Jump to content
HybridZ

Balltec LSD


kj280z

Recommended Posts

you are on the money, the bolt is used only to compress the belleville washers/springs during assembly. I have not taken mine apart and just looking at the housing it looks like the 2 clutches are only their to project the casing and the drums and not for any slip control like a normal CLSD. I will take a look down the axles hole and see if I can see any spider gears.

 

One of the centre has some paper inside it that cam from the packing so I will ,at somepoint, strip this unit down and when I do I will take lots of pics for you guys but don't expect that anytime soon as I currently don't want to do that until I have diff I want to install it into - ie only have gear oil smell once in the garage.

Link to comment
Share on other sites

  • Replies 54
  • Created
  • Last Reply

Top Posters In This Topic

Here is another try at the video showing how the two drums could rotate opposite eachother inside the ring gear case, eliminating the need for spider gears.

 

The answer is either this, an internally slipping splined section, or hidden spider gears. I don't think there are spider gears here which is why it's so innovative.

Baltec-Internal-Differential.zip

Link to comment
Share on other sites

ok just located another R200 4.1 (open centre has been welded) it is in another part of the country so I should have it in a few weeks. I will then strip one of the Balltec down and take lots of pics - I have to finish up my brakes so I can get some bench space back to do this task.

Link to comment
Share on other sites

ok just located another R200 4.1 (open centre has been welded) it is in another part of the country so I should have it in a few weeks.

 

And I'm hoping that I might find an R200 with 3.36s. As least you have what you are needing. ;)

 

The unit looks like it only has 4 drive clutches, so at 2 per side that may be a weakness. Big torque may strip the tabs off the clutches just like it does on the 300ZXT diffs...

 

Guess that is another reason for everyone to upgrade to a 6 clutch setup in their Z31 LSDs, eh? :)

 

You drag racers blow my mind with that kind of grip to tear stuff up like that. Being a road racer, I just can't imagine that kind of "off the line" grip. With a 4L60E and DOT race tires (road course), I'm thinking I won't my stuff. (hopefully) ;)

Link to comment
Share on other sites

Ok I decided to pull the first Balltec that I purchased (the one with some packing material inside it) anyway here are some pics - too many for one post so I will do a few.

 

Now as stated I have 2 versions of the Balltec LSD's so I think one is a early version and the other a later version. These were commonly installed into S13 then S14. So I think I have one of each. As stated ones take the input shafts with the c-clips retained inside the centre aka Z31 CV axles the other uses the axles that retain the c-clips ie 5 star. So I have taken pics down the input to show the differences between the two.

 

1. So first up is the top of the LSD that I took apart.

2. Next is looking at the down the input of the centre that retains the clip

3. Then down the input of the one that has the clips retained on the axles - this is the one I am taking apart.

4. There are 2 belleville springs between the drum and the external housing.

5. Starting to remove the drums, balls and plates.

 

Next post for more pics

Balltec#1_thumb.jpg

Balltec#2_thumb.jpg

Balltec#3_thumb.jpg

Balltec#4_thumb.jpg

Balltec#5_thumb.jpg

Link to comment
Share on other sites

Next and last pics of the series II version of the balltec

 

If you look at the first post with the attachments you will see in pic #2 it is the same as the units that are shown on the sites I posted above with a large spring in the centre etc so I assume if I pull this one apart it will be the same as those units ie clutches etc. However you will see this version is different and when you see inside the drums there is no signs of anything ever begin between the two drums.

 

6. The larger 1/2 of the external cage - here you can see the slots for the balls to sit in (belleville springs still in the bottom).

7. The drums removed.

8. Balls and plates removed from the drums - I might add tricky to get back together this is why there is all that grease to hole every thing in place.

9. The bottom drum as it was removed. You can see that the input spline is part of the drum so no spider gears.

10. The other drum you can see that there has never been anything between the drums in this version of the LSD.

 

So there you have it - the version 2 Balltec as I call it in bits. I will not pull the other one apart as it is the same as those stripped shown on the Japanese sites listed in the post further up in this thread.

 

Cheers

Mike

Balltec#6_thumb.jpg

Balltec#7_thumb.jpg

Balltec#8_thumb.jpg

Balltec#9_thumb.jpg

Balltec#10_thumb.jpg

Link to comment
Share on other sites

This unit listed on ebay looks to be the same as the unit I just pulled apart tonight you can see there is nothing in the centre if you look at the pics in the auction

http://cgi.ebay.com/ebaymotors/Balltec-180SX-2Way-LSD-R200-S13-A31-C33-R32-Silvia-JDM_W0QQitemZ140283097870QQcmdZViewItemQQptZMotors_Car_Truck_Parts_Accessories?hash=item140283097870&_trksid=p4506.c0.m245&_trkparms=72%3A543|65%3A12|39%3A1|240%3A1318

Link to comment
Share on other sites

Wow great photos. It looks like a nice piece of machinery! I think I am correct in that the left side and right side spin opposite eachother as the balls "carousel" left to right in the tracks. This eliminates the spider gears! Very cool design!

 

Link to comment
Share on other sites

AH HA!!!! I think I figured it out...

 

cygnusx1, you're right that they spin separately from each other with the balls bouncing back and forth. but I think the difference in angle of the zig and the zag is where the locking torque comes from. Its still got the preload all the time, but when the drums spin separately that difference in angle is going to force them apart or together, producing an applied-torque dependent locking torque.

 

I think =)

Link to comment
Share on other sites

AH HA!!!! I think I figured it out...

 

cygnusx1, you're right that they spin separately from each other with the balls bouncing back and forth. but I think the difference in angle of the zig and the zag is where the locking torque comes from. Its still got the preload all the time, but when the drums spin separately that difference in angle is going to force them apart or together, producing an applied-torque dependent locking torque.

 

I think =)

 

Yup, that's it! You get one breakaway torque under decel and a different breakaway under accell because they are on the steep ramp during accell and shallow ramp during decel. No?

 

 

John, picture holding the left drum and right drums clammed together in your hands. Rotate them opposite eachother, twisting them. The ball tracks will wiggle back and forth as they spin. This would make the ball-pairs zig and zag left to right, following the horizontal straight tracks inside the outer housing.

Link to comment
Share on other sites

Pleased the pics I posted helped you guys figure it out.

 

I am told is it a very smooth operation - I will endeavour to get one of the Balltec's I have installed into a centre and into a running car before the 1/2 year is out.

Link to comment
Share on other sites

If you look at your solidworks animation (I'm designing LSD's in solidworks right now... for old F1 cars!!) it works because the ramps are the same angle... now imagine that when the top ball is going up its ramp, the bottom ball is going up a ramp of a different angle... this is going to force the 2 drums together or apart. So its the difference between the two angles on each drum that is going to produce the lockup. I think if the ramps were all the same angle, it wouldn't do anything at all. The ring gear and housing would spin, while the balls just go back and forth and don't transfer any force to the drums.

 

my brain hurts

Link to comment
Share on other sites

If you look at your solidworks animation (I'm designing LSD's in solidworks right now... for old F1 cars!!) it works because the ramps are the same angle... now imagine that when the top ball is going up its ramp, the bottom ball is going up a ramp of a different angle... this is going to force the 2 drums together or apart. So its the difference between the two angles on each drum that is going to produce the lockup. I think if the ramps were all the same angle, it wouldn't do anything at all. The ring gear and housing would spin, while the balls just go back and forth and don't transfer any force to the drums.

 

my brain hurts

 

I see exactly what you mean. So the drums are actually going to spread sideways a little against the clutch springs (belville washers) to increase/decrease breakaway. However that would not allow them to spin freely opposite eachother without "lumping" over.

 

 

How do you model a zig zag track around a cylinder in Solidworks? I did it in a round-a-bout way using my knowledge from a 1 week crash course I took for work. Can you send me an sldprt file? I can PM my email address.

Link to comment
Share on other sites

This thread re-affirms that there's certainly a higher caliber technical crew on hybridz... If you did a search prior to this discussion on this LSD you'd find next to nothing as far as any technical analysis on the design.

 

I have to admit, I'm still "fuzzy" on the details, although the pictures are helping me...

 

So... a question for the members here that seem to have differentials in their blood... Does this LSD seem like something worth trying out?

 

It sure seems like the choices for LSD's for the R200 are getting more scarce, so having an alternative like this would be attractive if it truly had merit...

Link to comment
Share on other sites

No matter how cool and crafty the engineering looks on paper...it don't cut the mustard unless it has been tested on a track and evaluated by drivers/teams in the know. IMHO, it's really cool, classic, mechanical engineering. How it performs on the track or on the street, I don't have a clue.

 

Flexi, I also use Solidworks 2007/2008/2009 at work.

 

I have a few questions about it's application:

Was it really a factory supplied diff in the JDM Silvias?

Do the splines match 280Z/280ZX inner axle stubs?

Does it fit into the 280Z long nose R200's?

Link to comment
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...