kjc

Your tranny? You might want to start a new thread when you have questions. The thread you jumped in is a couple years old
If you mean is your rear main oil seal a 1 or 2 piece, if it's a 4.0 L it's a two piece.

XxRoll4LifexX

ya my bad i didnt read the dates on the last comments, and yes i was referring to the rear main oil seal... but i just moved the jeep last night and the new oil spots are coming from under the engine not near the middle or towards the back

black_771

So seriously, what are the odds of doing this job without breaking any pan bolts off in the block? I'm extremely leary of working on my Jeep because of broken bolts.

5-90

Pretty good, if you're careful.

I do suggest having a few replacement sump screws on hand - 1/4"-20x1/2" socket head capscrews. Why? Not because the screws get broken, but because I've had cases where the pan get mildly "sprung," and having a socket head capscrew allows me to use a hex key to drive it - which allows me to push directly on it and use it to lever the "sprung" holes into place.

Torque on the sump screws is 7 pound-feet/84 pound-inches for the 1/4"-20x1/2" (7/16 wrench,) and 11 pound-feet/132 pound-inches for the 5/16"-18x3/4" (1/2" wrench.)

Use either LocTite #222 or RTV on the screw threads as a low-strength locking compound. I do generally suggest replacing those screws out of hand, since they're "undercar" they're subject to a lot of exposure, so I replace them with CRES or brass machine screws. (Most carbon steel screws used undercar I replace out of hand with CRES or brass - if an undercar screw in a low-stress application fails, it's usually due to corrosion. I don't replace the suspension screws that need to be very strong - like leaf spring screws or linkage screws - but I do tend to replace just about everything else.)

xjtd

hi im replacing my rear main oil seal on my 2.5td oil burner!
ive got the gearbox, or tranny as you guys call it!
the flywheel is off and ive got the old oil seal out, the question ive got for you guys is does the thrust washer, 2 part just sit inside the recess on the back of the crank? it doesnt seem to secure anywhere!!
other than this its not a terrible job, just parts are so damn expensive
i did my head gasket a few months ago and the turbo bolts on these cause a few expletives!!! gotta say though i love the old girl!!
any comments would be appreciated!!

5-90

You've got the overseas VM Motori 2.5L TD, or a 1985-1987 US-production with the Renault 2.1L (126ci) TD? Makes a difference (for instance, I may have a manual covering the Renault. I'm sure i don't have one that covers the VM Motori...)

Some general points, however:
- A two-part rear main will not be visible from the back of the engine. You'll find it once you've removed the rear main cap.
- I don't think I've ever seen an engine that had a dedicated "thrust washer" for the crankshaft as a separate part. Commonly, one of the main bearing shell sets will have perpendicular flanges on it that would extend onto the cap/web, this is commonly referred to as a "thrust bearing" and is referred to, for instance, as "thrust on #3" (meaning the third main bearing back has the thrust flanges on it. It will almost never be on the front main or rear main - because it provides a "thrust surface" on both sides of the bearing. A lot of V6 and V8 engines are "Thrust on #2," four-cylinder engines are either "Thrust on #2" or "Thrust on #3," the AMC sixes are "Thrust on #3" - but an I6 can have up to five main bearing webs - out of a potential seven - to have thrust bearings on.)

For hardware subject to exhaust heat - I like to replace screws and nuts that are not subject to a great deal of preload (most aren't) with a copper-based alloy - I've had good luck with 60/40 Naval brass, silicon bronze, or aluminum bronze. The problem is that iron & steel will seize against each other when subjected to exhaust heat (primary,) and the exhaust gets hot enough that it causes an incremental loss of strength over time, as the steel is gradually annealed (experimentally verified.) Cuprous alloys won't seize against ferrous alloys, and brass/bronze will get incrementally harder due to heat cycling (copper and its alloys respond to heat-cycling in the opposite manner as iron and its alloys - to soften a brass rifle cartridge (to remove work-hardening) you would stand it up about halfway in a pan of water, heat it to dull red with a torch, then tip it over into the water. With brass, that makes it softer. With iron, you've just made it harder.)

I've been doing brass/bronze hardware on exhausts for over thirty years with no trouble, just be mindful that brass and bronze are somewhat softer than iron/steel, and work accordingly!

I have had good luck finding brass/bronze hardware, when I need it straight away, at the marina supply houses - if I know in advance that I'll need it, I'll go with an MRO house and order it in (it's cheaper that way.)

However, for a two-part thrust washer to work, it has to be positively retained in position - which is why the thrust bearing on a crankshaft is an extension of a "middle main" bearing. If you're seeing a two-part "washer" that's loose back there, I'm inclined to think it may be a "spacer" - or that it may be extraneous. Before you got into this, did you note a knocking or tapping at the back of the engine?

xjtd

hello mate cheers for the info, yes it was in two parts the thrust bearing!
yes it has always had a knocking noise, when you release the clutch, its a blueprint part so i im hoping it s not the bits that are faulty, but id love to get to the bottom of it as its pretty annoying, if you hover your foot on the clutch, as in take up the slack it seeems to go away, im wondering if its a lazy slave cylinder? i contemplated lengthening the rod on the slave... last resort, either that or im gonna go mad!!!

cowleyp

This is all you need to know, apart from what you need to do to clear the exhaust and pan. this guy is good!
http://www.dailydriventj.com/forum/viewtopic.php?t=811

97charliexj

doing mine this weekend, i hope its as easy as it sounds.

ianridlon

Hi just replaced my RMS now there a loud grinding or squealing coming from that area around flywheel anyone have experience with this? No leaks no chipped teeth etc... anyone know what happens if you overtighten bearing cap?

SeaVee

I just picked up 2001 Cherokee for my daughter, pretty much perfect with the exception of a leaking rear seal( I assume) what's the downside of leaving it as is, aside from a dirty driveway? Will they continue to deteriorate ? What type of cost ( ballpark) if I take it to my mechanic ( not a dealer!)
Thanks and Happy Holidays!

94XJAZ

I have been reading the CF for a few months now, joined and this is my first post. Last weekend I pulled my pan and replaced the rear main seal on my 94XJ. What a lot of dirty work! Not overly hard but my god, swimming in an oily mess!. I have read a bunch of questions and responses on CF about this job and wanted to put in my two cents and hopefully help someone. My Drivers side motor mount and trans mount was bad, I did not want to change the trans mount till the oil leak was stopped, the oil destroys the rubber and i'm not one to do things twice just for the fun of it. After I did all the tips to get the pan out of my lifted 3' plus XJ short of removing the control arms, I discovered something. (yes I got the pan out and back in before the discovery, but it was a um "not a fun adventure!"... Replace the mounts before you do the pan/RR seal! I had to lift my motor over an inch to get the new mount in, same with the trans mount. That INCH would have been PLENTY of room to drop the pan without issue. We learn as we go LOL. Installation tip, use small zip ties to hold the pan gasket in place on the pan till you get a couple bolts started, then just snip and remove the zip ties. DO NOT tighten the pan down then yank the zip ties out, it WILL damage the gasket. Don't forget you will need extra oil to refill your motor, some of the oil does not come out during a regular oil change(1/2-3/4 qt) so have an extra qt over what your normal change is. Hope this helps, wish I had of done the mounts first ha ha.
An after thought, I am not sure how much room the motor has to move but, unbolting the motor mounts and lifting the motor with an engine hoist might have been extremely helpful and less work than what I did,,,,, Sheesh

99 Jeep Cherokee 4.0L

The Jeep 4.0L main bearing cap bolts are custom bolts found only at a Jeep dealership. All 14 of these bolts have a 1/2" diameter partially threaded (1/2 - 13) hex bolt that hold the bearing caps to the engine block. The other end of the bolts, have a 3/8" diameter threaded (3/8 - 16) stud that holds the bearing cap brace/girdle to the seven bearing caps.

You will need a 13/16" deep socket for the custom hex bolts and a 9/16" socket for the nuts that hold the bearing cap brace to the bearing caps.

The 13/16" hex portion of the bolt is torqued to 80 ft/lbs and the 9/16" nut holding the bearing cap brace to the bearing cap should only be torqued to 35 ft/lbs.

If you over torque either portion of the bolt, Replace the Bolt!
You can only find these custom bolts from your Jeep Chrysler dealership from the Parts department. As of November 2015 in my region, a new main cap bolt runs around $6 and a new nut for $1.

Beyond my better judgement, I used a cheap torque wrench that did not pop at 35 ft/lbs after moving from 80 ft/lbs and the nut received probably about 60 ft/lbs before realizing that something was definitely wrong with the wrench. Needless to say, at approx. 60 ft/lbs the 3/8” threaded stud thinned/twisted/stretched where the nut was over torqued so I can imagine it probably wouldn’t take much more force before twisting/breaking the 3/8" threaded stud right off the bolt.

1996 and newer engine models have a main bearing cap brace/girdle, so if you have a brace and are considering an upgrade to ARP hex bolts or studs instead of factory replacement bolts, the bearing cap brace will not work as it can only fit over a 3/8" stud; ARP bolts and studs are a solid 1/2" diameter end to end and possibly too short for the additional thickness of the brace. As of this writing, ARP did not make a two size bolt or stud for the Jeep 4.0L to compensate for a bearing cap brace if you have one. FYI
I preferred the extra structural support the brace provides to the main bearing caps so I went with one factory replacement bolt and nut which was also much less expensive and time consuming… $7 in my case.

So my two cents to those replacing the rear main crank seal for the first time:
Do Not Use a Cheap Torque Wrench! They may not be reliable.
Don't go over 80 ft/lbs and don't go over 35 ft/lbs and Do Replace the Bolt from your Jeep dealership if either gets over torqued!

I hope this can be as useful to someone out there like the Cherokee forum posts have help me avoid some of the pitfalls in Jeep maintenance.

sambolambo

My 96 jeepcherokee 4.0 is different. It does not have a bottom bearing cap. Any help would be very appreciated! How can i post pics to share?