4x4

I just bought my truck, a 95 with the 4.3.

I was driving along and shifted it into 4hi from 2hi and it took no problems. When I tried to shift back to 2hi the light flashed several times but did not shift. I came to a stop and tried again, same flashing except this time I heard a clicking noise and the lights in my truck flickered. Went straight to the parts store, checked the fuse and it was burnt. Bought a 5 pack and burned through 4. Drove home and parked it for the night. Driving it was somewhat like driving with the ebrake on. A friend suggested that the hubs were perhaps partially disengaged.

When I awoke I ran out to my truck and tried it, sure enough it shifted to 2hi. I followed instructions from my manual on "calibrating the transfer case" or whatever and shifted to 4hi while in neutral, then shifted to park. It shifted back to 2hi no problem, but I'm not touching it again until I know what's wrong. Drives no problem now.

Any ideas?

It probably sat forever, wherever you bought it from. It may just need a little "exercise" to loosen it all up again, but now that you are the new owner...

I would change all fluids and filters ASAP. Cruddy fluids in the transfer case contribute to shifting problems. Front and rear differential fluids should be immediately replaced, and then looked at at least once a year, fluids changed completely at 2 1/2 to 3 years.

Welcome to the forum and the madness of owning a Blazer! I keep a grouchy '95 LS running as a daily driver with relatively little problem. These trucks are high maintenance, but treat them good and they'll always get you home. :)

I'll get on that. I've been working on doing the simpler/cheaper maintenance first. I have most of my own tools but I don't have a garage anymore, so I often don't have much choice in when I do things like oil changes. For someone who is fairly handy, but hasn't done much more than do the typical wires/plugs/cap/filters type stuff, how difficult is it to change the transfer case and diff fluids? I have a friend who worked in a tranny shop and he said that the transfer case is damn messy.

It can be messy the first time, the fluid wants to rush out in one go through one huge plug hole. Remove the top filler plug first, this not only vents the case but ensure that you can fill it up again. Then remove the bottom plug and have your catch pan close. It's going to drop a little over 2 quarts nearly all at once. :icon16: Pour in some fresh fluid to flush the case and any residuals left behind, and then insert your bottom plug. Fill it up with Dextron-III Type-H and it's done. I refilled mine with Redline Dextron-III high temp fluid. Again, pricey, but the synthetic fluid helps in gas savings. You fill it until fluid starts to dribble out of the top hole.

For the differentials, the front will have to be pumped out. I have a $12 hand pump from the local Autozone and put 2 feet of hose on it. Angle the hose in through the filler plug until you hit bottom and then pump the gear lube out. Refill with 75w-90. I suggest a good GL-5 rated synthetic like Valvoline. Pricey, but it pays for itself in gas savings. (I paid $9.00/quart for it at NAPA)

The rear can be done the same way. You *may* unbolt the rear cover to drain it, but I find it less messy to pump it out through the fill hole and you can skip re-sealing the rear with a new gasket if it's done this way. Fill the rear with the same GL-5 75w-90. In both instances, one would fill up to the bolt hole until it just dribbles out. If you opt to take off the rear cover, the gasket can be had for $3.00. Remove the bottom and side bolts completely, loosen up the top bolts just enough to break the seal. Use a soft faced hammer to bump the cover off it's seal gently. Let it drain with the bottom of the seal broken and then remove it completely. Use a copper pipe flattened at one end (Central Air conditioning 1/4" tubing works GREAT for this) with a hammer as a gasket romoval tool, use acetone on a rag to soften up what does not scrape off easily and scrape again, or use a wire brush. (Brass bristles, never steel!) Put down a bead of Permatex Aircraft sealant on the faces of the differential carrier and the cover plate and let dry in the open for 15 minutes. Seat your new gasket on the cover plate and use two bolts pushed through the holes to hold the gasket in place untill you can bolt it back to your pumpkin.
Permatex "Black" oil proof silicone sealant also works well here. If you use this; lay the silicone down in a bead that also surrounds the bolt holes and immediately place the gasket down on it and then bolt it on snug.
When you inspect a year later, pull the drain plug. If fluid dribbles out, you're still good. If it does not, insert a finger. If oil is present 1/4" below the hole, you're still considered full. Expect to use 2.5 quarts for the front, 3.5 for the rear, so buy at least 5 quarts. The oil should be replaced immediately if a "clear" liquid flows out of either differential, or a milky-grey/white fluid comes out. In the former, you have nothing but water in the carriers. In the latter case, you have water present that got thrashed into the oil. Either one is not good. I once pulled the rear drain plug on a Subaru I owned to find it filled with nothing BUT water! Good luck. :D

So I've had quite the interesting weekend! I'm happy to say that my 4x4 was quite easy to fix! When I opened the check level plug two quarts came pouring out!! And yes, I do mean the upper check level hole on the T Case, not the lower drain plug!!! I let her drain to level, popped the plug back on and she shifts in to 4hi, 4low, and back to 2hi no problem now.

I did, however, develop a problem on my way back from working on the truck. When I got off the highway and got to the first set of lights in town the truck quickly dropped below 500 rpm once I was parked, and stalled out on me. I was able to restart, but had to launch immediately or the vehicle would stall out again. Basically, I was able to come to a stop while in drive or reverse, but if I was in park or neutral I could (most of the time) keep the truck running.

I tried replacing the throttle position sensor and it didn't do jack. Reason being, when I removed the TPS sensor wiring harness the idling problems seemed to disappear, but in actuality that wasn't wholly the case. Nonetheless, I've been parousing the forum a bit since I joined and immediately had an idea of what to check for. I'm not sure if these would be signs of the fuel pressure regulator leaking, but that would seem to be the case. What do you guys think?

By the way, I've also attached pictures of my lower manifold. I'm going to have both cleaned at a shop or something.. the hole that I have an arrow pointing to is about 3/4 clogged. And that black stuff is hard as a rock.

Am I on the right track?

http://i15.photobucket.com/albums/a358/Cailen/UpperManifold.jpg

http://i15.photobucket.com/albums/a358/Cailen/LowerManifold.jpg

http://i15.photobucket.com/albums/a358/Cailen/LowerManifold2.jpg

by the way, is the upper intake manifold gasket kit a dealer only item? My local parts store came up with an "NF", so apparently they haven't ever carried it before. I guess I'll be checking NAPA tomorrow..

I should also add that since I bought the truck on long drives the vehicle smells strongly of gasoline and also of burning oil. I've been religiously checking my oil however, and it doesn't seem to be eating any. I'm going to try to figure this one out later, but I wanted to mention it in case you fellas think it may be interrelated.

Upper manifold gasket is a common item that can be ordered overnight from Autozone, or even NAPA. However, it looks like you have a few problems there. One is most likely a leaking fuel regulator causing the stumble and stall at idle and carboning out that one intake port. Also note the washing of the passenger side of the plenum.

If a ton of fluid leaked out of your transfer case, it is more than liekely that the seal between it and your tranny is leaking. This will cause the overfill condition on your X-fer case. Since you seem handy with tools, it will not be a problem. Remove the case, pull the old seal out with a seal prying tool (do not guge your output shaft or the splines!) and drive a new seal in with a large socket. Good luck, and good work!

Good to hear about the gasket... I assumed as much. I had this parts store tell me one time that I couldn't order a windshield wiper module from them. I ended up buying it from probably the smallest parts store in town.

And though it seems my worst fears (pressure regulator) have been confirmed, at least I know what to fix now.

As for that carbon build-up, I think I'd like to clean the upper and lower manifold thoroughly. Should I just soak em in varsol? Or maybe carb cleaner?

As for the Tcase and the tranny overflow, are you just referring to a general tranny service? I've planned for a couple weeks now to go get the gasket/filter kit and put some new fluid in, though I'm not sure this is the gasket you're talking about (the general service would just be the tranny pan gasket). Are you saying I'll need to remove the Tcase, and replace a gasket between it and the tranny?

Thanks for your help guy. I can hardly wait til all the mechanical stuff is working.. there are a couple other things I"d like to get started on with this vehicle!!

Flush the upper plenum and lower plenum with whatever you like. I stand by plain old carb cleaner, or for really gunky stuff, 3M stuff *works* but carries a higher pricetag. I would not soak them as they are aluminum and therefore highly reactant. A temporary dousing and scrubbing with a nylon brush with a follow-up dousing should do you. Make sure all gasket areas are *spotless* and scratch free. Running a rag soaked with acetone around the lips of the seal areas will suffice as a final pass before you apply silicone on the ends of your lower intake gasket. Make sure it is a sensor safe RTV formulation. Permatex makes a squeeze tube of silicone that's black, oil proof and sensor safe. That can be had for $3.00.

You are correct in assuming that the seal I mentioned in between the transfer case and the transmission. The output shaft seal on the tail case of the tranny is a common leaking spot. It's slow, just a few drops at a time, but it will slowly overfill the transfer case in time. That too is a quick, dirty and cheap fix. A regular tranny service will never touch this area. The T-case has got to come off, it slides back and down. Make sure you get the t-case control motor harness and associated vacuum lines removed first. THe job is made easier with a seal removal tool which looks like a curved talon of steel, but you can get it out with a flat screwdriver if you use predjudice and caution. Square up the new seal in the bore around the shaft and then tap it firmly and squarely into place with a hammer and large socket. After a few taps, it should bottom out in the bore and solve the leak for you. :thumbsup:

Edit:

Plenums are clean and ready to go back on.

Picked this up:
http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&rd=1&category=33554&item=7987097259&sspagename=WDVW

Pretty decent deal.. comes with EVERYTHING + the CPI is a "factory redesign" that apparently has been modified to correct the original problems.



I'm still boggling about how to clean that intake port below the lower plenum, shown in the final photo. Do any of you guys have any suggestions? Can I just spray a bunch of carb cleaner in it? I'm concerned that I'm going to knock that carbon in to a cylinder and do some serious damage.

Also, I'm having trouble finding good information on restricting the EGR. It sounds like I just use a washer, correct? I'm guessing that I just stick it down with some STV?

I explored some links in threads on this forum, and I'm still at a loss.