Steps in freshening up a drivetrain

[Automan2164]

Just wanted to run my plans by the general CC community. I have the drivetrain out of the '92 I bought as a donor truck, and it was a low mile (80K) running gear.

 

1992 4.0 H.O. / AX15 / NP231

 

It was pampered for the first 60K by an old man, and then beaten and abused by a hillbilly. When I picked it up, it had a bad slave, he had been starting it in gear and powershifting it to move it, busted the rear driveshaft and ran it on the front in 4wd, toasting the 231 because it lost all the fluid (I assume). He said the t-case was smoking.

 

Before I took it apart, I pulled the dist, primed the system with fresh oil, and fired it up. (It hadn't run in about 6 months) It sounded great. It ran good and had good power. I took it out for a test drive, and after some vigorous pumping, the clutch kinda worked. All the gears felt good, and the trans shifted smooth.

 

I plan on putting this in my project truck, but want to address any problems while I have it out. I plan on re-sealing the engine with a gasket set, but how far in should I go? Should I go as far as the head gasket? The trans will be flushed and filled as I imagine it could use it, and I am just going to write off the T-case as a loss. I don't know if its toast for sure or not, but I will just replace it. I thought about pulling some caps when I was in the engine, and plastigauging the bearing clearances, to see if it might be due for a bearing set. I plan on running an aftermarket header, and the '99 intake for mods.

 

Million dollar question:

 

If it was your drivetrain to put in, what would you do to it before installing it?

 

Rob L. :cheers:

[JeepcoMJ]

Everything but the head gasket unless you can see obvious scoring in the cylinders through the spark plug holes

[Eagle]

Million dollar question:

 

If it was your drivetrain to put in, what would you do to it before installing it?

I would not do the head gasket.

 

I WOULD do the rear main seal, because it's SOOOO much easier with the engine out and upside-down on a stand than when you're lying on your back under the truck. Once the pan is off to do the rear main seal, it sort of doesn't make sense not to replace the bearings. I wouldn't even bother to plasti-gage them ... just do a preemptive strike.

[jimoshel]

Rob, You asked for it, your gonna get it. As many opinions, all different, as there are CC members. If the motor is running OK now, with no obvious leaks or noises I would leave it alone. Put it in as is. One suggestion is going to be 'change the RMS because it's easy to get to now.' I've seen new seals go bad thousands of miles before a old one quit. Personally I would change it.

I would change the head gasket because they do seem to go bad and it will give you a chance to fully inspect the engine. Get the valves done while the heads off. Drop the pan and pull the rod caps. If they're good leave the mains alone. If they show wear then pull the main caps and inspect.

Suggestion. Make a list of every replaceable part in a motor. Then flip a coin. One flip for each part. If it comes down heads, replace the part. If it's tails, leave it alone. Back to first sentence. IF THE MOTOR IS RUNNING OK NOW, WITH NO OBVIOUS LEAKS OR NOISES I WOULD LEAVE IT ALONE.PUT IT IN 'AS IS,' One mans opinion. Good luck, Jim

:smart: :cheers: :dunno:

[HOrnbrod]

Stroke it! (w/o a cylinder bore unless it needs it) :cheers:

[kastein]

I'd replace the valve cover gasket, distributor gasket, timing chain cover gasket, front main seal, rear main seal, oil pan gasket, and freeze plugs... and then run it. Unless oil pressure seemed bad when you test drove it, then I might put bearings in it.

 

I think even the gaskets I just listed probably cost more than an engine at the junkyard... and a junkyard engine probably hasn't been abused by a retarded hillbilly (I recall your story of the dumbarse who sold that thing to you :ack: ) so much as minorly neglected by a distracted soccer mom.

 

Replace whatever's leaking already and run it till something else needs work, then maybe do a rebuild. Or stack it up with the others till 4.0s get more difficult to find and then rebuild and use it, right now there are hundreds going through the junkyards that are headed for the crusher, might as well stash a couple that can be fixed when needed.

[Automan2164]

Well, it is leaking from the pan, at the least it will get a valve cover gasket, pan gasket, timing cover gasket, intake/exhaust, and the main seals. I was thinking about just getting the "kit" and doing the whole shebang with the headgasket. I'll be right there, and I would think it is cheap insurance. Pulling the head off will also give me a chance to take a good look at the cylinder also.

 

Anyone have any suggestions for a place to get a set of gaskets besides the local parts jockeys? Or am I safe with them? :dunno:

 

Rob L.

[kastein]

rockauto.com is where I get almost all my car parts unless I am in a tearing hurry to get a project done.

[jimoshel]

I used Fel-Pro on the last overhaul I did. Was quite satisfied with them. McChord is also good. Avoid Charley China parts.

[terrawombat]

I'll second RockAuto...I've probably done close to 2 grand in parts orders from them in the past couple of years. Their prices are always lower than the local shops like Autozone, Advance Auto, Pep Boys, etc, AND their shipping prices are very, very reasonable. Plus you get the added bonus of getting a magnet with a CC member's rig on it ($500MJ)!

 

Rockauto stocks a lot of Fel-Pro products and I have had nothing but good experiences with their products. I replaced the 4.0L in my '01XJ with a JY engine and wound up having to remove the head. Used a Fel-Pro head gasket, valve stem seals, oil pan gasket, rear main seal, valve cover gasket, and oil filter adapter o-ring. It's been roughly 21K miles now and no leaks from any of those gaskets. If I would have replaced the rubber grommets on the top of my valve cover then I'd have a 100% leak-free engine. Possibly the only 4.0L Jeep engine in the country that doesn't leak...

[dasbulliwagen]

While I was in there, I might add a high volume melling oil pump too, just for good measure.

[87Warrior]

Rob I will be doing the same thing very soon. My plan is to replace every gasket and seal, valve stems, replace the rod bearings, and get the head cleaned up/ported. It seems silly not to stroke it since you are so close, but the line has to be drawn somewhere. However, if a 258 crank fell in my lap....

 

When I rebuilt my Rubi 4.0 I used all dealer seals and gaskets. That was 70K miles ago and the valve cover gasket is just now starting to ooze. I have been debating where to buy the parts for the MJ project as the dealer parts where a tad pricey. I may mix-n-match.

 

Just remember, it is NO FUN to do a head gasket with the motor in the vehicle. 75% of that battle is just accessing the head. My theory is replace what you can on the motor when pulled. Do that and you can expect another 250K miles out of it.

[Geonovast]

It seems silly not to stroke it since you are so close,

 

 

:rotf: :rotf:

[Eagle]

It seems silly not to stroke it since you are so close, but the line has to be drawn somewhere. However, if a 258 crank fell in my lap.....

I REALLY disagree with this.

 

Just "dropping in" a 258 (4.2L) crank and rods creates all kinds of problems. It is not a simple plug-n-play swap. The two engines had slight differences in deck height, which translates to a high compression issue with the "budget" stroker. If you are not prepared to deal with that, don't even start.

[Automan2164]

It seems silly not to stroke it since you are so close, but the line has to be drawn somewhere. However, if a 258 crank fell in my lap.....

I REALLY disagree with this.

 

Just "dropping in" a 258 (4.2L) crank and rods creates all kinds of problems. It is not a simple plug-n-play swap. The two engines had slight differences in deck height, which translates to a high compression issue with the "budget" stroker. If you are not prepared to deal with that, don't even start.

 

I am trying to build a very reliable, trouble-free engine, so anything involving replacing a crank with something other than a factory unit, is out. The only power adders will be external, in the form of a cheap aftermarket header, a '99 XJ intake, Bored throttle body, maybe 5.0 injectors, and a cold air. I looked up the seal kit from rock auto, and the only thing they show is a Sealed Power kit. Been a long time since I've been down this road, but I recall sealed power being a decent brand... Here is the info:

 

http://www.rockauto.com/catalog/moreinfo.php?pk=327788

 

 

114.79 + shipping

 

So what do y'all think of the sealed power brand?

 

Found the Melling pump on Quadratec, but sealed power also makes one, and its available through rock auto... Opinions?

 

Rob L.

[comenschen]

How much does the mopar performance thinner HG raise compression? I believe it comes with this gasket kit P4529245, and should come with everything except from what I can see the RMS? The kit is only like $40.

[comenschen]

Just to add... I have no experience with the Mopar kit but also want to refresh my engine before it goes in, and after some net surfing it seems a lot of people use it.

[DJM/78]

I've used sealed power kits before without a problem other than operator error ... :dunce:

 

Most of the shops around here carry Felpro in stock if not sealed power , I'm doing a half and half to a 5.7L TPI V8 for the 91" . ( half Felpro half sealed power )

[64 Cheyenne]

Me, I'm tired of using a lot of this summers free time on the 88 Chief.

With that being said, I would or should I say this is what I'm going to do to the 87. Just got an 95 XJ 150k mi, AX-15 231, 200$.

Aw heck, the 87 is the project truck, I say I just want to get it done, not make the to do list any longer. But what I say and actually do.... I've already got a huge amount of parts, done lots of work on it, I'm sure it will get a thorough inspection and leak down test then I'll decide further, if the engine has good oil pressure or not, whether to touch the caps or not.

All green lights: pressure, leak down = just basic gaskets and run it.

Anything else = more time and $

How far you wanting to go?

When will the insanity end?

Or the money run out?

Didn't we talk about money and our trucks worth a while back?

Insanity.......I love it :rotf: :rotf: :rotf:

[HOrnbrod]

Just "dropping in" a 258 (4.2L) crank and rods creates all kinds of problems. It is not a simple plug-n-play swap. The two engines had slight differences in deck height, which translates to a high compression issue with the "budget" stroker. If you are not prepared to deal with that, don't even start.

 

:shake:

 

I am trying to build a very reliable, trouble-free engine, so anything involving replacing a crank with something other than a factory unit, is out. Rob L.

 

Double :shake:

 

Care to elaborate?

[Automan2164]

 

I am trying to build a very reliable, trouble-free engine, so anything involving replacing a crank with something other than a factory unit, is out. Rob L.

 

Double :shake:

 

Care to elaborate?

 

Tell me why I should on a limited budget and how I would go about it.

 

Rob L.

[HOrnbrod]

I am trying to build a very reliable, trouble-free engine, so anything involving replacing a crank with something other than a factory unit, is out. Rob L.

 

Tell me why I should on a limited budget and how I would go about it.

 

What I meant was your quote about reliability and trouble-free. A mild stroker is no more less reliable or trouble-free than a normal 4.0. But since all you want to do is freshen up, not rebuild, and you're on a limited budget, you probably should skip it as it's a bit more expensive than rebuilding a stocker, but not by much. More bang for the buck.

 

Stroker basics from Dino: http://www.angelfire.com/my/fan/stroker.html