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Transfer Case Shot, or Just Bad Actuator?

D

DieselAmateur

She ain't revved 'til the rods are thrown...
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Location
Upstate NY
Howdy gang,

So out of nowhere, at a very inconvenient time, my 4WD decided to stop working.

Short history: T- case is original as far as I know. Drained and filled with new fluid last April.

4WD worked last Friday. Topped off gear oil in front diff as I had a long day of hauling ahead of me Saturday. Towed empty equipment trailer down to southern PA, towed back ~9k load same day. Smooth sailing and no issues that I know of, although transmission is dying a slow death but that's another story and I believe to be independent from this 4wd issue.

Went to move truck and trailer today, still loaded down, and truck will not go into 4 high or low.

Checked fuse 24 (4wd) in side dash fuse panel and it was blown. Of course it couldn't have been that simple, replacing the fuse made no difference.

When shifting into 4HI, the light around the floor shifter doesn't light up, and 4wd doesn't engage, but stays engaged in 2wd as truck will still move in gear.

When shifting into 4LO, the light on the floor shifter does go on, but truck seems stuck in neutral as the truck won't move when transmission is put into gear.

The previous owner had already upgraded the 4wd actuator to the newer non- thermal type.

Truck drives fine/ normal in 2wd

So, based on all the above information, any ideas on what the issue is? I cleaned the electrical connections on the 4wd actuator wires and the wire that plugs into the top of the t-case, not the one at the end of the tail shaft (think this one is for speedo?) Cleaning these electrical contacts didn't help/ change anything

What has me tricked up is the light going on in 4HI but not 4LO. And the fact that the rear is still engaged in 4HI but nothing is engaged in 4LO leads me to believe the culprit is the T-case and not the actuator. I'll happily swap in a working actuator before pulling the t-case, but if there's anything else to test/ check, I'd sure appreciate the help :)
 
Remove actuator, turn on ignition switch, try shifting into 4hi, 4lo and 2wd and see if actuator moves any. 🤷‍♂️
other than that, I know nothing. In My best sergeant Shultz accent.
 
If it is in neutral when light shows 4LO it sounds like a linkage issue...floor shifter right?
The differential actuator is different than the 4wd actuation at the t-case.
 
Manual transfer case.

Looks like the case is dying an accelerating death. Coasting down a hill today in 3rd gear and the case popped into neutral. Awful clacking/ grinding sound. I can put it back into 2wd just fine once stopped. I'm no expert in these cases, just watched a handful of videos on youtube, but I'm guessing one of the forks is worn and the synchro assembly may be going too.

I have a spare t-case bolted up to a NV4500 that came from my wrecked '99 in the shop, so I'm probably going to order a rebuild kit for that unit and hopefully get around to swapping it in before the case in the truck grenades on me.

If anyone has recommendations for a rebuild kit, I'd love a reference. Going to do bearings, seals and chain at a minimum, hope the spare in my shop won't need much else with regards to gears, forks or synchonizer. From what I've watched these aren't too complicated to tear into, famous last words I know 🙃
 
Oh my heck. ANY chain driven case, when it starts popping out of gear- tow it on a flatbed. Chains stretch and create the issue. But if it jumps a tooth it can destroy everything in the case and the case itself.

I can’t say best place to get the kit- but do not buy the kit until you have it apart. I have seen many people buy kits online l, then enough extra parts were needed that a new assembly was cheaper and they lost more money on returning the kit.
 
On RockAuto, reman cases are $700-$1000. Most expensive bearing and seal kit I've found is $225, not sure if that includes chain or not. Looks like at worst I'll spend half the price of a reman unit for bearing and seal kit and new chain

Hence my plan to take my spare '99 241 and out of precaution put in new bearings and seals and chain into a known working unit that has sat in my shop since 2017. Last thing I want to do is just throw in a used case only to have to pull it in a few years again. Then the case in the truck now will occupy the space vacated by the spare lol
 
If you catch it in time- just a chain and shift fork pads are all it needs.
I have seen bearings and gears last over 500,000 miles.

If I was rich and famous like you guys, I would jump to an Atlas 2. So bulletproof, choose 2wd/4wd, but you can do front wheel drive only if you want. Sounds dumb in a truck until you drive one like that. Traveling on the hiway it is supposed to be better mpg for front wheel drive. (Idk if it is). But the gear selection is awesome. Getting into the 4 speed units that have is insane. But the already painful price of $2800 goes up to $3700 for that monster. But if you ever wanted 10:1. Hahaha.
 
Ok still waiting to hear back on a couple suppliers of kits, not sure if I'll get my hands on one by the weekend.

Anyways, question/ poll for you folks when it comes to reassembly of the case

There's no gasket for the 2 halves of the case, so some sealant must be used. I'm thinking of Permatex ultra black or right stuff.

Question is, do folks recommend laying down a bead and tightening everything down, OR lay down a bead, snug up case until sealant oozes out evenly, then let sit and cure for ~1 hour before tightening down for good?

I followed the latter directions for re-sealing my rear end diff cover and have no issues, but that's for sealing a cover as opposed to two halves of a case. I'm leaning towards the first option since the case sees more stress than my diff cover, but I'd love some expert advice and have always wondered what the proper way to do gaskets like this is.
 
Go to a motorcycle dealer, get a tube of Honda Bond or Yamabond. That stuff stays flexable and it will never leak.
What I have found with the RTV sealers is, if it is laid on very thick, it can take about 24 hours to cure through. I have used it both ways of what You have described. Sometimes the OH or repair manual will give specific instructions.
It seems when I am putting something together, I apply the sealer the fasten things down as described in the book.
I use that honda bond stuff on Triumph motorcycle cazes and it never leaks. Those cases are split vertically and they are prone to leak.
 
Do NOT use any type of RTV in that type of situation, as even fully cured and final torqued down it will STILL allow movement between the case halves under extreme duress/torque situations and can allow shifting of as much as .005", or even more - as RTV has NO shear strength - and that amount of deflection in a shaft can lead to early bearing/bushing failure.

Use Permatex #2 (I believe that's the number, I have a tube laying around forever somewhere in the tool cabinet for the last 30+ years, from back when I had my '84 Subaru Turbo 4WD wagon and we did a rebuild with new case halves back in '92, last time I found it, the tube's still soft! Or equivalent, what ever it is Subaru recommends for sealing the crankcase halves together on their horizontally opposed motors, because it cures solid rock hard, not rubbery, and as an uncured liquid [not thick goo like RTV] fills in any voids/irregularities between the two machined surfaces but allows metal-to-metal contact at the 'high spots' - thus preventing any type of creeping or shifting between the halves.) I can't remember the Subaru part # off the top of my head, but my Subaru mechanic buddy who rebuilt both my automatic transmission and the new motor case halves (I had bought it really cheap at an insurance salvage auction) it had been in a light frontal collision that had punctured the radiator with a small pinhole, the idiot owner tried to drive it home, it severely overheated, to the point the ethylene glycol antifreeze boiled, which set up an electrolytic reaction where the steel cylinder sleeve, aluminum lip at the top of the cylinder the sleeve pressed up to it from below, and the boiling antifreeze in the three cooling passages surrounding the cylinders all met. The aluminum block ate away and created three .010" gaps where the cooling passages to the head were that opened into the top of the cylinder about an ⅛" below the deck. The pair of EA80 (1800cc) block halves were only $600 ordered at the Dealership he wrenched at, for another $300 plus the cost of a new main bearing set, my buddy tore it all down, swapped over the rotating assembly, heads and external parts at his "side job" shop at home, and I had a "new" turbo motor for under $1000! Definitely remember that he had me buy that tube of Permatex for the case halves as it was a ¼ the cost of the much smaller Subaru product!
 
This stuff ? The no.2 comes in a jug with a brush in the cap.
www.permatex.com

Permatex® Form-A-Gasket® No. 1 Sealant

Fast-drying, hard-setting sealant designed for sealing rigid materials and flanges, or patching holes and joints where permanent assembly is desired. Temperature range -65°F to 400°F (-54°C to 204°C); resists common shop fluids and fuels.
www.permatex.com www.permatex.com
 
Remembering back, bought it in late '91. Dumped two bottles of Bars Leak into it and it managed to seal the block to sleeve leaks for about six months, until I started noticing a light whitish, sweet-smelling haze from the exhaust and after cool down, pulled #2 sparkplug and grabbed the inspection mirror and saw antifreeze sitting in the bottom of the cylinder. That was when the decision was made to pull the motor.

That new motor was a screamer! When my buddy went through Subaru mechanic training, they did have training on the EA81(T) (turbo version of the EA81 1800cc that ran 7.7 CR/95HP (vs 8.2/73N/A) and 7 psi boost stock. In class, to prove just how tough these motors were and well-designed, their instructor showed them how to cheat the wastegate/popoff on the Hitachi turbo and use a different MAP sensor in the system to build 25 lbs of boost and fool the MPFI's simple computer to fuel more and put out a dyno verified 205hp out of 1800cc, which was the setup in the Subaru Rally cars!

Needless to say. . .

It was quite fun on a Friday or Saturday night, to pull up next to some High School kid in a late 80's/early 90's IROC/RS/SS Camaro or Firebird that their parents bought them (me being an "old" 30!) at a stop light in an '84 Subaru station wagon with the 13" white wagon spoke wheels and 185/70-13 tires, signal to the driver that you wanted to race them to the next stop light, watch them grin and nod, then drop it into 4wd, stand on the brakes and bring the motor up to 3,000 rpm stall against the converter - then just plain rocket out of the hole when the light turned green without a chirp of a tire and be a good 100-150' ahead of the other guy, who was smoking both rears in the hole (if he had Posi, then endless spinning of the one) before even hooking up, and I'd already be on my brakes and down shifting from 65mph and stopped for the red light at the next intersection when they'd finally pull up next to me in shame.

As long as I kept my foot out of it, the mods didn't affect my fuel mileage too badly. Aftermarket electronic cruise control installed (Subaru didn't offer it on the GL equipped turbos in 84) and on, out on the Interstate at 55mph (remember, early 90's before the limits were raised again) I was getting 28 vs 30 before, around town about 20 vs 24 before (more acceleration). Remember, small rims/tires as only Subaru used a 140mm x 4 bolt pattern and no aftermarket manufacturers made 14" or larger rims in that pattern. 1970's Peugeot 504's ran that lug pattern in 14", but they used lug bolts, not studs and nuts and the machining needed to make seats in the rims to make them work wasn't really worth it $$$-wise. Besides their steel rim design precluded using any aftermarket hubcaps, and theirs were almost as ugly as their bare rims!

I'm sure the more power was why I needed a transmission rebuild in late '92, done by my buddy.
 
MrMarty51 said:
This stuff ? The no.2 comes in a jug with a brush in the cap.
www.permatex.com

Permatex® Form-A-Gasket® No. 1 Sealant

Fast-drying, hard-setting sealant designed for sealing rigid materials and flanges, or patching holes and joints where permanent assembly is desired. Temperature range -65°F to 400°F (-54°C to 204°C); resists common shop fluids and fuels.
www.permatex.com www.permatex.com
Click to expand...
Yup! That be it! That 60 and getting older brain fog again! Used for opposed cylinder flat 4 Subaru case half assembly, among other things!
 
Thank you for the advice gentlemen! I'd heard in disassembly videos that folks re- seal the cases with silicone. Glad I consulted the experts here first :)

So when using this hard- setting gasket maker, do I apply and torque down, or apply, snug down and let gasket form for _____ hours before tightening up?

I ordered a new chain, gasket & bearings and small parts from transmissionpartsdistributors.com for a total of $202, plus free shipping! Lots of stuff was on sale, such as the $98 bearing and seal kit priced at $66.77. They're out of NJ so maybe the parts will make it to me by the weekend after all.

For folk's future reference the right bearing & seal kit for the NP 241c found in our trucks is the BK241A kit and the chain is part HV-205

Will update once the bad case is pulled and opened, thanks again for the gasket advice 🙏
 
It's been three decades since the Subaru's case halves were joined, and I didn't do the work, my buddy who lives in another town 40 miles away did the teardown and rebuild at his home shop.

Here's a great idea, read the directions on the package for the manufacturer's procedure for use.
 
When I put items together with the NO1 Permeeeetex, I just bolt everything on down to torque.
BUT, I also think that Husker has the right idea, read the districtions on the package and also see of there is any mentions in the book.
 
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