Replacing Engine/Transmission Mounts Part III – Replacing Engine Mounts
Preface
I put in a lot of detail into this write-up and at first glance it may seem like a cumbersome and daunting procedure. It’s not. There's more detail than most people will need. When you boil this installation down there are basically 10 steps, or less, involved with replacing the mounts. It’s not a daunting task, take your time with it and you’ll be fine. In the end, if you're just not comfortable with raising and lowering your engine...don't do it. This installation guide is based on a Gen II Viper, specifically, a 2001 RT/10.
SAFETY
Now we get to the fun part of replacing our worn out engine mounts with Poly mounts. You’ll be working under the car for a good part of this procedure (unless you’re going to pull the engine out of the car). If you’re following Part I and have your car up on jack stands let’s remember some SAFETY guidelines from Part I:
- Always work on a hard level surface such as your garage floor.
- Use a floor jack and jack stand that’s rated to handle the weight of your car, at least.
- NEVER work under your car supported by a floor jack alone.
- Use safe jacking points under your car. A jack or jack stand in the wrong location can cause vehicle and body damage.
- Never jack up your car without blocking the wheels.
- Make certain your emergency brake is set and your gearshift is set in first gear before you jack it up.
- Keep a phone with you while under the car and have someone check on you periodically.
- Wear a pair of safety glasses or goggles while working under the car. I had all kinds of crud fall on me as I was pulling/installing the mounts.
Procedure
In a nutshell, the goal is to raise the engine about 3-4 inches off of the frame mounts, remove the engine mount assembly, replace the rubber mounts, install the engine mount assembly and lower the engine. The Viper has two engine mounts located on either side of the engine block towards the front-end. We will be replacing both mounts. We illustrated what an engine mount looks like in Part II.
1. Preparing to Raise the Engine – Check for Clearance
Before we actually raise the engine, we need to check for clearance around the exhaust headers, airbox and cowl. You don’t have to remove your side sills for this procedure but if you’re running aftermarket exhaust systems or have installed a wideband O2 sensor you should check your header turnouts for clearance in the frame.
I’ve installed Belanger headers and catback as well as an LC-1 Wideband Sensor in one of my turnouts. I needed to remove the WBO sensor so as not to crush it in the sills when raising the engine. Even with 3” exhaust pipe running through my frame I had plenty of clearance below:
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I simply needed to remove my WBO sensor. For stock exhausts, you should have plenty of “flex” with the stock flex pipe turnout and no need to remove the side sills for this procedure.
Next, check for clearance where your exhaust header collector passes through the frame:
Top View – Driver’s Side Headers:
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Even with my 1 ¾” Belanger Headers I had plenty of clearance between the frame. If you raise your engine and your headers hit the frame you may need to unbolt your headers in order to remove your engine mounts
Next, check your Air Box for clearance located on the passenger side whcih is mounted above the AC housing. I decided to remove my Air Box by removing two screws and two bolts:
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Removing the Air Box is not required but gave me a better view of the engine block and mount. Don’t pay attention to the heat shielding on the air box…that’s another project in progress.J
Check your cowl cover and ignition coils for clearance. You shouldn’t have to remove the cowl cover for this procedure and you should have just enough clearance so that your ignition coils/wires don’t hit the underside of the windshield. In this picture, I have my engine raised with the engine barely touching the cowl and ignition coils/wires safely away from the windshield:
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Lastly, let’s check the air intake box. I decided to loosen the air intake be removing the three screws that hold the air intake in place. This gave me enough flex so that the smooth tubes weren’t pulled off of the throttle bodies as I raised the engine:
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2. We need to loosen a few bolts that hold the engine brackets to the engine and frame BEFORE raising the engine. Let’s start by getting under the car and loosening the bolts that hold the engine bracket to engine. Each mount has two bolts. Using your 9/16” socket, ratchet or wrench we want to loosen these two bolts on both mounts. We only want to loosen them at this point and not completely remove them, yet:
Bottom View / Driver’s Side Mount:
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You’ll notice that the O2 wires are attached by a plastic hanger bracket located on one side of the engine bracket. These will get in the way in a hurry. Simply pop out the plastic retainer and move the O2 wires out of the way.
The passenger side is a bit of a tight space to work in compared to the driver’s side. In addition to the O2 sensor wire connector the passenger mount also has another wire attached to it via a metal bracket connected to one of the bolts. Simply move this wire out of the way and you’ll have enough space to work in:
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3. Next, we’ll need to remove the 3/4” retaining nuts located under the frame under each engine mount:
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My nuts were rusted and frozen pretty badly (insert your joke here). I sprayed penetrating oil into the nut and let it work for about 15 minutes. Using a 3/4” socket and long Flex-T handle I was able to break the nut loose and remove it.
At this point, you’ve loosened the bracket bolts and removed the isolator/frame nut on both mounts and you’re engine is ready to be lifted. You may also be wondering about that ‘other’ nut holding the engine bracket to the isolator (rubber mount):
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We’re NOT going to remove this bolt until we remove the bracket assembly. There’s no room to get a wrench or breaker bar in there and break loose this nut from under the engine. I tried…
4. Now comes the moment of truth…raising the engine. Using a floor jack (screw jack if you have it) we’ll raise the engine via the oil pan. I used my floor jack and a piece of 2x10 placed under the oil pan to raise my engine:
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With your jack centered under the oil pan, begin jacking up the engine. The goal is to raise the engine high enough in order to slide out the engine mounts, about 3-4”. You’ll hear some creaking and may feel the car rise slightly as the mounts loosen from the frame.
As you raise the engine, check the clearances we reviewed in step 1. If your headers, cowl, coils, etc. are hitting something STOP. We don’t want to damage any of these components. If your engine is not rising, rather the entire car is, STOP. Make certain you’ve removed the isolator/frame nuts in step 3.
After raising your engine a few inches, check the clearance of your mounts. They should be up off the frame with enough clearance to slide them out:
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5. With the engine raised, remove the bolts holding the bracket to the engine we loosened in Step 3. With a little finesse, you should be able to slide the entire bracket assembly out from under the engine block. You may need to raise the engine a little bit if you can’t clear the bracket from the frame.
After removing each bracket I then labeled them so I could keep track of the orientation and which side each mount belonged to:
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6. Using a bench vise, remove the bracket/isolator nut holding the bracket and mount together. My nuts were rusted and frozen so I sprayed more penetrating oil on them before loosening them. You’ll need a good amount of torque to get these nuts off (insert your joke here) so make you have a sturdy bench and vise to work on. Once you remove the nut the assembly will come apart and you’ll be left with the engine bracket, heat shield and rubber OEM mount. Toss the rubber mount.
7. Install your new poly mount to the bracket assembly. Whether you chose the Polybushings or Woodhouse mount, they both assemble in the same manner to the bracket. Make certain that the open end of the heat shield faces away from your headers and that close end faces towards the headers. You will need to reuse these heat shields even with the new mounts:
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You’ll notice my mounts don’t have the interlocking tabs protruding from one side. That’s because I’m installing the Woodhouse mounts which have an internal safety design.
Using a bench vise, torque the bracket/isolator nut to 75 ft. lbs. The aluminum brackets dent easily as you can see from the picture above so be careful.
8. Install the brackets to the engine block by attaching one of the two bolts to the bracket and engine block. Yes, there are two bolts but we’ll use one bolt for lowering so that the bracket will hang down enough in order to guide the engine and bracket back into the frame...I learned this the hard way. After initially bolting the bracket securely to the engine and lowering the engine my brackets didn’t seat properly in the frame mounts and looked like this:
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By installing the brackets with one bolt each, we allow the bracket bolt to guide the mount into the frame as we lower the engine:
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9. With brackets in place, we’ll lower the engine. SLOWLY lower your floor jack until the engine is fully lowered and the mounts seat onto the frame. If you followed step 8, the engine mounts will be guided into place and your mounts will sit flush on top of the frame.
With the engine lowered and brackets in place, torque the isolator/frame nut to 75 ft. lbs:
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Install the remaining bracket bolts to the engine & bracket and torque to 30 ft. lbs:
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Don’t forget to attach the wire/metal hanger on to the bolt before you torque down the nut. This is the wire/hanger we removed from the passenger-side mount in Step 2. Reattach the plastic O2 brackets and O2 wires to the mount we removed in Step 2.
Install your air box, WBO sensor, side sills and cowl IF you removed them. Tighten down your air intake box if you loosened the screws in Step 1. Do a once over on your hoses, wires and ignition wires to make certain nothing came loose when we raised/lowered the engine.
If you removed your wideband sensor for the installation, you may need to perform a free-air calibration before installing it back into the exhaust pipe.
At this point, you’re done with the installation. It’s time to time lower your Viper and enjoy the new mounts…or is it? OR, you can take this opportunity while the Viper is raised and possibly work on the following:
- Change the coolant, oil, transmission fluid, differential fluid
- Grease your ball joints
- Clean your rims, wheel wells
- Detail your undercarriage
For reference, if you’re going to flush your coolant then don’t forget to drain the coolant from under your engine block. Drain plugs are located on either side of the engine block next to the engine mounts:
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When you’re done…safely lower your vehicle and enjoy your new mounts. As always comments, suggestions and feedback are welcome.
- Tony
Don't let "DamnYankee" out do you
BRAVO!
