Long story short, driver side motor mount broken. Dealer wanted $1200 because they had to take the front diff out to do it. BTW, my truck is a 2007 Yukon SLT, 5.3 4WD with a 4spd. Things may differ a little for folks with other drivertrains and you 2WD guys will have it easy with all that room to work with.
Passenger side is ok as well as the trans mount. If you aren't sure if yours is broken, do this.
1) Pop your hood and crank the truck.
2) Engage parking brake
3) Rev in reverse
4) Rev in drive
If during the rev cycles you notice the motor trying to jump out of the engine bay, you probably have a broken motor mount. Reverse = passenger side, drive = driver side.
With that out of the way, I had a broken driver side mount. Purchased one from Amazon for $40, not ACDelco but I thought I'd give the cheap one a try because.... I'm cheap. The model was DEA A5365, and it DOES NOT come with the motor-side plate or heat shield. This is just the frame side and the rubber bit in the middle.
In pretty short order this became a pain in the rear. I'll include some of my pitfalls and learnings through the write up.
1) I did not jack up the truck. I'm leveled and have 33s so it's high enough for my big self to get under there already.
2) Remove driver side wheel well liner. The usual GM push clips/pins and four 7mm screws. There are wiring harnesses from the fuse box connected tot he top of the liner so be careful removing them.
3) Mark the steering shaft at the upper connection where it connects to the steering column. I used a marks-a-lot and subsequently a razor knife. Paint pen would've been better.
4) Disconnect the steering shaft using a 15mm socker/wrench.
5) Now it's time to loosen the three frame side bolts. I don't have pics but there are youtube videos out there that show their location. All three are 15mm. I used a combination of an electric impact, 15mm impact socket and three wobble extensions (3”, 6” and 10” I believe. To give me the length and flexibility needed to reach all three. The impact barely budged them so I broke out the ½ drive rachet, a 20” extension, and universal joint, a shallow 15mm socket and a 2-foot piece of pipe. This gave me plenty of leverage and put the flex at the end of the extension where it’s needed. I had to back them out a few turns, shoot some PB blaster on the threads, tighten them down and then back out again. After a couple of times that worked to get the threads loosened up and the impact brought them all the way out.
6) Once the frame side bolts are out, get AT LEAST a 4x4 piece of wood. I have two 2x4 blocks stacked on top of each other, a third would have been better. More on this later. Place the wood on your floor jack pad underneath the oil pan, between the cross member and sway bar (IIRC). Begin to jack the engine up with the wood between your jack pad and the oil pan. Don’t go crazy here, take a couple of looks to see how much clearance you’re gaining. I didn’t notice that the edge of my jack pad had contacted the cross member, this severely limited the room I had to get the mount out/in. A third 2x4 would’ve given me plenty of room. MAKE SURE IT CLEARS BEFORE PROCEEDING.
7) Now comes the fun park, getting to the engine-side bolts. FRONT BOLTS: I removed the front skid plate (four 15mm bolts) and set it aside. I could now almost it up in the engine bay between the motor and the fans. I tried using this as my access point for the front, engine-side bolts but it proved to be too much to keep a ratchet on the bolt. So I got out eh step stool and laid over the radiator support and loosened the bolts from the top by going down behind the alternator bracket, underneath the exhaust manifold. Once the bolts break loose you should be able to remove them by hand. These are 15mm bolts by the way. I ended up using a 15mm deep socket, 3”extension and a 3/8 drive ratchet to loosen them and the used a 15mm shallow socket at the 3” extension to remove them with my hand.
8) REAR BOLTS: Remove the straps from the front u-joint of the front drive shaft (four 13mm bolts IIRC). Make sure your truck is in 2WD so you can spin the driveshaft by hand. I then had to use a pry bar to get the front driveshaft out of the yoke on the differential, I then slid the driveshaft over towards the engine to give me more clearance between the driveshaft and exhaust. This is the hole I used to get to the two rear bolts on the engine side. I used a the same combination for the front bolts on the rears as well.
9) Just a note about the order of the bolts, leave the top ones for last. I heard this from one of the videos and didn’t see why it would matter. It matters, the mount will try to lay back onto the frame if you take the tops out first.
10) You now have the mount loose and just have to get it out. I have to break the mount into pieces by removing the two 15mm bolts that hold the engine plate and heat shield to the frame mount. I then took the heat shield and engine plate out the top and wiggled the frame mount out through the wheel well.
11) Now if you bought the mount I did, you’ll have to reassemble it. I had to do this with the mount sitting in its new home on the frame. If you weren’t a knuckle head and got plenty of clearance by using an extra piece of wood to jack up the motor, you’ll probably be able to reassemble the mount outside of the truck and them slide it in from the top and at the very least you’ll have more room than I did to reassemble in down on the frame.
12) Set the frame side mount in place where the old mount once lived. There’s a guide pin that must sit in a hole on the frame and you’ll see the bolt holes line up. Take your heat shield and set it in place over the studs on the frame mount, now set your engine plate in place and get the nuts threaded on as much as you can by hand. Now get a 15mm wrench (I used a ratchet wrench) and get the nuts tightened down on the engine plate studs. With my lack of room, I had to use the 15mm wrench then switch to a 15mm shallow socket and ratchet to finish tightening the nuts.
13) You’re no ready to bolt the mount to the engine, just reverse the steps from 7 & 8 above.
14) now you have to gently sit the motor back down on the frame making sure the guide pin drops back into the proper hole on the frame. Just take your time and don’t drop the motor all the way back down yet, you have to get the frame bolts aligned. Test thread the frame bolts by hand until they line up. Once you’ve got them lined up, tighten them down and drop the motor back down completely.
15) Put back on all the crap you took off and go take a shower. You will be filthy.
Passenger side is ok as well as the trans mount. If you aren't sure if yours is broken, do this.
1) Pop your hood and crank the truck.
2) Engage parking brake
3) Rev in reverse
4) Rev in drive
If during the rev cycles you notice the motor trying to jump out of the engine bay, you probably have a broken motor mount. Reverse = passenger side, drive = driver side.
With that out of the way, I had a broken driver side mount. Purchased one from Amazon for $40, not ACDelco but I thought I'd give the cheap one a try because.... I'm cheap. The model was DEA A5365, and it DOES NOT come with the motor-side plate or heat shield. This is just the frame side and the rubber bit in the middle.
In pretty short order this became a pain in the rear. I'll include some of my pitfalls and learnings through the write up.
1) I did not jack up the truck. I'm leveled and have 33s so it's high enough for my big self to get under there already.
2) Remove driver side wheel well liner. The usual GM push clips/pins and four 7mm screws. There are wiring harnesses from the fuse box connected tot he top of the liner so be careful removing them.
3) Mark the steering shaft at the upper connection where it connects to the steering column. I used a marks-a-lot and subsequently a razor knife. Paint pen would've been better.
4) Disconnect the steering shaft using a 15mm socker/wrench.
5) Now it's time to loosen the three frame side bolts. I don't have pics but there are youtube videos out there that show their location. All three are 15mm. I used a combination of an electric impact, 15mm impact socket and three wobble extensions (3”, 6” and 10” I believe. To give me the length and flexibility needed to reach all three. The impact barely budged them so I broke out the ½ drive rachet, a 20” extension, and universal joint, a shallow 15mm socket and a 2-foot piece of pipe. This gave me plenty of leverage and put the flex at the end of the extension where it’s needed. I had to back them out a few turns, shoot some PB blaster on the threads, tighten them down and then back out again. After a couple of times that worked to get the threads loosened up and the impact brought them all the way out.
6) Once the frame side bolts are out, get AT LEAST a 4x4 piece of wood. I have two 2x4 blocks stacked on top of each other, a third would have been better. More on this later. Place the wood on your floor jack pad underneath the oil pan, between the cross member and sway bar (IIRC). Begin to jack the engine up with the wood between your jack pad and the oil pan. Don’t go crazy here, take a couple of looks to see how much clearance you’re gaining. I didn’t notice that the edge of my jack pad had contacted the cross member, this severely limited the room I had to get the mount out/in. A third 2x4 would’ve given me plenty of room. MAKE SURE IT CLEARS BEFORE PROCEEDING.
7) Now comes the fun park, getting to the engine-side bolts. FRONT BOLTS: I removed the front skid plate (four 15mm bolts) and set it aside. I could now almost it up in the engine bay between the motor and the fans. I tried using this as my access point for the front, engine-side bolts but it proved to be too much to keep a ratchet on the bolt. So I got out eh step stool and laid over the radiator support and loosened the bolts from the top by going down behind the alternator bracket, underneath the exhaust manifold. Once the bolts break loose you should be able to remove them by hand. These are 15mm bolts by the way. I ended up using a 15mm deep socket, 3”extension and a 3/8 drive ratchet to loosen them and the used a 15mm shallow socket at the 3” extension to remove them with my hand.
8) REAR BOLTS: Remove the straps from the front u-joint of the front drive shaft (four 13mm bolts IIRC). Make sure your truck is in 2WD so you can spin the driveshaft by hand. I then had to use a pry bar to get the front driveshaft out of the yoke on the differential, I then slid the driveshaft over towards the engine to give me more clearance between the driveshaft and exhaust. This is the hole I used to get to the two rear bolts on the engine side. I used a the same combination for the front bolts on the rears as well.
9) Just a note about the order of the bolts, leave the top ones for last. I heard this from one of the videos and didn’t see why it would matter. It matters, the mount will try to lay back onto the frame if you take the tops out first.
10) You now have the mount loose and just have to get it out. I have to break the mount into pieces by removing the two 15mm bolts that hold the engine plate and heat shield to the frame mount. I then took the heat shield and engine plate out the top and wiggled the frame mount out through the wheel well.
11) Now if you bought the mount I did, you’ll have to reassemble it. I had to do this with the mount sitting in its new home on the frame. If you weren’t a knuckle head and got plenty of clearance by using an extra piece of wood to jack up the motor, you’ll probably be able to reassemble the mount outside of the truck and them slide it in from the top and at the very least you’ll have more room than I did to reassemble in down on the frame.
12) Set the frame side mount in place where the old mount once lived. There’s a guide pin that must sit in a hole on the frame and you’ll see the bolt holes line up. Take your heat shield and set it in place over the studs on the frame mount, now set your engine plate in place and get the nuts threaded on as much as you can by hand. Now get a 15mm wrench (I used a ratchet wrench) and get the nuts tightened down on the engine plate studs. With my lack of room, I had to use the 15mm wrench then switch to a 15mm shallow socket and ratchet to finish tightening the nuts.
13) You’re no ready to bolt the mount to the engine, just reverse the steps from 7 & 8 above.
14) now you have to gently sit the motor back down on the frame making sure the guide pin drops back into the proper hole on the frame. Just take your time and don’t drop the motor all the way back down yet, you have to get the frame bolts aligned. Test thread the frame bolts by hand until they line up. Once you’ve got them lined up, tighten them down and drop the motor back down completely.
15) Put back on all the crap you took off and go take a shower. You will be filthy.
