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Trooper Engine Rebuild Questions

5445 Views 95 Replies 12 Participants Last post by  truisuzu
OK, here's a single topic for my engine rebuild questions.

Tearing things down and disconnecting the wire harness stuff. There is one sensor down by the oil filter which does not seem to have a plastic disconnect (see attached image). It has a rubber outer skin. Does this thing have a disconnect under the skin?


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Thanks very much for this info!
If the engine will be sitting out uninstalled for over 6 months. I have a secret for that situation.
Please share, if you would. My 1 week install turned into a 1 year install. :eek:

Rear Main Seal Housing Bolts

The manual says to use new bolts for this housing. Not sure why exactly.

(There are six M8 1.25 x 16 bolts and two M8 1.25 x 25 bolts each with the flared bolt head style - somewhat greenish gray in color). Any idea what type of metal/bolt/grade to look for to get exact replacements for strength, etc.? Marking on the bolt head is 8 A.

Oil Pump Install

The manual has a drawing showing how to apply an RTV bead around the oil pump mating surface. It's a bit over-complicated but it seems to basically be saying 'make a continuous, unbroken bead of 3.5mm' around the mating surface. Somewhere it also mentions 'put RTV in these bolt holes/bolts' (don't have the manual in front of me at the moment).

When I look at the old bolts, there is RTV on all of them.

What I'm wondering is... do I squirt RTV in the bolt holes or put it on the threads of the bolts and screw them in?

Also, when I opened my FelPro engine bottom gasket kit... it contains gaskets for stuff which the manual say to use only RTV on. For example, it has a gasket for the crankcase to engine block, and the oil pump to engine block, etc. I've been proceeding to only use the RTV and not the gaskets. Hopefully, that's OK.

I just discovered that the manual doesn't mention that of the oil pump bolts to be torqued down, two of the bolts belong to the oil filter assembly which hangs off the front of the oil pump. This filter assembly is not yet ready to install (hasn't been cleaned yet) so I will wait on installing the oil pump until the oil filter assembly can be installed at the same time so the full torque-down can be done.

Also, there is a steel plug (12mm allen key) in the side of the old oil pump and a hole (but no plug) in the new oil pump. This will have to be moved over. Is this plug the location to attach to to prime the oil system before 1st start?

Lots of mfr's use only RTV to seal the oil pan to the block. ZuZu 2.6 is like that, with its cast aluminum main pan which uses no gasket. If you were to put a gasket in where there's not supposed to be one, it could mess up critical clearances. I recall doing a Cast-Iron-Duke 2.5 in an '86 Jimmy and there was no gasket, just rubber seals fore and aft plus RTV on the rest of the block. That being said, using a gasket on the oil pump flange, if it doesn't change how it fits in the space it's in, ain't gonna hurt anything.

Be sure you're extremely sparing when spreading RTV sealer on critical areas such as the oil pump sealing surface. Very thin bead and you can use a rubber/vinyl/etc gloved finger to spread-out the sealant. You don't want a big gob of silicone oozing out into an oil passage and hardening/blocking.

I've used the Permatex Gold sealer for pans before, it works well. But the Permatex Ultra Grey is a newer product and likely better than the Gold:

Far as priming the engine goes, does the manual have any suggestions on that? I'd think that you could spin the oil pump pulley before you install the timing belt, and that would do a pretty good job of priming the engine. Chuck a socket adapter in a drill motor and prime away!
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Thanks for the ideas!

Just surprised these gaskets were included in the kit since the manufacturer wants it done a different way.

The steel plug is a bit of a pain. Don't know why the new pump didn't come with a plug in place. It's frozen in the hole of the old pump and if I put the pump in a vise it seems like it's really gonna tear up the pump... which I'd rather not do at this point. Not sure if I could buy a new plug from the hardware store.

Thanks again.
A little heat from a propane or MAP torch might help get that plug unstuck. That plug very likely has metric threads.

You could carefully clamp the pump in a vise, cushioned by shop rags or a thin strip of wood on either side. Long as you're just holding it securely, and not crushing it, should be OK.
Oil pump plug removed and installed in new pump.

Next question.

On the block in the valley between the heads... at the rear of the valley there is a small hole (about 1/4 of an inch) which is pretty much above the rear main seal area. If water or coolant fills the valley, it will drain through this hole into the bell housing area. When the engine and trans were removed, the pilot bearing in the end of the crank was VERY crusted and corroded and appeared to be frozen up. The inside of the bell housing area also had a rusty crust on everything (although everything was dry).

I want to plug this hole in the valley so no water can ever drain into the bell housing region.


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I do have a welder... but my overhead welding is not great. The bolt is now hollowed out. I will try some heat and the extractor again.
I have a 2001 3.5 with 160k miles availible for sale in seattle.
Oil Pump Install
When I look at the old bolts, there is RTV on all of them.
What I'm wondering is... do I squirt RTV in the bolt holes or put it on the threads of the bolts and screw them in?
Only two bolts require RTV on them. This is because these 2 bolt penetrates through the block & into the oil gallery. Without sealant on these bolts oil will seep past them and drip onto your timing belt. Most people out of habbit seal all the bolt & that is ok. Everyone applies the sealant differently...with one exception (I'll get to that later) there is no right or wrong way. I find when you coat the bolts themselves the sealant finds it's way from your hands to you shirt, face, tools & engine. Personally I like to squeeze a little bit of sealant into the bolt holes & this stops the sealant from spreading everywhere.

There is one big no no when applying sealant. Novice mechanic always gets this wrong and it caused more damage than the good intended.

Applying too much sealant will cause premature engine failure expecially at this location. When too much sealant is applied, the excess spluges out from in-between the mating surfaces and into the oil pump. When the excess falls off it will clog a oil passage inside the engine block causing the engine to fail. Applying too little sealant and you run the risk of having a oil leak.

The 3.5mm bead of sealant applied in the center of the mating surfaces must precisely be fallowed. No more than 3.5mm & no less than 3.5mm.

No textbook, no repair manual & no college automotive class will teach you the trick to applying the prefect amount of sealant.

--- Here is the trick to getting this right everytime. ---- The tube of sealant came with a long plastic applicator. Measure this plastic applicator & cut it where it measures 3.5mm in dimiter. Now when applying the sealant make the bead of sealant the same size as the tip of the applicator. By doing so you will be laying down a uniform bead that is 3.5 mm all the way around the mating surface....
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Thanks for the ideas!

What about plugging this drain hole in the valley. I don't want water entering the bell housing area. I plan on plugging it with RTV.

3.5L Engine Timing

So I went to do the timing belt setup and I have it setup properly (I believe) as the process went perfect. But one step seems wrong.

I have both the service manual and a great instruction sheet that came with my Aisin Timing Belt Kit. I primarily used the instruction sheet while cross-referencing back to the service manual instructions.

After the timing belt has been successfully installed, there is a double-check step that says:

"Turn the crankshaft two turns clockwise and ensure that the timing marks 6, 7, & 8 are aligned."

(6, 7 & 8 are crankshaft mark, R cam pulley mark and L cam pulley mark).

When I put my breaker bar on the crankshaft with the bar starting in the 12 o'clock position and spin... it takes 3 turns of the crankshaft to make the timing marks line up again properly.

2 turns of the crankshaft doesn't do it (the crankshaft mark will be lined up again but the cam timing pulley marks won't).

3 turns and the marks line up perfectly. What's up?

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Your reference documentation is incorrect.

The crankshaft sprocket has 26 teeth and the camshaft sprocket has 39 teeth which makes the ratio 1.5 to 1. The camshaft sprocket drives a 30 tooth idler inside the head, this gear drives the 40 tooth camshaft drive gears at 1.3333 to 1. Therefore, 1.5 x 1.3333 = 2 so the crankshaft to camshaft ratio is 2 to 1 as expected but the crankshaft to camshaft sprocket ratio is 1.5 to 1 so it takes 3 rotations of the crankshaft sprocket to get the belt marks to align
Thanks very much for this confirmation and explanation!

I will press on!

Thanks again.
I have been working for days trying to stab the AR5 transmission back onto the engine with no joy. (Working alone... no helpers).

I do not have a transmission jack... just my regular floor jack with a welded riser platform attached. Transmission jacks basically come in two types... your vehicle is on the ground or high on a lift. My Trooper is jacked up to an intermediate height which a floor jack (with trans adapter) will not reach. My welded platform works great to get the trans into the right zone. From there I shim and wiggle, etc.

I have removed the crossmember below the mating surface and can see the alignment of the engine/trans planes pretty well. I have gotten the trans to mate to the point of only 1/2" of space left to go. The splined shaft is clearly through the clutch plate hole but I can't get it into the pilot bearing hole.

Before attempting this, I put the new clutch plate over the trans splined shaft and it fit fine. But I forgot to put the pilot bearing over the trans shaft before I installed it in the crankshaft. I'm pretty sure it is correct as the pilot bearing came in my Exedy clutch kit.

When I take the plastic clutch alignment tool and push it into the clutch plate and pilot bearing, it goes in nice and easy through the clutch plate hole but there is a very, very slight amount of friction when it goes all the way into the pilot bearing hole. When I look through the clutch plate hole, the pilot bearing hole seems to be centered.

All I can think to try is to remove the clutch pressure plate and re-align clutch plate and try again.

Frustrating to say the least!
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Still no joy.

I loosened the pressure plate and re-centered the clutch plate with the plastic alignment tool and re-tightened the pressure plate. The alignment tool slides all the way in and out with no resistance now.

The plastic alignment tool measures 16.75mm at the tip where it goes into the pilot bearing. The trans splined shaft measures 17.0mm. I'm pretty sure the bearing is correct.

Guess I still don't have plane match right yet.

Truisuzu, If you are in So Cal , you can use my transmission jack . Eric
He's in the mountains of Colorado.
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