1969 Mustang: Clutch and Transmission

Our 1969 Mustang came equipped with a toploader four speed from the factory. It was working fine but beginning to show its age. The transmission felt a little notchy going into gear and it leaked gear oil like a sieve. After dropping off the transmission at the rebuilder’s shop and opening it up, we were greeted with OEM Ford parts throughout.

10172841_10153265745559231_7655767444786533217_nIf the transmission was ever rebuilt, it would have had to been a very long time ago when these parts were still readily available. Everything inside the transmission was either stamped FoMoCo or Made In USA, indicating that this was either an untouched unit or just a very old rebuild.

The rebuild consisted of an assortment of seals, new synchronizer assemblies, bearings and speedometer gear drive. Lucky for us, all of our gears were in pristine condition and didn’t require any replacing.  The case along with the rest of the transmission guts were hot tanked in order to remove the years of caked on grease, dirt, and grime. The shop also painted the transmission with Cast Blast paint to mimic the look of cast iron. The transmission was never painted from the factory and would develop a layer of surface rust rather quickly. Technically speaking, the paint is not concours correct, but it sure does look great!

Once the transmission was home, it was a matter of installing the block plate, flywheel, clutch and bellhousing. The flywheel bolts are coated in thread sealer then torqued to 85 ft/lbs. The clutch disc is installed next with the alignment tool to keep it centered and the pressure plate is bolted over it. We torqued the pressure plate bolts to 35 ft/lbs while checking to make sure the clutch disc didn’t move out of position.

IMG_3333The clutch fork pivot on our bellhousing was a bit loose from the years of being actuated. The rivets holding it in place were drilled out and replaced with grade 8 bolts and washers. We used plenty of loctite to prevent these bolts from backing out!

Once the bellhousing was installed, the transmission was hoisted onto our floor jack then lifted into place.

Top loader 4 speed transmissions are NOT light, be sure to have a helper when installing it! We weighed ours dry and it was just under 100 lbs. They are awkwardly shaped and it’s not easy to wrestle them in. Four bolts hold the transmission to the bellhousing, be sure to have them handy once the transmission goes in. From here, the cross member and transmission are installed along with the driveshaft. The last thing to go in is the speedometer cable and the shifter. This is where that picture of how the shifter linkage is routed comes in handy!

As for fluid, these transmissions require gear lube, not ATF! We filled ours with 85-90w Stalube GL4 gear oil.

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Once buttoned up, our Mcleod clutch requires a 500 mile break in period. Take it easy on the clutch and don’t hammer on it, this will ensure plenty of trouble free miles.