[Rusty Bird]

Hello everyone, new member here, have been looking for a Pontiac Forum for some time, and saw this one come up on a FB group post today. I much prefer forums to fb groups, so hoping to get some good advice here!

I have a 1980 trans am, at some point in the past somebody dropped a 1975 400 into this car. It was not running that well, so about a year ago I pulled the motor and had it rebuilt. Finally got around to dropping the motor in last weekend and having trouble getting the mounts to line up. I guess these are the 'clamshell' mounts - with the 3-bolt bracket on the motor side, and the rubber mount attached to the frame. I replaced the frame side mounts - after some trial and error finally found a pair that seemed to match the originals size, and bolt pattern.

On the passenger side, I am sooo close, can see the hole through the mount, and get a small screwdriver through. Pretty sure I'll be able to get that one with a little more effort. Problem is the driver's side, it's not even close. If I had to guess, I would say that the mount is sitting a couple inches too low on the frame, based on where the motor is sitting. Or perhaps the motor is hung up on the little 'tabs' protruding on the mounts.

Any tricks to get this motor in? Does it have to drop close to level, to clear the tabs on the mounts? I've seen some youtubes that advise clipping off the tabs, but they seem to be what holds the motor in place?

thanks!

[77 TRASHCAN]

Are you doubly sure you got the clam shells back in the same holes?

There is more than one possible way to mount the clamshells. The "f" bodies came with more than just the Pontiac engine.

One way. But NOT EASY, you could unbolt the clamshells from the frame. Bolt the clamshells to the engine brackets. THEN align the clamshells with the appropriate holes in the frame.

Make sure the engine brackets are on the proper sides, I'm not sure if they could be bolted up to the wrong side. Seems like they are labeled R and L, possibly.

Double check your clamshells to make sure they are EXACTLY the same as the old ones.

2 inches is waaay to far off, having the correct parts.

I ran into a similar snafu on my TA. I was swapping an engine. I was trying to use the engine brackets off of a full size car. They looked like they would work. But sure did not.

[Rusty Bird]

I am sort of afraid that I didn't put the new mounts onto the same bolt holes - but thankfully I had pictures of the old mounts, before I removed them - so close to 100% sure I got that right. But still no guarantee.

Also, pretty sure I held the old and new mounts together, and they matched. But thinking some more, I may have only confirmed the bolt holes for the frame lined up, without comparing the rubber inserts. Sadly, I was not wise enough to keep the bad mount (driver side) but might have the pass side sitting around my garage.

thinking about unbolting the transmission, so I'll have more freedom to lift and drop the motor a million times as I deal with this --- but looks sort of painful to try and "recouple" them in place?

[Sirrotica]

If the engine came out of any other body than an F body, the steel brackets that bolt to the engine are specific to what chassis it's going in. Yes, they look the same, but as you may have found out, they're not. Stamped into the the steel mount it will say F body if they are the correct bracket.

I've seen people pull an engine out of a full size car, and try to put it into an F body and of course the chassis is narrower in the F body and the mounts will allow you to get one bolt in, then the other hole is way off to the outside of the frame. Until you have the correct bracket for the chassis, you'll be stymied on getting the bolts to line up with the frame portion of the mounts.

This may, or may not be your problem, but it needs to be checked.

You'll need the clamshell for 75 and later F body Pontiac Stratostreak engine, and the engine bracket to match the chassis.

[johnta1]

If these are the same mounts as when pulled and they fit then, You could be cocked on one frame mount which is holding it up. It's basically not level.

Try raising the engine a little and cocking it up on the side that is close to the mount. The engine mounts need to slide evenly onto the frame mounts.

[Skip Fix]

Another thing I found is sometimes the engine mount has been squeezed and is too tight the slide down on the clamshell. Of course I found out when trying to drop the motor down!

[Rusty Bird]

Originally Posted by Sirrotica

If the engine came out of any other body than an F body, the steel brackets that bolt to the engine are specific to what chassis it's going in. Yes, they look the same, but as you may have found out, they're not. Stamped into the the steel mount it will say F body if they are the correct bracket.
.

I pulled this motor out of my car, and only replaced the 'frame sides' of the mounts, so was thinking that's where the problem was. But now you've got me thinking!

When I took the motor to the shop, it still had the motor side brackets bolted to it - but he took them off and handed them back to me. I brought them home and put them in my parts box, which happened to already have a pair, from who knows when/where. When I was dressing up the motor to go back in, I saw two pair that I thought were identical, and grabbed one of them. Maybe I grabbed the wrong ones. Will give that a try tonight. thanks!

[Sirrotica]

Originally Posted by Rusty Bird

I pulled this motor out of my car, and only replaced the 'frame sides' of the mounts, so was thinking that's where the problem was. But now you've got me thinking!

When I took the motor to the shop, it still had the motor side brackets bolted to it - but he took them off and handed them back to me. I brought them home and put them in my parts box, which happened to already have a pair, from who knows when/where. When I was dressing up the motor to go back in, I saw two pair that I thought were identical, and grabbed one of them. Maybe I grabbed the wrong ones. Will give that a try tonight. thanks!

[Rusty Bird]

Getting closer - if I could drive around with one side bolted, and a phillips head screwdriver holding the other side - I'd be done. But the drive side bolt hole is still about half blocked by the rubber mount....If I could get the mount up, by about 1/4 inch, I think I'd be good.

not sure if this pic is clear, but the blocked hole is shown.

[johnta1]

I'd say it is hanging up or cocked a little.
If you can get a larger size drift/punch started in that hole, try trying to pry it down over the frame mount. Might have to try taking some weight off the frame by lifting the engine up some. If the other side is able to take a bolt, try putting the screwdriver or little bigger punch in that to keep it from pulling up from frame mount.
Hard to explain over the internet, but just needs a little persuasion.

[Sirrotica]

Originally Posted by Rusty Bird

Getting closer - if I could drive around with one side bolted, and a phillips head screwdriver holding the other side - I'd be done. But the drive side bolt hole is still about half blocked by the rubber mount....If I could get the mount up, by about 1/4 inch, I think I'd be good.

not sure if this pic is clear, but the blocked hole is shown.

On new mounts, they seldom line up, I've had to align them the best I could with tapered drifts etc. and then drive the bolt into the mount. The current mounts are at best, poor quality. You're just going to have to make it conform to where it needs to be.

[Sirrotica]

Originally Posted by Rusty Bird

Getting closer - if I could drive around with one side bolted, and a phillips head screwdriver holding the other side - I'd be done. But the drive side bolt hole is still about half blocked by the rubber mount....If I could get the mount up, by about 1/4 inch, I think I'd be good.

not sure if this pic is clear, but the blocked hole is shown.

On new mounts, they seldom line up, I've had to align them the best I could with tapered drifts etc. and then drive the bolt into the mount. The current mounts are at best, poor quality. You're just going to have to make it conform to where it needs to be.

Jack up the engine a tiny bit, and push the inner sleeve around until it lines up. Believe me after installing hundreds of engines, it goes with the territory. Engines seldom just drop right in, and bolt up without some persuasion when rubber mounts are in the equation.

[Don 79 TA]

one thing, learned the hard way of course, is keep all bolts loose and get everything aligned, then tighten down
this, aside from making sure correct brackets and mounting locations might be the ticket, along with maybe needing to loosen the trans mount/crossmember for some possible wiggle room too.
had scenarios like that bite me in the past so to speak...

[Rusty Bird]

thanks everyone, was finally able to get both mounts bolted last night. Gave up on positioning the engine hoist level enough to drop squarely onto the mounts, and instead used jacks on both sides of car to lift the car up onto the motor at the same angle as the hoist. took forever but done now!

But my exhaust is not here yet. Please tell me I don't need to lift the motor back up to attach the manifolds (or headers if I go that route) ?

[Sirrotica]

You could probably get the log manifolds in without lifting it, headers, I never install them without lifting the engine. No matter which you install, because Pontiac exhaust points downward, you gain a whole lot of better access by lifting the engine when installing it. Lifting just one side at a time tends to roll the cylinder head upwards, also giving you much better access to the bolts.

After the mounts sit bolted in, the rubber may conform to where it needs to be, the longer it's bolted up the more it conforms. Not saying it will be easy to get them bolted back up, but it may be easier than the initial operation.

[Skip Fix]

Passenger side headers usually need oil filter housing off but all of mine I could slip in motor bolted up.

[Sirrotica]

Having done it both ways, I'd never do Pontiac headers with the engine bolted down. it's so much easier to be able to get your hands into tight spaces with the engine raised, and rolled up on the side you're working on, but that's personal preference. Cars with A/C also make it tougher to install whatever you're bolting to the heads.

Also, chase the bolt holes with a tap before you try installing the bolts in the heads. If you can turn the bolts in with your fingers, it makes the job much easier. I also use never seize on the bolts.