed a little when we were buying it to wait out for a 4wd but they didn't want to... they said I'd just take it and start "fixing" it... can't argue with that so I shut up :)
 
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