A place for more technical discussions. Please make sure you post in the correct section on the site, this way it keeps the site tidy AND ensures you get a more relevant answer.

2015 jimny rear diff center rebuild info

More
11 Jan 2024 15:41 #253434 by Old Neil
Hi all
Ive had the misfortune to trust a mechanic to rebuild my jimnys rear diff centre for i wasnt confident in fixing it myself but now its worse than before.
I would be greaty appreciate any help with technical info,torque settings,pinion preload and crown wheel backlash ect.

Thanks Neil

Please Log in or Create an account to join the conversation.

More
11 Jan 2024 16:48 #253435 by facade
What is worse about it?

If it is whining then you'd be better off getting a quiet one from a breakers- check that the there are the same number of teeth on the crownwheel.

If they have been run with the pinion out of adjustment for a long while they wear a pattern that will cause noise even when everything is set back correctly.

By all means check it yourself.

1) The correct preload on the pinion gives a starting torque* on the nut of  0.9 - 1.7 Nm (7.8 - 14.7 lbin) without the crownwheel in place.
Pulling on string wrapped round the flange 18 - 34 N (4.0 - 7.5 lb)

2) Then the crownwheel is put in and adjusted over to give a backlash of 0.10 - 0.20 mm at the outer edge of the teeth

3) Then the crownwheel bearings are tweaked tighter to preload them, this causes an increase in starting torque of between 0.2 - 0.3Nm (0.9 - 1.3 lb)
Pulling on string wrapped round the flange an increase of 4.0 - 6.9 N (0.9 - 1.3 lb)

4) So the overall starting torque for the assembled diff is between 1.1 - 2.0Nm or pulling on string 4.9 - 8.8 lb.

Preloading the crownwheel affects the mesh & backlash, so the trick is to set it initially to the top end 0,2mm and only tighten the adjuster on the outside so it pushes further into mesh, then as long as there is still 0.1mm backlash it is done.


* It says Starting torque, but then rambles on about turning at 50rpm, so I'm not 100% what they mean, as starting torque will be a lot more than moving torques.

Assuming it is the starting torque, you can whip the diff out and check 2) & 4) without disturbing anything

 

If it suddenly breaks, go back to the last thing that you did before it broke and start looking there :)
The following user(s) said Thank You: Old Neil

Please Log in or Create an account to join the conversation.

Time to create page: 0.230 seconds
Joomla template by a4joomla
We use cookies to give you the best online experience. Please let us know if you agree to all of these cookies. Accepting the Cookies also accepts the Disclaimers for the website.