240ZMan

I'm installing a rear wheel bearing on my '73 240 and have it all back together. I made sure both the outer bearing is all the way down on the axle stub, and the inner bearing is all the way in against the lip inside the hub. When I apply 150 lb-ft of torque to the lock nut (the max my torque wrench can measure) the effort to turn the flange at the wheel bolt is so high I can barely move it with one hand. If I back the lock nut off so it's almost loose it moves with no significant resistance. I made sure to put the spacer/sleeve on between the bearings. The Haynes manual says to start with 180 lbft and go up from there. I'm not even close. Any suggestions?

I happen to have my square port header off the engine at the moment. I could trace the flange on paper if that would help.

I was wondering the same thing. But my father has had the car for the last almost 20 years and I KNOW he didn't abuse it. And I've gone over all his service records and there's nothing done to that side, although the other side was replaced in '92 and it did require a replacement stub axle (no mention of why). I will say that I love hard cornering, and had 3 track days last year. But I wouldn't call that abuse, and one would think the car could take that occasional stress. For now I'm treating it as a case of just being unlucky.

Well, it turns out I only wish it had been the wheel bearings. When I pulled the half shaft away from the hub the nut fell out! I guess the threaded end had sheared off the rest of the stub axle. Needless to say I got lucky in that at first I didn't notice the vibration until 70+ mph. Looks like new ones are around $280. Any thoughts on a used one, assuming I can find one in good shape?

Spent some time tonight under the rear of the car and I think all the U-joints are ok as they all feel tight with no play. However, where the passenger side half shaft connects to the RR hub there is a lot of play between the flange and the housing. From what I can see in the Haynes manual I'm guessing my inside wheel bearing is shot. Does that diagnosis make sense? The manual suggests you need a slide hammer to remove the axle shaft stub. Do you really need one? I assume I'll need to get a machine shop to press the old bearing off and put the new one on? Any suggestions to make the job easier?

In my case, one of the first things I did was suspect the fuel float levels. I played around with setting them higher or lower than spec ( there's only a little you can really do before the float hits the side) and it made no difference. I even put new float valves and seats in and swapped floats from anther pair of carbs I have. Still, Carl, I have to think there is something going on with them Dave, I too have a header but I fabbed a large heat shield that completely shields the carbs. Plus, I had this problem before I put the header on. And I know plenty of others run with headers and I don't hear them having this issue. BTW, I had misfires at high revs on really hot days with a lot of heat soak in the engine. Try routing the vents away from the carb intakes and see if it helps. It's a quick and easy experiment and cheaper than a new coil.

If you're like me, when researching here you sometimes wish the final results got posted. Hopefully this is one of those times... Last weekend I picked up a new clue as it was warm enough that sometimes the problem would continue (engine stumbling periodically at idle) even with the hood up. Turns out that if I took off the air cleaner top with the filter, the problem immediately went away, at least mostly. I tried removing the filter but as soon as I put the top back on the problem returned. I tried routing cold air to the intake on the filter but this made no differnce. This bugged me for the last few days and today I figured it out. I have one of the early 70's air cleaners and there are fittings for the vents from the carbs to be connected via rubber tubing. As soon as I disconnected the tubes from the carb vents the problem went away completely. Of course, now I need to figure out why the vents are discharging enough fuel vapor to cause the engine to stumble. I know fuel evaporates at elevated temps, but why am I having this issue when others in warmer climates, such as Arizona don't have it? Anyway, I thought I would try to bring a little closure, and if anyone can offer any insight it will be much appreciated.

Thanks Dave, found it. Turned out the top end had become too hot and the plastic had lifted the fuse end away from the contact. The fuse was intact, but stuck in there. A quick splice of a new fuse holder and life is good again.

http://www.classiczcars.com/forums/showthread.php?t=5069&highlight=fan+fuse I'm having the same issue as this thread in that my fan never comes on. I've checked and the accessory relay activates as it should, but there is no voltage on the contacts. The wiring diagram suggests there is a 20 amp inline fuse somewhere, but I haven't found it yet. Any suggestions where to look on my '73?

I tried Carl's suggestion and rotated the drive shaft 180 degrees and the vibration is better, but still worse than before the swaps. I'd guess the drive shaft and diffy are having "issues" together. So does anyone know if it's possible to get the driveshaft balanced while in the car? I read once that one way was to put 2 hose clamps around the drive shaft and start with the clamps opposite each other. From there you make small adjustments until the problem goes away. Seems like a lot of trial and error. Anyone tried this? Jason, I'm guessing it's not a u-joint issue as this came about only after I did the swaps. I guess it could be a coincidence, but for now I'm guessing that's not the issue.

I just finished putting a 5 speed transimission and 4.11 R180 into my 73 240. So far I really like the new ratios, but above 70-75 mph or so I start to feel a vibration that doesn't feel like a tire, but gets stronger as I go faster. It feels like it's vibrating the whole rear end of the car and it wasn't there before the transplant. So here's where I need help from the group. I figure it's either the tranny or diffy that has a balance issue (since that's what I changed), OR maybe it is the driveshaft which is now turning faster. Here's my reasoning: I have things right in my head, given my old diffy was a 3.36, for the same speed my driveshaft should now be turning about 22% (4.11/3.36 = 1.22) faster. So if I always had the driveshaft balance issue, I wouldn't have seen it until over 85-90 mph before. Given the roads around here I rarely go that fast. So my questions are: 1) where would you start? 2) have any of you had a diffy or tranny that was out of balance? I have to say I've never heard of that before. 3) I assume it would be posssible to remove the driveshaft and take it in to a shop to have it balanced? Any of you done that, and what are the things to look for? Thanks, Daniel PS. I'm hoping it's the driveshaft as that's the easiest to deal with:)

If you have the stock exhaust manifold I imagine that would help. But if you have a header then it's not so easy. I already had the engine out of the car so everything was off and out of the way already. Definitely made things easier.

I just filled my "82 5 speed and it took a bit less than 2 quarts.

I just put a 5 speed in mine and used my floor jack. It went up and in much easier than I had expected. But a tranny jack would be best if you can get one.

To Phred's comments, perhaps I should explain what I'm doing. This is a project to replace dished pistons with flat tops. I had to take the head off anyway to solve the coolant leak problem, and at this point I have the block out on a stand and completely dissassembled. The bottom end has about 80k miles and didn't burn oil. Compression was 155 - 175. It's a weekend car for fun, not a daily driver, and I'm not looking to get another 100k miles out of this rebuild. I'm sure I'll want to change something else before then As it was explained to me, the advantage of the berry glaze breaker is that it will conform to the full range of the cylinder from top to bottom, even at the top of the piston travel where there is usually some amount of a ridge. The rigid stones are designed to finish a cylinder after it has been bored and is now perfectly straight on the sides. They will have a problem making good contact just below the ridge at the top. FWIW, I called the machine shop that's done the work on the head and he was pretty neutral on this. He reminded me that because of the ridge I wouldn't see the cross hatching towards the top of the piston travel anyway. Hope I don't sound like I'm trying to argue with those who have much more experience than I do, just trying to reconcile the different opinions I'm hearing.

I finally found a place to rent a berry glaze breaker and I need some advice on the best way to use it. The Datsun Engine Rebuild book doesn't discuss this. My current thoughts are to use my Makita drill on its slower speed range (0-200 rpm). I understand I should go up and down in the bore to try to generate a cross hatching pattern. My question is roughly how long should this take (1 minute, 5 minutes, more?) for each cylinder? Should I use it dry, or have some engine oil on the bores? How careful do I need to be to not take too much material off? I realize this is mostly a function of the condition of my block, but I'd appreciate any advice in advance. This is definitely one of those jobs I only want to do once

I had looked at this very closely. It didn't line up as perfectly as I would like, but it wasn't bad enough either that it looked like it would be a problem.

BTW, the cam is .441 lift and 260 degree duration.

Just got a call back from the shop and the head has a hole in it. He says it's under one of the valve springs and "it's a gusher". To recap, it's an N42 that was recently cleaned up by the previous owner with good condition (but not new) valves, stock springs, new valve seats, and a slightly warmed over cam. Until this I was very happy with the head. The rest of my engine is as follows: - N42 block with dished pistons - I'm going to be installing a set of flat top pistons as part of this project - 6:1 header with 2 1/2" exhaust - Stock SU Carbs I'm looking for feedback on what to do next. Option 1) Get the existing N42 head repaired. I have no idea if this is really a good idea. I'm out of town and haven't seen the head yet, but the shop says he can't tell if it's a crack or a void. Do any of you have any experience with fixing these heads? Option 2) I have an E31 head with the smaller valves that was cleaned up with SS seats by the PO. I could install this as-is. Option 3) On the E31 head I could swap my warm cam over to it. I expect I would need to get new lash pads and carry the rocker arms over as well. Any other issues that might come up? Option 4) Have a machine shop install the larger valves from my N42 head into the E31 along with the necessary machining to enlarge the valve holes. Swap the warm cam over as well along with the rockers. Probably not cheap. Any one done this? Option 5) I also have a stock N47 head with about 80k miles on it. I could swap my cam to it, and replace my header with a round port unit. Still not cheap though. Option 6) Anyone have an N42 head in good condition they want to sell Thanks for staying with me on this. Looking forward to hearing from others who have done things like this.

I had the block deck and head checked for flatness today and the shop said both were fine. They suggested pressure testing the head and I've dropped it off at a different shop for that, although it will be at least a week before I get it back. FWIW, both shops thought it very unlikely that the block would have an internal crack so the focus is on the head for now.

Thanks for the many suggestions. Last time I did chase the threads with a tap before torquing as well as cleaned the bolt threads and I don't think my torque wrench is off as it's a reasonably new Craftsman and I reset to zero before storing. I don't use it as a breaker bar either I have used the head bolts several times and I've got a set of turbo bolts to use this time. I didn't retorque the head after a few hours as the head gasket (Felplro) says right on it that no re-torquing is necessary. I've read contradictory advice on this and wonder how to know when to ignore the manufacturer? I'll get the head and block deck checked for flatness this week and see what that tells me. Thanks to everyone for the advice.

Great call Kinfish, the piece is from an impeller, although this one is complete. I'll guess the PO had one fail and this one is a replacement. So I feel a lot better about this right now. As for the head bolt torque, I didn't check them before loosening, but they did seem to come off easier than the previous times I've removed them. I just don't know how much of that could be due to having used anti-sieze on them. The head gasket looks perfect. I've gone over it several times and I just can't see anything wrong with it. It was only one for a few thousand miles and it looks practically brand new. I'd like to think the coolant leak was due to the head not being torqued down enough. I'll be taking the head in to check for flatness next week. So my question remains if I should just reassemble, or what?

Well, today I pulled the water pump and timing cover and I can't see any sign of corrosion or a leak. I pulled the block and while turning it over on the engine stand with the head off a piece of metal fell out of one of the coolant passages. I've attached a picture with several views of it. It's approximately 1/2" x 1/2". Given I haven't found any obvious sources of the coolant leak and now having found this piece of metal, I'm very suspicious of the block. I'm looking for suggestions on what to do next.

I've read the same thing in many places, but my experience just doesn't match it. I've got the stock M/C and my pedal travel isn't more than before the swap, or if it is, I can't tell the difference. Of course, I also switched to performance pads and SS lines at the same time, so perhaps those improvements offset the larger volume that the new calipers are supposed to require. FWIW, when I'm braking hard the pedal height matches that of the accelerator pedal for easy heel and toe down shifting. I believe the heights can be adjusted, but my point is that I didn't have to make any changes to them after the conversion. I can't help but wonder if those claiming the M/C needs to be swapped are "bench racing" rather than speaking from experience.

14 x 7 Enki 92. I haven't measured the offset, but I'd guess it was close to zero as they are a rather old wheel.