Testing your Transfer case without using the Jack Test

[AWD_E30]

Stumbled on this thread after finishing up some testing with my lathe. I figured I would share my results with you guys. I made a sort of pesduo-dyno out of my lathe in preparation for cutting viscous couplers open and making them rebuildable.

I will admit I am absolutely surprised by the torque transfer these are capable of. A stock Subaru center differential viscous coupler is rated at 4 kgf-m @ 100 RPM. I interpolated my peak torque results and found they were around 16.5 kgf-m @ 100 RPM. Now I don't know if their ratings are at peak torque or a certain time after the test begins. The more colorful plot below shows how quickly the torque falls off.

Also I had a really difficult time stopping the viscous coupler quickly at higher RPM. This caused the peak torques to be lower than perhaps they could be. The 220 RPM settings shows this slipping that occurred when I wasn't able to stop the viscous coupler quick enough.

Curious if you guys have any feedback or tests you'd like to see? I am thinking the next batch will be at different temperatures of the coupler at the 110 RPM setting (closest to the 100 RPM rating of viscous couplers). For example soaking them at the following temps until thoroughly at these temps (0°F, 32°F, 45°F, and maybe closer to boiling temps) then running a test before they change temp. It'll take a couple of days but should be pretty cool :)

Cheers!
Devon

[The Dark Side of Will]

Somebody's running for office and trying to hide his sordid past?

[flyboyx]

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this is odd.

[notanawdix80]

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[ndfspd67]

Broken or welded.

Talked to the previousprevious owner and he confirmed his mechanic welded something.

Yesterday i splitted the tcase to take it to the press. I will take a look later to see what is welded

Post pics I am curious to see what they were going for there. I also have a t-case and axle if you are in the market

[notanawdix80]

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[AWDBOB]

I just had a tcase that was locked just as yours is.... I was going to tear into it but scrapped it. I pulled it off of a car from someone who welded the front DS onto the car because they couldn't figure out how to remove/install it properly. It remains a mystery.

[The Dark Side of Will]

If one output is held, the other will be stiff and only turn slowly, but it will turn.

If they're actually locked together, some hard part is broken inside your T-case

[flyboyx]

it should not be locked. you should be able to spin the two independently of each other. if it were mine, I would take it apart to see what's going on in there.

[notanawdix80]

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[The Dark Side of Will]

The VC will have a spec like XXX torque at YYY RPM. The torque and speed are related.

Alternatively, the check for one of the Chevy T-cases with a VC is to remove the front driveshaft and put a torque wrench on the front output with the trans in neutral. Put XXX torque on the output flange and if it turns 90 degrees in under ZZZ seconds, then the VC is bad.

[D.Martijn]

Oke guys, I just measured the torque valvue of the VC I just put in my uncles iX.
I started with my smaller torque wrench at 10Nm (7,3 ftlbs) which was no problem to get, I went up 10Nm each step and quickly got to 60Nm (44 ftlbs).

I switch over to my bigger torque wrench and was able to get up to 120Nm (88 ftlbs). I couldn't go higher as that was the limit of my torque wrench.

Here's a little video on how I tested it. I started at 60Nm up to 120Nm. (camera doesn't focus when I show it.)

https://www.youtube.com/watch?v=x-YquXzAB_0

[D.Martijn]

please do. this would be a fantastic addition to this thread. I know the value you come up with will be somewhat arbitrary, but at least its a baseline between a used vc and a new one.

Before installing it this weekend I'll put it on the bench and use the vice to block it. Although it's not a new VC, there is 66134 written on it. I'm guessing that's the milage. Since we use km here that would be 41k miles.

[flyboyx]

please do. this would be a fantastic addition to this thread. I know the value you come up with will be somewhat arbitrary, but at least its a baseline between a used vc and a new one.

[D.Martijn]

I haven't tested the new transfer case I got for my uncles iX with a torque wrench but I did notice when doing the test on my own to feel the fluid resistance, I could not block the front axle by myself. Even with the help of someone else, it still is hard to block the axle when blocking it with their feet. Makes me think this VC is still very good.

I'll also try and get some measurement before mounting it in the car