You’ll want mounts that firm up driveline control without falling apart: Energy Suspension’s 3.1108R Hyper‑Flex urethane is a durable OEM‑fit for GM swaps; the broader ENERGY SUSPEN lineup (race‑proven urethane) covers TH350/TH400/700R4 swaps; Allstar’s solid steel mount gives absolute rigidity for ’58–88 GM muscle; a GM TH350/TH400/700R4 rear urethane mount balances durability and fitment; the 3.1106G variant offers similar benefits. Keep going to see fitment, pros, and install tips.
| Energy Suspension 3.1108R Transmission Mount for GM |
| Professional Grade | Material: Polyurethane Hyper-Flex | Intended Use: Transmission mount (GM) | Performance Focus: High-performance, longer-lasting vs rubber | VIEW LATEST PRICE | Read Our Analysis |
| ENERGY SUSPN Transmission Mount |
| Best Durability | Material: Hyper-Flex polyurethane | Intended Use: Transmission mount (vehicle specific) | Performance Focus: Superior performance (race/off-road/street) | VIEW LATEST PRICE | Read Our Analysis |
| Allstar Performance Solid Transmission Mount for GM (1958–88) |
| Ultimate Stiffness | Material: Steel (solid) | Intended Use: Transmission mount for GM (1958–88) | Performance Focus: Eliminates twisting/flex for rigid support | VIEW LATEST PRICE | Read Our Analysis |
| GM TH350/TH400/700R4 Rear Transmission Mount Compatible |
| Complete Replacement | Material: Urethane | Intended Use: Rear transmission mount (TH350/TH400/700R4) | Performance Focus: High-quality urethane for durable support | VIEW LATEST PRICE | Read Our Analysis |
| Energy Suspension 3.1106G Transmission Mount |
| Long-Lasting Performance | Material: Polyurethane Hyper-Flex | Intended Use: Transmission mount | Performance Focus: High-performance, engineered for longevity | VIEW LATEST PRICE | Read Our Analysis |
More Details on Our Top Picks
Energy Suspension 3.1108R Transmission Mount for GM
In case you need a durable, high-performance transmission mount for GM vehicles, the Energy Suspension 3.1108R is a top choice because its Polyurethane Hyper-Flex construction replaces stock rubber to resist contaminants and permanent compression, giving longer-lasting, professional-grade support under heavy use. You’ll notice firmer, more consistent transmission positioning under load, since Hyper-Flex components won’t sag like rubber. Installation matches OEM fitment for GM, so you won’t wrestle with alignment. You’ll get improved durability and reliable performance for demanding applications, and because it’s engineered as a professional product, it stands up to corrosive fluids and road grime that degrade standard mounts.
- Material:Polyurethane Hyper-Flex
- Intended Use:Transmission mount (GM)
- Performance Focus:High-performance, longer-lasting vs rubber
- Durability/Resistance:Resists permanent compression; stands up to contaminants
- Fitment/Compatibility:GM-specific fit
- Professional/Aftermarket Grade:Professional-grade replacement
- Additional Feature:Polyurethane Hyper-Flex components
- Additional Feature:Replacement for rubber
- Additional Feature:Professional-grade design
ENERGY SUSPN Transmission Mount
Should you want race-proven durability and firmer drivetrain feel, the ENERGY SUSPEN Transmission Mount is built for you—its Hyper-Flex polyurethane and vehicle-specific fit deliver performance gains on track, off-road, and the street while outlasting rubber mounts up to five times. You’ll get a cost-effective upgrade from Energy Suspension, a brand known for performance polyurethane and backed through 10 U.S. patents. The mount resists oils, coolants, UV, and pollutants, so it won’t deteriorate prematurely. It fits domestic and import cars and trucks, including front-, rear- and 4WD setups, and works with both older and newer vehicles.
- Material:Hyper-Flex polyurethane
- Intended Use:Transmission mount (vehicle specific)
- Performance Focus:Superior performance (race/off-road/street)
- Durability/Resistance:Outlasts rubber 5:1; resists oils, coolants, UV
- Fitment/Compatibility:Vehicle-specific fits (domestic & import)
- Professional/Aftermarket Grade:Energy Suspension performance aftermarket (patented designs)
- Additional Feature:10 U.S. patents
- Additional Feature:Proven on race track
- Additional Feature:Outlasts rubber 5:1
Allstar Performance Solid Transmission Mount for GM (1958–88)
Built for racers and restorers who need absolute drivetrain rigidity, the Allstar Performance solid transmission mount swaps rubber compliance for a 3/16-inch steel build that stops twisting, flex, and distortion. You get a black oxide–finished, solid steel mount sold each, designed for GM cars from 1958–1988. It fits TH350, TH400, Powerglide, Borg-Warner, Muncie, and Mopar 4-speed transmissions, providing rigid support for hard-launch and high-torque applications. Don’t pair it with rubber engine mounts — they’re incompatible and will undermine alignment. Install it whenever you desire maximum drivetrain stiffness and predictable power transfer for racing or heavy-duty street use.
- Material:Steel (solid)
- Intended Use:Transmission mount for GM (1958–88)
- Performance Focus:Eliminates twisting/flex for rigid support
- Durability/Resistance:Solid steel resists flex/distortion (no rubber to degrade)
- Fitment/Compatibility:GM vehicles 1958–1988; multiple transmissions
- Professional/Aftermarket Grade:Aftermarket solid performance mount (sold each)
- Additional Feature:Solid steel construction
- Additional Feature:Black oxide finish
- Additional Feature:Fits many classic transmissions
GM TH350/TH400/700R4 Rear Transmission Mount Compatible
Should you’re swapping or upgrading a GM TH350, TH400, or 700R4, this rear transmission mount (3.1108G) is your best bet for Chevy Turbo applications because its high-quality urethane stands up to oil and under-car chemicals while keeping the driveline secure. You’ll find it fits GM cars and trucks, and works with manual and automatic transmissions. The mount replaces the factory rear trans mount and ships with studs, nuts, and washers to simplify installation. Because the urethane resists deterioration and rot, you’ll get durable service under harsh conditions. See product details for fitment specifics and torque specs.
- Material:Urethane
- Intended Use:Rear transmission mount (TH350/TH400/700R4)
- Performance Focus:High-quality urethane for durable support
- Durability/Resistance:Resists deterioration and rot from oil/under-car chemicals
- Fitment/Compatibility:GM TH350/TH400/700R4; Chevy Turbo; manual & automatic
- Professional/Aftermarket Grade:Aftermarket replacement with included hardware
- Additional Feature:Includes studs, nuts, washers
- Additional Feature:Compatible with Turbo applications
- Additional Feature:Fits manual & automatic
Energy Suspension 3.1106G Transmission Mount
Should you want a transmission mount that lasts through heavy use and exposure, the Energy Suspension 3.1106G is engineered with Hyper-Flex polyurethane to resist contaminants and permanent compression better than rubber, making it the right choice for performance drivers and shop technicians who need durable, consistent mounts. You’ll get a professional-grade design focused on high-quality, high-performance operation and improved longevity versus rubber mounts. The Hyper-Flex material maintains stiffness under load while reducing degradation from oils and road chemicals, so vibration control stays reliable. In case you require a tougher, longer-lasting transmission mount, the 3.1106G is worth considering—see more product details.
- Material:Polyurethane Hyper-Flex
- Intended Use:Transmission mount
- Performance Focus:High-performance, engineered for longevity
- Durability/Resistance:Withstands contaminants that destroy rubber; resists compression
- Fitment/Compatibility:GM (implied/application-specific)
- Professional/Aftermarket Grade:Professional-grade performance product
- Additional Feature:Polyurethane Hyper-Flex components
- Additional Feature:Professional-grade design
- Additional Feature:See more product details
Factors to Consider When Choosing Performance Transmission Mounts
Whenever choosing performance transmission mounts, you’ll want to weigh mount material, fitment and compatibility with your drivetrain, and how well the mount manages vibration and noise. Also consider durability against oil, road salt, and heat, plus whether the kit includes proper installation hardware and clear instructions. Making the right trade-offs up front saves time and prevents premature failures.
Mount Material Choice
Although your choice of mount material could seem like a small detail, it controls how much the transmission moves, how much vibration you feel, and how long the mount lasts under performance conditions. Choose polyurethane should you want stiffer support and crisper shift feel; it typically outlasts natural rubber by 3–5× in performance use and resists chemicals better whenever engineered. Solid steel or aluminum gives the ultimate rigidity and nearly zero flex, but expect much higher vibration and noise transfer. Dual-durometer or multi-stage elastomers give a compromise: a softer outer layer for NVH control with a firmer core for load support across operating ranges. Avoid soft rubber for heavy use—heat, oil, and ozone make it compress and lose alignment over time.
Compatibility And Fitment
Because transmission mounts have to mate precisely with both the gearbox and the chassis, verify exact transmission model, vehicle year/make/model, and mount location before you buy. You’ll need to confirm bolt pattern, stud spacing, and clearance for specific transmissions (TH350, TH400, 700R4, Powerglide, etc.). Check whether the mount is for manual or automatic use and whether it’s front, rear, or center—designs and load directions differ. Match material and design (solid, polyurethane, rubber) to existing engine mounts and driveline geometry to avoid incompatibility. Measure transaxle/frame clearance and required stud length or plate thickness to prevent interference with exhaust, driveshaft, crossmembers, or braces. Finally, review torque specs, included hardware, and whether adapters or special studs/brackets are required.
Vibration And Noise Control
With fit and mount location confirmed, you’ll next want to focus on how a transmission mount affects vibration and cabin noise. Stiffer mounts (polyurethane or solid) cut drivetrain movement and twist, improving shift precision and lowering gear lash, but they usually pass more NVH into the cabin. Tuned-durometer polyurethane and multi-stage designs balance reduced movement with controlled damping to curb low-frequency shunt and high-frequency buzz. Harder mounts reduce transient vibration amplitudes yet can raise perceived noise in lieu of several dB in certain bands unless isolation features are included. Match stiffness across engine and transmission mounts to avoid vibration coupling that amplifies noise. Finally, pick materials that retain damping properties over time so isolation doesn’t degrade and cabin noise doesn’t progressively increase.
Durability Against Contaminants
Anytime you’re shopping for performance transmission mounts, prioritize materials and hardware that withstand the harsh undercarriage environment so isolation and fit don’t degrade. Choose polyurethane or metal mounts because they resist oils, coolants, road salts, and undercarriage chemicals far better than natural rubber. Look for compounds or coatings rated for UV exposure and atmospheric pollutants to prevent cracking and embrittlement. Prefer designs specified to resist permanent compression and creep, since heat and contaminants can soften materials and reduce load-bearing capacity over time. Check for corrosion-resistant or plated steel components, because rusted studs, bolts, and brackets often fail whenever exposed to moisture and chemicals. If available, review lab or industry test data—oil-swelling, UV-aging, and chemical-immersion results—to quantify performance.
Installation And Hardware
Having durable, contaminant-resistant mounts is only part of the equation—you also need the right hardware and proper installation to get the expected performance and lifespan. Verify whether mounts include studs, bolts, nuts, and washers or require you to source them, and match grade and size to factory specs so clamping force and safety are correct. Support the transmission with a jack and wood block to maintain height and orientation while you remove and install the mount. Clean mating surfaces and inspect or replace crossmember, brackets, and isolators to guarantee alignment and load distribution. Torque all fasteners to manufacturer values with a calibrated torque wrench, then road-test and re-torque after 50–100 miles to accommodate initial settling and prevent loosening.
