Diff Gods, please help..

[abes]

I've been working on my R200 for over a month now and I'm tired and just want to toss it...I bought new clutches for the LSD so that I could have what I thought would be a fresh rebuilt diff, not the case thus far...I purchased new all new bearings (except the NLA front pilot bearing) and seals and went to town. Took it all apart, cleaned it, reassembled the LSD and pressed those bearings on, no issues (I even decided to buy my own 12 ton press). Now comes the fun part. I pressed both front and rear pinion races into the housing and pressed the new bearing with the original washer/ spacer onto the pinion gear (per the manual). I slid it all into the housing with the (cone looking) adjusting spacer and washer then dropped the new pinion bearing, with the pilot bearing spacer and the pilot bearing with the flange at the end. I did not install the oil seal yet. Placed it into the press and slowly pressed down from the pinion side until the bearing inner race was sitting, it pretty much stopped.

 

When i took it down and tried to turn the flange it was hard!!! I don"t have a inch/ lbs. torque wrench but it was not easy to turn by hand. This was the second time as i had just disassembled and reassembled the entire pinion set up (bearings and races) because I couldn't figure out why it was binding. The first time around I just torqued the pinion flange w/o the oil seal to 140lbs and the same thing happened. I took off the flange thinking it had something to do with it but it made no difference.

 

Would the new bearings make that of a difference?? I don't what else to do. I'm using all of the original spacers and washers in the same order.

 

HELP PLEASE....

[JMortensen]

Sounds like the pinion bearing spacing is off. That might not be so bad if you can just shim it right. The bigger question is WHY is it off, and if it is off, is the pinion depth also off.

 

I would suggest that you read this manual and get some gear marking compound. Check the pattern and see if the pinion depth is right. If it is, reset the pinion shims to get the correct preload and you should be good to go. If it is wrong, then you'll have to pull the pinion bearing and shim it until it is right. If you get it wrong, the diff will howl.

 

http://www.ringpinion.com/Content/HowTo/TechnicalInstructions/Yukon_Installation_Kit_Instructions.pdf

 

The pilot ball bearing is almost always the one to go bad. If anyone else is thinking of doing this, I'd suggest inspecting the bearings and replacing JUST the pilot if the others look good but it feels like there is sand in there when you turn the pinion with the carrier out. That way you don't get into any of the preload/depth hassle.

[ezzzzzzz]

The front bearing can be purchased but it is hard to locate. Tidewater Z Auto Service in Poquoson Virgina (http://www.tidewaterz.com) can sell you one. He still has several on the shelf. I have no business affiliation. We just belong to the same club.

[abes]

Sounds like the pinion bearing spacing is off. That might not be so bad if you can just shim it right. The bigger question is WHY is it off, and if it is off, is the pinion depth also off.

 

I would suggest that you read this manual and get some gear marking compound. Check the pattern and see if the pinion depth is right. If it is, reset the pinion shims to get the correct preload and you should be good to go. If it is wrong, then you'll have to pull the pinion bearing and shim it until it is right. If you get it wrong, the diff will howl.

 

http://www.ringpinion.com/Content/HowTo/TechnicalInstructions/Yukon_Installation_Kit_Instructions.pdf

 

The pilot ball bearing is almost always the one to go bad. If anyone else is thinking of doing this, I'd suggest inspecting the bearings and replacing JUST the pilot if the others look good but it feels like there is sand in there when you turn the pinion with the carrier out. That way you don't get into any of the preload/depth hassle.

 

 

How do you think the pinion depth changed? I'm using the same set up except for the bearings.

Thanks..

[abes]

Well, now I'm p'd off...I disassembled the entire thing, replaced the pinion bearing with a different new bearing (Koyo) and even purchased and replaced the front pilot ball bearing (Thanks to TidewaterZ and ezzzzzz). I scoped all the sizes with the original bearings and everything matched. Pressed the entire assembly and same s#!t.... Im stuck and don't know what else to do.

[JMortensen]

If you mic'd all the bearings and they're dimensionally the same, there shouldn't be any bind in the pinion. The fact that there is means that something has changed. If you missed a pinion shim, that would cause the pinion to bind up.

 

Once you get the pinion spacing right, then you can put the carrier in and check for pinion depth. But you can't really check the pattern without being sure that your pinion is seated all the way, so that means that you'll need to figure out your pinion bearing preload first. On most diffs you don't have the front ball bearing, so it's less of a hassle.

 

If you're completely stuck you might take it to a gear shop along with a FSM.

[abes]

If you mic'd all the bearings and they're dimensionally the same, there shouldn't be any bind in the pinion. The fact that there is means that something has changed. If you missed a pinion shim, that would cause the pinion to bind up.

 

Once you get the pinion spacing right, then you can put the carrier in and check for pinion depth. But you can't really check the pattern without being sure that your pinion is seated all the way, so that means that you'll need to figure out your pinion bearing preload first. On most diffs you don't have the front ball bearing, so it's less of a hassle.

 

If you're completely stuck you might take it to a gear shop along with a FSM.

 

Thanks for all the help so far. Unfortunately, I haven't been able to figure it out yet and I haven't found anyone locally who can help so... I guess I'm gonna need all of your patience. This is what I'm doing:

- I have (and read both) the factory SM for both the '83 280zx and '88 300zx which both show the r200. Funny enough, some of the torque numbers don't match. Somehow, I don’t think I’m getting it. Also, have you ever used any of the set up tools or adaptors?

- All of the bearings are brand new. Mic'd to exact tolerances as the originals.

Order of assembly:

1. Pressed the pinion height adjusting washer and bearing onto the pinion/ gear. There was only one washer which is what I used.

2. Pressed the outer races of the pinion rear bearing and the pinion front bearing onto the diff carrier.

3. I slide the adjusting spacer on- with the adjusting washer right after.

4. I slide the entire assembly into the carrier and hold it in place with a small piece of wood which slides in through one of the side openings. I then flip it over, slide the pinion front bearing, front pilot spacer, pilot bearing and the flange onto the pinion shaft.

5. I place it in the press and slowly press in the assembly from the pinion gear side. RIGHT AFTER THIS STEP, IT LOCKS UP. I’ve also tried assembling it the sme but instead of pressing it all the way into it seats, I torque slowly until I reach the 160lbs +/-. STILL LOCKS UP. IM ASSUMING THAT THIS IS PRELOADING??

 

I‘ve sourced some shims from a driveshaft shop, which actually helped. I put in the thinnest shim that would work (placed on top of the adjusting washer) which freed up the assembly. I placed the front seal and re-torqued the flange. All good so far..

 

I slid in the ring gear/lsd assembly with the new bearings and spacers as originally assembled, tapped the caps into place so far so good, torqued and then…. IT LOCKS UP. HARD TO SPIN THE FLANGE. IT TURNS A FEW TIMES FREELY AND THEN LOCKS UP. Zero backlash. Does this change the pinion depth?

 

Since I added a shim to the adjusting washer, do I need to reduce the pinion height adjusting washer size? If so how? Am I missing any steps?

 

I'm extremely tiered and don't know where to head. Any direction would be greatly appreciated……

Edited March 28, 2011 by abes

[JMortensen]

Pinion bearing preload is effectively setting the distance between the two tapered roller pinion bearings. If you are missing a shim, the distance set is too short, and when you put torque on the pinion nut it pulls the bearings hard into the the races and locks it up. Adding shims will decrease the load on the bearings when the pinion nut is tightened. Too many shims will leave the pinion loose. There is a spec in the Factory Service Manual, I can't recall what it is and I don't have the FSM anymore, but if you find that spec it will tell you how much drag there should be at the pinion nut. In order to test the drag, you need a 1/4" torque wrench. Using a 1/4 to 3/8 and a 3/8 to 1/2 adapter, you put your socket on and turn the pinion nut as slowly as possible for you to get a smooth measurement. As I recall the FSM has specs for with pinion seal installed and without, be sure you use the right one.

 

I don't think you're to this point yet, but It is possible to have the pinion seal installed but not bottomed, and in that case the little dust seal can hit the pinion flange and drag a lot. I experienced that one myself.

 

Your work on the LSD is premature. You need to get the pinion spacing corrected, THEN do the LSD. If you don't have the pinion right and for instance you have too many shims in there so the pinion can move around laterally, that might cause the lockup you're describing. If you have the pinion secured, installing the LSD should be next, and then you check the backlash. Backlash won't change based on you turning the pinion shaft, so your experience there means that something is wrong with the pinion.

 

I have disassembled and reassembled a couple R200s, swapped the ball bearings twice, changed seals, added clutches and shimmed the LSD's. I believe there are a couple people on here with more experience than me, Mike C and zcarnut and maybe SATAN being the ones that come to mind. They might have some insight that I do not.

 

John Coffey has suggested Unitrax as a shop that can build R180s and R200s in the past. If you get really stuck you can probably ship it to them and have them fix it. You might consider buying another diff, swapping the ball bearing and installing the LSD and leaving the rest of it alone. The bearing swap in an R200 costs probably $400 in parts, plus shipping, plus labor if you send it off, and doesn't get you ANYTHING if the bearings aren't damaged.

[Mike C]

Is this a complete 3.70 LSD center section or are you swapping into another housing at the same time you are rebuilding? Or changing gear sets for that matter? Trouble shooting an anomaly is always a hassle.

 

My process for doing pinion bearings is to always measure the installed height of the pinion so you can check height on reassembly. Obviously without a depth checker you can't do that, or if you have already taken it apart, so next... Now that it has been reassembled and we find an issue this is where I would start:

 

Step 1: Disassemble. The whole thing unfortunately. You need to make sure there is neither a burr or piece of trash caught between the pinion depth setting shim and bearing or any of the races in the housing. While it is apart cross check all bearing and race part #'s and visually compare the old and new bearings just in case.

 

Step 2: Reassemble pinion gear, bearing, and depth shim. With the original pinion depth shim cleaned & deburred, re-assemble pinion bearing and shim onto the gear. Make sure bearing is pressed all the way down and is even all the way around.

 

Step 3: Inspect and clean/deburr housing where the pinion bearing cups install. Re-install bearing cups. Make sure all cups are fully seated and square in their respective bores.

 

Step 4: Finish reassembly of pinion with all existing parts and see how tight the assembly is. From the centerline of the pinion, a 10" long bar with a 1 lb weight on it should NOT rotate the pinion, but on a 13" bar will. You should be able to rig something up, just snug up on it until you get there, that will be just over 10 inch pounds. Beam type inch pound wrench is available for about $30. It's kind of surprising how much 10 inch pounds is.

 

Step 5: Now that you have preload set, you can check for play using your dial indicator by pushing and pulling on the pinion and checking total movement. This will give you a starting point for adjusting shims if needed.

 

Step 6:And this is a little out of the normal order as before I finish shimming and adjusting the pinion I would-

 

Step 7: Put the carrier back in and check for backlash. Once again, backlash is something I measure before I take it apart so I can compare on reassembly. If you skipped that, then we are measuring to see how close it is to spec. If it specs, now time to run a gear pattern. If the pattern looks good (and check it with the pinion loaded somehow to really squeeze out the marking compound) pull the carrier and finish adjusting the pinion bearing preload through trial and error shimming.

 

Step 8: If pattern is whacked, then you have to look at some pictures and figure out what spec has changed. If it is pinion depth, somehow you need to verify what the correct depth would be. I don't remember how/if Nissan marks the pinion head to show depth or if it is assembled without any markings ala GM. This will require getting a pinion depth checker if you have depth info. Summit and Jegs both have house brands for about $100.

 

Step 9 and Beyond: Once we know the pinion depth is right, we can move side shims to adjust backlash. This can all be quite the pain with assembling and disassembling the whole thing, but at least the carrier shims are not BEHIND the bearings like on Dana axles.

 

Good luck and I hope this makes sense. I have read it and read it looking for inconsistencies in my descriptions, but they might be there!

[zcarnut]

I agree with Mike C. I would remove the pinion races in the housing, clean them with solvent followed by a blast of air, and re-install them. You may have trapped a tiny piece of debris under one of the pinion races and this would cause one to be slightly askew. Do not over lube them before installation. A very thin coating of lithium grease is all that is required.

 

You should not have torqued the pinion nut to 140 ft-lbs initially. You should tighten the pinion nut lightly (by hand) initially, check (measure) the pre-load with an inch-pound wrench, and then gradually tighten the pinion nut in stages, checking the pre-load as you go. If the pre-load is ever excessive, then STOP. Pre-load will only increase as the pinion nut is tightened.

 

Your initial application of 140 ft-lbs (when the spacing washer is too thin) is may have damaged the pinion bearings.

 

It is not unusual to have to change the pinion pre-load adjusting washer when the pinion bearings are replaced. I have re-built about a dozen R200 and R180’s and three of them required different (new) pinion washers.

 

Note: Use a “regular†nut for the pinion nut when you are checking the pre-load as you may need to remove and install the pinion shaft several times. The stock pinion nut is a true lock nut and should only be used once.

[abes]

Thanks for all your help guys. I was able to locate and order a inch pound TW which my wife just brought home for me. I will disassemble everything, clean and reassemble according to your directions. Hopefully the next time I'm on i'll be sharing good news...

[abes]

Well, I was able to finally assemble everything (after minor shimming) and put it all together. Slapped it in the car and drove it around. It has some minor whine but only at about 60mph (under load) bearable for now. It may also be the tranny but at this point, I'm not too concerned.

 

What is driving me CRAZY is the MAJOR CLUNKING!!! I drove it around a bit to make sure the fluid (Swepco) gets into the clutches and gears, did about 10 circles in each direction, drove it some more, drained and re-filled it.

 

I've driven about 150 miles on it and this think makes some harsh clunking. It only happens under load and while I'm turning at slow speeds. I've narrowed it down (so I think) to it being the clutches. It went from a worn 2-clutch LSD to a new 6-clutch with God knows how many miles through it. I didn't put any spacers in it cause I wanted it to be as streetable as possible but that is certainly not the case.

 

What I think it may is that the spider gears are worn to the point that there is a significant amount of play between them and when the clutches are under a bit of torque, they want to lock and then release causing the MAJOR CLUNK. It sounds like the gears are jumping through broken teeth and the whole car moves with it. It can be heard pretty loud from the outside.

 

I lifted the car and removed the back cover to see if there was anything visibly wrong. There was a small amount of metal shavings on the magnet but none that I was concerned with. There was alot of play between both wheels- shifting back and fourth. I know there should be some play but it seems a bit excessive to me. When I put in gear and let it spin, it doesn't make the noise but once I let it idle in gear while, i can hear it hitting. It's kind of hard to describe but it spins the wheel and when it reaches the speed or spins a little faster, there is enough play that it hits and makes noise.

 

I feel that all that play plus the clutches locking the diff may cause the noise.

 

Anyone have an experience like this???

[abes]

Well, I was able to finally assemble everything (after minor shimming) and put it all together. Slapped it in the car and drove it around. It has some minor whine but only at about 60mph (under load) bearable for now. It may also be the tranny but at this point, I'm not too concerned.

 

What is driving me CRAZY is the MAJOR CLUNKING!!! I drove it around a bit to make sure the fluid (Swepco) gets into the clutches and gears, did about 10 circles in each direction, drove it some more, drained and re-filled it.

 

I've driven about 150 miles on it and this think makes some harsh clunking. It only happens under load and while I'm turning at slow speeds. I've narrowed it down (so I think) to it being the clutches. It went from a worn 2-clutch LSD to a new 6-clutch with God knows how many miles through it. I didn't put any spacers in it cause I wanted it to be as streetable as possible but that is certainly not the case.

 

What I think it may is that the spider gears are worn to the point that there is a significant amount of play between them and when the clutches are under a bit of torque, they want to lock and then release causing the MAJOR CLUNK. It sounds like the gears are jumping through broken teeth and the whole car moves with it. It can be heard pretty loud from the outside.

 

I lifted the car and removed the back cover to see if there was anything visibly wrong. There was a small amount of metal shavings on the magnet but none that I was concerned with. There was alot of play between both wheels- shifting back and fourth. I know there should be some play but it seems a bit excessive to me. When I put in gear and let it spin, it doesn't make the noise but once I let it idle in gear while, i can hear it hitting. It's kind of hard to describe but it spins the wheel and when it reaches the speed or spins a little faster, there is enough play that it hits and makes noise.

 

I feel that all that play plus the clutches locking the diff may cause the noise.

 

Anyone have an experience like this???

[JMortensen]

Sounds like clutch chatter. Solution is to add friction modifier until it goes away. SWEPCO has enough that a stock LSD won't chatter. I haven't tried it with the extra clutches or with a shimmed LSD, but adding the modifier isn't a big problem either way. Clutch chatter with no additive can be really bad. I installed a Toyota LSD that I installed without additive and it sounded like the differential is going to fall out of the back of the truck. I thought something had gone horribly wrong. Added some friction modifier, and it worked silently.

[abes]

Finally!!!! Some good news. The chatter is gone. I poured 1-1/2 bottles of LSD additive (just because I bought 2) in the diff and drove around-vioala,no more chatter.

 

 

JMORTENSON.. THANK YOU!!!

[JMortensen]

Sure thing. Glad it's back together, and FWIW I think R200's are just kinda noisy, especially if you're running poly bushings. I'd call it done and drive it.