while I'm doing the rear main seal--what else to do?

hey guys

i think im finally going to break down and take a day off work to do my rear main seal.


ive got the good website link from jeepin.com on how to do it, so im not worried about that...

but...
(ive searched and searched)

is there anything else that would be good to do once i have the oil pan off?

I'm going to clean it really well, obvoiusly...
but should i consider doing anything with the oil pump/screen? (cleaning/replacement?)

i figure while im under there it would be a good time to do other stuff.

let me know please!! :rof:

thanks!!

CaptTrev

i would make sure the oil pump screen is clear, also you might want to make sure the oilfilter adapter seals arent leaking, when they do, oil runs down the side of the pan and drips at the rear suggesting the rear main is leaking

I replaced my oil pump while I was in there...just remember to pack it with vaseline first.

CaptTrev said:

is there anything else that would be good to do once i have the oil pan off?

Click to expand...

It depends on how enthusiastic you are!
You could replace the pump/pickup... cheap and easy
Plastigage your mains and rods... cheap and time consuming
Replace your mains and rod bearings... expensive and time consuming

-Brian

i think i would prime it with motor oil, not thick vaseline

Yes, if you have the pan off change the oil pump and pick up. It only two bolts which hold it in place. The pain of installing the new pump is installing the new pick up into the pump.

Be careful when removing the oil pan, it is easy to bend the lip. Buy the new pan gasket at the dealer, it is a one piece. Buy yourself a good gasket scraper and get all the old gasket off. If you damage the pan too much you will be paying the dealer $100 or more for a new one.

When you install the new pan gasket apply a small bead of RTV to the block and bolt the gasket to the block using all the bolts. The RTV is just "glue" to hold the gasket in place. After 2-3 hours remove ALL the bolts and then install the pan.

Changing the oil filer mount O rings might be smart but I may wait on that till I have to change the motor mounts. I know on a renix 4.0 you have to remove the oil filter mount to get the center bolt out of the motor mount.

It up to you where to buy the oil pump and pick up. I wanted to avoid any problems and just got them at the dealer. Also make sure to get the gasket used between the oil pump and engine block.

The AMC/JEEP engine overhaul manual for my 88 4.0 says the following but this is not a complete write up and may be different for your year XJ on the torques:

PUMP ASSEMBLY

NOTE: To ensure self-priming of the oil pump, fill the pump with petroleum jelly before installing the oil pump cover. Do not use grease.

Apply a bead of Loctite 515, or equivalent, and install the pump cover.

Tighten the cover screws to 8 N-m (70 in-lbs) torque.

OIL PUMP INSTALLATION

Install the oil pump with a new gasket

Tighten the short bolts to 14 N-m (10 ft-lbs) Torque

Tighten the long bolts to 23 N-m (17 ft-lbs) torque

PS: You will have to find out the bolt torques for the pan bolts. the different diameters have different values. You don't want to mess up that new gasket by over tightening...

cool

thanks for the helpful ideas!

Looks like I'll have plenty of work to do under there...

but i'd rather do this stuff now!

thanks for the exact torque specs and instructions---the more instructions the better!

thanks guys!

CaptTrev

I second the suggestion to plastigage the rod bearings. The main bearings seldom go bad, but the rod bearings sometimes get work right through the babbit material down to the copper shell. Plastigage is cheap.

One more thing, it sounds like you do not own the shop manuals for your XJ. I recommend you spend the $100 for them. Do a google search for "techauthority" and you will find the Chrysler publications people. Order your manual, that torque values and other "tips" make the book worth it's weight on gold.

I also recommend you get a subscription to www.alldatadiy.com for your XJ. It like $25 for a year but you get ALL the Technical Service Bulletins (TSBs) for your XJ. They also have instructions on doing jobs like changing the oil pump. Another cool feature they give you is the part number of the replacement dealer part, price of the replacement and book labor to do the job.

It from alldata where I found out some bolt torques for the engine mounts had been revised. If you plan to work on your XJ then time to get manuals.

If money a problem then get only the alldata subscription but if you can swing it get the factory manuals also.

Martin-- (and Eagle)

you guys are absolutely right, i know, i know. i need to get those manuals

im very handy at doing my own work, but its always the little details that keep me from attempting certain projects without first consulting this forum first

im definately going to look into ordering those books

im definately a huge subscriber to the theory behind spending money on tools and books and learning how to do stuff yourself

i havent let a mechanic tough my jeep in probably like......6 years maybe
(not including having the tire guy mount my tires etc)

anyway

ill get those books for sure

as always, thanks

CaptTrev

the sad part is, i can do more engine work on a 12V71 detriot diesel, than i can do /(have done) on my 4.0 I-6

hehe

Eagle said:

I second the suggestion to plastigage the rod bearings. The main bearings seldom go bad, but the rod bearings sometimes get work right through the babbit material down to the copper shell. Plastigage is cheap.

Click to expand...

Sorry to bring up an old thread, but what's plastigage?

AlabamaDan said:

Sorry to bring up an old thread, but what's plastigage?

Click to expand...

Look it up. It's a "cheap way" to measure a small clearance - it's a soft plastic of a known dimension and known properties that is laid upon a bearing shell. The bearing shell is torqued down (do not rotate the bearing!) and then untorqued. The width of the plastic is then compared to a chart provided with the Plastigage, and that will give you the clearance.

It's not the best way to measure a clearance (I prefer to measure directly - inside the bearing and outside the journal - but not everyone has the tools,) but it does require rather less disassembly and is a bit quicker. To measure directly, you'd have to remove the cap, get the bearing off of the journal, install and torque the cap, and measure inside the bearing. Then, measure outside the crank journal and subtract. Then, lubricate and reassemble. Takes more time, but I tend to think it's more accurate.

I just replaced the RMS last week. I also changed the pickup screen. its a pita to get back in, just do not hesitate to force it in with all your strength, thats how it goes back in the hole

i'm not worried about the oil pump, i only have 176kmiles

one thing i do suggest, and if you can please do it. use a tap and clean out all the 26 oil pan bolt hol threads. they are usually filled with massive grease and old rtv. then brake clean the excess out of each. use a die on the threads of each bolt/stud removed. this will ensure proper sealing and no cross threading/ broken bolts.

I went the extra step, and heat treated and high temp/rust proof painted the pan and all bolt/studs.

make sure you get a one piece quality gasket for the pan, i used the zones Felpro and it is solid. even has the sleves made of metal for where the bolts go.

use small zip toes on each corner and the middle of the side of the gasket to oil pan and no need for any rtv. use a small amount of rtv high temp on the block outside of the rear main bearing cap. don not use rtv on the cap itself or you will screw up clearence.

get a haynes manual. if u have tons of work you want to do on your jeep, and the time and money to do it. get a workshop manual

When replacing your oil pump, get the higher flow pump. These have added several pounds of oil pressure, putting it back up to where is was when new.

holy old thread batman :doh: