2wd sy/ty
- Thread starter JoeLutz
- Start date
buickman69
Retired Buick Enthusiast
dave p from cali who has several sy/ty and is a ase certified mechanic told me that if ya wanted to pull it out drive a "SHORT" distance down the rd 1/4 mile and do a good burn out one time then it'd be okay.other wise "NNNOOO".said the visca clutches would burn out and etc,etc,.i'd advise talkin to him. Davep699@aol.com he has rebuilt several sy/ty trannys front transfer cases and entire trucks for that matter.he has helped me out a lot.
<font size=-1>[ This Message was edited by: buickman69 on 2001-11-28 00:42 ]</font>
<font size=-1>[ This Message was edited by: buickman69 on 2001-11-28 00:42 ]</font>
Tooky
Serious about performance
Joe if you should recieve good information can you ask permission to repost it here? I also would like to hear the answer to this. I know there is a TON of testimonys "I drove my truck for a month straight without a propshaft and had no problems when I went back to AWD" and I have even seen some of these examples first hand, but I also believe people like DaveP who really know the technical details. I just can't make sense out of the two contradictions :smile:
Mephisto
These trucks are cursed
i just recently had my propshaft out, not for a month or anything, but i drove around quite a bit, id say at least 60miles. i did a bunch of burn outs, and some donuts. then put the new propshaft in and i havent noticed any problems at all. if the tranny or transfer case goes bad in a few months then ill post it! and blame it on my need to drive around and do burn outs, and donuts.
Daron
Active member
This issue comes up every so often, yet I havent heard anyone add to Ivan's original research into the matter. It still sounds like theoritical testimony suggests that driving without the shaft may not be a good idea, yet folks get away with it for a time without obvious damage. There is no contradiction in my opinion. You do it long enough, the vicuous coupling will fail. How long it will last is kinda a crap shoot in my opinion. You gotta ask yourself " Ya feel lucky, punk"? I did, drove the Ty for a few weeks without a front shaft, no probs. Would I do it for an extended period? I am never that "lucky" so I wouldnt consider it.
Here is Ivans thoughts:
http://www.syty.org/archives/syty/9802/msg00715.html
From: "Ivan The Terrible" <trblty2@foxvalley.net>
Date: Sun, 22 Feb 1998 22:54:43 -0600
Sender: owner-syty@syty.org
--------------------------------------------------------------------------------
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. I have a few more questions for john
and will be calling him this week so if you want to know something, let me
know. Stay tuned for part two
BTW, John said he would be interested in a VC that has been driven for a
while in 2WD for inspection..... If you have one, let me know.. also,
you can visit there web site
http://www.gknplc.com/automotive/viscodrive.html but there isnt much info.
Ivan The Terrible
93 Ty wht/wht
91 Sy blk 17" OZ monte carlo wheels
96 Gary Fisher, Joshua Y
95 Gary Fisher, Kaitai
TRBLTY2@foxvalley.net
Chicagoland
Here is Ivans thoughts:
http://www.syty.org/archives/syty/9802/msg00715.html
From: "Ivan The Terrible" <trblty2@foxvalley.net>
Date: Sun, 22 Feb 1998 22:54:43 -0600
Sender: owner-syty@syty.org
--------------------------------------------------------------------------------
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. I have a few more questions for john
and will be calling him this week so if you want to know something, let me
know. Stay tuned for part two
BTW, John said he would be interested in a VC that has been driven for a
while in 2WD for inspection..... If you have one, let me know.. also,
you can visit there web site
http://www.gknplc.com/automotive/viscodrive.html but there isnt much info.
Ivan The Terrible
93 Ty wht/wht
91 Sy blk 17" OZ monte carlo wheels
96 Gary Fisher, Joshua Y
95 Gary Fisher, Kaitai
TRBLTY2@foxvalley.net
Chicagoland