93 s10 Blazer transfer case issue???
 

I have a 93 s10 Blazer with the electronic-shift three-mode New Process model NP 233 (2HI-4HI-4LO) transfer case with an automatic transmission.
4x4 works great but slips for a brief second and then grabs hard when starting out in 4LO and whenever hitting the gas hard. In 4HI it works great(no slipping) but when the front tires are turned all the way to the left or right it starts grinding and makes the truck stop until the gas is pressed or wheels are straightened out then it's fine and when cruising down the road in 2HI or 4HI there is like a intermittent braking feeling I have since removed the front drive shaft and now it doesn't do the grinding when the tires are turned but it still slightly does the intermittent braking feeling I thought it was the front differential or CV axles but had them checked out by a mechanic and are solid and working great. the noise is coming from the transfer case everything engages and disengages great . The blazer runs and drives great as is but I would really like a reliable transfer case before the snow flies.Do I swap the transfer case out for another? and if so is a 2000 SR1 s10 Blazer transfer case the NP233? and will it work if it is? or do I need a NP233 transfer case from a 93 and older?

Really!! nobody can give some helpful advice?

might be worth pulling the back case half off the transfer case. might be a bearing failing. does it have oil in it?

yeah full

It could be the U-joints. And when in 4wd you don't wan't to crank your wheels unless your on snow! If your on pavement of course your truck isint going to wanna move. And are you putting it in 4lo when in neutral? Also have you checked your vacuum lines with a tester? you could have a bad switch or bad lines, just a thought.

It could also be your brakes grabbing and going bad. Check your u-joints then check your brakes.

First off, dont stomp the gas in 4lo. The ratio is too high and your trans wont shift that fast and all that torque isnt good for components, i belive the "slip" your referring to is it shifting, be easy on it in 4lo!!! Second, the truck isnt supposed to have the wheels turned sharply with 4x4 engaged. These transfercases arent even supposed to be engaged on dry pavement. Offroad or snow/ice conditions only. Turning the wheels sharply will make things bind up, 4x4 on dry pavement will cause damage to the transfer case. There is more drag on the system as a whole when engaged. As far i see, other than the braking feeling in 2hi everything is working as intended.

brakes are all brand new and all the U joints are brand new too I just don't understand the braking feeling the transmission had a HD overhaul 2 years ago
4x4 works great other than the braking feeling??

it will only go into 4lo when in park and I don't stomp on the gas like pulling up a slight incline it slips but only in 4o

sounds normal to me. the braking feeling is because of all the extra drag on the truck, got a extra axle spinning. and its also normal for the truck to basically hit the brakes when turning in 4x4 unless you are in some really low traction like mud or ice. with the tires turn the back tires are trying to go faster then the front and causing a binding.

if it did it when you were going straight its possible you may have different size tires from front or rear or different axle gears front and rear

First off, forum rules state that you must wait 24 hours of not getting a response to bump your own thread.

ok you say in 4lo you feel the drag like braking. thats ok because in 4lo it give you the best torque meaning more power to all wheels. in which you cant go over say 15- 20 mph. if you do then it will start to brake when you let off the gas cause of the low gear ratio. and if pushed really far the chain will start slipping and make a grinding noise and you will feel it lock up kinda and the abs pulsating the breaks. only use 4hi. 4 lo is only for climbin steep hills at 20mph or slower.

Forum rules? please
 

Really??? well that's just stupid what if it's an emergency and you need an answer asap? well I guess I'll stick to the one forum that everyone helps each other as fast as possible and don't give a darn about a measly forum rule about bumping your own thread before 24 hours .
If I can't get good advice here then I have a better forum to spend my time on to get answers. see ya!!! would hate to be ya! especially here lol!

It does the braking feeling in 4hi and 2hi I'm thinking it's something with the transmission cause even with the front drive shaft off it still does it slightly
possibly the torque converter???

I need you to describe the brakeing feeling more. It could be too many things, i find it hard to think its your transfer case. Torque converter shouldnt do that. Tell me when this happens, what does the engine do when this happens. I think it may be the engine causing this. How long have you driven the truck in 4x4 on dry pavement? You may have damaged it. As a transfer case goes these are reliable, its the systems that engage the front axle or the electric shift motor that fail. But since yours engages already that is a good sign.

when the rear differential was failing in mine, it had all the symptoms you are describing. especially the slight braking feeling.

ok so it feels like it breaks all the time in all gears. ok. now there is a rubber hose that goes from the metal brake line to the caliper on the wheel. a long time goes by and thos rubber lines start to fall apart on the inside out. and what happens is that all the rubber thats fallen apart inside that rubber hose is that it blocks the brake fluid from comming back up when you let off the brakes. feeling like its braking all the time. is your front pads worn? have you replaced them recently? go take it for a spin and a good spin like maby 15 to 20min drive. i know a waist of gas right. but when you pull into your drive way squirt water on the rotors where the brakes grab at. if it is so hot that it evaporates the water as soon as it hits then the hoses are probally shot. and need to be replaced. could also be a trans problem but i doubt it. check the fluid is it dark brown or as red as can be. on a piece of paper towel. also check fluid when warmed up and running. should be in between hash marks. i always fill mine a little above the full line.

There is a lot of play in the rear diff

The brakes never get hot they are all brand new. the transmision fluid is redish pink and I also have it filled a little above the full line

When I pulled the cover off mine I was shocked that every pinion gear tooth had a crack at its root and 2 were nearly completely gone. It still drove, just the odd squeak and clunk and the braking feel you described.

when I jack the rear end up off the ground I can grab the passenger side tire and spin it back and fourth a good 5 or more inches before the gears grab and start spinning the other tire the opposite way Im thinking that much play is not good?

Take off the rear diff cover and inspect it. If it checks out then hey you just changed your diff fluid. Have a feeling you may find something there.

yea they all have that much play in it. my 93 and 94 did the same thing when you spin the one tire when there both off the ground. and you would hear a loud clunk from the rear when you put it into gear if there was alot of play in it.

5" of travel on the face of the tire isn't bad, there is play in the transmission, T/C, splines, gear lash etc that has to be taken up before it will rotate the wheel the other direction.

Try this. Put the transmission in neutral, then jack up ONE side of your rear axle and spin that tire with the other still on the ground. There should be a little resistance and a slight noise from your transmission/transfer case area(kind of a steady whirring sound if i recall), but it should spin easily. If you have a factory locker and spin it too fast it will lock the clutches and stop the tire. What you are looking for is any type of inconsistent resistance or noise from the differential area. In mine i felt a slight clunk at what seemed like random intervals when i spun the tires described.

If its been a while since you changed your gear oil, it would be a good excuse to do so and take a close look and eliminate it as a possibility anyway.

did you get this figured out?

The rear axle had super clean gear oil in it and the gears looked great.
Im gonna jack up 1 tire with the trans in neutral and do the tire spin and see. otherwise I have no fricken clue what could be causing the intermittent braking feeling. I've had 4 other s10 blazers a 87,89,98,99 and never had this issue until this 93

Does thia braking feeling happen with ur foot on the gas? Coasting? Can it happen in neutral? While turning?

if the gears looked good, there's no sense jacking up the rear.

maybe transfer case as you first thought. might be worth taking a look. have you changed the oil in the transfer case? might have tell tale signs in the oil if a bearing or gear has failed.

i kinda had a braking feeling coming home on the highway the other day. came home and since i never checked the transfercase fluid on this 94 i popped the FILL plug and had a oil pan to catch 3 Quarts of tranny oil. it was 3qts over filled. the front input seal in the transfer case goes bad and over a long time it overfills the t case. anyway on the highway it felt like a whooo sound and you could feel it kinda. and felt like it was braking idk. but ever since i popped that plug its never done that again. i have a video of it here when i remove the fill plug.

the braking feeling is the motor if I hold the gas pedal steady while driving it does it bad and as soon as I let off the gas it stops There is no check engine light could it be the tps?

I checked the transfer case fluid along with tyranny and rear differential they are all at level and clean

do you think your braking feeling is maybe an engine problem? In neutral hold the gas pedal a little to hold it steady just a hair over idle and see how it holds that rpm.

maby the transfercase switch is stuck and alowing vacuum to the front axle actuator and engaging the front axle. find the vacuum line going in under the battery tray and plug it. cut it if you want and get an adapter from the parts store to splice it back together only a few bucks. if you dont cut it you will have to route it all the way down to the top of the transfer case or take the battery out then take the tray out to get to it. this is a weird problem id like to know what it is if you figure it out. its kinda hard to tell you over the internet rather than actually being there and driving it.

Adding a bit to the confusion.

I have many many miles in 4WD LO/HI and offroad in my Blazer S10 1994.

Technically:
2 HI = Rear wheel drive through 4 speed automatic transmission throught transfer case to rear differential to wheels.
4 HI = Adds front wheels through transfer case which connects short drive shaft to front wheels via chain. (Method of changing, manual/electric is pretty much irrelevant because in either case the internals on the transfer case and front wheel drive are the same.)

NOTE: The S10 features NO differential in the transfer case. This is the cause for the stalling in idle when turning on pavements which have some friction, such as paved or a solid dirt road. It cannot equalize the different speeds between front and rear wheels. Sometimes when accelerating a bit you get a jumping sensation in the car when the wheels start to slip to force an equalization.

4 LO = Adds a reduction in the transfer case which is applied to the drivetrain rear-/forward. This doubles the torque and cuts revolutions to half (approximately). This means you need double the engine rpm to reach the same speed. At the same time the torque is doubled which means that the symptoms such as acceleration or the jumping and rubbing of tires on hard surface is more pronounced as well.

NOTE: This kind of 4x4 is not meant to be used on dry or hard surfaces with good grip and full turns at tight radii. I use my steering wheel on this kind of surface only for 3/4 of a turn and eventually back up to get around tight corners in order not to stress the drivetrain. On slippery surfaces it does a hell of a job because you always get torque to front and rear end. E.g. I had a Mercedes M standing still once because one of the rear wheels lost traction and because it has a central differential all the torque could take the one way to the spinning rear wheel. Not the case in an S10.

Because of the high rpm in 4LO required to drive the same speeds and a change in behaviour of the automatic transmission when releasing the accelerator pedal you have a strong braking sensation. It should be that way because it is designed to climb steep and descend steep without the need for braking in off-road driving.
I've been up 25 to 30 degree slopes in nearly idle. I've been up 45 degree (100 %) slopes - scary and down nearly as much without braking. The only pretty useless thing in offroading in the S10 is the ABS.

Hope that helps a bit of understanding to some of the behaviour described in this thread.

Somebody able to add more?

Good rides, Marc