# Finally a 4WD



## FS552 (Jun 17, 2004)

My wife and I bought a 2000 4WD Suburban and can't wait to hit the beach for some good family fishing fun with our 4 boys.
Anything I should know about Suburbans and the beach?

Thanks...FS.


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## Argo (May 21, 2004)

stay on hard sand until you get it lifted a little with wider tires to disperse the weight a little. that is a heavy vehicle for soft sand and skinny tires. you dont want to get that thing stuck while in 4x4 unless you have a buddy vehicle of almost equal size.


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## animal (May 20, 2004)

nice one fred ! .... i would take that puppy to ziebart and get it undercoated before u hit the beach... and i would suggest some bf goodrich all terrain tires :smile:


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## FS552 (Jun 17, 2004)

About how much higher should it be and how much will it cost to get it lifted.
Right now it has 265/70/16 Michelins Cross Terrain SUV's on it, are those the same as all terrains? Will they work for now? They look brand new and it be kind of hard to convince my wife to buy new tires.

Thanks....Fred.


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## gundoctor (May 20, 2004)

Get the metric equivalent of 31X10.50 and you should have no problem. I run a set of those on my 90 suburban and until I started having trouble with the front drive shaft slipping, I never had any problems with soft sand. I also didn't have to lift the truck for that size tires.


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## Lou (May 22, 2004)

*Nice Ride*

Been driving burbs for over 10 yrs, They are better in sand than pickups because of the weight distribution. Look a Capt. Billy, he's been driving them for ever. 
To keep from buying tires invest in a good air pump, then you can just lower your tire air pressure to about 18 psi and walk across that sugar sand.
It will do alot better than you think the way it sits. Had a friend that drove one thru more than I would have tried with standard factory tires. 
Hve fun and catch a few big ones
The buddy system is the way to go on your first few trips.


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## shrky2413 (May 22, 2004)

Hey FS552,
Honestly it will probably suit your needs as is. First of all stay away from agressive tires. You don't want anything that will dig (wider would be great). I think a 2" lift kit would be a good idea. I used to play with 4x4's. I had a 84 Chevy swb pu with 4" susp. lift 2"body 300hp 350 4bm on 38 radial SuperSwampers. It was hell on wheels in the rice fields but you had to be carefull on the sand. If you need any further help let me know, I'll do all I can. Oh yeah bud thanks for the tip on the 3/0 wide kits. I haven't heard anything yet but I certainly appreciate the effort. Feel free to email me if you want. Hell of a nice ride bud. I'm happy for you.


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## Profish00 (May 21, 2004)

I have a 2002 sub,4x4 the lifts are very expencive about $2800 for 3" just because the push button controll it need a special part. I have BFG 285 70 16 
allterains and it looks sweet.


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## Argo (May 21, 2004)

285/75/16 or very close to it is a good size to go with. No mud terrain tires, they dig in the sand too much and will get you stuck before helping you. My first truck was a blazer w/ 38" swampers and it did alright but would overheat because the tires would do too much digging in the soft sand. You want weight distribution. My last truck was a chevy z-71 w/35 x 14.5" tires and 6" lift and did great but was overkill for a beach. The truck I have now is an expedition w/ 3" lift and 33" bfg all terrains and is suited perfect for the beach. Your tires should be fine but they are a little skinny is all I was saying. You should be able to fit 285/75/16 all terrains on it which is equal to 31/10.5" tires.


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## Argo (May 21, 2004)

BTW if you dont have the autotrack system in the suburban the lifts are not that expensive for 3". In the $500 range. My 6" on the z was around $2000 including installation but that replaces the entire front end of the truck. The 3" just gives you longer control arms or a drop pitman arm which cuts the cost of the lift significantly. If you have the Autotrack you are SOL on cheap lifts though. Autotrack is like all time 4x4. I have a similar all time 4 on my expy which is great on slick roads and dirt roads for handling but is hell on MPG


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## purpletdude (Jul 7, 2004)

I've got a 2001 4x4 Blazer. It's an s-10 and not near as heavy but has the same weight distribution. Very different than a truck. I put 30x9.50 BFG A/T and I love the look it gives my blazer but my stock Laredo tires did better in the soft sand than the bfg's do...they dig in ALOT more. It takes alot more gas to go a long way on the beach in soft sand...ie...PINS trip. I have slowed down fishing way up matagorda beach due to the gas situation. The big upside to the offroad tires is when your not in the sand. There are plenty of places around the beach that can bury you in a min. Having those good tires means the difference from getting out or getting your wallet out for a tow. I pulled a full size f150 4x4 out of the mud at high island. He had those stock goodyear wranglers on it...he was smart and didn't bury it so it was really easy to yank him out. A word about road driving.....I find the bfg a/t's to be very harsh on the road and also very hard to keep balanced...just my own experience. I actually like the road ride on the mud terrains better....just my opinion...


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## purpletdude (Jul 7, 2004)

One more thing.....do yourself and your suburban a favor and get some offroad shocks installed. i'm not a mechanic and I did it myself. I have the rancho rsx-9000x shocks. They are very adjustable for road driving or offroad driving, you can even get a switch to adjust the ride that mounts indash. They were very affordable considering how much they help your stock ride when getting into the beach driving environment. It can get pretty rough in the remote areas where you need a 4x4. The feel of the ride on my blazer is totally different now...much much better.


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## Argo (May 21, 2004)

I think the gas situation has more to due with lack of power in an S-10, I used to have one and moving to the bigger tires is a B. My expy sees no difference when driving on the sand to the road. Going to the end of pins and back would take me a about 1/3 tank maybe a little more. That is what I would get out of it on the road too. My old z would use half a tank but it was a hog anyhow. I really never sweat the gas thing too much though. My boat takes $200 plus for a solid day of fishing so I try to keep in all in perspective.


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## animal (May 20, 2004)

you could also look into a body lift... they are a whole lot cheaper than suspention lifts.. i got mine for something like $200.... and it was a 3 inch lift... i was able to fit 32x11.50 tires on there after that pretty easy... i could probablly fit 33x12.50's but dont want those cause i will eat up more gas..... these tires i have now run great in the sand even though i dont have 4x4 lol .... body lifts are pretty easy to install too... my friend and i put mine on in 2 days... but it should only take 1 lol


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## Argo (May 21, 2004)

I have had a body lift and they are good for looks but fall apart after a couple of years. They put extra stress on the mounting location on the body and after lots of offroad use they will pull out and you will start dropping the poly spacers out. I used my truck with the body lift offroad alot and ended up loosing 3 spacers total. Never had any problem with any suspension. The body lift is harder in my opinion to put on than a 3" suspension. There is alot of cutting and bracket relocation for the body lift. With the 3" suspension you put blocks on the rear and the hardest thing would take a couple of hours for an inexperienced person which is putting on either the drop control arm or spindle. Much sterdier than the body lift. Every truck I have had has been lifted. 1 with body lift 3 with suspension. I learned from my mistake with the body lift on the first one. Again if it is going to be used on the road/for looks mainly then you should be alright with the body lift.


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## FS552 (Jun 17, 2004)

Thanks for all the info guys, I really appreciate it. I don't want to get into any trouble down the beach so i'm really absorbing all this usefull info. My family and I drove down PINS this evening. We drove about 6 miles past the 4WD drive sign and drove through some really soft stuff. I pushed the 4HI right away and we went right through it. I don't know if I did the right thing or not but we did not get stuck.
I wanted to go further but I was traveling by myself with my family and we were losing daylight quick and didnt want to risk getting stuck in the dark.
Can you all tell me the when is the best time to use 4HI, 4LO, and Auto 4WD.
Also is the Auto 4WD drive the same thing as the auto track you all were mentioning earlier?
Oh and should I stop before I engage in either 4hi or 4lo? Or can I just push the button while i'm driving. If not, well I already did it once LOL. 
The ride was bumpy, but the boys loved it. The electronic lumbar support on the captains chairs came in usefull with the bumps.
What kind of equipment should I carry when I go down PINS. So far i'v come up with a shovel, Lou mentioned an air pump and gauge.
Oh say I get a flat how do I keep the jack from sinking in the sand while trying top lift the truck
I feel like i'm asking alot of dumb questions and i'm sure i'll have alot more but this is my first 4WD and I want the trips down the beach to be an enjoyable expereince.

Thanks....FS.


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## Profish00 (May 21, 2004)

For 4x4 low you need to STOP and put the trany in NEUTRAL then put in low only in extreme conditions. 4x4 high you can put in at all speeds to a certain 50 mph as far as auto 4x4 that is auto trac as we were saying.. it knows when there is slippage in the tires/differental I keep a strap and just a regular safety kit. flairs,firstaid kit, triangle. My F250 has a 12000 lb winch, but thats another story..for a flat..find some wood to stabilize the jack in the sand. hope this helps.. I have 3-4x4 trucks and believe in them!


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## Mustad7731 (May 23, 2004)

FS552;
I've been on the beaches in 4X4's since '75. I think that you new rig will do just
fine. One thing I would suggest you pick up is 50'-100' of 1" nylon rope. It makes
an excellent "snatch strap" that will allow others to help if required. If you can
put eye splices in each end that would be fine, if not learn to tie a bowline.
Jackie


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## gundoctor (May 20, 2004)

Fred, nearly all modern 4X4 auto trannys are still set up for running on pavement, not soft sand. The shift points are set at too low RPM for low speed driving in soft sand, so a lot of 4x4s overheat on the beach. 
When you are in soft sand, keep a eye on the temp gage, if it begins to climb, shift to 4X4 low. This will increase the RPM your engine is turning and make the cooling system pull more air through the radiator. Most people on the beach wait until they get in much worse conditions to shift into 4X4 low than they really should. 
Lugging along in 4X4 high through long stretches of deep soft sand is much worse for your engine, than the extra RPM you turn at the same speed in 4X4 low. Just because your truck has the power to lug through a bad stretch, don't mean you should abuse it by not downshifting. If its a short stretch, 1/4 mile or less, you're probably not going to hurt much by not downshifting, unless its really bad,


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## Catn' Around (May 21, 2004)

Argo said:


> 285/75/16 all terrains on it which is equal to 31/10.5" tires.


I'm pretty sure 25 millimeters = 1inch 
285/75/16 = 32 /11.50/ r16
265/75/16= 31/10.50/r16


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## Profish00 (May 21, 2004)

285x75x16 fill up the wells,but dont rub...They say a Goodyear ATS 305 will work as well, I have both and the 305 on my F20 seems just a little wider.


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## Argo (May 21, 2004)

*shrug* , 265's just didnt look that big to me when I had them on my Z to begin with.  I am sure you are right, 285's look better and have a wider track, that is the size I would say to use.


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## Freshwaterman (May 21, 2004)

Hey Fred email me so I can send the picture of the shark. Nice ride by the way.

magy

[email protected]


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## FS552 (Jun 17, 2004)

SSISharklady said:


> Hey Fred email me so I can send the picture of the shark. Nice ride by the way.
> 
> magy
> 
> [email protected]


Thanks...you have mail.


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## bigdav160 (Aug 25, 2004)

FS552 said:


> Can you all tell me the when is the best time to use 4HI, 4LO.


Your truck has a real 4WD system meaning you DO NOT want to use 4WD on pavement. It will bind up and if enough traction is available, something will break. Use it only in low traction situations.



> Also is the Auto 4WD drive the same thing as the auto track you all were mentioning earlier?


Yes, GM has named their push button 4WD system "Autotrac"



> Oh and should I stop before I engage in either 4hi or 4lo? Or can I just push the button while i'm driving. If not, well I already did it once LOL.
> .


Unlike other brands, 4Hi can be engaged at any speed. I've engaged mine doing 70mph after encountering snow and ice in the mountains of New Mexico.

4Lo can be engaged at speeds under 3mph. As others have mentioned, it is probably easier on the transfer case if you stop, put the transmission shifter in neutral, then put in 4Lo.



> and Auto 4WD


The best part! Normally the transfer case enters 4WD followed by the front axle engaging. Auto 4WD, engages the front axle first and in milliseconds uses clutches to engage the output of the transfer case if a speed difference is encountered between the front and rear wheels. You can drive in Auto 4WD on any surface at the penalty of slightly diminished fuel economy. It really shines when road conditions are changing like rain, snow and ice.


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## Profish00 (May 21, 2004)

"well said" welcome to the board. I always wondered how the auto works


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## Argo (May 21, 2004)

Big Dave, auto trac is not just push button 4x4 it is all time 4x4 that has a computer control telling it which wheel to send the power too when there is slippage including front wheels. I have a similar system on my ford and it is all time 4x4


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## bigdav160 (Aug 25, 2004)

> Big Dave, auto trac is not just push button 4x4 it is all time 4x4 that has a computer control telling it which wheel to send the power too when there is slippage including front wheels. I have a similar system on my ford and it is all time 4x4


Sorry to politely disagree. I worked for GM up through 1999. I spent two day of training on the autotrac system and it works just as I discribed. GM did offer an "all wheel drive" on the smaller trucks/suvs but not on the full size. Quoting from the training manual:

Auto 4WD: The transfer case control module engages the front axle. The transfer case utilizes a clutch pack similar to an automatic transmission. Under certain conditions the clutch pack is applied, locking the prop shafts together. If the transfer case control module detects a difference in front to rear wheel speed, it reacts within 200 milliseconds to apply the clutch pack.

2HI: The transfer case control module disengages the front axle and operates in 2WD HI only. In this mode the transfer case (NV246) operates exactly like previous 4WD systems in 2WD HI mode. Torque is transmitted to the rear axle only.

4HI: The transfer case control module moves the PWM motor to apply the transfer case clutch pack. It engages a clutch brake to hold the clutch pack in position, then engages the front axle. In this mode it operates exactly lke previous 4WD systems in 4WD HI.

4LO: the transfer case control module reverses the PWM motor. The motor moves the shift sector in th opposite direction into 4WD LO.

Neutral: Disengages both axles for towing.

A mode shift from 2HI to 4HI or Auto 4WD can be cmpleted in any transmission gear position and at any vehicle speed.

2HI, 4HI, or Auto 4WD to 4LO
4LO to 2HI, 4HI, or Auto 4WD can be accomplished only if:

The engine is running
The transmission is in neutral
The vehicle speed is below 3 mph
The transfer case motor/encoder signal is present.

Hope it clears it up.


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## Argo (May 21, 2004)

*4x4 Systems*

http://www.chevrolet.com/pop/blazer/4x4_systems.jspThe standard Insta-Trac 4x4 electric transfer case system (on 4x4 models only) lets you shift on the fly from 2WD to 4WD HI and back with the push of a button. An Autotrac 4x4 system is available on 4x4 models with an automatic transmission. Along with the ability to manually select 2 HI, 4 HI and 4 LO, when AUTO 4WD is engaged, Autotrac automatically transfers power between rear and front wheels whenever rear-wheel slippage is detected.


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## bigdav160 (Aug 25, 2004)

Argo, you are quoting the page from the smaller truck. (i.e.Blazer). I think they stopped using the manual lever 4WD in those trucks around '94.

The push button "Insta-trac" was optional then, I believe, standard equipment in '95 4WD Blazers. It used a vacuum motor/cable to engage the front axle. The similar Oldsmobile Bravada (and Astro Van) used a single speed "All wheel Drive" that was a "full time" system.

LOL, http://www.chevrolet.com/pop/blazer/4x4_systems.jsp shows the same control buttons for Instatrac and Autotrac. Only the Autotrac has the "Auto 4WD" feature.

The full size GM trucks have three systems available:

The single speed, full-time AWD in the Denali and Silverado SS. 
The manual lever, part-time 4WD that standard when ordering 4x4
The push button, part-time Autotrac that is optional.


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## Argo (May 21, 2004)

Tell me then what happens when you push the button to engage the auto trac system? I seem to remember having a Tahoe z71 with this option that I drove a little while and once I pushed the autotrac it put it in an alltime 4x4 mode that controled which tire got what amount of power. This is what my expedition now has except I cant turn off the AWD feature on it like you can on the z71. (BTW-I know ford and gm are two different things)


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## bigdav160 (Aug 25, 2004)

*Any Ford experts?*

Argo, I'm not an expert on the 4WD system Ford is using in the Expeditions (ContolTrac/AdvanceTrac). They appear very similar to the GM system. Both GM and Ford use a planetary geared transfer case that normally divides the torque about 40/60 front to rear. GM uses the clutches in the transfer case to lock it into 4WD. Ford slips the clutches in a way to allow even less torque to reach the front wheels if it is not needed.

It appears the BIG difference is Ford allows the front differential/driveshaft to turn all the time. Without locking/unlocking hubs this system must add friction and wear that would adversely effect fuel economy. GM has an actuator on the front axle that disengages the front axle from the wheels allowing it to act like any 2WD truck.:spineyes:


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## Argo (May 21, 2004)

The only thing that I was saying about the chevy auto track is that once you push that Auto 4wd button (autotrac) it is in AWDand the front and rear wheels will be getting power at a computer/traction decided level and this is different from 4HI. Right or wrong? Because of this autotrac feature it adds alot of cost to the lift.


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## bigdav160 (Aug 25, 2004)

> The only thing that I was saying about the chevy auto track is that once you push that Auto 4wd button (autotrac) it is in AWDand the front and rear wheels will be getting power at a computer/traction decided level and this is different from 4HI.


Yes and No. The Auto 4WD function works by engaging the front axle. At this point it is working like your Ford in 2WD. No power is getting to the front axle but it is turning. Once the Autotrac computer sees a difference in RPM between the front and rear (like 15rpm difference) it know to engage the 4WD transfer case clutches. GM claims the clutches in the transfer case can be locked up in as little as 200 milliseconds. The transfer case module then cycles the clutches ever 50 millisecond to release pressure on the clutches to see if 4WD is needed. If it determines there is no more slip between the front and rear wheels it releases the clutches completely basically returning it to 2WD mode except for the front axle being engaged.


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## Argo (May 21, 2004)

BTW my fuel mileage does stink.


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## FS552 (Jun 17, 2004)

Argo said:


> BTW my fuel mileage does stink.


Tell me about it. It took $44.00 to fill up the suburban yesterday. I ententionaly
let it run close to empty so that I coulld figure out how many miles per gallon I was getting. Turned out to be 13.65 miles per gallon.
Does that sound right bigdav160?


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## FS552 (Jun 17, 2004)

bigdav160,

So should I use the Auto 4wd button down the beach or just use 4hi or 4lo
when the conditions require me to use 4wd.

Also is it pretty much safe to say that my suburban is beach worthy just as it is?
Thanks to argo, bigdav160 and everyone else that has supplied their input.


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## Argo (May 21, 2004)

I would just the auto 4x4, I never lock my expy into 4hi unless it gets real soft and nasty. And yeah, go hit the beach.


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## FS552 (Jun 17, 2004)

Thanks argo,
BTW...how many mpg's are you getting on your expy?


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## bigdav160 (Aug 25, 2004)

> Tell me about it. It took $44.00 to fill up the suburban yesterday[\quote]
> 
> You should have bought a '92-'99 model Suburban. 42 gallons of fuel. It takes about $70 to fill mine up.
> 
> ...


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## Argo (May 21, 2004)

I get 11.5 to 12.5 mpg


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