MM + R200 = trashed diff.

[2eighTZ4me]

Finally got the racer roadworthy and took it out yesterday for a little extended spin. A little history first. R200 CLSD that I had put over 60K on with in my DD. MM billet Z31 CF's. Factory axles out of 87 turbo car. Pulled and labeled by myself - with cages flipped. AZC tubular LCA's. Solid AZC diff mount. AZC mustache bar and diff hanger. Rear ride height set to 7.25"

 

I had driven the car up and down my street a few times with no evidence of binding, grinding, or otherwise at low(er) speed. Got out on a 45mph street and I go about 2 miles (and a couple heavier throttle takeoffs) when all of the sudden this horrid howling sound begins every time I hit the gas and put a load on the diff. Let off the gas - sound goes away. Reverse = no sound. It is literally loud enough in the car to rattle your brain and give you a headache. I was lucky to be very close to the house when it started, so I coasted it in for the most part, hoping to avert possible further damage.

 

Pulled the car in to the garage and put it up. Both wheels still turn the same direction, everything rolls smoothly. Took it back out up and down the street. Was able to make about 2 laps (1/2mi.) with no noise, and then it starts again. Guessing it may be heat related at this point.

 

I have the diff 95% of the way out as of last night and will be draining/inspecting this evening. I've read on other posts that pressure from the longer shaft can cause undue stress on the pinion bearing. I'm guessing this is the case, based on the conditions under which it starts howling.

 

I put 60K on this diff in my DD, and while it made a little whirring in that car, it howls like a banshee now in the 240. I've also done the CV conversion to the DD with the weld-on MM flanges, and I've put over 1200 miles on the car with nary a problem at all.

 

My question is - is it possible for a fairly mechanically inclined individual to replace bearings inside a R200 CLSD? I don't know at this point what all is trashed (but something sure as heck is), but is sure sounds bearing related, and based on what I've read, am almost sure of it.

 

Will be grinding the ends off the shafts while the diff is out, and go back with an open diff I have lying around, while tending to the bruised and battered CLSD. I had heard gnosez killing a Quaife, and he wondered if it was specific to those LSD's. Can't say my situation was 100% caused by the shafts, but I'm leaning heavily in that direction, and it was a factory CLSD, not an aftermarket.

 

Where would you guys recommend getting bearings from? Pull the old ones out and take them to a bearing retailer and have them match them up. Or is this a part(s) you would buy only from the dealer?

 

I believe I am the first on this forum to eat up a CLSD, as I've read over every thread pertaining to this conversion, and have not read of anybody else eating up a factory unit.

 

Just crap.........don't even get 5 miles on the car and I've torn something up already. I hope this isn't a sign of things to come.....

[johnc]

Gear oil in the diff? Maybe a CV shaft is bottoming and putting a side load on the diff?

[2eighTZ4me]

Yes - Royal Purple gear oil filled while car leveled until it dripped out the fill hole. I'm thinking the same thing - a side preload from the long shaft pushing something cockeyed. I can't imagine a sideload on the carrier bearings translating up to the pinion bearing though. I'm not in the least bit savvy with rear ends, so hopefully someone can educate me. I'm just going on what I've read on this forum.

[JSM]

Can you throw your old R200 axles in and give it test drive? I know this would require changing the Companion flanges again, but it may tell you whether your getting a binding issue.

[2eighTZ4me]

When I installed the CV's, I compressed the rear suspension to get enough clearance to fit them in. Didn't compress all the way, just enough to get them in. As I read in another post, you get more clearance the more you compress the suspension. I had a tougher time with the conversion of the DD than I did getting this together. I will pop off the end caps of the shafts this evening and see if the shaft end has made any marks on it. That should tell me if there is any bind on the axle. For safety sake, I think I am going to grind off the excess on the shaft end.

 

At this point, I'm almost convinced the diff is going to require parts of some nature. I guess I'll know when I pull everything apart tonight.

[TheNick]

When I installed the CV's, I compressed the rear suspension to get enough clearance to fit them in. Didn't compress all the way, just enough to get them in. As I read in another post, you get more clearance the more you compress the suspension. I had a tougher time with the conversion of the DD than I did getting this together. I will pop off the end caps of the shafts this evening and see if the shaft end has made any marks on it. That should tell me if there is any bind on the axle. For safety sake, I think I am going to grind off the excess on the shaft end.

 

At this point, I'm almost convinced the diff is going to require parts of some nature. I guess I'll know when I pull everything apart tonight.

 

 

 

Quick tip for the grinding - take some cardboard and cut a hole in it the size of the splined shaft end - place it over the shaft so that it pokes out and the rest of the CV is covered by the cardboard. This way you can grind away on the shaft without worrying about getting metal shavings in the grease of the CV.

 

I did that yesterday and it worked very nicely.

[2eighTZ4me]

Nick - you rock buddy. That's a great idea. Especially after seeing getz's shafts after he ground them. There was metal shavings all over the place. That must have been fun cleanup work.

 

So - did you guys use a bench grinder, or a die grinder with a cutoff wheel?

[Flexicoker]

Take the bearings to a local bearing distributor, they should be able to find the same things for cheaper. The FSM has diagrams on how to set the pinion depth and such.

[TheNick]

Nick - you rock buddy. That's a great idea. Especially after seeing getz's shafts after he ground them. There was metal shavings all over the place. That must have been fun cleanup work.

 

So - did you guys use a bench grinder, or a die grinder with a cutoff wheel?

 

4.5" Dewalt handheld grinder with grinding wheel that it comes with. Probably could have used a flap disc but it would have taken longer.

 

I installed mine with an open R200 but won't ever run it it that way - I'll pull it again to put the LSD in and take a little more off the shafts when I do. I don't think I took enough off. Grinding more than you think you need in this case seems to be a good idea.

[JMortensen]

Take the bearings to a local bearing distributor, they should be able to find the same things for cheaper. The FSM has diagrams on how to set the pinion depth and such.

The FSM describes using a Nissan pinion depth tool as I recall. I think its a fairly safe bet to say that if you reuse the shims for pinion depth and preload with new bearings that it should be pretty close to right. You could do that and then check the pattern and go from there. I'd be checking the ring and pinion REALLY closely though, because if they got some funky wear due to the side loading of the carrier, that could mean it's time for a new diff (which would probably be the cheapest way out anyway).

[getZ]

Especially after seeing getz's shafts after he ground them. There was metal shavings all over the place. That must have been fun cleanup work.

 

 

Believe it or not I had the whole assembly masked off pretty well when I grinded. The only place I couldn't mask off real tight was around the splines themselve and I wiped the whole thing down several times with alchohol before taking the picture. Without the flash you could not see any of the dust in just normal lighting. The camera flash really makes it look filthy, but it's fine dust not shavings.

 

I used a cutoff wheel on a dremel tool, it sounds slow, but it only took about 15 minutes a side and never put enough heat into the shaft where it was uncomfortable to touch.

[z-ya]

Jon is right, check your ring and pinion. Your CLSD is probably fine, but the R&P are probably toast. If the CV axle is too long to allow full suspension travel, it will beat the ring gear into the pinion on every bump. This is what happened to Gnosez's 3.9:1 R&P after less than 100 miles.

 

Pete

[2eighTZ4me]

On the good side - it happened real close to the house, so I basically coasted in and tried to avoid putting any more pressure on the unit.

 

Again - I compressed the suspension about 3/4 of the way from where it would be normally operating at in order to get the shaft in. Under full compression, it will give me additional clearance. Top that off with the fact that I'm running 345lb rear springs - the suspension does not travel much at all. I was not going around any wild corners or doing any off-roading - just putzing about the neighborhood on flat roads.

 

Will go over everything with a fine toothed comb tonight and probably take pics for your opinions.

 

One other thing. I have the AZC adjustable rear LCA's. Would it behoove me to take the adjusters out as far as they will go to allow more clearance? Makes sense that it would.

[JMortensen]

One other thing. I have the AZC adjustable rear LCA's. Would it behoove me to take the adjusters out as far as they will go to allow more clearance? Makes sense that it would.

Not in my opinion. The further the rod ends are threaded out, the weaker they are. The rule of thumb here is that you should have 1.5x the diameter of the shaft in the threads. Taking into account the 3/8" thick standard jam nut, this means that you should turn them out so that no more than 5/16" of thread shows.

 

I'd suggest that before you run it again you pull the rear springs and manually move the suspension through its range and check for bind. When I say manually I mean by hand, not with a floor jack.

[2eighTZ4me]

OK - I screwed the pooch. johnc moves to the bonus round for his quick (and correct) answer. No gear dope.

 

Go ahead and think it, but please don't post it - I beat myself up thoroughly last night when I pulled the plug and a couple ounces came out.

 

No excuses. Blatant stupidity. I thought I had filled it when I put it in over 8 months ago. Funny how old age and memory tends to fail somethimes.....

 

On the good side though, when I unbolted the shafts with the suspension at full droop, they both pulled right out of there with almost 1/4" clearance. No marks on the endcaps, so I did indeed have the clearance I needed.

 

I must retract any bad statements or connotations about MM - their product works as designed, and is a very good product(s).

 

I checked the pinion bearing and carrier bearings. Smooth as silk with no binding whatsoever. I checked the ring and pinion gears. No chipped teeth or anything broken. The ring gear was worn dry, but no bluing had occurred from heat, so at this point, I'm gonna clean the heck out of it, chuck it back in (and then fill it with dope) and run it and see what happens. The drain plug magnet had some fine shavings on it, but no chunks, so I think I'll be ok. I've really got nothing to lose at this point.

 

What do you guys recommend for gear oil for the CLSD? I've used the Royal Purple before and it says it has the limited slip additive in there, so was wondering if that is enough, or what "cocktail" you all use.

 

Apologies again for my own stupidity and oversight. Anybody got any barbecue sauce for the crow I'm eating??

[woldson]

I've filled an engine once, started it, let it run just a bit.

No oil pressure. Investigation reveiled............. FORGOT to put in oil plug!!

BTW I was 14 or 16.

 

It happens. I will keep my fingers crossed for no damage.

[johnc]

Use an 85W-140 GL5 gear oil and add two bottles of friction modifier. I put a little manila paper tag on diffs, engines, transmissions, and radiators with the word "DRY" written on them whenever I re-assemble or install the part.

 

http://www.uline.com/BL_3018/Uline-Manila-Shipping-Tags-Pre-wired

[md614]

What do you guys recommend for gear oil for the CLSD? I've used the Royal Purple before and it says it has the limited slip additive in there, so was wondering if that is enough, or what "cocktail" you all use

 

Mayolives recommended Synergyn gear oil to me. I have had good results from this . I use it in my trans and diff. Noticed the trans shifted a whole lot better. A benefit is you dont have to use any friction modifier.

[JMortensen]

I use SWEPCO 201, and haven't needed additive buy there's no harm in adding it if you do get some chatter. Any good gear oil will work, I don't think any of them are "miracle oils" anymore. SWEPCO 201 and ATF 50/50 works really nicely in Nissan transmissions, but I'm sure a lot of other oils do too.