Hi All, some time ago I posted a thread on here asking for advice on a funny noise I had on my Z. Allways hard to give help on a noise on a forum without hearing it. But I suspected bottom end.

 

Anyway, no one had any real idea, so I stripped the bottom end, in the car.

I had some very poor advice, not from here, about how hard this was and how long it would take. Basically I was told it was a pig of a job and would take many hours.

 

My son and I had the sump off and the bearings inspected in about 2 hours. It was so easy.

 

Upon inspection there was no sign of problems, until I looked at the thrust bearings of the main bearing shells. One side was worn to the brass/copper looking metal.

 

So I replaced both big ends and main bearings, by the way inside the engine was spotless.

 

Started the car recently. It took probably 4 hours to put it back together again, and, touch wood, it is now sweet again. Held at 2000rpm it is like a sewing machine. That good by the way.

 

Hardest thing was to get the correct parts, as there are so many variations (Jeff TT supplied them, thanks Jeff and Son)...

 

So anyone thinking of doing this, do it, its easy. Dont let others tell you different. Dont take the engine out just for bottom end probs unless you need a crank grind etc.

Hardest thing was to get the correct parts, as there are so many variations (Jeff TT supplied them, thanks Jeff and Son)...

 

.

 

little lost as to why its difficult Mark, Nissan make it very easy as all the numbers are stamped either on the block, crank or connecting rods and the manual gives very clear instructions on how to read these , how is it you got conflicting info ???

 

Ryan

Ah well, this is where things get interesting.

 

When I spoke to you you said this, ie, about the sizes stamped on the crank etc. However on my engine the stampings are NOT the same as the shells that came out. I know this is a fact because the stamps list 3 different sizes of bearing, (big end) and yet the journals and the shells are all the same. And the journals are the correct size for the shell.

 

So you might say, ok the cranks been reground. But the size of the journals is standard. I had to buy a micrometer to measure them.

 

Also it appears that the part numbers change when compared to the actual bearing and the box they come in, depending on the quantity inside the box.

 

So, all in all I couldnt make up my mind what to do for a while, in the end, after buying a mike and measuring lots I simply replaced the shells for like sized new ones. As the shells were almost perfect apart from the thrust parts of the mains I felt safe.