Need advice from experience for an M42 rebuild

[bmwman91]

Are the alignment sleeves in the block in good shape? If they get bashed, they will go out of round and not permit the transmission to seat all the way.

[JonsE30]

correct. slave cylinder not installed. its all the same parts from when it was removed before sending block to the shop.

[roguetoaster]

You might have a pilot bearing/input shaft size mismatch, there are two sizes. Slave cylinder not installed, right?

[JonsE30]

i'm at the stage to mate the transmission but i've having a hell of a time and look to you all for some advice.

i reinstalled flywheel, the clutch with the alignment tool and pressure plate, then pulled out the alignment tool and proceeded to stick the transmission on. i feel it catch on the splines. i cant rotate the shaft from the guibo side so i think it's inserted, but i am still maybe 1/2 inch away. i tried wrestling, finagling,shimmying it and i always get stuck 1/2 inch-ish away.

i thought it was my alignment so i took out the pressure plate and clutch disc and try to put the transmission on to see if it hits the block and lines up with the holes and it does. so then i though the spleens were off but i was able to slide the clutch disc on the transmission input shaft while it was just resting on the floor.

the clutch release bearing looks like its the right one. what else am i missing?

[bmwman91]

With paper gaskets, particularly thin ones, I avoid RTV big time. It allows/causes the gasket to slide and squeeze out of the joint when tightening. Even too much of the spray-a-gasket sealer can cause this, with a notable case for me being the (relatively) thick thermostat housing gasket.

In my opinion, either use the paper timing case gaskets dry, or skip them and just use RTV. With the RTV, the install procedure is a little different and takes longer. You need to apply a little bit to the mating interface, install the cover, finger-tighten the bolts, let it sit until the RTV cures, and then tighten the bolts all the way. If you tighten everything while the RTV is uncured, you tend to squeeze it all out.

Personally, I have not really had issues with the paper gaskets leaking, even with synthetic oil. I used to blame them for oil seepage, but it was always due to a small gap or something where the profile gaskets butt-up against one another, or further up near the valve cover where the upper cover gasket sometimes leaves a gap.

[roguetoaster]

Yeah, a sealant on both sides of those is what you want. Deoending on actual thickness you can use anything from copper spray gasket to lightly applied RTV. If the gasket is truly paper thin I might sub in RTV by itself.

Remember that any sealant can cause the gasket to bind/pinch, so be sure that you can see it around the entire perimeter before tightening. Nothing worse than getting the t case back together only to notice a pinched gasket at the bottom, ask me how I know.

[JonsE30]

thanks roguetoaster for the tip. i will keep that in mind for the next parts order.

i am buttoning up the lower timing case and the gaskets i got are the paper kinda. i was trying to do research on this but should i use permatex block with the paper gasket? the paper gaskets look really thin. also do i put on both sides of the gasket? if just one side, which side?

[roguetoaster]

All you need is the rebuild/upgrade kit and just the short shift lever if you want a notchier shift feel. Link 1 has lots of important bits that link 2 does not.

[JonsE30]

everything is coming along, test fitted the parts again: a/c bracket, alternator bracket, engine arms, oil filter housing,etc all bolt up just fine. need to scrub and clean all the slude off it, maybe spray it with high temp paint to give it a uniform look with the rest of the engine. i already got started on the transmission and damn that was disgusting haha. i spray a bunch of zep degreaser and scrubbed with a brass brush. this after 1 saturday morning. still needs another round of cleaning, but i just want to get it clean enough to handle for reassembly.




but i want to address the shifter before putting everything back since i dont want to re-access this area. i was looking at the short shift kit vs the shifter rebuild kit are these the same thing? the short shift kit is cheaper. i figure anything is better than what i got right now.

https://www.ecstuning.com/b-assemble...5117519669kt5/

https://www.ecstuning.com/b-genuine-...25117527252kt/

There are the 2 examples i am looking at on ecs. the short shifter buy sounds like knocking 2 birds with 1 stone, unless i am missing something?

[JonsE30]

small update. looks like the 2 nut method worked once i figured it out haha. i transferred the stud bolts to the rebuilt head and test fitted the lower manifolds to see if all was good and straight. i also started taking off the old fuel hoses off the rail. i need to add those to the next parts order for misc items.

[roguetoaster]

I realized on the priming front, there is a drain with a hex on the front of many oil filer canister housings that seems to feed directly from the oil pump. I'd backfill from there if priming is a concern, but some grease in the pump is also good insurance.

[Gloff]

Man, I thought my engine was clean when reassembled, that timing case looks brand new. Good work so far!

Word of note on first start, when I did mine, I pulled the spark plugs and leads off the coil pack to prime the oil pump, but when I put the leads back on, it wouldn't start, I had to disconnect the battery for 15 min for it to reset the computer.

[JonsE30]

roguetoaster good tip i'll inspect them and if good i'll try the 2-nut method.

Gkwan Thanks for the vote of confidence!

[Gkwan]

JonsE30 I saw your posts on IG of your engine rebuild and started following you! Awesome to follow your rebuild and keep up the posts with the progress pics.

Good luck with the rebuild!

[roguetoaster]

You can try to use a two nut method for removing studs, or you can grab them with vise grips where the fastener would not need to engage. I would also really consider the condition of the exhaust side studs before reusing as they do have a real tendancy to rust to near useless states, at least in terms of removal/installation of the exhaust manifold.