Motor mount replacement

[Stallion]

So I had a real bad scraping sound when I would torque the engine up, and found out that it was the engine fan actually rising enough to scrape against the shroud. So, I'm thinking that the problem here is the motor mounts are going and allowing the engine to give too much, and eventually will just rip off. So, before I get to that point I need to put in two new motor mounts. No?

Is it a big deal to do this? What does it take? I don't need a cherry picker for this, do I? How would I support the engine to get the mounts out? Are they tough to wrench out and get to?

Thanks!

 

[dfw81shark]

So I had a real bad scraping sound when I would torque the engine up, and found out that it was the engine fan actually rising enough to scrape against the shroud. So, I'm thinking that the problem here is the motor mounts are going and allowing the engine to give too much, and eventually will just rip off. So, before I get to that point I need to put in two new motor mounts. No?

Is it a big deal to do this? What does it take? I don't need a cherry picker for this, do I? How would I support the engine to get the mounts out? Are they tough to wrench out and get to?

Thanks!

Throw a hydraulic jack with a block of wood under the oil pan and do one mount at a time. It isn't hard at all, although you might want to get to the bolts from the bottom, so you'll need 2 jacks.

 

[Stingray6974]

Stallion,

Just don't by the cheap ones. They're not worth the effort.

Mike

 

[Stallion]

dfw81shark, that won't crush the oil pan?

Mike, which are the cheap ones and which are the good ones??

 

[Stingray6974]

Usually the ones around $20-30. Many companies sell these mounts and are wrapped in a bag marked "Made in India". I'll do some checking and see if I can find a good deal for you.

Mike

 

[Stallion]

I was looking in Eckler's and they have them for about that price each, so I should assume these should be fine? And I'm not going solid, right? Stock and recommended is the urethane or whatever they are made out of?

 

[dfw81shark]

dfw81shark, that won't crush the oil pan?

Mike, which are the cheap ones and which are the good ones??

Nah, that's what the 2x4 is for, to distribute the weight. Make sure it is 12 to 18 inches long or so, should be no problems if the motor has a place to go (i.e. you removed one of the bolts).

I am using the energy suspension polyurethane from Autozone. They are $32 each- so far so good. Previous were cheapy rubber ones I got at Oreilly. Not to say you can't get good ones from Oreilly, I just happened to be at Autozone when I needed new ones. The cheapy Oreilly's separated after about a year.

 

[Jack]

Throw a hydraulic jack with a block of wood under the oil pan and do one mount at a time. It isn't hard at all, although you might want to get to the bolts from the bottom, so you'll need 2 jacks.

Ditto

I am using the energy suspension polyurethane from Autozone.

Ditto (they were great in my blue 71 ... had es poly trans mount too).
JACK:gap

 

[WayneLBurnham]

I have to speak up for all steel

I have the BB ones from Moroso. They are anodized gold. (The pattern is the same, but the material is thicker.)

I would avoid chromed ones at all costs. When I was planting this troubled mill, I was cleaning up the chromed SB Moroso's I had put on the first motor about 6 months before (a similar problem to yours - scraping fan).

I was stunned to see BOTH of these all steel mounts had severe cracks - from a tiny 225 max hp motor!!! When I bought the new thicker BB ones (I had to bend them or slightly enlarge one hole on them as I recall) I noticed while also from Moroso, they were gold. It dawned on me the chroming was an after-aftermarket deal and they had hit it with too much currrent for too long and given them a bad case of hydrogen embrittlement - always a danger with plating, especially the 3-7 passes of chroming.

I did not notice a lot more noise from the engine, although I did some more. I like the sound though, so I'm just weird. I did use a urethane tranny mount though.

Generally, you'll never break or wear out a steel motor mount - and in a noisy car like a C3 vette, there isn't a huge premium on extra sound anyhow.

 

[Vettehead Mikey]

And I'm not going solid, right? Stock and recommended is the urethane or whatever they are made out of?

There's no benefit to solid mounts for a street driven car, just more boy-racer stuff that transmits vibration (low and high frequency) to the rest of the car. Stick with the stock rubber mounts.

 

[JohnZ]

And don't do the Bubba trick of jacking up the engine with a piece of wood under the pan; it can distort/deflect the bottom of the pan enough to choke off oil flow into the screen on the pump - it's only 3/8" off the bottom of the pan to begin with. I use a saddle made from a 2x6 base and 1x6 sides, with the sides about 1" taller than the depth of the pan so it lifts on the pan rail, not on the pan; the notch is to clear the dipstick "bump" in the pan rail. Crude, but effective, and won't damage your oil pan.

 

[Stallion]

Did you use wood glue, John?

 

[dfw81shark]

And don't do the Bubba trick of jacking up the engine with a piece of wood under the pan; it can distort/deflect the bottom of the pan enough to choke off oil flow into the screen on the pump - it's only 3/8" off the bottom of the pan to begin with. I use a saddle made from a 2x6 base and 1x6 sides, with the sides about 1" taller than the depth of the pan so it lifts on the pan rail, not on the pan; the notch is to clear the dipstick "bump" in the pan rail. Crude, but effective, and won't damage your oil pan.

Didn't think my wood trick was bubba, but whatever. Call me bubba!

 

[Stallion]

John is just saying not to put pressure on the bottom of the oil pan, but rather put the force up to the railing of he oil pan, where no damage can be done...at least I think that's what he meant

 

[JohnZ]

Did you use wood glue, John?

Nope, used four 3-1/2"-long wood screws on each side, driven up from the bottom through holes in the base into the side pieces. Make it so the distance between the inside of the side pieces is about 1/8" wider than the width of the pan, and it'll snug right up against the sides of the pan. It's a one-dollar tool than can save you MAJOR problems.

 

[WayneLBurnham]

But this boy-racer LIKES the vibration!!!

There's no benefit to solid mounts for a street driven car, just more boy-racer stuff that transmits vibration (low and high frequency) to the rest of the car. Stick with the stock rubber mounts.

Never happened on the vette, but I broke too many motor mounts on other old cars and trucks to trust plain rubber again. Then again, as noted, my first steel ones were rendered defective by some silly chroming....

I never really thought of it as a "race" part - more a noisey tractor part that won't fail. I can't really think a single one of those....a 318 mopar 4 door, a 501 caddy (had to MAKE the solid mount for it), the 350 firebird....the Blazerstein had all that much power either - more a question really, I would guess of a 20-30 year old car with decaying oil soaked heat blasted rubber.

If not steel, I would definitely go with the urethane, although they too will almost certainly transmit a fair amount more sound than the rubber as well. At least they are tougher than the rubber from oil and heat though.

On this general topic: Has anyone ever felt the need for a bolt in crossmember at the motor mount area on the C3's for frame stiffening? I would think the block itself would serve as that crossmember sort of, but that would also seem to put more stress on the mounts, the bolts and the mounting "pods."

 

[JohnZ]

TR, new stock rubber mounts will work just fine, will isolate vibration as they're designed to do, and will probably only last 30 or 40 years; solid steel and poly engine mounts are a "hot-rod" aberration for talking points at cruise-ins, or for durability for pure race cars.

 

[Stallion]

TR, new stock rubber mounts will work just fine, will isolate vibration as they're designed to do, and will probably only last 30 or 40 years; solid steel and poly engine mounts are a "hot-rod" aberration for talking points at cruise-ins, or for durability for pure race cars.

Will do, John, thanks!

 

[Stallion]

TR, new stock rubber mounts will work just fine, will isolate vibration as they're designed to do, and will probably only last 30 or 40 years; solid steel and poly engine mounts are a "hot-rod" aberration for talking points at cruise-ins, or for durability for pure race cars.

I'm looking in the Ecklers magazine right now, and in the back they have the "restoration" parts for the Vettes, and they have the part:

68-82 Mount, Motor, All 17.99 ea
[Replacement with safety interlock]

Is this what I'm after?

 

[wishuwerehere82]

Mid America has them for $60.00 a pair for urethane. P/N 612-432.
Or locking P/N 609-543 $50.00/ pair

Or any NAPA store should have them.