More Help Needed With Motor Mounts - The 1947 - Present Chevrolet & GMC Truck Message Board Network

orange72350 · 10-01-2003, 12:42 PM

Got my new motor mounts and bolts and washers and all that good stuff yesterday. thought it might just be quick swap. ha. no way. my question is, can the whole mount be swapped with the engine in the truck? i know its gotta be lifted, but how high can i lift the engine with the tranny attached? i am told there is a seal that can be ruined by lifting the tranny to high. If the engine needs to be removed, ill wait a few weeks and pull it out and do my timing chain/pan gaskets all at once, as well as install a new cam/converter. If it can be done in truck, i would be much happier, as this is my main transportation besides the good ol footmobile. any tips/tricks to doing this? thanx in advance
dale
btw this is on a 72 gmc with a 350

**COBALT** · 10-01-2003, 12:53 PM

Here's what I did:

1. Unbolted the mounts from the engine.
2. Loosened the transmission mount.
3. Took my shift linkage loose.
4. Made sure my driveshaft was oriented so the U-joint would swivel when I raised the engine.
5. Unbolted a couple of exhaust straps so it could flex without breaking exhaust pipes or manifolds.
6. Took off air cleaner

I jacked up the motor about 2" using a block of wood under the oil pan - enough for me to get the old mounts out and the new mounts in.

When I lowered the motor I discovered that the holes in the mounts wouldn't line up with the holes in the towers. With the motor EXACTLY centered the holes and the towers were both 1/8" off, where both mounts needed to go down a bit to get the clearance for the center bolts.

...so after messing with the engine to get it to sit correctly I decided to get drastic:

1. I unbolted the towers
2. Bolted them to the mounts
3. Took some 3/8" bar stock, and cut 2 of them about 5" long
4. Loosely bolted one tower to the frame
5. Put bar stock through one hole in the top of the remaining tower, and one through the bottom.
6. Twisted them until I got the remaining hole in the tower to line up, installed a bolt and tightened it as much as I could.
7. Tightened loose bolts on other tower.
8. Pounded out the bar stock pieces with a 5 lb BFH and another piece of bar stock or a 3/8" bolt I had laying around.
9. Installed remaining bolts.
10. Torqued to spec.

orange72350 · 10-01-2003, 01:00 PM

Thanx Cobalt. that sounds rough. what kind of a time frame am i looking at here? like a weekend job, or something that can be taken care of in one long evening?

**COBALT** · 10-01-2003, 01:19 PM

I performed the first set of steps on a Saturday. I was so tired from fighting the engine I quit around around 5:00 pm. I got up early on Sunday, and managed to get it done around 1:00 pm.

You might want to reserve at least an entire day, so you have another day to deal with problems. You can do it in a weekend if you start on Saturday morning, or even Friday night.

tom hand · 10-01-2003, 02:32 PM

I have put these things in a couple hours while drinking beer. It's harder if you have power steering. I have never loosened anything but the motormounts themselves. Motor only needs to be jacked up just enough to get the mounts out...1/2 inch will usually do it . Install all bolts before you tighten any of them. And I always use locktite.

10-01-2003, 12:42 PM	#1
orange72350 Registered User Join Date: Jan 2003 Location: Cold, Snowy High Level, Alberta Canada Eh Posts: 394	More Help Needed With Motor Mounts Got my new motor mounts and bolts and washers and all that good stuff yesterday. thought it might just be quick swap. ha. no way. my question is, can the whole mount be swapped with the engine in the truck? i know its gotta be lifted, but how high can i lift the engine with the tranny attached? i am told there is a seal that can be ruined by lifting the tranny to high. If the engine needs to be removed, ill wait a few weeks and pull it out and do my timing chain/pan gaskets all at once, as well as install a new cam/converter. If it can be done in truck, i would be much happier, as this is my main transportation besides the good ol footmobile. any tips/tricks to doing this? thanx in advance dale btw this is on a 72 gmc with a 350 __________________ 2003 yamaha raptor. Stock, but it still hauls!!!! 2000 skiddo mxz 700. Camoplast 1.5 inch track, jaws twin pipes, b+b can, custom built and weighted clutch, wiseco piston, high comp heads. its very fast. wow. 72 c-10 longbox. Bright Orange. Brand new 350, rv cam, performer intake, qjet, headers, 2 1/2 inch exhaust into hooker areo chamber mufflers. Body work coming soon. "dont let yer mind wander, its to little to go places by itself." "Forget the herse, cause i'll never die"-ACDC Back In Black "If It's To Loud, Yer Just Too Old" "I Love Anything Fast Enough To Do Something Stupid In" "Instant idiot, just add beer!!""

10-01-2003, 12:53 PM	#2
COBALT Senior Member Join Date: Sep 2001 Location: Seattle, WA, USA Posts: 5,817	Here's what I did: 1. Unbolted the mounts from the engine. 2. Loosened the transmission mount. 3. Took my shift linkage loose. 4. Made sure my driveshaft was oriented so the U-joint would swivel when I raised the engine. 5. Unbolted a couple of exhaust straps so it could flex without breaking exhaust pipes or manifolds. 6. Took off air cleaner I jacked up the motor about 2" using a block of wood under the oil pan - enough for me to get the old mounts out and the new mounts in. When I lowered the motor I discovered that the holes in the mounts wouldn't line up with the holes in the towers. With the motor EXACTLY centered the holes and the towers were both 1/8" off, where both mounts needed to go down a bit to get the clearance for the center bolts. ...so after messing with the engine to get it to sit correctly I decided to get drastic: 1. I unbolted the towers 2. Bolted them to the mounts 3. Took some 3/8" bar stock, and cut 2 of them about 5" long 4. Loosely bolted one tower to the frame 5. Put bar stock through one hole in the top of the remaining tower, and one through the bottom. 6. Twisted them until I got the remaining hole in the tower to line up, installed a bolt and tightened it as much as I could. 7. Tightened loose bolts on other tower. 8. Pounded out the bar stock pieces with a 5 lb BFH and another piece of bar stock or a 3/8" bolt I had laying around. 9. Installed remaining bolts. 10. Torqued to spec. __________________ '69 3/4 ton C20 2wd-350ci/TH400 '69 3/4 ton Custom 20 2wd-350ci/4sp Manual '99 2wd 5.7 Chevy Tahoe Seattle, WA.

10-01-2003, 01:00 PM	#3
orange72350 Registered User Join Date: Jan 2003 Location: Cold, Snowy High Level, Alberta Canada Eh Posts: 394	Thanx Cobalt. that sounds rough. what kind of a time frame am i looking at here? like a weekend job, or something that can be taken care of in one long evening? __________________ 2003 yamaha raptor. Stock, but it still hauls!!!! 2000 skiddo mxz 700. Camoplast 1.5 inch track, jaws twin pipes, b+b can, custom built and weighted clutch, wiseco piston, high comp heads. its very fast. wow. 72 c-10 longbox. Bright Orange. Brand new 350, rv cam, performer intake, qjet, headers, 2 1/2 inch exhaust into hooker areo chamber mufflers. Body work coming soon. "dont let yer mind wander, its to little to go places by itself." "Forget the herse, cause i'll never die"-ACDC Back In Black "If It's To Loud, Yer Just Too Old" "I Love Anything Fast Enough To Do Something Stupid In" "Instant idiot, just add beer!!""

10-01-2003, 01:19 PM	#4
COBALT Senior Member Join Date: Sep 2001 Location: Seattle, WA, USA Posts: 5,817	I performed the first set of steps on a Saturday. I was so tired from fighting the engine I quit around around 5:00 pm. I got up early on Sunday, and managed to get it done around 1:00 pm. You might want to reserve at least an entire day, so you have another day to deal with problems. You can do it in a weekend if you start on Saturday morning, or even Friday night. __________________ '69 3/4 ton C20 2wd-350ci/TH400 '69 3/4 ton Custom 20 2wd-350ci/4sp Manual '99 2wd 5.7 Chevy Tahoe Seattle, WA.

10-01-2003, 02:32 PM	#5
tom hand CCRider Join Date: Feb 2000 Location: Olive Branch,MS,USA Posts: 2,232	I have put these things in a couple hours while drinking beer. It's harder if you have power steering. I have never loosened anything but the motormounts themselves. Motor only needs to be jacked up just enough to get the mounts out...1/2 inch will usually do it . Install all bolts before you tighten any of them. And I always use locktite. __________________ 72 GMC Sierra SWB almost finished---- 84 Softail Olive Branch MS



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