Testing your Transfer case without using the Jack Test

[nando]

you could use a lathe but I don't know how you would attach it or the torque wrench.

[2002tiiguy]

http://www.omega.com/pptst/TQ513.html

http://www.omega.com/pptst/DFG35.html

Come on guys, everyones got one of these things attached to their $10,000 lathe nowadays, catch up.

But seriously, I was tryin to come up with a way to measure the torque as well, does anyone have a way to spin it at 150 rpms? If you could, you could just put a torque wrench on the stationary side and measure the torque on it while the other side spun.

[flyboyx]

honestly, i think it would be all but impossible to spin the tail stock @ 150rpm with a hand wrench. the length of the torque wrench handle is about 20". this x 3.14" x 2.5 = 157"/second or about 13 feet!

i do think it might be possible to spin it momentarily pretty close to that speed. the problem is that it would be impossible to quantify the rpm.

[spdracrm3]

i would flip that setup around so you can get a clear 360 deg of rotation at rear output flange with the Tcase on a separate table strapped down and front output locked in vice with rear output hanging over edge of an appropriate height table . i think you need to get a smooth consistent 2.5 turns a second (2.5 X 60 sec = 150 RPM,should be close to do-able) to get a good reading on the beam torque wrench to have a better reading than just 45 deg rotation, as stiction will affect initial reading from a stop and i think a couple rotations would be needed for VC fluid to start locking up.

[95BMWIC]

Decided to try this myself on an unknown unit (believed to be good - but who the hell knows)

Loaded up a manual trans case onto the work bench and placed the drive shaft into the Monster vice (I bought last weekend..weeee)


Next I tried spinning it by hand and it took some force to spin the shaft - does not spin easy..

Pulled out the trusted Harbor Freight clicker and basically I was getting around the 18 foot pounds with an even steady slow pull - If pulled faster it clicked. I could if I tried to just move it very slow I could at 10 foot pounds..

Ok - so I pulled out the spring inch pound and measured the torque of the initial pull to get it to move - and I was reading around 50 inch pounds (around 4 ft pounds) -

If I tried to follow what Nando suggested to pull has fast as I could (limited to only 45degrees of pulling action) - starting from a dead stop - to see how fast I could spin it - I Maxed my gauge at 600 inch pounds (or roughly 50 ft pounds of torque) although it was really hard to tell exactly what the number was as I didn't have enough rotation to get a steady number.

Disclaimer - the spring gauge is old and hasn't been calibrated -yada, yada - so I take these measurements as an approximation..

However - I can see that "steady pull" would be the issue - that is why I tried to measure what the initial resistance (force) it took to begin rotation..

The TC acts as though it meets the requirements - meaning the force it takes to rotate faster grows - versus spinning one with no resistance..

So I wonder if this is good or not..?

[packratbimmer]

How about fabricating a knob to attach to the torque wrench handle. I bet after testing a few good ones, one would develop a "feel" for the condition.

[95BMWIC]

This is why I love this site..

[packratbimmer]

OK now folks - no getting clocked in the head by a flying torque wrench - LOL

Awesome work!!! Much needed testing methods!!!

[flyboyx]

i saw the one you are talking about. i seem to remember it was from a subaru. i also seem to recall they had some special tools made up.

angus, i added the spec sheet to this thread. thank you for posting.

[nando]

ok, here's an idea.

Set your torque wrench to 51ft/lbs. move it as fast as you can and see if you can hit that. if it's too easy/fast then it's probably on the way out or dead.

I think without a way to set RPM, there's no way to standardize it. I read an article years ago about a shop that used a lathe set at a specific RPM to measure a VC, but I'm not sure how you do that (not like you can put a torque wrench on it while it spins).

[spdracrm3]

Hmm. how would we control for the speed?

that makes total sense though. the faster you slip the VC, the more it will lock. maybe we can finally kill the myth that it works via heat..

Yea,something i've been trying to get across for years , if heat changed the slip characteristics would BMW use this technology ,i think not.

if you read the spec sheets on Polydimethylsiloxane its dynamically stable over a wide temperature range which is one reason its used for this application

i posted the spec for the Torque value here some time ago ,right off a factory Tech sheet or manual
and heres the link http://www.r3vlimited.com/board/show...ng+torque+spec

[nando]

Hmm. how would we control for the speed?

that makes total sense though. the faster you slip the VC, the more it will lock. maybe we can finally kill the myth that it works via heat..

[flyboyx]

that bottom test looks easy enough. I'll test my new one and post results. I have the same HF click wrench. they're supposed to be fairly accurate, actually.

it occurred to me after i posted this that it seems to me that the faster you spin the vc, the higher the torque reading. i'm going to update my initial post with this info.

[e30s50dan]

I just did the bottom test side by side of a BAD one and GOOD one!

[nando]

that bottom test looks easy enough. I'll test my new one and post results. I have the same HF click wrench. they're supposed to be fairly accurate, actually.