Not sure if this is the right area if not could please move to correct area but recently the front transfer case went out on my 1984 AMC Eagle Sedan. I was driving down the highway and heard this sudden grinding. Would not accelerate faster then what I was going and when I turned into a gas station and had to go up hill I slowed to barely moving. Took into summit transmission thinking that was the problem as when I put it into park it made a horrible sound and I could still push it and it would roll.
They said the transfer case was empty of fluid and most likely shot. Now they are trying to find the parts to rebuild it. Are there any places that still sell parts for the NP 129 or would it be easier to put in another like the NP 119? What advice could you offer. Thanks for your time.
I did a quick search on Yahoo, this is what I found:
http://www.drivetrain.com/index2.php?option=com_content&task=view&id=261&pop=1&page=0&Itemid=784
Quote from: potent357 on June 04, 2012, 09:01:52 PM
I did a quick search on Yahoo, this is what I found:
http://www.drivetrain.com/index2.php?option=com_content&task=view&id=261&pop=1&page=0&Itemid=784
Thanks. I think my coupling should still be good. Does that rebuild kit include the pump?
I have a good used NP129 for $100 in Seattle. If yours stopped moving, the VC is probably toast. I would lift one front tire and try spinning it to see if the driveshaft spins or not.
You must have the silicone fluid in the viscous coupler for it to be able to work. This fluid is retained by a single O-ring. All the cases I've opened had globs of the thicker silicone fluid at the bottom of the case because it leaked out past that O-ring. Once that O-ring fails and the silicone fluid leaks out the viscous coupler is a fancy paperwieght. If you drain it during the rebuild process then you just destroyed it in a sense. No replacement fluid is available anywhere because its toxic and out dated.
The good news is that the viscous coupler has an open differential incorporated into the design. The car drives perfectly fine without it. In fact a 1986 Eagle or Full Size Jeep will have the exact same transfer case except the viscous coupler is eliminated. Those are called NP128 and 228. Few customers knew the difference. The all wheel drive is still much better than rear wheel drive in every driving condition even without the viscous coupler.
In later Jeep Grand Cherokees they made the 229. It has a different viscous coupler without an intergrated open differential. When it fails the vehicle must be towed. The smaller 249 viscous coupler is much more robust and reliable however than a 229 unit. It has much more than the dinky O ring keeping the fluid inside it. Because its smaller, the extra room in the case allows for a nifty oil pump that circulates transfer case fluid better than the older cases. The 229 was replaced by the 247. The 247 has a more durable limited slip differential that does the same job as a viscous coupler except faster and without the toxic silicone fluid.
I personally am scrapping all my old 129's. I only use the NP242. It's a very easy and cheap conversion. I used my original driveshafts without any welding or fancy modifications. A 247 is a great choice too but I value the two extra functions that the 242 has more than the 247 traction benefits. Do not use a 231 or a 241. A 249 works well and are common but the New Old Stock viscous coupler's are already expensive and they will never be made again. They'll continue to get expensive and rare. Avoid a 249 from an early year of production because they do not have a fully locked 4 wheel drive. You might need that to limp home if your VC burns out.
A 241 is nice if you get the 4:1 low range in it. ;)
Quote from: carnuck on June 05, 2012, 12:12:27 AM
I have a good used NP129 for $100 in Seattle. If yours stopped moving, the VC is probably toast. I would lift one front tire and try spinning it to see if the driveshaft spins or not.
How much would it cost to ship to Indiana, is it still for sale, do you have any pictures. How much longer should one last? Trying to get something that is quick with the least amount of work for now. Out of a Job so prefer not to do too much to the car. How many miles does it have?
Hello. Are you still there I apologize if I am asking to many questions or being impatient about the transfer case you said you have for sale but this could be the difference between keeping the car or not. Have a nice day.
NP119 was only '80 till early '82 AFAIK. NP129 came after that with a temporary switch to NP128 in '86 then back to NP129.
Was not really able to check for false neutral as summit transmission has taken he transfer case completely apart. Though when I looked through the parts I did find a round silver piece with 4 screw holes that got slightly smaller by steps as it got near the center that was broken in 3 pieces. Two small ones and the big one. Looks like it cracked then broke. defiantly will need a new one. Also mine was made august 1983 and has the front end where there are vac um lines going to part of the front end that is one the passengers side, next to the c-joint for the passenger side front tire. Is it shift on the fly. I will have to doulbe check but I am pretty sure it also had a round pump like thing next to it, like in this picture
http://i1181.photobucket.com/albums/x427/captspillane/Eagleweb%20Postings/DSCF0846.jpg
Sounds like the front axle disconnected and the VC self destructed
Quote from: carnuck on June 07, 2012, 06:51:47 PM
Sounds like the front axle disconnected and the VC self destructed
so mine is the not locked front axle then? when did they switch that for shift on the fly? was it after mid 1983. I am guessing August is mid.
The first couple years (80/81) were solid (4x4 only, aka New Process Quadratrac) then vacuum axles (with Selectrac that has 2wd/4wd option) till late '85, then shift on the fly till the end in '88.
I had the VC on my 82 SX4 rebuilt in early 2011 at a transmission shop. They can be repaired and serviced. You just need to find a shop that has the right knowledge.
If I was feeling well enough, I'd get the weight, etc of the NP129 I have for shipping, but I'm so dizzy I can hardly stand due to a pinched nerve in my neck that's been driving me nuts for 3 weeks
Quote from: Eagle1984 on June 04, 2012, 09:23:36 PM
What do you guys think of this site. They mentioned they sell trans rebuilds.
http://www.midwesttrans.com/prodlk.html
I contacted them and although their web site only lists a complete remanufactured transfer case they told me they can sell me a rebuilt viscous coupling for my NP119 for $345.