Jump to content
HybridZ

OBX LSD for 240sx R200


Clifton

Recommended Posts

  • 3 weeks later...
can someone post another thread on how exactly one would mod this to fit and work properly?

 

 

There aren't really any modifications necessary. The ONLY dimentional difference I could see between the OBX diff and the stock open diff was the size of the holes for the ring gear bolts. I made bushings to compensate, but I don't really think its necessary. The bolts shouldn't be shear loaded anyway if they're torqued correctly...(or impacted on in my case).

 

Update...since I've had the car together, I've probably made 50 or so 120+ mph passes behind our warehouse....most of first and second gear have been with tires spinning. The diff works very well. When I was bedding in the brakes, I was basically driving around powerbraking the car to get heat into the brakes. Around corners, applying power with the brakes on fooled the diff to start working and the rear of the car hopped around like crazy....thats how I know it works:mrgreen:

 

I swapped out the 3.54 gears for 3.90s today and decided to tear into the diff to see how all the pieces looked. Everything looked good. No major wear on the washers, the gears looked a bit polished, but no real wear. I'm happy with the diff. It works as its supposed to and seems to be holding up well.

 

PS: the 3.90 gears woke up the car something fierce.....I can't wait to try the 4.64s that I have coming in at the end of the month.

Link to comment
Share on other sites

  • 2 months later...

I posted some info in another thread aswell so hopefully this isn't too much of a double post.

 

I have been working with the OBX FWD diffs for over a year now and provide kits to replace the bolts and washers to make it easy for everyone to rebuild them.

 

I don't actually own a 240 diff since I have a FWD project car (sorry). I have worked with some 240 owners closely to get the washer setup right though.

 

From what I found the washers should be arranged ))))(((( so that they stay in place in the 240 diff. Unlike the FWD diff the washers are not enclosed in a sleve and should be in this config so that they are held together and don't come loose in the diff. )( doesn't hold together as well as ))) does. The stack should be about 13mm tall. I can offer stacks that are either 35% or 55% stronger if more preload is desired.

 

Overall the bellevilles are just for taking up slop and keeping things quiet. This has been confirmed by quaife designers.

 

Let me know if you want a replacement kit.

 

Here is some info: http://rbryant.freeshell.org/obx_washers

 

I think the honda link earlier verifies that I have been selling them to peopel for quite a while now. :)

 

If I am out of line for offering them forsale in this post then I am fine with the moderator killing the last section of this post and I will be sure to do it the right way. :)

 

Thanks,

 

Rich

Link to comment
Share on other sites

I posted some info in another thread aswell so hopefully this isn't too much of a double post.

 

I have been working with the OBX FWD diffs for over a year now and provide kits to replace the bolts and washers to make it easy for everyone to rebuild them.

 

I don't actually own a 240 diff since I have a FWD project car (sorry). I have worked with some 240 owners closely to get the washer setup right though.

 

From what I found the washers should be arranged ))))(((( so that they stay in place in the 240 diff. Unlike the FWD diff the washers are not enclosed in a sleve and should be in this config so that they are held together and don't come loose in the diff. )( doesn't hold together as well as ))) does. The stack should be about 13mm tall. I can offer stacks that are either 35% or 55% stronger if more preload is desired.

 

Overall the bellevilles are just for taking up slop and keeping things quiet. This has been confirmed by quaife designers.

 

Let me know if you want a replacement kit.

 

Here is some info: http://rbryant.freeshell.org/obx_washers

 

I think the honda link earlier verifies that I have been selling them to peopel for quite a while now. :)

 

If I am out of line for offering them forsale in this post then I am fine with the moderator killing the last section of this post and I will be sure to do it the right way. :)

 

Thanks,

 

Rich

 

Thanks for the info....

 

If you read through the FAQ that I wrote up, 8 washers, even if they were flat, would not be sufficiently retained by the 2 little punkass retainers....the 2 center washers are retained only by their own springiness, and when assembled, all of the 8 washers are completely compressed flat. I think this is the design flaw with the OBX. If the washers are assembled )))(((, they will stay put. If the washers are assembled ))))((((, the 2 center ones will fall out, which is what happened in my case. We reassembled TonyD's diff (my old OBX) using 6 washers, in the same manner as the quaife stack, but I haven't had any feedback as to weather or not it worked.

Link to comment
Share on other sites

Thanks for the info....

 

If you read through the FAQ that I wrote up, 8 washers, even if they were flat, would not be sufficiently retained by the 2 little punkass retainers....the 2 center washers are retained only by their own springiness, and when assembled, all of the 8 washers are completely compressed flat. I think this is the design flaw with the OBX. If the washers are assembled )))(((, they will stay put. If the washers are assembled ))))((((, the 2 center ones will fall out, which is what happened in my case. We reassembled TonyD's diff (my old OBX) using 6 washers, in the same manner as the quaife stack, but I haven't had any feedback as to weather or not it worked.

 

Hmm I will look up the measurements I have but I didn't think they compressed flat when installed. I agree that the cup shape is the only thing that will hold them together.

 

From the measurements I had there should only be about 1-1.5mm (.040"-.060") of compression on the whole stack when the assembly is tightened.

 

This can be confirmed by checking to see when the stack gets loose relative to the turns on the 1.25mm pitch bolts. The stacks start to get loose after a little over a turn so that means they are only compressed 1mm.

 

The washers have .030" of compression each before going flat (height-thickness). This means that they shouldn't be anywhere near flat in this configuration. They should actually only be about 1/4 compressed max which is about where a belleville should be.

 

Alternatively we could start using larger bellevilles in the center so that they are centered by the housing rather than the sleeve but it makes things complex and shouldn't be needed.

 

Were your flattened washers the replacements or the originals? The originals from OBX will flatten out or crack in just a few whacks from a hammer which is similar to what is happening inside of the diff. So that in its self will cause the problem you describe real belleville washers won't do that.

 

-Rich

Link to comment
Share on other sites

 

Ok I read it over again (and more carefully this time).

 

I agree that they are there to take up the slop.

 

Stacking them )((()))( as you mentioned will fully compress the outside washer which isn't what we want because only one washer on each side is doing the work and it is too tall of a stack that makes the outside washers compress flat... Stacking )()()( like the FWD cars will allow them to fall out and cause problems.

 

 

The washers should give a stack height of 13-13.5mm if stacked ))))((((.

This will take up the 1mm of slop perfectly when only compressed about 25% and not fall out. This will let them seat in the retainers properly and hold the stack together since they are all interlocked. It is almost like the )spacer( setup that was mentioned in a later post except a bit stiffer and it shares the job accross 4 washers on each side rather than just a single washer on each side.

 

I doubt that the bolts are streaching but I also provide new 12.9 certified bolts in the kit.

 

-Rich

Link to comment
Share on other sites

  • 1 month later...
We reassembled TonyD's diff (my old OBX) using 6 washers, in the same manner as the quaife stack, but I haven't had any feedback as to weather or not it worked.

 

HAW! It's still under the back seat of my truck. Though now wrapped a bit better with some cardboard, duct tape, and a real big ziplock.

 

Things come together 'slowly' in my world.

 

One day it will go into the Shark Car.

 

But now, I'm putting up concrete forms and digging drainage trenches before 'the rains come' so I have a concrete place to work this winter!

 

Concrete, as opposed to mud...

Link to comment
Share on other sites

  • 4 weeks later...

I'l probably end up getting on of these, considering the powerbrute is now out of comission (japan earthquake destroyed the tooling). Just got a 5 speed out of a 83 zx and I'll be going back for the 3.90 diff tomorow. My future diff will most likely end up in that one. Should be fun.

Link to comment
Share on other sites

  • 2 weeks later...
  • 2 weeks later...
so if the obx from a 240sx fits the 280z r-200.

will an oem lsd from an 240sx fit in a 280z r-200?

 

prolly been answered but I didn't find it.

peace

tc

As stated the answer is yes but also as stated the issue is the different input shaft requirements = a bit of a hassle.

Link to comment
Share on other sites

  • 2 weeks later...

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...