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Do you ever use your truck anywhere other than pavement, or even in the snow? Takes you a lot further than simply donuts and burnouts.
No not really. Did'nt buy a $35000 truck to off road or race, call me crazy!
I do however tow a 28ft travel trailer, with no problems, but to each his own
"is the truetrac going to give me both tires spinning when i take a corner and give it gas and when i go up hills off road in 2WD?"
Spinning both tires while taking a corner will get you sideways whether you want to be sideways or not.
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I just mainly really dont like only the inside tire spinning on corners in slippery conditions like snow, i find myself putting it in 4WD alot!
4WD isn't a precious resources to be preserved for only the worst emergencies. It's a system that you already paid for that will seize up and fail if you never use it. It's especially appropriate to use in snow.
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Originally Posted by SCORCH
just did the RPO decoder and looked and there was no G80 code
You shouldn't need to feed it into the decoder to figure that one out. If you didn't type "G80" into the decoder then you definitely don't have the G80.
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Originally Posted by SCORCH
"is the truetrac going to give me both tires spinning when i take a corner and give it gas and when i go up hills off road in 2WD?"
"Spinning both tires while taking a corner will get you sideways whether you want to be sideways or not."
didnt mean spinning meant pushing so that it would eliminate the inside tire from breaking loose on wet pavement
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I just mainly really dont like only the inside tire spinning on corners in slippery conditions like snow, i find myself putting it in 4WD alot!
"4WD isn't a precious resources to be preserved for only the worst emergencies. It's a system that you already paid for that will seize up and fail if you never use it. It's especially appropriate to use in snow."
it gets its use trust me, i just prefer not to be running around constantly in 4WD in the winter; bad mileage and just more wear and tear
Quote:
Originally Posted by SCORCH
just did the RPO decoder and looked and there was no G80 code
"You shouldn't need to feed it into the decoder to figure that one out. If you didn't type "G80" into the decoder then you definitely don't have the G80."
i know that i just worded it wrong
but thanks everyone, i think i now have the understanding i was originally looking for
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1998 GMC Sierra SLE Z-71 5.7L 350ci chrome diamond plate toolbox, true dual exhaust into glasspacks exiting at 45's, AEM Brute Force cold air intake
well last night i went to pull in the garage and i spun the tires i little on the gravel(does it in both forward and reverse), this doesnt usually happen when there is no locker does it??
AND the BIGGER problem. to night i was riding a round and my finger slipped off the shifter into the push button 4x4 HIGH. went to take a corner and there was a ton of binding(harder to turn the wheel and took higher rpms to push the truck) way more than usual. The truck started to jump like the rear end kicked only every other second and the inside rear tire, from what i could tell, was squaking on the pavement everytime it kicked. This was the first time i had had it in 4WD in at least a month. a couple of friends thought it was the locker about to go but according to my codes in the glove box i have no G80. (whos to say the guy before didnt put a locker in, but as previously stated above, my inside tire and only inside tire slips a lot on corners and there seems to be no locker)
can i get some info here guys?
thanks
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1998 GMC Sierra SLE Z-71 5.7L 350ci chrome diamond plate toolbox, true dual exhaust into glasspacks exiting at 45's, AEM Brute Force cold air intake
well last night i went to pull in the garage and i spun the tires i little on the gravel(does it in both forward and reverse), this doesnt usually happen when there is no locker does it??
With no locker it's more likely that one tire spins and the other one doesn't do anything, but it is possible for both to spin without a locker. With a locker you're almost assured that they would both spin.
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AND the BIGGER problem. to night i was riding a round and my finger slipped off the shifter into the push button 4x4 HIGH. {...}
It sounds like you were merely in 4x4, not like anything special was happening.
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whos to say the guy before didnt put a locker in
Post a photo. Maybe it's visually distinguishable from the open diff (I don't know).
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my inside tire and only inside tire slips a lot on corners
What's the outside tire doing when the inside tire slips?
well last night i went to pull in the garage and i spun the tires i little on the gravel(does it in both forward and reverse), this doesnt usually happen when there is no locker does it??
AND the BIGGER problem. to night i was riding a round and my finger slipped off the shifter into the push button 4x4 HIGH. went to take a corner and there was a ton of binding(harder to turn the wheel and took higher rpms to push the truck) way more than usual. The truck started to jump like the rear end kicked only every other second and the inside rear tire, from what i could tell, was squaking on the pavement everytime it kicked. This was the first time i had had it in 4WD in at least a month. a couple of friends thought it was the locker about to go but according to my codes in the glove box i have no G80. (whos to say the guy before didnt put a locker in, but as previously stated above, my inside tire and only inside tire slips a lot on corners and there seems to be no locker)
can i get some info here guys?
thanks
Quit listening to your friends. You dropped your truck into 4x4 on hard pavement through a turn. What do you expect to happen?
If you are genuinely interested in knowing what's inside that axle, post a picture like Rick said. It won't take but a few minutes to yank that cover.
First post here: I have a 1999 Tahoe 4x4 w/ the 3.73 (GT4) and the G80 "locking" diff. I believe that it's finally died and I'm deciding what to put in as a replacement. The Detroit TruTrac seems to be a popular option, but where can I order one and how much? Also, I'm not sure if I have the 8.5 or 8.6 rear-end. Additionally, I'm a little skeptical about replacing the limited slip with another just to get the same results.
On the vehicle I drove in high school, 1992 "Z-71" I could spin both tires in the dirt, snow, etc. but it definitely didn't have a locker. A lot of the OBS trucks got those Z-71 stickers slapped on them for looks. Open diffs can, at times, spin both tires if there is little to no resistance, such as a dry gravel road.
You driving around that corner in 4wd sounds perfectly normal to me, it will bind and pop and make you think things are going to break if your on pavement.
As for shopping around for a locker, just check out the usual places. Summit, JEGS, truckaddons, the vendors on here, etc....They all should have them.
well last night i went to pull in the garage and i spun the tires i little on the gravel(does it in both forward and reverse), this doesnt usually happen when there is no locker does it??
AND the BIGGER problem. to night i was riding a round and my finger slipped off the shifter into the push button 4x4 HIGH. went to take a corner and there was a ton of binding(harder to turn the wheel and took higher rpms to push the truck) way more than usual. The truck started to jump like the rear end kicked only every other second and the inside rear tire, from what i could tell, was squaking on the pavement everytime it kicked. This was the first time i had had it in 4WD in at least a month. a couple of friends thought it was the locker about to go but according to my codes in the glove box i have no G80. (whos to say the guy before didnt put a locker in, but as previously stated above, my inside tire and only inside tire slips a lot on corners and there seems to be no locker)
can i get some info here guys?
thanks
Okay, really? You're serious here, right? You put the truck in 4wd, the front axles were locked in. And you were taking a corner...hmmm, yeah you were bouncing all over the place and it was harder to steer. You are driving a 4x4 that was locked into 4 Hi, you'll have that. FYI for future reference: A GM 4x4 has a slightly different gearing in the front axle than it does in the rear axle. When you are "locked in" (eg: in 4hi or 4lo), the front wheels are actually pulling the truck and the rears pretty much trail along until you loose traction up front. The front axles (when working properly and are stock) are truly LOCKED (meaning both wheels are going to want to spin the same speed at the same time). When you are turning, geometry and physics wants the inside tire to spin at a different speed than the outside tire, but this cannot happen when your front axle is engaged, so something has to give... in the case of a GM 4x4 on drive pavement in 4wd, that "something" that has to "give" just became the contact of your tires on the pavement since that was the weakest point in the picture.
As for your rambling on and on in this thread about your rear end... You have a typical limited slip rear end. I will bet you a cookie that if you jack the rear end of your truck up, put it on jack stands with the front wheels blocked so it doesn't roll away, have the truck in Neutral (and the ignition off OF COURSE!)... Turn the wheel on the Passenger side one direction, and I bet your Driver side tire spins the opposite direction. From the sounds of your knowledge of mechanics, physics, and sheer common sense, I suggest that your best bet is to take your truck down to your mechanic, and tell him to shim your rear end to tighten it up. That way, you will have "posi" (as far as you are aware) more often, but when you do something stupid like lock your truck in 4hi when taking a sharp off ramp coming off the interstate at 50+ MPH, your rear end can still be forced to slip instead of blowing up like a land mine in Iraq.
For your safety and that of those around you, steer clear of the wrenches and power tools... someone's going to get hurt.
With any good fortune, my future posts on this site will be more pleasant to read. I just really hate stupid people who want to "sup up" their cars/trucks and are not aware of what a Chilton's or Haynes manual is, let alone the actual working functions anything mechanical that requires even the most basic laws of physics. "Every action has an equal and opposite reaction." That's always a good place to begin your thought process...
EDIT: And I now feel like an idiot after scrolling back up and seeing ol' dude's last posted date in this thread... oh well, it needed said anyway
A GM 4x4 has a slightly different gearing in the front axle than it does in the rear axle.
Can you back that up with a reliable source? That's the first I've heard of it. I have experimentally used 4WD at speed on dry pavement and never had any problem while going straight; I assume it would bind after a while if the front and rear weren't perfectly matched.
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When you are "locked in" (eg: in 4hi or 4lo), the front wheels are actually pulling the truck and the rears pretty much trail along until you loose traction up front. The front axles (when working properly and are stock) are truly LOCKED (meaning both wheels are going to want to spin the same speed at the same time).
I wish my 2002 GMC Sierra 1500 4x4 knew about that. I've spent plenty of time spinning one front and one rear tire stuck in snow in my own damned backyard.
Can you back that up with a reliable source? That's the first I've heard of it. I have experimentally used 4WD at speed on dry pavement and never had any problem while going straight; I assume it would bind after a while if the front and rear weren't perfectly matched.
eg: Front Axle is a 3.72:1 while the rear is a 3.73:1. The front almost always has a slightly lower ratio gear than the back, this is designed to aid you in having better control (like steering the truck) in poor traction conditions.
I wish my 2002 GMC Sierra 1500 4x4 knew about that. I've spent plenty of time spinning one front and one rear tire stuck in snow in my own damned backyard.
Your vacuum actuator wasn't working properly. Mechanically, the front axle is open, if you had push button 4x4, when you pushed the button, your electric motor on the side of the case shifted the t case, and then the vacuum pod located under the battery tray(in most cases) locked in the front axle. GM had a TSB for a number of years on this issue, and it was a simple fix. From the factory, many of the GM's had the vacuum line from this pod routed as such that condensation would accumulate in a low spot in the loop, in the winter, this would freeze and A: Cause your 4x4 not to work at all, or B: Cause your front axle not to fully engage. This moisture freezing in the winter in colder climates could cause enough damage that you would still be left without fully functioning 4x4 in the summer as well.
I have owned dozens of GM 4x4 over the years, and every IFS 4x4 that I have owned has been the same in this area. The front axle was fully locked in when 4wd was engaged, and the front tires would try to "skip" across the pavement in the parking lot when turning. But that damn push button 4x4 always gave me problems that always ended up right back at the vacuum actuator or the vacuum lines controlling it. Typically, routing the vacuum line to where it does not have that "low loop" for condensation to sit in cures most of the issues with the 4wd...assuming the actuator isn't faulty when you re-route this line.
And as far as the turning radius changing, I can assure you it does. I have a 2000 Extended cab, long bed Silverado 1500 4x4 sitting on 34x11.50 Super Swampers (stock GT4 drive train, torsion bars cranked to max/level, no rub ) now, you simply cannot park her in a WalMart parking lot when she's locked in, but grab the stick and shove her back into 2wd, you can pull right in. And even with one front wheel off the ground the other is digging while the air born tire is still spinning when in 4wd.
If I've spent all that time digging and getting nasty kitty litter mud all over my winter gloves because of a malfunction, that would suck. I considered putting in a locking front diff but it was too expensive. This is the first I've heard of the stock diff being locking.
It's normal for 4WD vehicles without a center differential to skip and hop while turning on pavement, even if front and rear differentials are both plain old non-locking non-limited slip. That comes from the difference in speed between the front and rear axles.
Edit: Now that I think about it more, I vaguely remember reading about the slightly different front gearing than rear. If it's shorter 4.11 front vs 4.10 rear as you say, then the rear would push rather than the front pulling. As for the locking front; once after being really badly stuck, I posted asking which front wheel was more likely to spin in a low traction situation and nobody said they should both spin, they all just said whichever one has less traction would spin.
Front diffs on GM IFS are open, on everything from an 7.25" S-10 to a 9.25" 2500.
Word. Nothing wrong with your 4x4 system holycow, open front diff, in drive, front left wheel and rear right wheel will spin (if you don't have some sort of traction device in the rear).
Only consumer IFS with a locker that GM offers is in the Hummer H3 I believe.
Re: G80 locking differential questions
!
It sounds like you were merely in 4x4, not like anything special was happening.
