Jump to content

what is transmission wind up


Recommended Posts

just thought it would be good for the 4 paw owners (myself especially as i really don't understand it) if some of the more 'in the know' members could explain exactly what transmission wind up is - why it occurs and how its avoided.

for example, why is it if you have a differential front and rear, can you not have a solid shaft through the middle. is there any cars that dont have couplings in the middle?

also, if you have a turbo'd 4wd starlet with decent power doing a full launch its conceivable its gna break traction so talk me through exactly what happens with the viscous coupling during these moments.

Link to post
Share on other sites

Not sure if this is the same or not but my mate has a subaru justy awd with a swift gti turbo engine in it (currently running 214whp) and his used to run a viscous coupling just before the rear diff, he put a solid shaft in instead but had to weld the rear diff as it would have shat itself if he didnt. Oh he also got his prop mounts poly filled at the same time.

Needless to say he got his standing 1/4 mile down by 0.5secs from 12.9 to 12.4 making it the fastest justy in the country lol

Link to post
Share on other sites

nice mate thats impressive, so the vicous coupling is mainly there to take stress off the rest of the components then? i just cant see how the back end of the propshaft is ever gna be spinning faster than the front end at the transfer box. so i dont see why its so risky to just have a solid shaft prop

Link to post
Share on other sites

In the case of his car it was to reduce drag aswel, at it was originally only 75hp, meaning it was biased as a fwd car but when the fronts lost traction then the rears came in, but the way it worked only put a limited amount of power through (70-30 or something) which is why the rear diff never destroyed itself prior to the solid prop.

So if thats how the starlets work, I couldnt see why it couldnt be done?

Oh and now his car has a welded rear diff yes it is now a pain in the arse to turn tight corners!

Edit... just re-thought this and its prob the same setup as a starlet so diff wind up was prob some of the reason the rear diff needed welding?

Link to post
Share on other sites
  • 2 weeks later...

my ep85 viscous coupling was knackered when i got it. it went the opposite way to the way weejohn explained. some of the fluid leaked out so it needed more force to turn it. resulting in the split to the rear being even lower than as standard.

with the coupling replaced it made a noticeable difference to the power sent to the rear wheels :)

Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

×
×
  • Create New...