This adapter assembly makes for a strong and convenient adaptation of classic standard shift GM bellhousings to the T176 & T177 four-speed transmission, as was the optional transmission found in 1980-1986 CJ Jeeps.
This plate style adapter is machined from billet 6061-T6 aluminum alloy for superior strength. Included are the GM bellhousing locator / throwout sleeve, seal and hardware.
Engine bellhousings using a standard GM rear bolt pattern. GM bellhousings typically feature either a 4-11/16" rear face bore or a 5-1/8" rear face bore, the latter typically only from Chevy / GM trucks from 1968-1991. Our adapter will work with both. If you are uncertain of your bellhousing bore, choose the 5-1/8" press-on spacer ring that can be used or omitted to cover either situation. The ring is easily returnable for credit if not used in the installer's application.
The installer should note that the upper two ears of the transmission will need to be elongated with a round file or other appropriate tool. Because the T176 upper holes and the GM holes cross-over some, this is the only reasonable remedy and is not a difficult part of the process.
The T176 and T177 with ~6-3/4" stick-out input shafts from Jeep CJ's is compatible with this conversion. The similar T178 transmission from other Jeeps of this era feature longer input shafts and different gearing, and are not candidates for this conversion.
The BR4 ring is used to enable use of the SM465 5-1/8” bore bellhousing with 4-11/16” retainers.
If you need a bellhousing, would prefer a new enhanced casting version or would like the LS specific version they can be purchased here:
This is a beautiful piece and necessary for proper operation on LS based engines. They must have the LS crank offset to work properly. These will accept both the 11” and 12” clutch listed below. The page is here with details.
Bolts necessary for installation
Many common GM applications used the 10 spline 1-1/8” hub and as such, it is usually a matter of selecting the correct version. Three sizes are listed below. Most common is the 11” listed in the middle but all are serviceable depending on your needs. Generally the 10-1/2” is used on the smaller 153 tooth flywheel and is exclusive to that application. The 11” and 12” are usually interchangeable with large bellhousings and standard 168 tooth flywheels. Non-standard applications will need to watch for compatibility.
The disc can be purchased separately for those applications natively using a different spline count
While sometimes not needed in this application, it is priceless when clearances dictate its use. You may get lucky and find a correct height release bearing but this product will guarantee correct height when set up properly. Further information is here.
While sometimes not needed in this application, it is priceless when clearances dictate its use. With all the variabilities in flywheel and clutch height, we highly recommend its use. Further information is here.
And adjustable pivot is an additional noteworthy option allowing even more flexibility to this critical setting.
Though not required on all applications, now is an excellent opportunity to upgrade from the likely worn mechanical system. These mechanical systems are usually full of play which is aggravated by years of wear and much more affected by flex in the body/frame relationship, especially when in a twist off-road. You will find that your clutch release point will vary as things twist. With a hydraulic system, that is not the case. All flex is taken up by the braided stainless line which is unaffected by changes in frame to body relationship. If your Jeep has the master cylinder, that part can be reused. More information can be found here. Parts to do this swap are:
Because the transmission and transfer case shifters are often in a different location than factory in these Jeeps, this new transmission tunnel cover gives the installer a clean slate. There are no screw holes nor transmission & transfer case shifter holes, allowing the installer to drill and cut them as necessary. An easy way to get a perfect fit is to use the old cover as a template, making cuts as necessary, then overlay on the new aluminum piece for perfect holes.
The finish is natural brushed aluminum, which looks pretty terrific, but it can easily be primed and painted to suit, if desired.
The stock shifter may be reused but may opt for a twin stick setup.
The adapter is easily and quickly installed onto the T176. Due to design constraints, the transmission's two top ears will require slight elongation with a round or rotary file. This process is simple and will not compromise the strength of the flange. Cutting the transmission input shaft is not required as the adapter spaces the transmission properly for the GM crank and clutch assembly.
If converting to a V8 in conjunction with this upgrade, aftermarket engine mounts are available to ease its installation. Because of the broad spectrum of engines and vehicle combinations used with this adapter, it would be difficult to list them all here. Whatever your application, Novak likely has the perfect solution. From a 225 Buick V6 in a CJ2A to an LS3 in your JK we’ve got you covered.
Novak's engine mounts, featuring excellent vibration dampening, superior strength and impressive adjustability - adjustable even after the engine is installed. The design and strength and affordability of our mounts are second to none.
Engine placement in these applications is an effort in compromise to find the best position overall as a package. Generally the engine will be about 1” or even more towards the left, (driver’s side in the USA) away from the front differential in a CJ application. This gives the best balance of weight and more importantly clearance for the driveshaft going to the front axle. Your tight spots will be steering to exhaust on the left (hold that as tight as you can) and clearance for the front driveshaft on the right. On a driver’s side drop transfer case, usually the later Jeeps, things often get a little easier as steering and front driveshaft are pushing you the same direction. Fore and aft position will vary with the Jeep model and engine. Have a CJ5 and Gen I with a rear distributor? You’ll be better off a little forward for more rear driveshaft length and clearance for that HEI. If you are in a longer Jeep and using an LS engine with no distributor, you’ll have more fan clearance and better balance if you hold it to the rear. Usually for ground clearance tuck things up nicely for height to avoid damage to oil pans and other life giving parts in the Jeep. Common sense and taking a step back to look at things overall goes a long ways.
Driveshaft length changes are often required. Most conversions to these transmissions will require that the rear driveshaft be modified to be shorter and front driveshaft longer.
Some installers, concerned about the expense of new or modified driveshafts, attempt to let the existing driveshafts dictate engine, transmission and transfer case location, often to the detriment of the project. Our recommendation is to prioritize the correct position of drivetrain components over saving a few dollars which is usually regretted in the long run with compromised positioning.
Driveshaft modifications and rebalancing can be affordable when performed by driveline, RV or tractor implement specialists. New driveshafts are an option, but not necessarily a requirement in regards to the actual successful conversion if your existing driveshafts are in good condition.
Jeeps that require extensive travel or specialty-built driveshafts have this option available through several fabricators across the nation. These are normally specified after placement of the new transmission and measured at vehicle ride height. As the rear driveline gets shorter, it is often advantageous to us a Double Cardan or “CV style” rear shaft with the correct geometry at the axle to minimize vibrations and possible binding.
Use of factory axles is completely acceptable with this conversion. Axle upgrades are not necessary, but they may be chosen for reasons external to this transmission upgrade.