Jeep Enthusiast Forums banner
2501 - 2520 of 2589 Posts

·
Premium Member
Joined
·
11,018 Posts
It occurrs to me that more frequently these days that im willing to admit there’s things I don’t know. And I don’t think I know how to measure that. But to my eyes and mind that chain is a lot longer than the new one.
i think I’d change it with the sprockets.
 

·
Premium Member
Joined
·
4,660 Posts
I have done a couple of 4.0L timing chains. IIRC they do not have sag to them when they are new. As fish mentioned, sprockets are important to make them tight as possible because the chains wear into the sprockets also. Either way it is worthy of posting for future reference to others, what a tight chain looks like. I have done too many chains in too many different engines to remember them all. Many of them nowdays are three chains in an engine.
 

·
Registered
Joined
·
12,817 Posts
Discussion Starter · #2,503 ·
I'll return the chain and guide and get a kit. I was trying to save a nickel but I've been doing that my entire life with this jeep so maybe I should just...not do that, haha.
 

·
Premium Member
Joined
·
3,589 Posts
I'll return the chain and guide and get a kit. I was trying to save a nickel but I've been doing that my entire life with this jeep so maybe I should just...not do that, haha.
Be on your guard my friend. It seems like a little thing. At first you decide that it's time to give the jeep back a little for years of faithful service and get it something nice, like name brand replacement parts.
Then you turn your back for a few weeks and the dam thing sneaks you credit card out of your wallet at night and POOF! You wake up the next day with porch full of UPS boxes containing Fo'dees, bead locks, and all the pieces needed to link it... Not only that, but the degenerate vehicle will probably be passed out beside an empty gallon bottle of Boones Farm. SMDH
 

·
Registered
Joined
·
12,817 Posts
Discussion Starter · #2,506 ·
It is a slippery slope and making $50 purchases here and $100 ones here is an effort to trick me into thinking I’m not spending a lot but I’m not oblivious.

So, got my gasket kit, my timing set, ultra slick assembly lube and injector o-rings and filters. I’m just waiting on main and rod bearings and oil pump.

Question, what tolerances should both have? I assume I’ll need to plastigauge the rod bearings as well.

I also have been flushing the injectors with that kit and it works pretty well.
 

·
Premium Member
Joined
·
4,660 Posts
Did you ever get a chance to snap a pic of the rear crank journal?
 

·
Registered
Joined
·
12,817 Posts
Discussion Starter · #2,508 ·
Did you ever get a chance to snap a pic of the rear crank journal?
I plan to pull the crank out this weekend and I’ll snap some pics. More to come.
 

·
Registered
Joined
·
12,817 Posts
Discussion Starter · #2,509 ·
Glad I looked deeper into the main bearings. Pics below are of the #1 and #3. The #1 looks the worst.
I hope new bearings will be the solution.
 

Attachments

·
Premium Member
Joined
·
4,660 Posts
This bearing here has some small spots that look etched? I think it may be corrosion. Acids do form in engine oil. All of the bearings have a score line that is most likely in line with the oil holes of the crank. Maybe somebody had dirt in an oil filter when it was installed? There is not a lot of evidence of scoring that I can see. I do not think that the crank will look too bad. Make certain though that you clean the oiling passages in the crankshaft and block before assembling.
Water Gesture Fluid Liquid Thumb
 

·
Registered
Joined
·
12,817 Posts
Discussion Starter · #2,513 ·
The top bearings don’t look bad and there is no deep scoring on the crank.
 

Attachments

·
Premium Member
Joined
·
11,018 Posts
assembling.
Water Gesture Fluid Liquid Thumb
While that’s ‘not good’ it isn’t unusual to see that in a bearing imho. I light ‘wiping’ on the crank journal with a razor blade or knife will show if the crank is mostly ok; if it catches on a mark on the crank and stops the blade you ‘might’ want a polish; if you can feel the scratches with the blade (or not) but it just glides over, a quick dress with a strip of 800 wet’n’dry followed by (Dawn dish detergent) soap and hot water washing, hot water rinse, to get rid of the carbide grit (paint thinner, acetone, carb cleaner will NOT work). 1200 probs isn’t necessary. If it takes more than 20 or 30 seconds per journal you’re probably doing too much.
 

·
Registered
Joined
·
12,817 Posts
Discussion Starter · #2,515 ·
Good advice. I ran my knife blade over all the crank bearing surfaces and didn’t get any hard stops. I wiped all down and nothing major IMO. All I’m waiting on are the bearings. I’ll plastigauge for clearances. I think the mains are 0.001-0.003” clearance. I need to look up the rod bearings.
 

·
Premium Member
Joined
·
4,660 Posts
Took the #3 thrust bearing out and noticed the side facing the flywheel side was grooved. Crank is too. The other side is smooth. I’ll get a pic.
So it very likely came from a manual trans vehicle and a driver that used the clutch pedal for a foot rest. Did you measure the crankshaft endplay before you disassembled it?
 

·
Registered
Joined
·
12,817 Posts
Discussion Starter · #2,518 · (Edited)
I did not but this is the learning curve I suppose and yes, it was a manual, so that does make sense.

I got my new bearings in today and I installed the new pilot bearing last night. I also put the filters in the injectors and I plan to put them in the fuel rail tonight.
 

·
Premium Member
Joined
·
4,660 Posts
Ok. Just want to make sure you slow down a bit at this point and make sure you understand that a hand polish job on your crank may make things look a lot better with not much effort. A very thorough cleaning is needed.
 
  • Helpful
Reactions: fishadventure

·
Registered
Joined
·
12,817 Posts
Discussion Starter · #2,520 ·
Ok. Just want to make sure you slow down a bit at this point and make sure you understand that a hand polish job on your crank may make things look a lot better with not much effort. A very thorough cleaning is needed.
I can do that. My bearings were the wrong ones anyway so I can slow down (even more so, ha!) and get it cleaned up.

I saw fish say to use dish soap and warm water for cleaning. For polishing, 800 grit? What is the best method to do this? I've never done it.

BTW, I saw some where to use a little assembly lube for the injector o-rings. It worked beautifully. Some other things I need to do are:

Clean up the timing chain cover more. It had a gouge in the machined cup for the seal. I used a dremel to smooth it out and I'll probably put a thin layer of RTV black on the outer ring just in case.

Clean my intake manifold. I thought about removing the sensors and throttle body and pressure washing it after soaking in simple green or Dawn dish soap.
 
2501 - 2520 of 2589 Posts
Top