mdbrandy

Ok, to continue this thread... I've been exploring the diff, and I have one potential problem, and a few pics. The potential problem is that the RH flange and shaft has a lot of runout and movement compared to the LH (the LH essentially doesn't move at all in, out, or laterally). The RH shaft will move in and out 0.05 inch or more. In the picutre I've attached here, you can see a small gap between the thrust washer and the gear carrier when I push the shaft all the way in. In the next picture, you can see it closed as I pull the shaft outward. The whole assembly kind of "rocks" a little too. The third pic is of the RH bearing. Note that as I "rock" the shaft and/or pull it in or out, the rollers in the bearing don't move at all. Maybe I don't fully understand the geometry. Finally, is a pic of the ring gear teeth. Nice to be able to upload multiple pictures! Yeah!

Ok, so I'm getting ready to go over the differential I just bought before I put it into my 280Z. I've ordered new pinion and halfshaft oil seals that I will use, and since the cover was off when I bought it, a new gasket too (although I just read one of our tech articles that recommends Nissan silicone for that "never leak" seal). The gears seem to turn freely and smoothly, but I don't have any experience with working on the inside of a differential, so I don't really know what I'm looking for. I read the FSM section on servicing the R200, and while the diff itself seems reasonably simple, there appear to be a plethora of special tools recommended to set clearences, preloads, etc., that I don't have. So I really don't want to take it apart myself. The question is, should it be taken apart? My goal is to "freshen it up" so that I don't have to worry about it for many miles to come. New seals are a no-brainer, but what about bearings? I have no history on this diff. Without taking it apart, can I tell what condition the bearings are in? The teeth on the gears look fine as far as I can tell, although I'll inspect them more closely tomorrow. Are there some set of measurements that I could have a shop with the right equipment (I don't even have a dial guage yet) do that would diagnose any normal problems? Three things that the FSM say to do that don't require dissassembly seem to be pinion preload, ring/pinion backlash, and the tooth contact pattern. Would those measurements be enough to really tell the condition of the unit? Thanks in advance for your expert advice :classic: !

Hey, the way things are going on e-bay recently, pretty soon the set of braided hoses on that engine will be worth his asking price!!! ROFL LOL

I haven't had to use it for much yet, but I picked up one of these Clymer manuals on e-bay. On looking through it, I did like the info it contains - and the reason I got it is because it only covers 1970-71, so it hasn't been diluted with info from the later 240Z models. It does have many good illustrations, that do appear to come directly from the FSM (which I also have). FWIW.

FYI, assuming she's still around (I haven't seen or heard from Chloe in a couple weeks now), she sells Moog too. For my 280, I was agonizing over doing Nissan at almost $100 apiece or Moog for half that or so. I went with Moog since my 280 is not going to be original anyway, and Chloe says she's had no complaints about the Moog. That's still more expensive than the e-bay ball joints, but I try to avoid the generic import parts, especially for critical suspension and engine pieces.

Unfortunately, I don't know. This pic was taken over a year ago, and the parts are in one or more boxes right now. Also, I never got to actually drive the car, except from the PO's house to mine. So, if I had to guess, I'd say an ignition buzzer maybe? Sorry I can't be more help on that one. I took the pics so I could have a reference when it's time to put it all back together. Hopefully it will be enough . Mark

And one more, but probably not as useful.

Here's one of the best pics I have of that area from the disassembly of my '70.

Mike, I sure do hope that's the problem. Too much business is an interesting problem to have :classic:. However, I haven't seen ANYONE that says they've heard from her since I got a package from her on the 22nd, so I just hope all is well at MidwestZ, and just busy.

Got to admit, I've e-mailed her twice over the past 10 days without response. That is very unlike her.

My first car was a 1971 240Z. However, depending on the condition of the car you get, be prepared for work and downtime if it needs fixing up. When I got mine, it was only 7 years old! You'll be getting one that is 30+ years old! As long as you know what you're getting into, it could be great. They do rust, though. Make sure to search the forums on this site to learn about how to tell if a car you're looking at is even worth considering. Rust is our enemy!

We need an emoticon for "I AM REALLY, REALLY, REALLY JEALOUS"!!!

Thanks, Keith, at least I know it's a common problem now. This car sat for 10 years (well, it was driven 2000 miles in that time), so I'm having all sorts of interesting seal failures after having driven it another 4000 miles over the past 8 months. I'll top it off and hope it makes it long enough to get me to my diff replacement time.

So, it looks like I'll be working on the differential in the 280Z just in time. I have noticed an oil drip from the center/rear area of the car over the past couple weeks, so I put the car up in the air today and rolled under it. I was expecting to see a leak from the rear trans, but upon inspection, it appears as though it is the front diff oil seal. Is this a common seal failure? Within the next two months, I intend to drop the diff and replace it with another unit anyway - how critical is it to keep the diff completely full? So far, there is no noise. The area around the front of the diff is coated in oil, the weight below the front diff mount is dripping, and the driveway has 10 or 20 drip places on it from the past few weeks. Is there anyway to tell when it is getting 'too low'? Thanks.

Since I already have the 3.9 coming, and I am going to drop the diff this summer while I am replacing bushings and the diff and trans mounts, then I will probably install it. I can't really afford to go out and find a 4.11 for what BleachZee indicates would probably be at least a couple hundred $$, especially since I already have the 3.9 on the way. It's purely a matter of fun anyway, since I don't race, and unless I find more time and money probably won't. The 3.9 has to do something for the car, and the extra 0.21 on top of the 0.36 would only be incremental. If I was trying to race and be competative, I'd definately be taking this thread's advice and go for the 4.11. And I only get 17 - 18 mpg in the city now, so 25 would be amazing. The original EPA rating on the '78 280Z was 18 mpg, though, so I dont' think I'm doing too bad.

I like air dams on Z's, but this one is much to heavy and squared-off for my tastes. It looks like it belongs on a ZX. FWIW.

Interesting. From your gallery pics it looks like you have a 77 or 78 280Z. How about gas mileage? Did you see a change?

Thanks for all the impressions and knowledge transfer - that's what I was looking for :classic: . Bottom line is that if I ever get the 280 out on the track, it will be fun, but I have never done anything like that before, and it isn't in the short term plans right now. Mostly, I'm just looking for a little more "kick" in my daily ride. Now, this summer, I am doing the poly bushing/tokico illumina + spring upgrade, plus new tie rods and ball joints, so if I get some track time, I'll be ready ( or at least the car will!) . I am currently running 205/60/15's on the car. The transmission calculator indicated that with those, my speedo should be close to dead-on compared to stock tires, so I was assuming that the actual wheel/tire diameters are about the same as stock. 2manyZ's - is your guidance related to lower profile 14" tires, which would have a smaller overall diameter? And I wish my daily driver was a 240, but it's not, and I'm happy with the 280...for now. I'll keep working on #215, but I will probably never use it as a daily driver if I get it back to where I want it to be.

I got a new hardback book, a 1/18th scale model of a 1970 240Z, a nice steak dinner, and 5 hours alone in the garage, trying to find my real 240Z that has been slowly being buried under car parts and tools for the past 6 months. I am happy to say, I can almost work on it again now :classic: .

I just received a shipment from Chloe two days ago, so she was in and shipping late last week.

I remember back in grade school (and that was late 60's into early 70's), with the "new math" and introduction of the metric system, we were all told that the US would be completely metric within 10 years. RIGHT! When I did my engineering degrees in the 80's, we ended up learning both metric and US units. Learned to hate doing engineering calculations in US units. The metric system is SO much easier.

Yeah, I just found that one to, but it is a bit short on specifics. Apparently beandip forgot to update it, or didn't find the part numbers. The oil pressure cutoff actually is the way that late 280Z's and 280ZX's do it instead of the air flow meter. That's why the later 280's have oil pressure sending units that have two spade terminals instead of the single bullet terminal. I wonder if a late 280 unit could be adapted to do the job?

Somehow, you need to cut power to it when the engine is not running. In the FI system, the fuel pump contacts are in the air flow meter, so if there is no air flow into the engine, the contacts open and power is cut to the pump (probably through a relay - I'm not sure). On a 240Z, you don't have the sensors available to do this, but I'd think the later 240Z's that had electric pumps would have had some way to cut off fuel - does anyone with a later 240Z with an electric pump know how this works? My 240Z does not have an electric pump, so I do not know...

I don't know about the 240Z pumps, but the FI systems on the 280Z have circuits to cut off the pump when the engine isn't running, like after an accident. The cutoff is for safety. If you just wire the pump to run when the ignition is on, then it will continue to run in an accident while the ignition remains on. Just a thought.

If you were really ambitious, you could contact MSA and see if they'd use you as a supplier of the repro boxes. Could be a problem if demand got really hot, though ! They sell Charlie Osborne's floorpans....