tellis32

Thanks for the info fellas - I'm wondering if this was a Nissan stock hose or replaced by a prior owner. sblake01 - wow - I'm sorry to hear about the extent of the damage you describe. I'll have to closely inspect my timing cover tomorrow. Thanks again!

Hello So I'm driving my '73 240z automatic when it starts blowing coolant out of the radiator cap overflow. When I get her home, I see that coolant is leaking from the water pump. I figure this is a good time to replace the pump, thermostat, hoses, etc. When I pull the pump, I'm shocked to see the remains of a spring wrapped around the impellers. Then I notice there's more spring in inlet hole going through to the inlet hose. Loose in the hose mind you. My question is: what's the spring? Do I need to replace it? What's the thing for? I mean, it looks inevitable that the spring would eventually tapeworm its way down into the pump - which is apparently what happened. Pics below... Thanks in advance for any insight here!

Engima Yes! Those are the correct bolts! Tony

Problem solved! OK. I inspected each U-Joint and they were all good. Then I inspected and tightened every bolt (moustache bar, differential mount) but all was good. Crawling deeper under the car, I discovered two bolts (forgive as I did last weekend - I can't remember the size... 3/4"? ... big suckers) up on either side of the front nose of the differential where it connects to the driveshaft. This is where Carl Beck points out that there is a "strap" that runs over the top of the nose of the differential. The passenger side bolt was loose and I mean loose! I don't know what's for. Strap tension? At any rate, torquing this back down solved the problem. No more CLUNK. Thank you all for your thoughtful comments that helped me diagnose and solve this problem. It's a much more pleasant ride! Best Tony

Hi Beandip Well , what happens if you restrict the turning of the spinning wheel? If when you slow the spinning wheel you don't hear any clunking of grinding or such noise, things appear normal. >No clunking or grinding Could be that the brake shoes are slightly contacting the drum on the non-spinning wheel. > I can actually spin the non-spining wheel. No resistance what so ever. Since you have the care off the ground and hopefully on jack stands. Go under , never with just a jack alone holding the car up, and grasp the half shaft on one side and see if you can rotate it . Do the same on the other one. Check the ujoints closely for ANY play. > No play There should be zero. There will be a slight amount of movement in the diff. this is normal. Question , does the diff have any whine or howl? hopefully none . > No whine or howl have a look at the drive shaft ujoints also. While checking all the ujoints look for ANY signs of rust around the edges of the round parts toward the inner area of the ujoint. Any signs of rust color means the joint is toast. > Will do. One more thing , hold the half shaft and the wheel and check for ANY play between them. > None as far as I could tell Check the tightness of the two bolts on the back of the diff. where the moustache bar bolts up. The moustache bar should not have any play where it is bolted to the body on each end. > These are my next moves! this about covers what can cause clunking. You will never remove all of the clunking. This is just the nature of the beast. Gary I started this reply an hour ago but was interrupted. ha ha > Hey, I appreciate the reply and the thoughtfulness behind the information! - Tony

Thanks for the welcome Enigma! I have forum searched for this and have found a wealth of information on this topic! A far cry from the pre-Internet days when I owned my first '72 204z and there was no on-line resource such as this! It happens on acceleration. Not deceleration. Not at cruising speed. Not when I shift from P to D or R or any other gear (automatic). The frequency of this un-Godly CLUNK increases as acceleration increases. Right and left turns make it worse. From inside the car, it sounds like it's coming up from between the jack / tool compartments where the differential is located. My thought was to check all the recommended suspects (differential mounts, U-Joints, etc). But I stopped dead in my tracks when I spotted this differential behavior which Arne says is normal. Again, my thanks. What an excellent resource for a Z enthusiast! Tony

Thanks Arne! That's great information! Tony

Hello I'm trying to pin-point the source of my automatic '73 240z rear end clunk. I'm thinking it's the differential. Here's why: 1) I jack up the rear end and put the car in drive. Parking brake is off. 2) I'm noticing the passenger rear wheel is rotating (as expected) but the driver side rear wheel is nearly motionless. Hardly any power. The half shaft is connected and I'm not seeing any U-Joint play. As far as I can tell, it's a stock R180. Is this normal differential behavior or am I looking at a bad differential? Any insight is greatly appreciated! Tony