Pirate 4x4 banner

98 Suburban-Transfer Case Whine-Estimated time to self destruction?

14K views 11 replies 5 participants last post by  TexasT 
#1 ·
--98 Suburban 1500,5.7,4L60E transmission,dash switch,Auto 4WD,option code NP8,Model #246GM Ratio 2.72--
My Suburban has aquired a speed sensitive whine,took it to my mechanic this morning and he found it totally dry of fluid.He said it was a victim of the fluid pump piece putting a hole into the top of the magnesium case.He recommend's replacement.He refilled it with ATF? (some internet info say's synthetic oil or blue fluid?)
Local yard want's $950.00 for a used transfer case with 118,000 miles on it.
1- If driven in it's current state,will it destroy any other part's if/when it fail's?
2-What is my best option-replacing the 246 or going with a manual shift 241
3-I have to have transportation to and from work,that's why I'm considering driving it against his recommendation.Work is only a few miles from the house
4-Cost is a major issue,,Can I temporarily drop the transfer case and change the tail shaft on my transmission and run 2WD?
There are a hundred web sites to choose from.Please recommend a reputable rebuilt transfer case dealer from the forum here to try and do business with,that will give me the best price.
I appreciate your patience,my first post in here.
 
See less See more
#2 · (Edited)
You didn't say if it is still whining after filling it back up with fluid...?

The 246 does use DexIII for lubrication. Auto trac is the blue fluid used in GM truck's with "Auto 4x4" option. This is true for '99 and up I know, but not sure about older auto cases.

The 246 is a simple transfer case and probably wont break you to take it to a dealer and have them replace the case half, repair your scorched/damaged bearing, replace the pump and install a case saver kit. All the kit is really and some new replacement case halfs come with them is a peice of bent steel to keep the ear on the pump from chewing into the case from inside out. Some of these would leak from the top of the rear case half also from the oxygen sensor wiring rubbing through the magnesium case. (Yes the rubber will eat the magnesium over time through friction).

Then there's the do it yourself option which you could attempt because these aren't very difficult to repair.

241 swap would be almost ideal though if you can find one cheaper than the 246. Would bolt right up, and "more than likely" the exact same length, and would use the same D/L's but not 100% sure. Cut a hole in the floorboard for the shifter and salvage the trim peice/boot from the t-case donor vehicle.

Welcome to Pirate!
 
#3 ·
Thank's BurnBlue,
The whine diminished quite a bit,but is not gone.I plan to have the fluid checked again in the morning to see how rapid the loss is.Found a local transmission shop that said they would a rebuild my NP 246 for $850,had a used low mileage NP 241 for $350.Major price difference.He said there would be electrical issues,with the wiring harness switching over to the manual 241.
I searched and found a old thread here detailing how to handle that.
History on the truck is a GM crate motor 12,000 miles ago,new tires and brakes recently.Body is straight and excellent paint for it's model year.
This is my main mean's of getting around.A good truck I just need to get repaired the most economical way.
I have a little mechanical ability although the labor he quoted was only $150 to swap the cases out,that seemed really reasonable.
 
#4 ·
You need to fix the pump and case. Any good transmission shop can fix it for under 300 bucks. You can do it yourself, Contact trklr hes done a bunch of them
 
#5 ·
I can get the Transfer case out.Been looking at it.I will save that $150.00 he want's for labor.I've got a jack,stand's and wrenches.
I dropped a case on a 78 Blazer many moon's ago (with help),this one look's a ton lighter than that one was.
What about the bearings and other internal's?
How do I determine if the Transfer case need's a total rebuild while it is out,bearing's etc. ?
I failed to mention it has 256,000 miles on it.
Nice truck you built there ChevyBoy2010.Checked out your link there
 
#10 ·
Thanks for the compliment! Seriously though, I know I've seen a write up in the Chevy section from trkklr in there before. He did the exact tcase you have with a rebuild and case saver kit. Search there for it, you can do the whole job yourself.
 
#6 · (Edited)
You should be able to handle this yourself. I can't believe you can't find a used case for less than $850? I see late 90's trucks in the pull-a-parts near me all the time. Cases through them are only like $100. If I were you and truly couldn't find the used case in my price range, I'd do the 241 swap, especially since you've already found the info on dealing with the electrical issue. To me, for $600 or so in savings, it's well worth it. Again, it really seems like you should be able to find the parts for cheaper though. where are you located?

EDIT: Or start calling around to more shops in your area and see what they can offer you. Or look for a 4x4 shop in your area, they'd likely have cheaper solutions for you in this situation or at the very least, the guys that work and hang out there might be able to hook you up with some cheaper parts!
 
#7 · (Edited)
I'm located in Franklin Ky,6 miles from the Tennessee line on I-65.The $850 was for a total refurbished 246 unit,bearing's and all internal's,using my case.
That price is from a reputable rebuild shop here in town.
The $950 was for a very used 246 case with 118,000 miles on it out of a junk yard,that was ridiculous.
I would have no problem with the 241 manual shift,barring any unforseen complication's.I don't care for the Electronic shift that much anyway.
Will the driveshaft's swap directly out? In a google search i found something about a flanged front drive shaft being needed.
Thank's for the input fella's.

EDIT/ADD: I will pursue other shop's with the info and direction I receive here,Thank's
The truck doesn't blue book for 3k.Surely I can find some part's for a reasonable price once I get headed in the right direction with which option to pursue..
 
#8 ·
You might check with the shop your talking to and let them know your on a tight budget. Tell them you will remove the case yourself and take it to them. Talk to the tech that would be working on the case and let him know you just want to fix only the internals that are damaged, and make sure they put in a case saver kit. Just having the case in front of a technician on a work bench will save some money in labor for sure if they don't have to pull it themselves.
 
#9 ·
Although, with 200,000+ on it I'd think about replacing some or all of the wear parts in that case. That's a lot of miles and if you already have it out, in my mind it's worth it to just know that it's good for some more miles. I know you're on a budget, believe me, I know about that. This is also dependant on how badly you need the truck and how much longer you're planning on keeping it and using it. I know I need mine to be reliable and last me indefinitely at this point since I cannot afford another truck. So when the one front U-joint and hub bearing went, I replaced both front u-joints and bearings because I knew i needed the stuff to work and last a little while longer.
 
#11 ·
#12 ·
With no fluid I would expect some type of noise.

Drop that thing out , split it, put some jb weld on the holes, put a case saver or a case protector pump half in there, put some new bearings in if it needs it, put it back together and hoist her back in there. Just be sure to refill it with fluid.






One thing I did learn is that there are two flavors 27 and 32 spline inputs.


If all the balls aren't separated it tends to make noise


Case protector pump half.

We are about a month into this repair. It does drip a little trans fluid as I didn't have a gasket and used rtv between trans and t-case. I am going to r&r it again as I couldn't find a rear output bearing And I had to drive it to work so I put it back together.
rest of the pix if you're interested. http://s444.photobucket.com/albums/qq167/texastandgransport/Transmission/Transfer Case/
 
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top