I now have the rare 3.36 R200... but it's an open diff.

[2126]

For all who are interested.....and this is regarding the little spacers some us when installing a ring gear w/10mm bolts onto a carrier intended for 12mm bolts. OK, I know some think it really important, however if these spacers are ever so slightly too long, your ring gear will not run true. During my research on LSD (clutch type) I finally went with a unit called a POWERBRUTE manufactured by Precision Gear on the east coast. I specifically ask their set-up guy about using these spacers....he said you can use them, but in all the years and all the R200 differentials they have assembled, set-up and without a failure, he says they have never used any spacers and are not required. He told me.... think about it for a moment, the ring gear is piloted (centered) on the carrier and the torque on the bolts alone keep the ring gear from moving, so why would one want to add spacers that really do nothing? I told him that's what I thought also but just wanted to hear it from a reputable source. So, take it for what its worth....just my small contribution to the post.

[JMortensen]

The spacers are cheap and easy. Yes, it is true that if you make them too long you could have a problem. If you make them 1/8" too short, they still do their job and there is not a problem.

 

I've seen diffs assembled with no spacers and seen them run just fine. On my stuff I wanted the spacers, and there are just a few reasons why.

 

1. The pilot on the R200 carrier, at least mine and Mat's, was NOT a press fit. Since the pilot wasn't a press fit, and the ring gear bolts are obviously 2mm too small, there really isn't as much centering the R200 as there is other diffs where the pilot is very tight and the ring gear gets beaten on with a dead blow hammer. Think of this like a wheel. If the wheel is not hub centric, then it should be lug centric.

 

2. I talked to another guy on classiczcars.com about this and he was advised to clock the ring gear so that it rested on the bolts. There is a reason for this. IF the bolts should come loose somehow and they were able to move 1mm before hitting the carrier, they'd be much more likely to snap than if they were already resting on the bolts. Unfortunately for guys like me that doesn't cover every situation. I do a lot of engine braking and that is stressing the ring gear in the opposite direction. With the spacer I'm covered in either situation.

 

3. It's cheap and easy to do.

 

I think that 2126 is right that the ring gear bolt spacers are NOT absolutely necessary. But for me it was $20 worth of cheap insurance. BTW--the Power Brute is by all accounts made by the same company that makes them for Nissan.

[CruxGNZ]

Here's just one persons thinking on those ring gear spacers/sleeves. This is Hybrid Z, so most cars have quite a bit more torque than stock. In my mind this large amount of torque may move the ring gear as shown in my rather crude illustration below.

 

Now, what that illustration shows may or may not happen, but these spacers/sleeves will prevent that. Are the spacers/sleeves worth that peace of mind? In my opinion, yes.

 

Also, the ones I made were cut to the correct length, just even with the bottom of the chamfer on the carrier as shown in the above illustration, so you guys that purchased a set, don't worry about your ring gear not being true.

 

EDIT: D' OH! Jon posted his message while I was writing mine.

 

!M!

[Jolane]

I have to agree with John and Matt, I also would use spacers. I do believe that it could go beyond peace of mind. First, 2mm is a big deal when talking about screw clearances. That's 80 thou. A "loose" fit for a screw is typically ~14 thou. A tight fit ~3 thou. Regular ~ 7 thou. Even the loose is grossly oversized.

As for indexing the gear, I understand the agrument, but as John already said, what about engine braking? Also, by indexing, you have now removed material from under the head of the screw, effectively cantilevering the head off one side. This can induce a bending moment in the screw, NOT a good thing. Finally, there must be some degree of bolt flexing and gear slipping. I realize that the friction is rather high from the ring gear to the carrier, dependant on the screw preload, but I can't imagine that the bolt won't flex side to side under varying drive and braking loads. With the additional screw clearances involved, it has a lot more room to do this as well. If the ring gear was pinned to the carrier on the other hand (similar to how clutch pressure plates are pinned to the crankshaft), the slipping would be a none issue, and the screws would only hold the gear in place. Maybe issues will never arise, but maybe they will over time due to cyclic loading.

The only reservation I have about using 10mm bolts in a 12mm carrier is, Do the screw heads cover enough of the carrier? Can washers be used?

When I put an LSD in my diff, I will use shims if required and address any screw head issues.

Joshua

[Ezzie]

I'll just toss this in here as well. The R200 assembly procedure in the FSM says to Locktite the ring gear to the carrier as well as the bolts. Must mean to me that they don't want ANY movement there.

[2126]

The spacers are cheap and easy. Yes' date=' it is true that if you make them too long you could have a problem. If you make them 1/8" too short, they still do their job and there is not a problem.

 

I've seen diffs assembled with no spacers and seen them run just fine. On my stuff I wanted the spacers, and there are just a few reasons why.

 

1. The pilot on the R200 carrier, at least mine and Mat's, was NOT a press fit. Since the pilot wasn't a press fit, and the ring gear bolts are obviously 2mm too small, there really isn't as much centering the R200 as there is other diffs where the pilot is very tight and the ring gear gets beaten on with a dead blow hammer. Think of this like a wheel. If the wheel is not hub centric, then it should be lug centric.

 

2. I talked to another guy on classiczcars.com about this and he was advised to clock the ring gear so that it rested on the bolts. There is a reason for this. IF the bolts should come loose somehow and they were able to move 1mm before hitting the carrier, they'd be much more likely to snap than if they were already resting on the bolts. Unfortunately for guys like me that doesn't cover every situation. I do a lot of engine braking and that is stressing the ring gear in the opposite direction. With the spacer I'm covered in either situation.

 

3. It's cheap and easy to do.

 

I think that 2126 is right that the ring gear bolt spacers are NOT absolutely necessary. But for me it was $20 worth of cheap insurance. BTW--the Power Brute is by all accounts made by the same company that makes them for Nissan.[/quote']

 

I just thought I'd through that bit of info out for debate! Personally, I did as was talked about in statement #2....clocked the ring gear against the 10mm bolts, in the proper direction for accelloration, then loctited and torqued the bolts. One thing is interesting for sure, if in fact Precision Gear makes the POWERBRUTE for Nissan.....you gotta wonder why Nissan charges a couple of hundred dollars more than the manufacture for the same unit???

[Psykovertible]

Z Geezer........

 

how much? i am looking into the swap now. i like the idea because it should be easier than an R230 and parts are available.

 

jake in AZ