Buick Rainier, Chevy TrailBlazer, GMC Envoy

tlauro

Reading through the various posts regarding the rear lock up, it looks like it may be rear diff. thing....for locker equiped triplets anyway. Bravada's most likely will have the rear locker more often as it's an option on the TB and Envoy and they have to be ordered with it.

Any non-Bravada owners with a rear locker have this issue?

tlauro

I did a bit of checking and found that it most likely is the rear end...not the electronics of the A4WD or SmartTrak at Olds calls the same system....it's the Eaton Locker.

The system on the Triplets is set up with a flyweight governor that responds to differences in wheel speeds, and disc packs that are mounted between the side gear and the case.

Whenever one wheel is spinning substantially faster than the other, the governor spins rapidly, causing the flyweight to open. That flyweight then catches on a latching bracket and the lockup process begins.

During lockup, a self-energized clutch system causes a cam plate to ramp against a side gear. This ramping action compresses those disc packs mentioned earlier. The ramping continues until both axles - and therefore both wheels - are spinning at the same speed. This is full lock, and it prevents any further wheel slip. (Note: Axle lockup can only occur at speeds below 20 mph.)

The entire lockup process takes about a split second, and is virtually unnoticeable by the average driver. When both wheels regain traction, unlocking occurs and things go back to normal.

Check out http://www.torquecontrol.eaton.com/prod2.htm

for more and complete details.

paisan

" (Note: Axle lockup can only occur at speeds below 20 mph.)"

Does that mean that if you are trying to spin your way out of a mud-hole the rear won't lock-up?

-mike

tlauro

yep...one of the big things about the GM lineup is that I wish there was a limiter that would keep the rpm's down to avoid high speed spin off's like that. or better yet, if they would just Use a full electronic system to engage lock up. that would also prove safer for the 98% of drivers who don't go off road where a locker should be used...vs on the street in snow and ice where it can cause more harm than good in the hands of a 4x4 driver who has no practical experience or understanding of the systems use in real world applications. But that's just me ranting.

tomwilson1951

After leaving my wife's 2002 Bravada at the airport for seven days, we returned to find the battery completely dead. A jump got it running again, but I am concerned that there is a drain on the system. We will take it in later this week, but was wondering if this has been experienced by others? The Bravada is now one year old with 17k miles.

dkrdenvoy

I was quoted wildly varying prices on my 6yr/60K Major Guard plan coverage for my Envoy. The best dealer price (not where I bought my car) was $1295. GM does require you to buy the plan the "same" time you buy the car though so make sure you line up the deal ahead of time and watch the dates the dealer puts on the paper work. As long as it is within the same month (car & plan) you should be ok.

As I recall all the warranty providers plans prices went SKY high at 7 years and greater milage. Seems no one likes the long term outlook for these types of cars.

Tom

paisan

It's funny, the GM tranny on the Isuzus has a "winter mode" that will start you in 3rd gear when engaged, works pretty good for slippery conditions. That is a bummer about unlocking the diffy though, couldn't they have just gone with a traditional LSD?

-mike

rwspeicher

I had an unscheduled visit to the dealer today as my TB-LTZ went stone dead on Monday night. About 1.5 hours before the battery would only click the starter, my ONSTAR started sending out touch tones, with the key out and car off. I was unable to call ONSTAR after that, fortunately the car was in the garage, and not on the highway. Tuesday morning the car started like nothing had ever happened and ONSTAR was completely operational, they could not find any problems via diagnostics. They seemed to know that the problem occured at about 7:30 pm ... that's very interesting.

I also have the wandering mirror problem and showed the dealer the posts from "Tlauro" regarding the fixes - he of course informed me that I didn't have the easy/exit seat option set to on and that is why my mirrors don't restore properly (BS). Guess I will have to spend some time with him, going over mirror movement. Maybe I should use a Laser pointer with a target on the headrest "CBS/CSI" style to prove my point. Why are these guys so thick headed ?

tlauro

The Triplets utilize 2nd gear start. Just drop the tranny in 2 from a stop and it starts in second. Drop the gas pedal down a bit too far and the system will drop the tranny back to first gear though.

paisan

Yeah similar system as the subies use. Although theirs will not do anything but 2nd even when hitting the gas real hard. Which bummed me cause I used my dad's legacy to race Auto-x and couldn't put it in 2nd which on older cars did 1-2, so had to use 3 which does 1-2-3.

-mike

tlauro

I know the feeling...I Auto X and run my GTP at the track. 2nd actually holds the gears so I can shift, where 1 or 3 shifts by computer and 500rpm's too soon. Costs a good 2 tenths in the qtr.

paisan

Nice, what if you put it in "1" and just let it upshift at redline? Or would it bounce off the rev-limiter. I've seen some cars where it auto-upshifts if you hit the rev-limiter and some where it just bounces. What does the GTP do? And as long as we are on Pontiacs, I am considering going for the new GTO when it comes here. I've been lusting after a commodore SS for years!

-mike

tlauro

Putting the GTP in 1 causes shifts at orange not redline...500rpm short. Keep it in two and you'll hit the end of redline and full S/C Boost (7.5psi stock...I run 11.5psi) It also causes redline bounce at the end of 2nd....so if you're stock....you'll just barely clear 92-94mph depending on your Reaction time at the tree...but I run over 102mph so I have to watch the rpms and shift to 3 manually to make the best runs.

tim
1999 GTP @ 13.689 (Bone Stock Best of 14.667)
2000 Alero "GT" @ 15.591
2002 Trailblazer LTZ @ 15.675

spdmtr5

Could you use the hand brake to drop the speed at the rear wheels thereby allowing the LSD to function?

tlauro-Have you done any more with your TB exhaust?

funits

My Envoy has a locking differential and I have noticed a "shutter/chatter" from the rear wheels ONLY when making a left hand turn from a complete stop -- generally coming off the interstate and only lasting, at most, 1 second. Does not happen if you go straight ahead or make a right hand turn!!! Doesn't happen 100% of the time either. Of course dealer could not reproduce and they checked: fluid levels in rear end, brakes and tires -- all o.k. of course. If this problem gets worse I will take the mechanic for a little trip and reproduce it for them.

archdukerizzo

Well, this happens on my 3 month old Bravada all of the time now when I turn and go slow.
I have an appointment next friday to have ALL of my issues checked.
HVAC blowing cold
License Plate Gasket
Roof Rack (the passenger side front cap is warping upwards)
Fan at startup problem
Weather Stripping on back hatch is coming off
and this turning problem

So we'll see how things go when they look at it.
I'm expecting multiple "Can not duplicate problem" responses on the workorder....

mytrip2

My Envoy has 25000 miles on it. It does exactly the same thing as you described. Don't think it would do any good taking it to dealer for check. I have only noticed it about 6 times in a year.

tblazed

I am a ham radio operator and plan to install a dual-band (2m/70cm) transceiver in my TB-LS with a Larsen glass-mount dual-band antenna mounted where the OnStar antenna would go. Has anyone here installed a 2-way radio (amateur, CB etc) of any sort in one of these vehicles and if so, have you had any erratic operation from the computer or any of the systems while transmitting?

paisan

I've used several name brand through-glass CB antennas and found them to be worthless. I'm sure you probably know more about radios and such than I but you might want to try a hard-mount antenna for the ham radio.

-mike

cmack4

I haven't been in a mud hole with the eaton gov, but I have used it in loose sand. As long as you exert some control, the 20mph limiter shouldn't be a big factor. In fact, if you start out slow, and feel the locker engage, it doesn't disengage until traction is either restored, or you let off the throttle. After you feel it engage, you can give it a pretty good blip and it will stay engaged as long as traction is limited.

paisan

Oh, ok, I thought it would disconnect @ 20mph ala the 4wd cutout on the MDX at 20mph and the Yoda/MB tractioncontrol override that re-establishes itself over 30mph. My concern was if you entered a mud-hole locked up the rear, and hammered down the throttle in "1" or "2" and spun up the wheels to 25mph at 20mph the rears would unlock leaving you sinking in a whole!

-mike

tlauro

No new exhaust mods or trials. Back to running the Stock setup until I can find a bit more time to play. Vacation is on my brain and I'm preparing for that. Perhaps in June or July.
I'm going to look at changing out the suspension a bit and perhaps new rubber. Not sure.
Definitely want to get rid of slack in the curves.

paisan

Do you guys know of any triplets that have been modified/lifted for off-road use yet? If you have any websites etc. that would be cool.

-mike

ficuss

tblazed: given the unpredictable nature of some of the failures expressed on this forum, I would hesitate to install any medium/high power RF devices in any triplet. The drive by wire accelerator, and the multiple computers may be vulnerable to interference caused by the transmitter. There is a reason for the unexplained failures, G.M just hasn't found it yet. Who is to say that the engine shutdowns on the hi way aren't caused by some CB r or other transmitter next to the car. I also have a Mitsubishi Diamonte. Every time my cell phone rings when I am in the car, a relay under the dash chatters. I don't know what the relay does, but it is unnerving.

Frank

tlauro

I wouldn't say that the unexplained failures are due to the computers or controls in the TB being interfered with by other electronics.

With so many signals in the air it would be very evident and massively widespread. Heck I've driven behind state troopers with 7 antennas on their cars..who knows what all they are for, but surely there's enough stuff there on top of the radar gun in their lap to cause cancer to me in my SUV...but's never shut down my truck and I drive all over.

Of course I suppose it's possible, but not likely IMO.

YOU WROTE:
tblazed: given the unpredictable nature of some of the failures expressed on this forum, I would hesitate to install any medium/high power RF devices in any triplet. The drive by wire accelerator, and the multiple computers may be vulnerable to interference caused by the transmitter. There is a reason for the unexplained failures, G.M just hasn't found it yet. Who is to say that the engine shutdowns on the hi way aren't caused by some CB r or other transmitter next to the car. I also have a Mitsubishi Diamonte. Every time my cell phone rings when I am in the car, a relay under the dash chatters. I don't know what the relay does, but it is unnerving.

bricklayertx

I saw a TB (LS) in a Home Depot parking lot last week. Out of state plates, large logos on the back and side (Levellor/Rubbermaid). Curious so I hunted down the rep and asked him for a comment on the TB. He said it had 24K miles and had never had a problem. Said he 'loved' it. Said the company has approx. 300 in service with no serious problems.

For what it's worth. At least it's an upbeat entry for a change

pauleul

For any who want to know the part number on the tailgate/license pocket gasket (seal) that GM says doesn't exist, here it is:

P/N 15170981

It is in stock and ships from Flint MI

Many Thanks to,

Kirby (Body shop Manager)
Larsen Motor Co.
McMinnvile, Oregon
(800) 434-6199

At least there is a GM dealer who can give customer service even when GM itself can't! Now all who care can stop the paint chipping.

flopes

Pardon me if I'm being dense about this but....
In my 02 SLT, Bose w/6 disc changer, when I first press the auto volume button the display reads "Auto Volume Off". I press it again and it changes to "Auto Volume On". If I wait a few seconds and press the button one more time it's reverted back to the "off" message. I've even tried setting a radio station immediately after changing the auto volume to "on" by holding the station number in till it beeps, a'la setting the EQ settings for individual stations and still no joy.
I don't notice any difference in volume when I speed up or open the windows as I'm driving. I still have to turn up the volume manually.
I'm beginning to think this feature isn't working.
Has anyone else run into this, or is this working as intended?

Thanks

jepping

flopes: I have the Bose system in my Envoy as well. The auto-volume works as you explained. I believe the system turns on or off each time the button is pressed and I don’t think the preset buttons memorize the auto-volume status. However, I can certainly feel the difference when it is on, it works great and I hardly have to make any adjustments. There might be a problem with your sound system

pcrisp

Thanks for the info and part number! I hope that this is definately the right part. Then we can all sleep at night. Something funny, if this is the exact part, GM Parts Direct instantly popped up the item when I typed in the number and it is located in the "Tailgate" Category, and the Description is "SEAL". However GM big shots don't know that they actually make it. CRAZY! For info, the GM list is only $8.50, Parts Direct price $5.10. What's funnier? When I checked the shipping cost from Part Direct, I was stunned to see that if you order it by itself, it would cost $40.00 just to have the little piece of rubber shipped! Just interesting info. I'll let my GM service dept. take it from here. Thanks again to pauleul and his service dept.

tlauro

cool!

I'm still chip free on my black LTZ but will note the part number and potential fix. I'll stop by my dealer who helped resolve the wandering mirrors and have them get one on my truck well in advance.

Can someone email me good clear pics of what the damage looks like.

Also if I could get a close up of a Triplet with the gasket installed that would be cool. If not, I'll look on their lot in Thursday.

thanks!

tim

n2sjx

I had my dual band HAM radio in my '99 Jimmy with a through the glass antenna by Midland and it worked great! I am going to install the same antenna on my Envoy this weekend. I never had any problems with interference of any kind. I agree, with all of the radio waves and cell phone (Onstar waves) out there in this Universe, I really don't think you should have a problem.

JK

d2000one1

I stopped by a dealership today and took a look at the Envoy XL. I must say that this is an impressive vehicle. I sat in the 3rd row seat, which is by far the most comfortable 3rd row seat I've ever sat in. I'm 6'4" (mostly legs) and I had no problems getting in or out the 3rd row, and there was plenty of leg and head room while sitting in the seat.

If I needed a 3rd seat, I would definitely trade in my Envoy for the XL.

paulpro

I have installed a Nokia in-car kit with the antenna about 6 inches ahead of the On-Star antenna. No problems with either phone and the added electronics does not interfere with any other on-board electronics.

My phone used to create interference with my older (98) Jimmy radio but I haven't noticed it with this unit. As long as your grounds are good, I wouldn't anticipate a problem.

Paul P

gam2

It may very well be the rear end causing the problem. I pulled the 4wd fuse and I still had the problem. Reading about the locker however, I doubt it should operate going 2mph in my driveway.
It did not do it for the first 1000 miles. Maybe the unit has hung up somehow. What have others done to fix a similar problem? I can't say I trust technicians working on a differential.

GAM2

dshepherd3

I am pretty sure that you can purchase that warranty any time before 3/36, try gmpp.com, I believe you can get further info there.

dshepherd3

The Eaton g80 locking diff has had a history of staying engaged when not needed, you are feeling the clutches locked/chattering, try driving in slow figure eights to disengage, either way this is not normal, we used to put in a special posi-type additive to help this, but the dealer should be involved, this "no condition found" business is unacceptable, they know what this is.

vindog45

i bought 4 what they call "clean wheels" on my LTZ rims (on the inside)......look great!.....no more brake dust problem, and you dont see ugly disc brake pad thru rim either.

mrau

.. I posted some gasket photos on 4-7-2002. Should be post #4790 or #4793.

Thanks for giving us all the part # !!!!

Mike

iexplore2000

Okay.. now that we have access to the official gasket part number, anyone have any idea as to how complicated it would be to install this little do-hicky thing-a-mabob?? I am a little nervous with the idea of having to remove that center piece and whatever else that might be involved, but on the other hand, I would rather risk it instead of taking my Envoy to the dealership for it to end up with a couple of "Oh were did those come from" scratches! ha, ha..

Anyone care to take pictures of the installation and post them to this forum for us non-techie people to have a gander???

Thanks!

IExplore2000@aol.com

envoy2002

1700 miles on my Envoy; 4.10 axle; Highway driving in Central Ohio (Columbus to Dayton = ~ 70 miles)with (I shouldnt confess this)speed ranging 70 to 80, with occaisional gusts of 85 to stay with the pack)leveled me 18.5 to 19.5 mpg. City driving tends to average 14.5 to 16.5 mpg. Also, I purchased the 5 yr/75,000 mile GMPP warranty for $1290 with a $0 deductible.

dkrdenvoy

When talking about buying the warranty the same time you bought the car I was unclear. All dealers would sell me a warranty up to the 3 year mark but not at the same price. I am assuming the warranty cost will rise (based on this forum anyway ). Do what you feel comfortable with.

One dealer wanted more money because it was two weeks after. This could have been a ploy to up the price or make me buy sooner. The dealer I did get the best quote from also dated the sales agreement the day I bought the car. Maybe it was just less paper work that way.
Tom

sbindley

As part of a mild build-up on an Envoy SLT for Truckin's SUV Magazine, I had my truck run on the dyno yesterday with interesting results. Baseline testing on Project Envoy resulted in 193 hp at the rear wheels. It was hot and ths engine only has 1,000 miles, but that would not explain a 30-40 flywheel hp loss. I have not seen any other tests, so I don't know if this is common or not. I do know that our last project truck, a 1999 Blazer, was 30 flywheel hp overstated by GM across the board - hundreds of 4.3's only made 139 hp at the wheels. The good news is that the torque curve is very flat and that dyno owner Kenny Brown of Kenny Brown Performance said, "What a great motor, terrific for a six." He was not aware that it was supposed to me making much more power. He smiled when I told him as he is a leading Mustang tuner and recalls how poorly the previous Corbras were performing, causing Ford to recall them and add power pieces to make up the difference. If anyone has access to a dyno, please do some runs and see if there is a problem that GM should know about.

Scott

pcrisp

Has anyone installed an additional amount of wood (plastic) to their Envoy or Bravada. I have thought about purchasing a kit just to add some accents to the interior of my Bravada. Wood Dash Factory has an 18 piece ($173) add-on kit that says is "factory match color". I was just wondering how matched they truly are. I suppose that GM probably bought the original wood accents from some other manufacturer like this to begin with. Any info or pics would be great! Thanks.

drobin59

Thanks for the info on the gasket!

Now, how can I get my wandering driver's side mirror fixed? I gave them the part number that previous posts talked about and they ordered it - said it was a new mirror but had to call GM Tech line for help in installing it? Huh?

Thanks!

tblazed

Not sure how gmpartsdirect came up with a $40 shipping charge for a $5 gasket, but I ordered the front and rear mud guards from them 3 weeks ago, and the shipping/handling was 14.97. Came in a big box too. Maybe you calculated next-morning delivery?

spdmtr5

Could you tell us more of your modifications?If not,when is the planned publish date for the article?I'm glad to see more posts about changing and improving the new stovebolt.

pcrisp

I don't think that I was checking for next day shipping. I just checked again and it said the same $40 shipping if bought by itself. If you bought one set of mud guards with it, it went down to $20, if you bought 2 sets of mud guards, it went down to .92. My dealer is doing it for free so I guess that it doesn't matter anyhow. I just ordered mud guards straight through my dealership yesterday because the total will be $51 and I will have them tomorrow. If I would have ordered them through Parts Direct the total would be $50.62 including the $14.92 shipping. Paying 38 cents more isn't a big deal to me, plus I may even get them sooner than through parts direct. When I order running boards, I will definitely go with Parts Direct.

pauleul

For those who wish to "do it themselves".

Go to post #4765 (enter 4957 in the Msg# Go To box on the top of this page)for directions. You will need a 10mm Deep Socket, not just a 10mm socket (at least I did). Once you've loosened the pocket insert, you should be able to slip the gasket (seal) in, then re-tighten the nuts. I took it apart just to check it out and attempt a temp fix last week. I take my truck in tomorrow at 8 AM for the dealer to put the real thing in. Will post how it goes. I intend to assist since I have taken it apart and the dealer hasn't done one yet. Be careful when you go to put back the inside plastic cover. There is a clip in the center that doesn't want to hit the slot. I reached in with a thin bar to push it forward and line it up. It then popped right in. All in all, it is pretty easy.

For a picture posted here showing the gasket installed, go to post #4793 (enter 4985 in the Msg Go To box on the top of this page).

Anyone wanting more pics (with gasket) or (with chipped paint) showing, give me your email and I'll send them to you.

paisan

I've seen a bunch of DIY fixes for the Triplets on here. I wonder if you can back-charge GM for all the repairs!

-mike