OBX vs Quaife (with pixors)

[EMWHYR0HEN]

I stacked my washers in this configuration )))((( so that the washers act like 2 heavy washers. I was shooting for a heavy initial pre-load to compensate for gear/washer wear over time. I measured around 50-60 ft/lbs after assembly (dry). I'll have to measure it again after everything wears down a bit and gets lubed.

[John Scott]

I know I'm probably overthinking this but checking on some more measurements. I'm totalling the compressed washers, using clay for assembled dimensions, and find little if any room for the Mcmaster washers to do their work.

 

This has been discussed before, http://forums.hybridz.org/showthread.php?t=123654

but I see no "happily ever afters"

 

Assuming all washers are stacked flat, no spring capability left.

8 OBX washers stacked solid .40

8 McMaster washers stacked solid .50 (.496)

washer retainers touching, (space between inside retention lips) .31

clearance between floating retainer spacer and side gear .020 (other gear flush against case) measured with clay, assembled w/o washers

clearance between floating retainer spacer and top of retainer .040 retainers are slightly inset into spacer.

 

Total clearance is about .51x, about what the Mcmasters take up.

Original clearance for OBX original washers to flex would be aprox .15

With Mcmaster it is aprox .05. Seems you would want a bit of room for movement??

 

Now wondering if I shouldn't be considering dropping the # of Mcmaster washers to allow some movement. 7 stacked solid would be .434

 

Tight or with some compression room?

 

Keep reading and a few sources seem to favor the preload isn't that critical, as long as there is "enough" to limit a free axle.

 

No question the Mcmasters are sturdier, I just don't know if thicker is better. Wish I knew what Quaife has for clearance in the preloaded washers, once assembled.

Apparently, Quaife stacking )()()()( goes for deflection with no increase in load.

 

Originally Posted by Patent Office

Differential with preload spring

Document Type and Number: United States Patent 5524509

 

Abstract: An improved differential mechanism of the holdout ring type, characterized by the provision of a pair of annular thrust blocks engaged by sets of Belleville disc-spring washers which bias a pair of side gears axially outwardly apart against a pair of annular thrust washers, respectively, non-rotatably supported by the differential housing. By loading the side gears in the axial direction, the side gear radial freedom of movement is restricted, whereby the differential chatter and noise level during operation are significantly reduced.

 

No real other reason for preload.

I guess washer stacking is a science in itself. http://www.solonmfg.com/springs/features.cfm

 

One more edit, long post, but I think it's important.

I ended up using 7 Mcmaster washers stacked ()()()(.

Not to worry about the ( washer, my axle stubs aren't going to hit the washers, I measured. The reason I went this way was I believe Quaife stacks their washers in series, )()()(.. as posted above, for deflection, while relying on only the force of 1 Beleville to put force on the side gears. When I used 8 Mcmaster washers I got a lot higher "break away" torque than with 7. Since stacking Belevilles in series will not increase force, I feel the only reason I got higher break away was due to the binding of the sidegears against the case due to no clearance left. Using 7 left me about .12 for clearance. Others running 8 Mcmasters, 1.250 x 0.0630 x 0.062, might want to check for solid stacking and little to 0 clearance. I read another source on Belevilles and I don't believe they are intended to stack beyond a certain %, certainly not flat. Now only time will tell if this was a good way.

 

rbryant posted here a long time ago on an OBX washer topic supplies washers and bolts for OBX, reputed to have washers same thickness as original, so the flat stacking would not be an issue.

http://rbryant.freeshell.org/obx_washers

[John Scott]

above post too old to edit.

....I read another source on Belevilles and I don't believe they are intended to compress beyond a certain %, certainly not flat.

I should be saying compress(ed), not stack(ed).

[John Scott]

Finally received my side bearings, 30209-C from Autoparts Giant...lots of online complaints, use with caution.

Used the oven (200 degrees)/ freezer method for ring gear and bearing install. Overall, OBX was slightly wider, end to end, but from bearing mounting surfaces, came out nearly identical to the original carrier. Using original 3 shims, backlash is slightly tighter than the original .007+, now sitting right at .007. Stubs popped in, fluid filled.

Getting a nasty cold. So stopping for now. I'll update when I can throw some power to it.

[John Scott]

Yeeeehaw!

First drive. Right off I can say the rear is quieter than my original set up where I had a some subtle gear noise, especially at float. My car's exhaust is really loud, so in perspective now I notice no noise what so ever. Happy to call it beginners luck.

I am using the RT and stock mount in combination. Did quite a few lock to lock circles, no clicking, popping, grabbing. I'm not a track racer so little experience, but all I can say is leaning on the throttle allows a very linear oversteer. I've had some clutch LSDs and they tend to kick out as they lock up. Not so here. Absolute blast to power out of corner with force I've never been able to put down before. Also my 383 develops a fair amount of torque, so roll on burnouts are easy. Two nice even and loooooong black lines.

Most of the OBX gripes have been due to washer failure, it will be interesting to see which washer configuration is going to last.

So far so good. Too early to say anything else.

[cygnusx1]

I think it would be pretty easy to re-engineer the washer section to accomodate a couple of concentric coil (valve type) springs. Not sure we need to take it that far yet but it's not an unsurmountable mod if we need to go there.

[John Scott]

I think it would be pretty easy to re-engineer the washer section to accomodate a couple of concentric coil (valve type) springs. Not sure we need to take it that far yet but it's not an unsurmountable mod if we need to go there.

 

I don't think we need to go that far, though in the end it might be a more refined solution. The belevilles, when applied correctly, offer a reliable and inexpensive solution.

I don't believe OBX has any engineers or ongoing testing, thus the random assembly of the washers. Since the OBX design seems to be sound, except for the low quality of the original belevilles, and random assembly errors, someone with more brains than myself needs to figure out which belevilles and how many offer the right force and deflection with regard to the movement needed. I think Quaife uses the belevilles effectively using a fair amount of deflection to preload the side gears, allowing movement, without exceeding the spring capabilities of the washers. Again, these are probably here to quiet the operations, not provide a bunch of force on the side gears.

I can't see where axles coming together, stressing the washers to the max will have any long lasting positive results.

[Zee77]

First off, I want to thank everyone who has contributed to this thread; very educational! Because of the info posted here, I too decided to go the OBX route for my diff rebuild.

FWIW, I disassembled the unit today and it the gears were in mine upside down as well. And to add to the washer stack files, mine came like this: ((()()().

Now my question, how does one measure the breakaway torque mentioned in some of the earlier posts?

I stacked the McMaster washers )()()()( and am wondering how to measure how they stack up (pun intended) to what others have measured so far.

 

TIA, Kevin.

[John Scott]

I have probably the least amount of differential experience, but willing to state my opinion on using 8, 0.062 Mcmaster washers and feel break away torque has little to do with torque biased diffs. This isn't a clutch type diff. IMO I think they're too thick, especially using 8. The action depends on the twist rate of the helical in the side gear. The washers offer a touch of axle preload and keep things quiet.

I've put a few hundred miles on mine over the last few days. Pushing hard in corners, and lots of drag style clutch drops. I want to confirm its going to be reliable when I take it to the track. Still completely silent, working perfectly, only noticable when you need it. Anything goes wrong, I'll be the first to post.

I hope others are putting theirs to the test and will chime in.

 

Re: jmortensen below:

Anyone able to point to information on needing more preload and adjusting break away torque in a Quaife or OBX, please post the link. If spinning the inside tire on corners with high hp cars were a regular problem, wouldn't there be more posts on the internet and Quaife, beign a reputable company would have addressed it already? Maybe new ones come with stiffer washers??

I searched for days before assembling mine and never found anything except John's old post without any followup results. Surely John Coffey and some Viper(?) weren't the only ones experiencing the problem. There's got to be 1000s of other high hp cars racing Quaifes with no apparent issues.

Possible incorrect assembly, too few or wrong type Belevilles, from Quaife? I'm not doubting the potential problem, but if it is common with Quaifes running in high powered Zs, Vipers, other, wouldn't it and the solution be posted all over the internet?

.........VVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVV........

[JMortensen]

John Coffey had to preload his Quaife to keep it from spinning the inside in a long sweeper. I think preload can be beneficial in these diffs, although I don't think the measurement of 40 lbs breakaway will feel the same on a clutch diff vs a helical.

 

There is a breakdown of how to measure on a CLSD in this writeup: http://www.gordon-glasgow.org/lsd1.asp

[Zee77]

Jon, thanks for the link to the article. Having read it I see what you mean about it not exactly being an apples to apples thing between a clutch type & helical. It did answer my "how to" question though.

John Scott, thanks for your reply also. Since this is going in my street 280z with a mild motor (for now) I rearranged the washers to match your orientation based on your road report.

After many measurement & fit sessions with these washers in the various orientations I figured I would give the least aggressive (from a preload standpoint) setup a try. I figure can always add more preload down the road if the need arises. Since most everyone here is running more motor than I currently am, I think I am taking the conservative approach.

I am very curious to see how everyone else’s setups work once you each have a little more time & miles on them.

Kevin

[rbryant]

I have looked into the washers quite extensively. I have actually sold hundreds of sets of them to the FWD guys and ~15 sets for the R200 diff.

 

Quaife mainly put the washers there to take up the slop and keep things quiet. They should have some preload but it won't do much as you can usually turn the wheel over by hand if you leave the other side on the ground on my FWD OBX LSD. I suppose you could argue that it might give a faster response or give you some traction if one wheel is totally off the ground but it wasn't the main purpose to use them like a phantom slip sytle differential.

 

I provide a set of 6 washers (4 thick and 2 thin) that can be stacked in various combinations to yeild the desired preload. If they are stacked ())(() then they yeild the stock height as they were carefully measured compared to the stock height. Overall they vary some so you can change them to various combinations like )(())( which will give more height because of the way they sit in the retainer.

 

Be careful with the )()()( type combinations because from what I heard the retaining gears don't surround the center of the washer stack on the R200 differential so unless the stack is cupped in the center they could slide out and either lose the preload or jam things up (very bad).

 

I suggest the ())(() because the retainers cover the bold (thick) washers and the curve of the thick washers holds the center washers (mainly spacers) in place. The actual preload comes from the compression of the thick washers. They will compress more and more evenly than the ))))((((( parallel stack combo. The parallel stack also uses a much thinner and lower load washer.

 

I also agree that you want to get about a 50% load on the washers and not fully flatten them out. Anywhere from 25% to 70% is probably ok but the loads change (increase) with the compression amount and we don't want to go past 75% compressed in this application.

 

Also be careful that you don't go over 30ft*lbs on the case bolts they are only a M8 bolt!

 

-Rich

[John Scott]

Just an update. Really cool day on Wednesday, so dialing in my carb was really fun doing long third gear roll on burnouts. Spent a good part of yesterday at a private track day. Endless runs. OBX stood up to countless clutch drops, 2nd gear burnouts warming the tires. Took it for a nice weekend drive this morning. Still absolutely silent, working like new.

My 60' times are down 2 tenths from the open end, best of 1.701 getting real close to 1.6s. imo not an easy feat with a torque-y 383, and relatively skinny 225 50 16 tires.

So far so good. Anyone local wanting a ride to experience an OBX personally, let me know.

[z-ya]

Hi John,

 

Can you define silent? You still have the normal R200 bearing/gear noise as when you run poly mustache bar front mount bushings, right? It's not a gear whine, but more of a mechanical noise that varies with speed. Mine made the same noise when it was an open differential.

 

Pete

[John Scott]

Hi John,

 

Can you define silent? You still have the normal R200 bearing/gear noise as when you run poly mustache bar front mount bushings, right? It's not a gear whine, but more of a mechanical noise that varies with speed. Mine made the same noise when it was an open differential.

 

Pete

 

After I installed I can say mine is somewhat quieter than my open end... due to ?? Maybe my gears found a happier place with the OBX, backlash was slightly less than original where I had a touch of gear noise on float conditions. By silent, I mean the LSD is making no additional noise to indicate it is present. Of one 180, two r200s, the current set up with the OBX is the quietest. I am running all poly mounts, R/T and stock mount, as I was with the open end. I guess it is all relative to what you are used to.

[cygnusx1]

After I installed I can say mine is somewhat quieter than my open end... due to ?? Maybe my gears found a happier place with the OBX, backlash was slightly less than original where I had a touch of gear noise on float conditions. By silent, I mean the LSD is making no additional noise to indicate it is present. Of one 180, two r200s, the current set up with the OBX is the quietest. I am running all poly mounts, R/T and stock mount, as I was with the open end. I guess it is all relative to what you are used to.

 

I second the experience.

[matt_w]

Just got my OBX today...the gears were backwards on mine too. Mine also only came with 7 washers too. However, when I stacked up 8 of the better washers, the height was pretty damn close to the way OBX had their 7 washers stacked. Guess I'll stick with 8 for now!

[rbryant]

Just got my OBX today...the gears were backwards on mine too. Mine also only came with 7 washers too. However, when I stacked up 8 of the better washers, the height was pretty damn close to the way OBX had their 7 washers stacked. Guess I'll stick with 8 for now!

 

 

Just make sure that there is a reasonable amount of preload. Sometimes the FWD diffs come with 5 washers instead of 6. The washers shouldn't compress over 75% to keep a reasonable spring rate and I would generally say 50% or slightly less is a better target.

 

The kits that I provide use two different springs so that you can adjust it to whatever you want. If you are getting over 1.5 turns from the time the case is flush against the washers then it might be too tight. Less than 1 full turn is probably too loose. This is based on the threads having a 1.25mm pitch (one turn is 1.25mm).

 

-Rich

[matt_w]

I ended up going with the 7-washer arrangement that John did. Seems to work pretty well. Before putting mine back together, I soaked the case in degreaser and then ground down the sharper edges with a dremel(there were a lot of pits and pointy parts in mine). Doing that removed all the old packing grease and made the case appear more Quaife-like. Let's hope it stands up to the test of time!

[mcx]

excellent thread!!...any new updates on these installations??