While we have done over 10 engine replacements and 5 swaps here, we always did them by dropping the entire powertrain down with the cradle. I've seen transmissions being replaced while leaving the engine hooked up, in place and holding it with an engine support bar across the strut towers. Then just the cradle is removed to gain access to the transmission. It would seem that this method would save quite a bit of work and time as the fuel , water, battery and harness connections ( and for my car the intercooler lines) can all be left in place. If anyone has had success changing a transmission using this method please chime in. While the process seems straight forward, my question is how difficult is it to get the engine mounts to re-align and to bolt back up when reinstalling the cradle. Is this an easier process than dropping the entire powertrain down? Is it worth doing?
------------------ " THE BLACK PARALYZER" -87GT 3800SC Series III engine, custom ZZP /Frozen Boost Intercooler setup, 3.4" Pulley, Northstar TB, LS1 MAF, 3" Spintech/Hedman Exhaust, P-log Manifold, Autolite 104's, MSD wires, Custom CAI, 4T65eHD w. custom axles, Champion Radiator, S10 Brake Booster, HP Tuners VCM Suite. "THE COLUSSUS" 87GT - ALL OUT 3.4L Turbocharged engine, Garrett Hybrid Turbo, MSD ign., modified TH125H " ON THE LOOSE WITHOUT THE JUICE "
This was done to my car a few years ago. I did not do the work, but I recall no issues with re-attaching the cradle.
Thanks for sharing the photo. It looks like they disconnected the knuckles at the lower pinch bolts, left the brake calipers on the wheels, released the parking brake cables.but didn't remove the hubs. That's an interesting way to do it but is the cradle still attached. .
------------------ " THE BLACK PARALYZER" -87GT 3800SC Series III engine, custom ZZP /Frozen Boost Intercooler setup, 3.4" Pulley, Northstar TB, LS1 MAF, 3" Spintech/Hedman Exhaust, P-log Manifold, Autolite 104's, MSD wires, Custom CAI, 4T65eHD w. custom axles, Champion Radiator, S10 Brake Booster, HP Tuners VCM Suite. "THE COLUSSUS" 87GT - ALL OUT 3.4L Turbocharged engine, Garrett Hybrid Turbo, MSD ign., modified TH125H " ON THE LOOSE WITHOUT THE JUICE "
[This message has been edited by Dennis LaGrua (edited 06-27-2019).]
I have changed the clutch.....TWICE.....using the engine support; I installed a new clutch- and then the engine would not turn over....found out the pressure plate was machined wrong(Contacted the transmission).....So had to rebop the dang thing (Yes...I used a WHOLE french dictionary)
Anyway, supported the engine, then jacked car up and supported with stands, removed wheels, struts, hubs and half shafts, then swung cradle down on forward pivot bolts, then unbolted the transmission.....Made a plywood adapter for the top of my jack to hold the trans as I lowered it.
On the engine support, it is not centered on the shock towers vs the engine weight center, so I chained the rear end of the crossbeam to the engine torque strut bracket, making the whole thing more stable....
Used the engine support method here on the 87 GT. Worked very well after making my own support. Don’t waste your time with the Harbor Freight model as it will not mount correct on the GT’s due to limited surface area for the mount to rest on. Sail panels get in the way. Basically made a modified “H” brace with twin cross pieces. Then chained the engine lift points to the H brace. Dropped the cradle. Then tilted the engine to remove the trans. Replaced the clutch.
When putting the cradle back in I just loosened the engine mounts. Attached the cradle to the front mounts. Lifted the back of the cradle. Aligned engine mounts. And wella, done.
It all went pretty easy. Only need an extra hand for 15 min to lift the trans from above ( heavy rope and trusted friend) while I helped lift and bolted it in from below.
[This message has been edited by Kevin87FieroGT (edited 06-28-2019).]
I have used the engine support method several times on manual transmissions and prefer it.
First time I pulled a Getrag transmission 1000 miles from home in a house I rented for a week. I only used the bar (pipe purchased locally) a floor jack, couple of jack stands, and my normal travel tool kit. Try doing that using the drop the cradle method.
I now have a custom cross bar engine support. Last one I did was with my LS4/F40 to swap in a F40 with the 3.09 final drive swap. Not only is it easier and less work, it avoids mission creep that nearly always happens when the cradle/drivetrain is dropped...
As far as aligning mounts... that all depends how you designed the mounts. Mine are four 1/2" bolts through round control arm bushings - so super easy.
Now I can see some issues to removing the transmission using the engine support bar method. It appears that the std commercially available cross bar does not center on the strut towers and since the powertrain is not mounted along the strut tower centerline a special bar is probably best for support. Since my setups are all automatics its looking more an more like the engine and trans will need to be dropped down with everything on it. . It may be a bit more work but we have a two post lift and a 1000lb hydraulic table here so that will probably need to be the plan.
------------------ " THE BLACK PARALYZER" -87GT 3800SC Series III engine, custom ZZP /Frozen Boost Intercooler setup, 3.4" Pulley, Northstar TB, LS1 MAF, 3" Spintech/Hedman Exhaust, P-log Manifold, Autolite 104's, MSD wires, Custom CAI, 4T65eHD w. custom axles, Champion Radiator, S10 Brake Booster, HP Tuners VCM Suite. "THE COLUSSUS" 87GT - ALL OUT 3.4L Turbocharged engine, Garrett Hybrid Turbo, MSD ign., modified TH125H " ON THE LOOSE WITHOUT THE JUICE "
Having those tools should make it a fairly quick job. As you or someone else said “ mission creep” is an issue when the entire assembly is laying in front of you. In my case, cleaning up the trans and linkages took way more time than the clutch replacement. It also led to a rear main seal, cam cover seal, starter cleaning, clutch master, slave and clutch line, general clean up. Not hard at all, it’s just that a while your there kinda thing we all do.
If you plan to do more trans, just make a steel brace. As for getting the trans off while the cradle is dropped and engine is hanging, a simple stand can easily tilt the engine safely from the front mount area to facilitate getting the trans out. Also make your brace so the engine lift points line up directly under the brace attach points. Saves some engine movement as cradle is dropped and makes it easier to line up the mounts while lifting the cradle into position.
Having those tools should make it a fairly quick job. As you or someone else said “ mission creep” is an issue when the entire assembly is laying in front of you. In my case, cleaning up the trans and linkages took way more time than the clutch replacement. It also led to a rear main seal, cam cover seal, starter cleaning, clutch master, slave and clutch line, general clean up. Not hard at all, it’s just that a while your there kinda thing we all do.
If you plan to do more trans, just make a steel brace. As for getting the trans off while the cradle is dropped and engine is hanging, a simple stand can easily tilt the engine safely from the front mount area to facilitate getting the trans out. Also make your brace so the engine lift points line up directly under the brace attach points. Saves some engine movement as cradle is dropped and makes it easier to line up the mounts while lifting the cradle into position.
All good tips and info but at this point I am convinced that the best way to remove the 4T65eHD transmission is to drop the entire powertrain. It can probably be done bracing the engine, using the engine support bar with the trans jack. This can save you about 8 steps but this method is just not in my comfort zone. If any of my cars had a Getrag, I would leave the engine in place.
------------------ " THE BLACK PARALYZER" -87GT 3800SC Series III engine, custom ZZP /Frozen Boost Intercooler setup, 3.4" Pulley, Northstar TB, LS1 MAF, 3" Spintech/Hedman Exhaust, P-log Manifold, Autolite 104's, MSD wires, Custom CAI, 4T65eHD w. custom axles, Champion Radiator, S10 Brake Booster, HP Tuners VCM Suite. "THE COLUSSUS" 87GT - ALL OUT 3.4L Turbocharged engine, Garrett Hybrid Turbo, MSD ign., modified TH125H " ON THE LOOSE WITHOUT THE JUICE "
Technically this could be done with a automatic transmission...support the engine and transmission” using a support bar” drop the engine cradle after the engine and transmission mounts are loose....put a transmission jack” or modified jack under transmission...take the bolts out and split the engine and transmission apart....slowly lower transmission...and remove.
This saves time with having to reconnect wire harness, coolant ect. As long as engine is secure enough....making sure it doesn’t move an inch....it’s doable with a automatic.
[This message has been edited by Initial.F (edited 07-02-2019).]
Originally posted by Initial.F: As long as engine is secure enough....making sure it doesn’t move an inch....it’s doable with a automatic.
You want to support the weight of the engine, but let it dangle and free to move front/back and side to side. You want some ability to move it to help line back up the mounts and reinstall the cradle.
For what its worth, I screwed up using an aftermarket engine support bar. My bar sat on the strut towers but not over the CG of the engine. It probably didnt help that I had the dogbone disconnected. It really should have sat more forward but couldn't, like fieroguru's setup. When I dropped the cradle the engine fell down with it, but luckily, on its way down, the bar caught another part of the frame and only fell 10 inches or so. The GM OEM support bar also sits on the strut towers but bolts down.
[This message has been edited by gregr75 (edited 11-19-2022).]
My first clutch replacement (back in the 1990s) was in the driveway, with the car on jackstands and a piece of 4x6 lumber across the engine bay to hold up the engine. It was kludgy, but it worked.
