One Wheel Up Test Results - Viscous Coupling Unit VCU Torque Test - Freelander 1

My VCU's temperature measured 23 degrees before and after the testing. VCU temperature is an important factor which will produce different results, for the same VCU. My Freelander hadn't been driven over night to allow the VCU to cool to an ambient temperature. At the time of testing my VCU was 11.5 years old. It's an original Land Rover VCU supplied when my Freelander was manufactured in 2001. It's stamped GKN. Current mileage at the time of testing was 32,000 miles. My Freelander is a 2001 Freelander 1 v6.
Full information available in this link:
https://www.landyzone.co.uk/land-rove...

Test results:

Weight in kg / Time in seconds

3.0 kg . . . . . . . 80.0 seconds
4.1 kg . . . . . . . 49.5 seconds
5.0 kg . . . . . . . 35.5 seconds
6.2 kg . . . . . . . 25.0 seconds
7.1 kg . . . . . . . 20.0 seconds
8.0 kg . . . . . . . 16.0 seconds
8.9 kg . . . . . . . 14.0 seconds
10.0 kg . . . . . . 12.0 seconds
11.0 kg . . . . . . 10.0 seconds
12.4 kg . . . . . . 8.0 seconds
13.8 kg . . . . . . 7.0 seconds

A quick refresher of what we're trying to achieve here:

Q. What vehicles do the test results apply to?
A. Freelander 1. Other vehicles fitted with VCU's can perform the same test, but their results will differ due to rear diff gearing and their vehicles VCU design characteristics.

Q. Why are we doing this test?
A. To collate results from different VCU's in order to see if there's a common result trend.

Q. What would we like to get out of the results?
A. Hopefully a common trend which members could compare their test results too, in order to spot premature failure of VCU's before they fek up their Freelanders transmission (possible failure of IRD and/or rear diff).

Q. What does the test do?
A. It applies a known steady pressure (force) to the VCU (via the rear diff) while we time how long it takes for the bar to turn 45 degrees to the horizontal. This will give us a value in seconds we can use to compare different VCU's, whilst performing the same test.

Q. How do you do the test?
A. Chock front wheels. Release handbrake. Doesn't matter if it's a manual or automatic gearbox, or what position the gearbox is in. Jack up one rear wheel. Remove plastic centre wheel cap. Fit a 1.2m bar (made up of ratchet and wood) with a 32mm socket on the drive shaft nut. Raise bar and add a known weight. Allow the bar to start turning before the 45 degrees start point, in order to take out the slack in the transmission. Time the bar while it turns 45 degrees to the horizontal. Use masking tape markers to help you with the 45 degrees and horizontal stop/start positions. Place a sheet of cardboard between the Freelander bodywork and bar if you're worried about the paint work being damaged.

Q. What's your bar made of?
A. 32mm socket, small metal extension bar, ratchet to attach the length of wood to the drive shaft nut and length of wood with a nail in the end. Use several tie wraps to secure the wood to the ratchet. Measure a distance of 1.2m from the pivot point (extension bar) to the end of the wood. Cut the wood at the 1.2m point and put a nail in the end to use as a hook. Apply known weights to the end of the wooden bar (I used tie wraps hooked over the nail).

Q. Why have you repeated the test with different weights?
A. This gives an overall view of the performance of the VCU with different weights applied. It also allows us to compare other people's results if they've used a different weight.

Q. Can I do the same test too?
A. Yes. If we all carry out the same test and pool our results we will gain a better feeling of the average time to perform the test, as a comparison against others.

Q. Can you perform a similar test on a VCU on a bench?
A. Yes. I have done this already and will put up the results and video soon.