Blown up transfer case???

[JSM]

OK, I have been around since 98, aside from a few chain stories never heard of major transfer case failures.

If anybody has heard of one breaking blowing up post details what broke, happened, cause, etc?

Pic from last night. I got lucky prize on the ordeal of 7 stiches in my finger and much pain today. Typing is rather fun also.

 

[PPI Typhoon]

Re: Blown up transfer case???

That's nuts

 

[jwaller]

Re: Blown up transfer case???

yup. I just had to replace the planitary on a customers truck as well. he stopping driving it after it made it's first noise so it didnt explode as yours did, but it was trashed none the less, also replaced the chain as it had 130k miles on it and threw in new thrust washers and bearings.

 

[JSM]

Re: Blown up transfer case???

That case had ~55k miles. No signs before hand except a small leak in case.

Owner drove over last night, not hammering on truck, etc. Stopped in my driveway went to put in park and noticed the noise of parking prowl bouncing off the stops.

From that point truck had no gears at all, D, R, etc.

Would have felt better had it blown under a nice launch or something.

 

[Crimson93Ty]

Re: Blown up transfer case???

It doesn't sound like it broke under excessive power or anything. It's hard to believe all that damage happened at once. Man, that's a mess. Planetary bit it bigtime. Where the pinion gears ride in the planetary looks REALLY thin. Are there enough of the pieces left to see if that's where it broke initially?

 

['JustDreamin']

Re: Blown up transfer case???

Sorry to hear about 7 stiches, Jeff...Hope your finger is feeling better....I find the 12oz pain relievers in a can tend to help in that kind of situation. Unless it interfere's with doctor prescribed pain medication.

'Dreamin'

 

[JSM]

Re: Blown up transfer case???

Finger doesn't hurt much anymore.

I do want to rip stiches out as they hurt more than anything.

Tip of finger is numb also, not sure if that is normal or not.

 

[Typhoonracer]

Re: Blown up transfer case???

Jeff,
I still have some parts from the one I took apart...
I will get you a list....

Steve

ps

Sorry to hear about your finger....

 

[sy2185]

Re: Blown up transfer case???

A guy that used to run his truck at the 1/8 mile track where I work(on race days) named Fred had to replace his t/c due to a catastrophic failure. His truck was plenty quick, putting down low 7s in the 1/8th but with all he had it should of been much quicker. It was a full Kenne Bell truck and if you've ever run into one of those you'll know what I mean. Wierd stuff and good stuff, A/A, big turbo, k/b headers, drag radials, 10" K/B conv., built motor, etc. But like so many K/B trucks, it was wierd- no boost guage except the stock one, no ext. trans cooler, no d/m or diacom, some funky k/b or atr chip that had so much timing in it his 'guy' up in LA area had told him to only run c-16 116 octane race gas, a strange K/B "boost-a-pump",all kinds of things. He blew his t/c hard, but it was expected after watching him do 4 wheel burn outs at the b/o box to heat his drag radials. Last time I saw/spoke to him I took a bunch of pics of his truck and posted it here in the forums for like 18k, or something. Never heard what ended up happening. Cool older guy,though.
That same visit he offered me his 2nd set(had 2 made)of 315cfm Brodix heads for $1500, or maybe it was $2200, some outrageous amount. Posted pics of those bad dogs on the board too.
Jeremy
SY2185

 

[TT350]

Re: Blown up transfer case???

Jeff since the viscous coupling is toast open
it up so we can see what’s inside!

 

[JSM]

Re: Blown up transfer case???

Once my finger recovers enough I can operate power tools, lathe, etc I will do that.

 

[Crimson93Ty]

Re: Blown up transfer case???

Found this in the hotrodder's archives that they got from the syty archives that they got from....

"After spending a day with my nose in the factory service manual staring at the blow-apart drawings of the transfercase and reading the whole chapter on rebuilding one (in a stroke of devine inspiration) I finaly understand how the transfer case works. Here is the low down as it relates to the removal of the prop shaft.

The transfer case alone (with no viscous clutch) functions like an open differential. With no VC, if you were to lift the rear tires off the ground, all of the torque would go to them and the fronts would not turn. Ditto for the front, actually with the open FRONT diff on our trucks, just one tire off the ground would stop the rest from turning. So, without a VC in the transfer case, torque goes to the tires with the least grip. So, if you were to remove the front prop shaft (with no VC) and you try to drive, the front output shaft would spin like crazy and you would go nowhere.

The VC is what transfers all of the torque to the rear. The viscous clutch functions like this (this is straight from the service manual)

"The viscous clutch used in the Borg Warner 4472 (transfer case) is a torque distribution device and is nonserviceable. The internal construction of the viscous clutch consists of alternating plates that are connected to the front and rear outputs of the transfer case. The viscous clutch is filled with a high viscosity fluid which flows through slots in the plates. The resistance to sheer causes the plates to transmit torque."

Like I said in my original post, I was interested in finding out what type of dammage might be caused by the removal of the front propshaft. The book basicly refers to the FLUID transfering torque. How can fluid transfer all of the torque to one output (wont the fluid slip a little)?? What happens after a while?? Does it get worn out kinda like a shock?? What is the service life of the viscous fluid?? The book doesnt really go into detail on the VC so I took it upon my self to find out.

Well, after two days and 14 phone calls to 4 different states, I finaly got ahold of John Barlage (senior production engineer) of GKN Viscodrive. This is the manufacturer of the VC that goes in our trucks. So here is the beef as was related to me.

Basicly the VC progressivly locks the front and rear outputs together when there is a speed difference between the two. The bigger the speed differnece the faster the VC locks the outputs together. The VC is compleatly transparent untill there is a speed difference between the two outputs, at this time the viscous fluid tries to speed up the slower plates transmitting torque to the slower output. As this is happening the fluid is heating up. The fluid has two special qualities, 1 the resistance to sheer and 2 a high rate of heat expansion. The VC is purposly not filled compleatly with fluid. A certain amount of air is left in it to give the fluid room to expand. Once the fluid expands to fill the VC the internal pressure starts to climb rapidly, this actually forces the plates together (can you say metal to metal contact??) This condition is called self induced torque multiplication or HUMP (kinda cool huh)

It takes 110 to 140 degrees C to get to full HUMP (takes me less, hee hee) For those in the states thats 230 to 284 degrees F. At this point, the VC wont heat up any more (no more slipping = no more heat) but, as it cools it will start to slip again.

I asked if the heat would thin the fluid and John said that actually the opposite happens. The metal particles from the metal to metal contact create a condition called jellification. I bet you can guess what that means... If you cant... The viscous fluid ends up solidifying. This equals no speed differentiating between the front and back which equals worn tires or broken transfer case.
"

Might explain why they act the way they do. Sounds like the transfer case REALLY needs to cool off in between passes to let the pressure in the VC go down. Cooling the transfer case fluid might not be such a bad idea.

Might look something like this inside:

I wonder if they have an updated replacement for the 15 year old part?
Found some more:

http://translate.google.com/transla...tml&prev=/search?q=John+Barlage+GKN&hl=en&lr=
It's google translated from German but may tell you something.

Found a pump I'm gonna try.
Shurflo model 8000-643-236 $178.81
12 volt with buna construction for pumping oil or diesel fuel. Should be able to just use the stock ports and run it through a cooler.

 

[HighPerformanceTrucks]

Re: Blown up transfer case???

How did you mess up your fingers? Did the transfer case grenade sending flying metal through the floorboards????????

OK, I have been around since 98, aside from a few chain stories never heard of major transfer case failures.

If anybody has heard of one breaking blowing up post details what broke, happened, cause, etc?

Pic from last night. I got lucky prize on the ordeal of 7 stiches in my finger and much pain today. Typing is rather fun also.

 

[JSM]

Re: Blown up transfer case???

The transfer case basically feel on top of it, splitting it wide open.

7 stitches later, it stopped bleeding.

Still hurts though a week and a half later, half of it is numb.

 

[jwaller]

Re: Blown up transfer case???

CV products sells a oil type electrifc fluid pump for turbo apps where the turbo is mounted under the oil pan. I'm sure this would work great in this app. I have always thought about cooling the xacse somehow but was just too bosy to mess with it.

 

[SpoolingTurbo6]

Re: Blown up transfer case???

Scew the pics the the trasfer lets see that finger

let me know if you nee another one transfer (not finger).....well I can gan give you one of them too JK
Tyson

 

[Try Me]

Re: Blown up transfer case???

Jeff see if you can find those exploded transfer case pics and fix the links, i'd like to see them.

Here is mine from this past weekend. Went 1.500 60 ft the run before with no burnout, so the track was hooking pretty good. This happened on my second run at the end of the burnout when the tires hooked. I heard the noise but didnt think anything of it till i let off the brakes to launch and did a fwd burnout.