DIY VCU service

Thanks HTR passed on information they now have people scouring what GPO manual,s they can find online in archive (surprising amount).
What I can tell you is that I sat at a workbench last night and even in a wheelchair I was able to break apart a modified VCU In under 10min no oil in it but still that easy.
There getting to the stage where they have to start costing I looked at it roughly yesterday and was pleasantly surprised: with parts and labour at 145 euros and after including purchase of a duff V C U 30-35 euros its coming out at under 200 euros £150 an exchange price, for a unit that you would be able to service yourself forever more!! I Can see a time when you will be able to spec these VCUs to your own needs
Some one had a worry about balancing Balancing does not seem to be a problem the Oil seems to act as a balancing agent

MORE LATTER

Yes I guess the 'oil' will balance out by centrifugal force as the VCU spins.

That enclosure was an old one even then and likely dated from the prewar era! It was nicely made. We had to be reasonably careful when doing them up to make sure the thread engaged properly. Some jointers even applied a thick silicon grease to the thread as sealing insurance but this made the enclosure a pig to undo when cold! Ah I've just recalled where it was. It was for communication and control cables in an old hydro electric power station near here. It was built in 1907! Replaced long ago in the 1980s. It could have been an old seimens or westinghouse equipment.

Good luck. I think a lot of use are watching this with great interest!

Small set back we have had some flash floods here today plus golf ball size hailstones and one of the test beds has spun the collar of the VCU whilst getting itself out of a mud slide. The chaps have just taken my trailer to bring it back for investigation

fredi250 said:

Small set back we have had some flash floods here today plus golf ball size hailstones and one of the test beds has spun the collar of the VCU whilst getting itself out of a mud slide. The chaps have just taken my trailer to bring it back for investigation

Click to expand...

it sounds like it needs a washer as used on the rover ball joints to lock it in place or some thing similar and a reverse thread
Ron

Pin the thread

Got a bit further on today...managed to install the grease nipple and threaded the drain bolt hole....tomorrow might have a go at filling it, this could get messy, the fluid is very sticky...just getting in the grease gun could prove fun...I got 30,000 cts in the end.

Well all seems to be going well...got some fluid in the vcu now....I recon about 150ml has gone in so far....it feels far to stiff for me moving it via a spanner, but with I breaker bar it not too bad...still i don't like this type of resistance going through the transmission, but is must be the way they are...

Im currently trying to replicate the Bell engineering vcu on bench test..

I am using a 4.5kg weight instead and my vcu its rotating slightly faster... which is good for me as I want a loose vcu...

Still no sign of lockup thou...suspect I need more fluid in it....but then the vcu tends to get tighter which is not what I want....

I dont know if anyone will know the answer to this but......

How much/many times does the vcu slip when doing a full 360 degree turn?

Does it slip one full rotation, half, quarter etc

its not how much it slips, but how quickly it locks - see the vcu fred.

I know this.......I would get lockup I suspect if I fill with more fluid.....but my aim is conserving the transmission.....there is enough resistance from the vcu to give me rear wheel drive...but how much I dont know......it seems to me a stock LR vcu is pretty stiff. Looking at bells video on you tube. ..

Hmmmmm I might just fill it some more tomorrow until I feel lockup....supose I can always drain some out again..

yu do realise that there is a set amount of fluid supposed to be in the VCU?

I would have thought that on a bench it would be near impossible to check for lockup as the sheer forces occur very quickly and it locks up in about 1/4 of a turn of the slipping wheel I understand.

The Mad Hat Man said:

yu do realise that there is a set amount of fluid supposed to be in the VCU?

Click to expand...

Yup...read it somewhere....but ive no idea what it is.. Im just doing it by feel and using the force

I'm pretty happy with it so far but its all new to me.....I pretty sure I can replicate Bells video for the resistance vs time video.....but they dont show lockup

Epicuser said:

I would have thought that on a bench it would be near impossible to check for lockup as the sheer forces occur very quickly and it locks up in about 1/4 of a turn of the slipping wheel I understand.

Click to expand...

Well again just by feel and using the Force, im pretty sure I would be able to feel lockup..... as I understand it, with the right amount of fluid installed....the faster I turn the vcu the more it should stiffen until it locked up?

Now its this how much of a turn of wheel/vcu before lockup occurs im trying to figure out...

Will have to youtube hippo's stuck in mud videos

Would anyone be able to tipex mark their vcu and then preform a full lock 360 turn and note how much the vcu moved from the marks....

"Now its this how much of a turn of wheel/vcu before lockup occurs im trying to figure out..."

why dont yu just read the thread?

I doubt you will be able to turn it fast enough to get it to lock up like it does on the car.

Epicuser said:

I doubt you will be able to turn it fast enough to get it to lock up like it does on the car.

Click to expand...

why not you can with rrc and p38 viscous couplings

The Mad Hat Man said:

"Now its this how much of a turn of wheel/vcu before lockup occurs im trying to figure out..."

why dont yu just read the thread?

Click to expand...

Cant find it the bit about how many revolutions before blast off..

Epicuser said:

I doubt you will be able to turn it fast enough to get it to lock up like it does on the car.

Click to expand...

I could feel it stiffening up with the old fluid in it.....the faster I tried to turn it, the stiffer it got.....until my arms dropped off

jamesmartin said:

why not you can with rrc and p38 viscous couplings

Click to expand...

Tell us more James

rrc viscous will lock in less than a turn you can only turn it slowly

jamesmartin said:

rrc viscous will lock in less than a turn you can only turn it slowly

Click to expand...

So turning it slowly it will turn forever. ...but as soon as you fire up the beans in less than a turn you can feel the vcu stiffening/locking up....

Can you explain how you did this just out of interest, I might have missed something....all info is welcomed

jedi said:

So turning it slowly it will turn forever. ...but as soon as you fire up the beans in less than a turn you can feel the vcu stiffening/locking up....

Can you explain how you did this just out of interest, I might have missed something....all info is welcomed

Click to expand...

we used to test the v/c secured in a rig and with a torque wrench and stop clock, the greater you pulled the stiffer they got

Thanks, thats my understanding of things too....any info on fluid viscositys used or amounts?

So in theory lockup could be tested with the one wheel up method...

Push on the breaker bar slowly then really give in some welly, taking care not to smash your face into the ground......you should feel it stiffen up