Removing manual transmission

[Kurtanius21]

Hello eggxperts. I did the biggest job of my life last winter and replaced the old Previa engine with a JDM unit. Engine works great, no problems, except for one nagging mistake. Clutch shudder. The clutch vibrates sometimes during engagement and I have decided to try and fix it. I believe the cause is too much grease on the clutch spline. Since it was my first time, I didn't consider the consequences of "more is better." So I am wondering, how hard is it disconnect the transmission with the engine still installed? Has anyone done it? It seems to me that the transmission mounts make it very difficult to slide the transmission rear wards away from the engine. The transmission will need to be lowered enough so the mounts clear the cross member. Is that right? I installed the engine and transmission together last time. Can the mounts be separated from the transmission? Any help please!

[tbkilb01]

Reads pretty basic. Put a jack under it. Remove bolts and slide back. Do you have access to FSM?

[Kurtanius21]

I do. It isn't too clear on handling the transmission mounts. The mounts in a manual are U-shaped,and won't clear the frame without lowering the transmission, and I don't want to do that while the transmission shaft is in the pilot bearing. I think I can make life easy if I add one additional step and disconnect the mounts from the transmission also, not just from the frame. That way I can pull the transmission exactly parallel from the engine. I'll let you know what I find. That being said, changing the clutch on the previa seems a lot easier than the vast majority of fwd cars, and other rwd vehicles

[Jonny]

This is quite an old thread so I'm assuming you did the clutch fix, but I'm wondering if you (or anyone else) have any tips for other people (like me, like now) who may be doing a manual transmission removal. It does sound straightforward in the FSM, but as always the devil is in the details. If one lowers the transmission for the rear mount to clear the frame does the front engine mount have to be loosened (removed?) to avoid tweaking things? And how do you get to the bell housing bolts which are hidden up against the body. And where is the stiffener plate located? I went looking for it just now and damned if I could see it.

[pdgizwiz]

Jonny, I think I've done this but it's been so long that I don't remember distinctly. I've never had a stick-shift Previa, so there's that. But the A/T is heavy, and my contraption to lift the engine from inside the van is near it's load limit, so I figured that taking the transmission off first might help. Having it off allows the engine to tilt back more as it's coming out, but pulling the mounts off the engine helps with that, too, making it unnecessary. I do recall using a very long assembly of socket extensions to reach the upper bell housing bolts, possibly with a wobbler at the socket itself.

[Jonny]

Thanks for those tips.
I, like you by the sound of it in other posts, am confined by resources to pull the engine and/or transmission outdoors and move it into the garage for working on. My project involves new clutch and new head gasket. Living in SLC and having the repairs occur in winter made the weather window something of an issue and I bit the bullet and lowered the whole engine and transmission assembly today ahead of the soon-impending icy misery. Hooray - the removal went OK after a long and stressful prep and much fretting about everything imaginable. It is my first engine removal ever and being a complete noob, even the standard processes take on outsize proportions.
Although the factory service manual, various posts here on TVT, and videos on YouTube were very helpful, there were still a bunch of details which were quite problematic for a first-timer to figure out. It's funny how so many YouTube videos have obvious cuts/discontinuities which clearly were for editing out problems so that the dude looks like a hero. We all run into these problems and benefit from knowing about them, so I plan to create a new FSM engine removal supplement thread right here for the future inexperienced as soon as the snow comes.

[pdgizwiz]

Bravo! I've yanked engines out of a lot of vehicles but the Previa is the most challenging by far. Without a big shop, a lift, and other commercial gear we're forced to improvise. But meeting the challenge is a satisfying feeling. Previas are worth the aggravation. And if you can get it out you can get it back in. Pat yourself on the back!

[Jonny]

It sure feels good to have that lump in the garage now.

Here are answers to questions posed earlier in the thread.

Remove the lower nut from the tranny mount, in addition to the two bolts through the frame, and the bracket falls down out of the way.

Previa transmission mount 1.jpg

I always find it useful to see how a component is assembled...
The upper nut holds the rubber bushing thing to the tranny, the lower nut holds the bracket to the bushing, the upper two bolts (removed) hold the bracket to the frame.

Previa transmission mount 2.jpg

After removing the starter you can get at the stiffener plate. This is it here, high up near the body, linking the rear part of the engine with the clutch housing. The two bolts shown aren't too bad to get at.

IMG_1951.jpg

This third bolt holds the stiffener plate through the bell housing. This one probably wouldn't be too bad to get to either with the engine in.

IMG_1952.jpg

When attempting to remove the transmission with the engine installed, these two bolts at the top of the bell housing, especially the left one which is at the highest point, would seem to be the crux.

previa bell housing top bolts.jpg

The front engine mounts have pretty thick rubber bushings and would seem to accept a small amount of distortion. If I couldn't get to that top bell housing bolt I'd be tempted to lower the rear of the tranny a tad to see if that helped. I took the entire engine/trans assembly out for a head gasket job, so this is untested conjecture.

[Previologist]

The front engine mounts have pretty thick rubber bushings and would seem to accept a small amount of distortion. If I couldn't get to that top bell housing bolt I'd be tempted to lower the rear of the tranny a tad to see if that helped. I took the entire engine/trans assembly out for a head gasket job, so this is untested conjecture.

That's what some people with 3rd gen manual 4runners have done. There is plenty of flex in there, though probably best for old bushings to keep it to a minimum.