Gm m85 manual transmission

This is the only GM 3 speed with the same bearing front and rear. This transmission is found in performance applications. Has R cluster gear. Found in heavy-duty applications. Casting number TXX or are on passenger side of case.

They all have 9-bolt side covers and 36 tooth synchro rings. Reverse shift lever is located in the extension housing, along with main shaft reverse which is a straight cut gear. Some of the early units, found mostly in Corvettes, have a front nut like the Muncie M The side cover has 7 bolts and 2 shifter cams. The synchro rings have 36 teeth and the unit has a 4-step cluster gear. Reverse gears are helical cut and are located in the extension housing. The side cover has 7 bolts and 3 shifter cams.

The synchro rings have 30 teeth and the unit has a 5-step cluster gear. Reverse gears are straight cut and are located in the main transmission case. Shifter assembly is attached to the top of the extension housing where the two arms meet.

The main case is open at both ends, the bell housing. There is an internal single-rail shift linkage with the shifter mounted on top of the extension housing. Front and rear main bearings are ball type and the cluster gear has a shaft running through it, that is supported by loose needles.

Case casting is number Front and rear main bearings are tapered. The cluster gear is solid and is supported on each end by cylindrical roller bearings located in the case. Case castings numbers are or The Isuzu logo is cast into the left side of the case. Is not found in the Chevy LUV. It has a rectangular cast iron front bearing retainer and a 27 tooth rear output shaft. The front and rear countershaft bearings are both 25x62x Side-loaded with either aluminum or cast iron case and used in both gas and diesel applications.

All of these units are 3 speeds with Overdrive. Cast iron case with cast iron top cover. All gears on the countershaft are removable except for 1st.

Early units have threads on the input shaft and do not have a front seal. Has GM casting numbers and one P.

Cast iron case with cast iron top cover from and an aluminum top cover Non-synchronized 1st with brass synchro rings for 2nd-4th. All main shaft gears ride on bushings pressed on the shaft. The only gears that are removable from the countershaft are 3rd and 4th. Has GM casting numbers and two P.

Main bearings may be either ball or tapered design. Non-synchronized 1st gear, synchronized 2nd-4th. There are no brass synchro rings. All gears, including reverse, are helical cut. See New Process for more information. The bell housing. It has a removable tube that the throwout bearing rides on.

The main bearing in this unit is comprised of caged needles in shell races. Loose needles and flat thrust bearings are used throughout the transmission. Casting number is Limited parts availability. Parts List 54 Aluminum case, end-loaded unit with an integral bell housing.

Isuzu logo is cast into the drivers side of the case. This is found only is GM diesel applications and has a different starter position than the unit that goes into the Isuzu vehicles. Aluminum case with top cover, internal single-rail shift with the shifter mounted on the extension housing. Casting numbers on the case, cover or extension housing are or The cluster gear is supported on both ends by cylindrical roller bearings. Modern 6-speeds are easy to spot, and 5-speeds are not difficult either, but when it comes to older 4-speeds and automatics, the increased variety can muddy the waters.

So, whether you are heading out to check out a "For Sale" ad that could be your next project or trying to make heads or tails of a junkyard find, the following charts can be useful guides when it comes to GM transmission identification. The easiest method of GM automatic transmission identification is to examine the transmission pan.

New transmission designs came with new, unique pan shapes, and the general shape of the pan often paints a fairly clear picture of which automatic transmission you are dealing with. Once you identify the pan, count the number of transmission pan bolts for confirmation.

Here's a quick overview of the first model year for each transmission. Although they are no longer offered on new vehicles, rebuilt and aftermarket versions are still available for each of these models. You can find replacement parts for each of these transmissions here:. As mentioned above, modern 5-speed and 6-speed manual transmissions are easy to identify, but older 4-speed transmissions have more variety.

While there are no distinctive pans and bolt counts to make transmission identification simple, 4-speed manual transmissions can be generally identified by examining the side profile.

The shape of the main housing will give a reasonably reliable indication of the transmission group to which your gearbox belongs. Unfortunately, this makes transmission identification difficult to accomplish while the gearbox is installed in the vehicle. Here are reference images of the three most common 4-speed manual transmissions: Muncie, Saginaw, and Borg-Warner.