First.. Looks like i found the place to ask my questions you all seem very knowledgeable. I searched my issue and didn't really get the answer I wanted,so I decided to quick make an account and just ask.

Let me start. I looked at this truck last night, two things I noticed that I'd have to fix right off the bat, I'd like opinions on.

First thing: evidently these trucks come with a remote oil filter set up, well the lines we coated in oil like they were leaking bad. The oil looked to be mixed with water(had that grey sludge look) the dip stick looked like clean oil I didn't see any water in the oil. Are these 2 lines somehow affiliated with the coolant system? or could the fact that the oil on these lines are exposed to water from driving cause them to look like there is water in the oil?
How hard are these lines to replace? I'm not a mechanic, but I am capable for the most part unless there are specialty tools required.

Second thing: the rear differential cover was leaking gear lube pretty bad, is that just a matter of pulling the cover and installing a new gasket? I've done that before on old muscle cars when I was younger so that task doesn't scare me as long as a leaking cover doesn't signify damage some where.

This truck is in decent shape a little rust, and will need tires by spring but other than the two areas I'm inquiring about it looks dry underneath, the catalytic converters are new, new emissions crap. new ball joints, a few other things that escape me right now it has 230k miles on it mostly highway (i admit that scares me a little, but my budget limits my choices), this was supposed to be just a truck for me to use for hunting around the area and occasional hauling to the dump. the asking price is $2,000 with tax title and license that brings me around $2300 I've looked at the oil line replacement Rock auto has it for $112. He has been trying to sell it for a while now so maybe there is some room to negotiate. Depending on the answers you guys give me, I'm going to offer him less that the 2 grand he is asking Also anything else I should check that I may not know about these trucks?

Thanks in advance I truly appreciate your help in limiting my mistakes with the limited budget I have.

 

The diff cover doesn't have a gasket from the factory, they use RTV. However, Fel-Pro does make a gasket for it. You do need to look closer and see if it's a bad pinion seal and the lube is just blowing back.

No coolant that I'm aware of anywhere near the remote oil filter setup. Again, you do need to determine exactly where the oil is leaking from.

 

Personal observation for what it's worth. My truck (also a 98 4x4 5.4 with a remote oil filter and not quite as many miles) has the same oil soaked lines. There are no other oil leaks. The dipstick level has no noticeable loss over the 6 month change cycles in the year and a half I've owned it and I've only ever noticed a few drops on the ground where I park, two days this past summer when it was really hot. Nothing the summer before. So if it is still leaking it's very little. Mine isn't greyish from water but then it's usually pretty dry here. Because it was temperature related I'm guessing it's just a poor seal where it connects and probably normal for some seepage to occur, adding up to the mess it is over the years.

 

If you have a code scanner, plug it in and see if there are any codes showing-either active or pending. You can also read the real-time data and do a lot of diagnostic work/trouble shooting with one. And, any puzzlers you have you can give more information and get better answers.
I've got a 98 Scab 4X4 4.6 and have been fixing it up for the better part of a year. Sometimes the obvious answer is not the right one....:-(

 

I have the remote oil filter on my truck and it had alway sweated a little oil once in a great while it wil drop a drip but thats it. I've had it since 07 and I thought about fixing it but I dont think its worth it unless it get worse. I take a rag once a year or so and wipe it down. All good.
Remember at this point that 98 is 15 going on 16 years old. Your gonna have to do some wrenching to keep her going. Good Luck!

 

Permatex makes a gasket gel that is specifically for diff covers; did mine a month ago and it seals perfectly. One tube is more than enough. I also replaced the diff cover. Can be had for around $35.

I never had any issues with my '97 remote oil filter and hoses.

Jim

 

The rear diff covers rust easily. Check to see if it is rusted through. It's also easy to not use the rtv properly and get a leak. I'd use a Fel pro gasket. I don't know why anybody would want a remote oil filter. If you turn the steering wheel to the left all the way, it's easy enough to get the filter off as installed at the factory.