Install Engine with Transmission attached or not??

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My Car
1972 Mustang Coupe
I’m putting the 351 Cleveland engine back in my 72 mustang and the transmission is still in the car. Do I pull out the tranny and install it to the engine before putting the engine back? Just looking for some opinions.
 

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If your transmission is already in the car, I think its easier to leave it there and just drop in the motor. Then mate the two together from under the car.

Flexplate attached to the motor, torque converter sitting inside the transmission.
 
I concur with the other boys here. Having the trans in chassis already gives you the added benefit of not having to sling as large a monolith up over the fenders/radiatior support, and is lighter to manuver. When I have done fresh engines in the '65-'66 cars, it's interesting that you can install a 289 into the frame mounts with no trans on it, or the car, and the 289 will sit balanced on it's mounts only...easy. On my car, I'm soon going to replace the engine, leaving the trans in place. Once running again, I'll drive to the trans shop for a service and seal up. Those guys can yank a trans and put it back in in an afternoon, including adjusting. New motor mounts and/or trans mounts will sometimes affect starting as the shift linkage will now and again be slightly out of adjustment and the neutral safety switch isn't in adjustment any more. At this point, I'm not happy to lie under my car for too long........oh yes, install your oil deflectors onto those rocker arm fulcrums before you start it. From your photo, it appears they are not there.
 
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Looking at your pics, I would remove the trans, give it a good cleanup and install new external seals and gaskets.

At the very least, you need to install a fresh pump to converter seal. That one's guaranteed to leak if you don't replace it.
 
I concur with the other boys here. Having the trans in chassis already gives you the added benefit of not having to sling as large a monolith up over the fenders/radiatior support, and is lighter to manuver. When I have done fresh engines in the '65-'66 cars, it's interesting that you can install a 289 into the frame mounts with no trans on it, or the car, and the 289 will sit balanced on it's mounts only...easy. On my car, I'm soon going to replace the engine, leaving the trans in place. Once running again, I'll drive to the trans shop for a service and seal up. Those guys can yank a trans and put it back in in an afternoon, including adjusting. New motor mounts and/or trans mounts will sometimes affect starting as the shift linkage will now and again be slightly out of adjustment and the neutral safety switch isn't in adjustment any more. At this point, I'm not happy to lie under my car for too long........oh yes, install your oil deflectors onto those rocker arm fulcrums before you start it. From your photo, it appears they are not there.
Hi, that was an older picture. Valve covers have been installed. Thanks for the all the information.
 
I'll go against the grain on this one. I find it easier to install the engine with the tranny attached. I did it with my new 393C stroker build. However, I was also installing a new AOD tranny at the same time. It was easier for me to stab the torque converter to the flexplate and turn the crank to install and torque the nuts while the engine hanging on the lift. The only time I just did the engine was when attaching it to a stick tranny. When the tranny spline contacted the clutch disc, I made sure I was in 4th gear and gave my car a slight shove from the rear and the spline lined up and slid thru the clutch disc nicely.
 
I'll go against the grain on this one. I find it easier to install the engine with the tranny attached. I did it with my new 393C stroker build. However, I was also installing a new AOD tranny at the same time. It was easier for me to stab the torque converter to the flexplate and turn the crank to install and torque the nuts while the engine hanging on the lift. The only time I just did the engine was when attaching it to a stick tranny. When the tranny spline contacted the clutch disc, I made sure I was in 4th gear and gave my car a slight shove from the rear and the spline lined up and slid thru the clutch disc nicely.
If you make a list of the work each method saves you vs what it requires, leaving the transmission in the car is less work.

With the transmission in place, you avoid futzing with disconnecting and the reconnecting the cooler lines, removing the driveshaft, or draining the transmission fluid and having to refill it. All those make up for it being a little more annoying mating the transmission and engine together while inside the car.
 
If you make a list of the work each method saves you vs what it requires, leaving the transmission in the car is less work.

With the transmission in place, you avoid futzing with disconnecting and the reconnecting the cooler lines, removing the driveshaft, or draining the transmission fluid and having to refill it. All those make up for it being a little more annoying mating the transmission and engine together while inside the car.
Thank you. I think that’s where I’m headed.
 
I would also recommend leaving the trans where it be. However, be very diligent in making sure the converter pilot hub and attachment studs are lined up. You can make 4 guide studs from some 5/8" X 3" bolts with the hex cut off.
DO NOT use the trans case to engine bolts to "draw up" the trans to the block. If things seem to be in a bind, find out why. Otherwise you will end up in a bigger bind. I know from experience! LOL
 
I worked several years for a shop whose bread and butter was complete engine and transmission rebuilds. To the best of my memory, we (namely me, haha) never Removed/Replaced the engine and trans together. The only time I can remember R&R'ing them together, was when I was helping out friends. I think the shop's ceiling height and the lifting capability of the hoist plays into the choice.
 
Thank you. I think that’s where I’m headed.
Thank you. I think that’s where I’m headed.

I would also recommend leaving the trans where it be. However, be very diligent in making sure the converter pilot hub and attachment studs are lined up. You can make 4 guide studs from some 5/8" X 3" bolts with the hex cut off.
DO NOT use the trans case to engine bolts to "draw up" the trans to the block. If things seem to be in a bind, find out why. Otherwise you will end up in a bigger bind. I know from experience! LOL
Thanks for the tip!! L
I worked several years for a shop whose bread and butter was complete engine and transmission rebuilds. To the best of my memory, we (namely me, haha) never Removed/Replaced the engine and trans together. The only time I can remember R&R'ing them together, was when I was helping out friends. I think the shop's ceiling height and the lifting capability of the hoist plays into the choice.
yes, one factor is the hoist but thanks to everyone I’ve decided the tranny stays in!! Thanks.
 
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