R180 Axel geometry and stregth with LSD

[rudypoochris]

hi i know this has been talked about alot but i havent been able to find a clear cut answer to either of these questions.

 

1. Can the r180 with a 3.90 gear and LSD take 225hp and 300 lb/ft of torque, how about 340hp and 310lb/ft (no clutch popping but some 3,000 rpm starts)

 

2. Can the r180 in earlier cars be moved back to correct the half shaft angles with out modification to the half shaft's length's? (so can the mustache be flipped and the diff moved back without cutting the half shafts shorter)

 

thanks!

[blueovalz]

The shafts will do fine if you move the differential rearward. I believe all that is needed is the later model mustache bar and mount to do this. The driveshaft length will need to be addressed as well.

 

Will the R180 hold up to the 300lbs+ of torque? I'd say marginally. I've personally only known two folks using stock powered 350 SBC powerplants (both with automatic transmissions) and one broke the R180 twice, the other never. So....

[2126]

I think the key to an R180's strength is having a 4 pinion spider assembly in the diff carrier assy. The stock open units have a 2 pinion spider...as well as the stock R200 open diffs. Fortunitely, most every LSD carrier I've seen or installed have a 4 pinion spider assy.

[JMortensen]

I've seen 2 people break a 180 LSD behind L6 motors. Neither engine was built either. Both people drove the car hard, one snapped the mustache bar prior to actually breaking the carrier. I had assumed that they both had the 2 pinion LSD just because it broke, but I'm not sure. One of these two actually broke the carrier itself.

 

Only the early cars had the funky axle geometry. 70 and early 71, after that they were switched so that the axles line up with the diff. The quick and easy identifier is the transverse link. If it is straight, then the car has the diff forward. If it is curved, then the car has the diff moved back. Some of the 70's and 71's had the diff moved back after customers complained of vibrations, so while most 70's and early 71's have the diff forward, I've come across a few that were already moved back.

 

You don't need to worry about halfshaft length when you move it back. If you go to CV shafts you can leave it where it is, but that's not as easy with the R180 as it is with the R200.

[260DET]

Not all R180 diffs were created equal, the later ones had thicker stub axles, a very desireable feature. Don't ask me to define 'later' because apparently in this area what the US got was not always the same as elsewhere.

 

All I can say is that before removing the R200 and going with a ATB R180 using the skinnier 4wd stubs, after doing the research I was happy to do the change, anticipating up to 280 rwhp and turbo torque once the goodies were screwed up.

 

But thats with a rolling start, no clutch dumping which kills transmissions.

[rudypoochris]

http://www.nismoparts.com/catalog/?section=530

 

nismo 4 pinion lsd up to the task? i have a 71 240z most likely the earlier r180 and it isnt in the set back position, hmmm

[JMortensen]

Now you're going to hit another snag. In 74 or 75 they changed the ID of the ring gear and the later one is more common. So IIRC that LSD that you linked to won't fit your 240Z diff.

 

I don't think the early diffs came in 3.90, so if you have that it's probably a later diff swapped in. Easy solution is to get the front diff out of a mid 80's Nissan 4x4 which came in 3.90 and 4.11 I think. Those will fit the LSD and give a much better ratio than the original 3.36 (manual) or 3.54 (auto) that came in the early Z's.

[johnc]

Regarding R180 strengh; a lot depends on what you're going to do with it.

 

Autocross: Marginal at 300 ft. lbs.

Road Racing: OK at 300 ft. lbs. Heat is the biggest issue and a cooler will be required.

Drag Racing: Won't survive at 300 ft. lbs.

Street: Probably OK as long as you don't imagine yourself as a Junior John Force.

 

All the above assumes the Nissan 4 pinion LSD or a Quiafe.

[dirty white boy]

Now you're going to hit another snag. In 74 or 75 they changed the ID of the ring gear and the later one is more common. So IIRC that LSD that you linked to won't fit your 240Z diff.

 

I don't think the early diffs came in 3.90, so if you have that it's probably a later diff swapped in. Easy solution is to get the front diff out of a mid 80's Nissan 4x4 which came in 3.90 and 4.11 I think. Those will fit the LSD and give a much better ratio than the original 3.36 (manual) or 3.54 (auto) that came in the early Z's.

 

 

so let me get this straight.....i found an 84 720 4x4 w/4:11 front diff.

 

is this a direct bolt in in a 73 240 with the r180?

 

can i keep the 4x4 stub axles and bolt my half-shafts to it?

 

also will the drive-shaft flange on the 4x4 diff work with the 240 drive-shaft?

[Zmanco]

so let me get this straight.....i found an 84 720 4x4 w/4:11 front diff.

That's how I sourced the diff for my 73.

 

is this a direct bolt in in a 73 240 with the r180?

Yes, but you have to swap the flanges.

 

can i keep the 4x4 stub axles and bolt my half-shafts to it?

Do you mean stub axles or flanges? I swapped the stock half shaft and drive shaft flanges to the new diff before installing.

 

 

also will drive-shaft flange on the 4x4 diff work with the 240 drive-shaft?

No, but you can swap from your existing diff. It's a lot easier if you have an impact gun.

[dirty white boy]

thanks a lot zmanco.

 

i'm not familiar with all the terms yet......

 

in the haynes book they're calling it a flange yoke (what i was calling a stub axle) but from what i gather if i use all my 240 stuff on the bare 4x4 (chunk) it's a direct bolt in.

 

is that right?

 

also is it a LSD?

[Zmanco]

The stub axles are what connects the wheel to the half shafts. You don't want to change those unless you have to - not a fun project.

 

The diff I pulled was open, and I suspect they all will be - remember this is coming off the front of the pickup. Probably not a bad idea to pull the cover and check things out inside. You should also check the side bearings before you install it. I didn't bother and found out that they were shot once I drove it - nothing like pulling it back out the very next day

[dirty white boy]

thanks zmanco.

 

i had PM'd katman before i posted in this thread and he just got back to me. he says.....

 

Quote....First, they run the diff backwards on the front of the truck so the gears are broken in a different direction so it may whine (which we didn't care about because it was on a race car).

 

i'm gonna run it in a street car and don't mind a little whine but what about wear on the gears if any?

 

what results have you had with yours?

[johnc]

Never had an issue with the truck R180s.

[Zmanco]

There is whine between 50 and 60 mph when under accel but not on coast/decel, but it's more of a resonance than gear whine I think. From what I've read, this was a common issue for early Z's "in the day" and there was a TSB to add a weight to the diff. I tried that and it only helped a little. It's silent the rest of the time. The rest of the car is loud enough that it's not an issue for me.

[dirty white boy]

are the 4x4 diffs 2 or 4 pinion? or could it be either?

[Zmanco]

are the 4x4 diffs 2 or 4 pinion? or could it be either?

I'm afraid I don't remember - I swapped it out for a CLSD a few years ago. Perhaps someone else knows?

[johnc]

Two pinion. No Nissan R180 came to the US with a four pinion open diff or a LSD.

[dirty white boy]

are all r-200's 4-pinion or could it be either?

[MAG58]

are all r-200's 4-pinion or could it be either?

 

 

Got'cha covered.

 

http://forums.hybridz.org/showpost.php?p=683833&postcount=1