The Stovebolt Site Forums The Shop Area Engine Shop 1946 Chevy 1/2Ton - Front Motor Mount

Anyone have instructions or pictures of how the front motor mount goes together? I have the kit from Jim Carter, but unsure of how each piece goes together and didn't want to guess.

Oh wait. Just read another thread and the front of my engine looks the same as this. I probably have the wrong engine mount.

John, Here's a pic from the 48-51 Truck Shop Manual - Should be the same as your year.
Plate 2 goes on to the rubber piece #1 with the flanged edge facing down. The small big bolts go thru the front plate of the engine, and down thru the center holes in the rubber and plates, with Item 3 over pieces 1 and 2 as a cover (facing down). The big small bolts go thru the outer holes before the cover goes on (lumps over the bolt heads,) and thru the frame crossmember with washers and nuts on the bottom.

Hope that helps.

You can grind a flat on the heads of those carriage bolts to fit in your engine plate and use the mount kit you have. That center plate is not on my engine. You just need to get the bolts to fit flat on the mount plate. You might also need to file the two holes straddling that doubler plate square so the carriage bolts fit thru. Or you could use hex head bolts with one side of the head ground off so they don't spin.

If you need it, I can post a pic of the front plate on my engine, which uses the kit you have.

Plate #2 - Flange pointed down and to the front or back? I think this will work. Thanks for the assistance Kevin! A picture is always helpful if you have one.

I was mistaken on the bolt positions. The bigger ones go inboard and the smaller ones outboard. (I'll fix my post above) Here's a couple pics of my front engine plate with the mount bolted to it. The flange on mine is pointed to the front. I'm not sure if that matters, though.

Denny Graham has a photo library that shows a lot of pictures of the front mount .I found the library by googling his name and it showed up as his name and 1950 3604 truck.click on his pictures and the motor mount is under the engine tab.

Kevin - I noticed my big bolts wouldn't fit through the small holes and figured you had them reversed. The pictures are helpful. Thank you.

Kevinski - Denny Graham's documentation in pictures were great. I was going to install my mount and I didn't even think about paint to keep them from rusting. I'll probably just clear coat them today. I was also thinking about upgrading the bolts to Grade 8 just for peace of mind.

Thanks all! Probably going to waste some time today going through the rest of Denny's pictures.

FWIW, I don't thing going thru Denny's pictures is a waste of time. I have invested time in doing just that.

Roger that on investing time in viewing/reading info from other Bolters. Amazing how much I have learned from scrolling through other peoples posts.

Agreed. I was flying blind and sometimes guessing at certain things before I was directed to this site. Model specific information makes life a lot easier.

Alright - I got my front engine mount installed. Maybe a little different, but I could not get the bolt to go in from the top on either side and the hole is round not square. Just not enough room even after grinding one side of the bolt flat. I went with some Grade-8 bolts from the bottom. I flattened one side of the lock washer and used a Nyloc nut to secure it. Not sure about any science of going from the top or bottom? I might go back and cut some of the threads off to shorten, but it looks like they won't interfere with anything.

The reason to put the bolts in from the top is if the nut comes loose, the bolt won't just fall out.

I would keep grinding on those carriage bolt heads, and file the holes square to fit the square below the bolt head.
I wouldn't grind on a lock washer like you did.

I thought about that and on the right side (in the pic) I might be able to get the bolt in. But, the angle is so tight on the left side, I'm not sure I can get the bolt to fit. Good thing is the engine is out and I can try different solutions right now. I appreciate all the input.

Thanks Fibonachu - Makes perfect sense and good to know.

How were the bolts installed at the factory?

And I'm confused that the holes they're going into are round, not square. What keeps/kept the bolt from spinning? Am I misunderstanding something?

I'm pretty sure this engine mount would fit my 1946 216 engine (maybe I'll do some testing), but this is a 1960 235 engine and I haven't found a place that sells the different mount. I think originally (but I'm not sure) the mount would bolt to the center threaded hole? I read somewhere that this mount is very hard to find. I'll try to find some pictures.

This looks like the newer engine mount that fits when there's that little metal block welded in between the holes. It looks like the mount screws into the threaded hole in the center and no bolts on either side of the metal block?

I had a 1959 235 that had the front cover like yours and it originally used side motor mounts. I believe it came from a car. I did the front mount just like your doing. I've seen some front covers didn't even have holes in them.

I just saw in the Tech Tips section that motor mounts were the same from 1929-1957 - I think that's for trucks. It also says these bolts should be installed before the harmonic balancer.

John that is the correct looking mount with a bolt attaching up through a center whole in the mount threaded into that welded on square plate on the bottom of your front plate. I have the same setup on a '62 235 I have waiting in the wings. This design did away with the metal shields around the rubber mount, often leading to eventual deterioration of the rubber when the front seal leaks. These mounts are also known to compress (squat) over time along with the oil damage, sometimes leading to the balancer "rubbing" on the bulged out mount rubber.

Just my opinion, but I think Kevin's suggestion about a little further grinding in the head of the carriage bolt and opening the through holes in the front mount plate for the square shoulders of the carriage bolt to nestle into is a good idea.

They make grade 8 shoulder bolts. I believe the generic ones from the hardware store have lower tensile strength (60,000 vs 150,000 psi). Instead of modifying the hole, you could grind of our cut down the square shoulders in a lathe.

Another idea would be to tack weld a small piece of key stock to a regular hex head bolt.

More options.

John

I grinded the carriage bolt a little more and was able to squeeze it in place, but no way to make it fit on the other side. I'm going to go with the bottom up solution.

I had a similar issue on getting the bolt in place on my truck. I opened up the hole just a little to allow the bolt to drop in. When I got the truck it had a hex head bolt with part of the head ground away to allow it to clear the timing cover.

My ‘59 235 from a passenger car does not have that flat bar welded to the mount. Not the best picture but you can clearly see it not there. I wonder when they made that change?

I had the same issue getting the passenger side bolt it. I bet the factory installed those bolts before the timing cover went on.

Yep. In the Tech Tips section there's a write-up and it says these bolts should go in before installing harmonic balancer. I guess they knew it would be a tight fit. I'm going to look at the front of my old 216 today to see the setup.

Is that block in the middle which is interfering with your bolt heads spot welded on?
If so, why not drill out the spot welds and remove it?

That's not a bad idea, but his engine is fully assembled and drilling out spot welds would mean additional holes in the bottom of the mount plate, unless he disassembles the engine to remove the front plate and work on it. At that point just changing the front engine plate would be easier. (I know of a couple that are handy) Also would need to square up the bolt holes like I suggested above to use the original style carriage bolts. As far as getting the bolts in, like I said, opening the hole up just a touch allows the bolt to go in from the top without removing the timing cover.

Phil, From my research on the subject, this style front plate and corresponding front engine mount were used for 1960-62 Trucks as noted in the below screen grab from a 1933-62 Chevrolet Master Parts and Accessories Catalog. Passenger car front mount plates were different and did not use this mounting design.

Yes - my engine is fully assembled and I'm not wanting to take it apart. And it is a 1960 model. Right now I'm satisfied with my solution and I'll just have to cross my fingers. I believe it will work just fine - time will tell. I'll check it often to make sure nothing is coming loose.

Great idea with the cotter pins but I would remove the lock washers and replace them with flat washers. You can grind them to fit. Grinding the lock washers compromised their integrity. If they crack and most likely will, they’ll fall out and now your mount will be loose.

I will replace the lock washers with flat washers. I did not use the same ones from the pictures above, but I did grind the new ones a little less. Still, I'll get them changed out tomorrow. Thanks.

OK - I believe I'm done with the front engine mount. I removed the lock washers I grinded a little and replaced them with flat washers. Thanks for all the input guys!

Rock and roll - Woohoo!

Looks good, nice work!