So I've got about 165k on the 4.0 and I know I have a few issues to tackle.
The first thing I know needs to be corrected is the rubber on the harmonic balancer is coming out. As long as I'm in there, I'm thinking I should go ahead and replace the timing chain.
So here are the questions:
1. If I'm replacing the timing chain, should I go ahead and replace the sprockets as well? That is, should I purchase the whole set or just the chain.
2. I've read where you don't have to remove the oil pan in order to to do the timing chain - however, as long as I'm messy, should I go ahead and do the seal on the pan?
2a. If I'm going to do the oil pan, should I just go ahead and do the oil pump?
2b. If I'm going to do the oil pan, should I just go ahead and attempt the rear main seal? It might be leaking, but it might be the oil pan/valve cover.
3. Lastly, if I'm going to have the bottom off the motor, obviously going to inspect everything... Should I go ahead and re-do the gasket on the valve cover and inspect the topside. (btw, I'm a noob so I'll probably just say "wow, looks cool" and put everything back together...)
Any suggestions on parts sourcing and part numbers will be helpful. Also, beside the harmonic balancer puller and the pullers for the timing chain, are there any other special tools I'll need to rent?
FYI, I've got O'Reilly and Napa local.
1991 YJ 4.0 | NP231 | AX15 | Dana 30/35 | Front Locker | Tom Woods DS | M.O.R.E. SRS
2003 TJ 4.0 | STOCK X
Our favorite game is 'SMACK A JEEP' - started off as a way for my buddy to get even with his girlfriend's slug-bug fetish. Simply smack her in the face as hard as you can when you see a Jeep Wrangler and yell, 'SMACK A JEEP!!!!'
Never actually smacked anybody, but my kids LOVE the game. Now my whole family plays it - and so do my kids' friends!