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r200 LSD and Non LSD gear set compatability????


stony

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Im sure this question has been asked but i cant find it in the serach....Can i swap the gearset from a r200 non lsd diff to a LSD r200 diff? I would love to go to a 4.3 ring and pinion and they are readioly available in japan on non lsd cars.

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Then yes but I think it would be easer to swap the LSD carrier into the diff that has a gear set you want. I have heard that changing the pinion gear is a royal P.T.A. I have found (in my limited experience) the carriers from R200 old and new are the same size with the exception of the ring gear bolts and diffrent side stubs (LSD-VLDS-helical (japanese syliva?)). I have tried these and they all seem to bolt in with exceptions.

 

Don

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Yes you can swap R-200 ring and pinion gears and cariers around. The only issue is the ring gear bolt size (others do apply). Most pre-1984 stuff is 10mm bolt where as the later is 12mm, for the Z anyway. The later version of the R-200 with the short snout used different tooth count so they are not innerchangable, but you would only want to use a matched set anyway. Installation isn't as bad as one would think. Much like installing engine bearings. You need a magnetic base and dial indicator and some Dyechem or other wipe removal agent to get the ring gear mesh with the pinion gear correctly. Same stuff you would use to get a wipe pattern on the cam follower. For what you want I'm guessing your going to need bushings for the bolts. Any machinist can make those items and MM has told me they can be done. I have also heard that the ring gear can be bored and taped to the larger bolt. Mike

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Guest Your Car is Slow

I have a similar question along these lines :)

 

Ive recently discovered (after cracking it open to clean last night) that the R200 I purchased is not an LSd but an Open Diff.

 

Anywhoo...since this is going to be a drag car...I could probably just weld it...but it will drive on the street....just not all that much :) and id rather have an LSd rear so im not hoppin around corners..

 

My question is this. Is an R200 LSD carrier something readily available? Or am I searching for a holy grail here? Whats the difficulty of the swap (although I think thats exactly what stony was asking above).

 

I dont want to give up this R200 because it has a 3.36 rear end which is exactly what im looking for.

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The easiest way to do this is to swap the LSD into an open carrier, duplicating the backlash of the gear set on the open carrier. Swapping gears from case to case requires setting the pinion depth. This is not hard, just requires a $100 tool. Proform makes a universal pinion depth checker that aligns off the bearing cap flanges. Since the gears are not marked, you have to measure in one case and transfer those settings to the new case. The diff is the LSD or the open differential, and the case I'm referring to is the cast iron housing.

 

To change just the LSD from one case to the other, measure the backlash before disassembling the orignal 3.70 gearset, swap the LSD into the new case, and check backlash. If it is the same, great. If not, you'll have to adjust it by buying shims from Nissan. Expensive. If you have enough parts diffs, you may have a good assortment of shims.

 

If you are going to put gears into your case, you need to measure the pinion depth in the original case, then match it in the new case. This is to be completely correct. I have swapped all the guts from one case to another in GM diffs without chaning anything and had them last 100k miles.

 

The shims not only control backspacing, but they preload the bearings as well. This is something to consider when doing it. The gears are usually a slight interference fit and will have to be knocked off the LSD and open carrier respectively. I put the bearing opposite the ring gear on a piece of plywood, then use a punch in the bolt holes working across to knock it off. To put it back together, I put the diff in the refrigerator for 45 minutes and the gearset in the oven at 150 degrees for same time. They then slip together and you don't have to use the bolts to pull it up which has the risk of warping the ring gear flange on the diff. Also, replace the bolts. They are not designed to be reused and they are not cheap. If your car wasn't knocking on the 10 sec barrier, I would reuse them.

 

It is not a hard job, just requires careful attention to detail, a few special tools, and at minimum, a Nissan service manual NOT a Chilton's, Haynes, etc.

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Guest Your Car is Slow

After talking to a few people running welded opens...ive decided to go that route.

 

Simple...and certainly the cheapest option.

 

Obviously not a solution for anyone who wants to turn...but the only turning this car will do is "turn 1" from the staging lanes to the waterbox and "turn 2" at the end of the race :)

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ok heres a question... how much play should there be in the input shaft of the diff where the driveshaft hooks up???? I'm talking rotational type of play where you turn the driveshaft from just as the wheels start to move to the other side where the wheels start to move the other direction. mine has 1/8 inch rotation before it engages in both directions. the other diff i have on the floor has virtually no play????? if bad what is causing this and is it fixable?

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Guest Your Car is Slow

Id have to assume that the pinion gear and the ring gear werent exactly lined up properly thus allowing the pinion gear to move a hair before its teeth engaged with the ring gear.

 

Although thats just me thinking out loud :)

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That is what backlash is, but not measured at the yoke. It is measured by holding the pinion in place and seeing how much rotation the ring gear has using a dial indicator on the ring gear .005-.008 is normal for most diffs, but I think the Nissan manual said .010 to .0015? Don't quote that! You can't really tell anything by twisting the pinion as slop in the differential side and spider gears can come into play, you need to remove the cover and use the dial indicator perpendicular to the ring gear.

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Although thats just me thinking out loud :)

 

I'll also think out loud a moment on this one... I think that would be the backlash.

 

Looking in a FSM I have' date=' (was in a 80zx parts car I bought) it shows that backlash can be adjusted several ways, by adjusting pinion depth, and by shifting the carrier to one side or the other.

 

[img']http://home.hpphoto.com/servlet/LinkPhoto?GUID=37d54846-b25e-1755-71ba-5d437c2aa954&size=[/img]

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