Transfer box question/opinions please?

[Angry Badger]

I have a 4 speed auto with Borg Warner Transfer box (viscous coupling) with a suspect viscous coupling.  Also the car has a Detroit locker in the rear and a Truetrac in the front.

Question is: Is it worth replacing the viscous coupling, or would I be better off changing transfer box for an LT230?  

Here's the reason for the question: Because the rear diff is permanently locked and releases when required automatically and the front diff is "semi" locked (torque biasing), I am likely to get a degree of transmission wind up when driving on the road with the VC due to being, to all intents and purposes, a limited slip diff.  Or, will I get less (I accept I will get some) with a fully open centre diff as fitted to a conventional transfer box.

What do you think guys?  Cost is not really an issue.  Replacing axle diffs is not an option

[extreme90]

hmm id say lt230 if it was me
it seems the sensable option,
but 1st just see how much winde up in the transmission there is, jack the front tho as the rear will be locked  :roll:
dont like detroits they usless  :roll:
dan

[Angry Badger]

Just out of curiosity, Dan...What do you dislike about the Detroits?  Can't say I've ever experienced problems with them either on or off road.

[extreme90]

woods, they s***
trust me    :lol:  
ask disco v8 aswel he back me up as his disco with one fitted just about summed up my opinion with them
you want to go in a straigh line, naturally the locker wants to push you sideways, on firm stuff they great and come into there own
but woods  :roll: , when you need a open diff you cant have a open diff
dan

[disco-v8]

everone to there own dan....

fare enough ill admit, the thing didnt stop going sideways cuz it was permanitly locked and both wheels spining, but uve got more money than sence and love to get the best (ARB).....

i think my detoit is great and i can feel the differnce in grip straight away, and has made the truck go even further, as u saw, i made it stright up the hill.....

but like you said ithey are good on the hard stuff but not so good on the loose, but in my fairness i did have all my tyres at 35PSI so didnt get asmuch traction as i could of had, you no my let down is my tyres and been remoulds they arent the best in the world, just good for the money, they will be no where near as good as your simex...... just put it this way, do you think i would of managed to do what i could on that day, if i just had the standard diff????? asoon as that wheel span i wud of just sat there, atleast when i was going sideways i manged to find some sort of traction.........

bloody hell thats the longest reply ive done lol

just trying to defend my self by the way.....

[Angry Badger]

Thanks for the honest reply, Dan.  I can see what you mean by pushing the car sideways.  I did experience this to some (minor) degree on loose stuff when I only had the locker in the rear.  Fitting the Truetrac at a later date balanced the whole thing out and, if anything, holds it's line much better now than when it was runnng std open diffs.  The occasions when an open diff would be of real use are far ouweighed by the benefits of running the lockers all the time for me and I accept they might not suit everybody.

Having had a better look at my transfer box VC, I can rule that out as a problem since it's not faulty, but would still value opinions on the original question.  Is anybody out there running a similar setup to mine?

[Range Rover Blues]

Sometimes it's a hinderance to have both wheels locked together, on slippery stuff they both spin and you loose all control.

ANyway, back to the question, because of the way the Detroit works, the amount of 'wind up' in the viscous coupling will become greater, effectively the detroit is llike a pair of freewheel hubs so on a corner only the inner wheel is driving, the outer is free wheeling so the difference between front and rear axle speeds will be greater than normal.

The visocus coupling is a bunch of plates with grooves and stuff in them, half connected to each end alternatley 9like bvattery plates) and separated by a thermo-viscous fluid.  As you stir the fluid it gets hot very quickly and thickens up, sticking to the plates and grovves therein, so it's a reactive LSD.  If you ever driven a proper LSD you'll know how much better a viscouos coupling is, see comment above Re detroit lockers.

Incidentally, Seirra XR4x4 had them in the middle and rear, then again Schuler were fitting them in the 70s.