I've had a foot dragging project changing out motor mounts on an automatic 88 GT with a previous 3.4 swap since last fall. The car has always had a clunk sound when going into drive. I've been told the likely cause is old motor mounts so I thought I would give this a try. I ordered the mounts and I read up on the various topics here. I struggled with getting the old mounts out because I couldn't get at the upper nuts on the engine mount. I have come to believe this may have something do do with the 3.4 swap since I have discovered that the engine mount bracket looks different from the service manual drawing. I think the bracket and mount must have been installed before the engine and cradle were placed into the car. There is just no other way to get at those upper nuts.
So, the weather and my available time and motivation all finally lined up and I decided to proceed with just the two tranny mounts. I removed all of the lower mounting nuts so I could jack up the engine using a floor jack and a 2 x 4 on the oil pan as recommended. Well, the forward mount went OK but I could not get the necessary clearance on the rear tranny mount and decided to just say screw it. I was able to get a closer look at the mounts after I had them loosened up and had the engine jacked up and they looked fine. No tears or obvious damage and I was willing to just cut my losses and move on. So, after replacing only the forward tranny (drivers side) mount I started the reassembly. I had all the nuts on the new mount loosely installed and then loosely reinstalled all three nuts on the rear tranny mount. When I went to reinstall the lower nuts on the (passenger side) engine mount (which I was never able to remove) I found the bolts were not lining up with the holes in the cradle. Somehow the engine has shifted a bit and the holes don't line up. I've made sure all the nuts on the other mounts are loose but I just can't seem to man-handle the engine to get the holes to line up. I can just see the edge of both the bolts through the holes in the cradle so the engine only needs to shift forward and inboard about a half inch.
At this point I am desperate to finish this project. Any helpful advice or suggestions to get this project done will be greatly appreciated.
[This message has been edited by Rsvl-Rider (edited 04-02-2017).]
I'm not sure what is going on here; It appears that you replaced the forward Trans mount- but not the rear and not the engine mount....Correct? I have a manual trans, so I may not have the same mounts(Although I think they are the same)....You always leave them all lose to allow the engine to self center...After all bolts have been inserted in their respective holes and the engine is settled(And the torque strut has the bolts installed, then you can start to torque the bolts.
If the engine is not centered properly(The engine mount studs are not entering their respective holes, then the engine may have shifted; I know that my 88 ENGINE mount has the bolts offset so that it can only be installed one way...Did you possibly rotate it? Also, if the studs don't start in at the beginning, then the weight of the engine will flex the mount to push the studs to one side. Try jacking the engine back up(Leave the trany mounts lose but "Nutted") and then try to use a screwdriver to flex the mount slightly...The other bolts to the engine mount should be lose until the others are centered in their holes. Send me a message if you keep having problems...
I have looked at trying to make better replacement rubber trans mounts. Having bought a few front and rear aftermarket rubber trans mounts I can say the quality of them is very poor. The steel is much thinner and the position/angle of the welded in studs is absolutely terrible.
Ed Parks used a 85-87 steel engine bracket when installing a 3.4 in an 88 Fiero. He redrilled the 2 motor mount holes in that bracket more towards the passenger side. But you can only go so far. It was not quite enough and it moved the engine/trans some towards the drivers side some. I used to know how much. Maybe like 10 mm?
So you probably have these 2 things working against you here.
------------------ Rodney Dickman
Fiero Parts And Acc's Web Page: All new web page!:www.rodneydickman.com Rodney Dickman's Fiero accessories 7604 Treeview Drive Caledonia, WI 53108 Phone/Fax (262) 835-9575
I'm not sure what is going on here; It appears that you replaced the forward Trans mount- but not the rear and not the engine mount....Correct? I have a manual trans, so I may not have the same mounts(Although I think they are the same)....You always leave them all lose to allow the engine to self center...After all bolts have been inserted in their respective holes and the engine is settled(And the torque strut has the bolts installed, then you can start to torque the bolts.
If the engine is not centered properly(The engine mount studs are not entering their respective holes, then the engine may have shifted; I know that my 88 ENGINE mount has the bolts offset so that it can only be installed one way...Did you possibly rotate it? Also, if the studs don't start in at the beginning, then the weight of the engine will flex the mount to push the studs to one side. Try jacking the engine back up(Leave the trany mounts lose but "Nutted") and then try to use a screwdriver to flex the mount slightly...The other bolts to the engine mount should be lose until the others are centered in their holes. Send me a message if you keep having problems...
That is essentially correct. I removed all the lower nuts on all three mounts and jacked the engine up with a floor jack and a 2x4. I never loosened the upper engine mount nuts (pass side) since I couldn't get at them, so that mount was never moved at all. I only got the front tranny mount replaced and left the other two. When completing the job I left all the upper nuts on both the front and rear tranny mounts loose. I lowered the engine jack enough to get all four bolts on both tranny mounts to protrude through their mounting holes and then loosely installed their lower nuts. When I went around to the passenger side to do the engine mount the bolts would not line up with the holes. They are only off a bit, as described above, but no amount of maneuvering will make them line up. It seems obvious that the engine must have shifted somewhere in the process but I can't get it back in the right spot.
I gave up in frustration last night. Now I think my only option is to remove all the lower nuts on the two tranny mounts and jack the engine back up until all their bolts clear the frame. From there I will lower the jack a bit and try to move the engine around to line up and then loosely "re-nut" the two (pass side) engine mount bolts. Then return to the tranny mounts and hope that the remaining bolts will line up properly since those holes are slots rather than perfect circular holes. I hope this makes sense.
I am hoping this will work since I discovered the engine mounting bolt holes are perfectly round but the others are made with elongated mounting holes / slots. If I can get the round holes to line up then I might have more success working with aligning the bolts to the remaining slotted holes.
Your plan appears sound. Do you have a long prybar? Very helpful.
I have a 6 foot, 20 lb., steel post-hole digger bar at work that should do the trick. I'll have to get it home in the company vehicle. It won't really fit in my other daily driver.
With the jack supporting most of the engine weight, use a pry bar or a hammer and drift to move (deflect) the engine mount so the studs fall down into the holes.
Are you working on a lift? The drivetrain can be easily moved with a 2 - 3 foot pretty easily. They aren't all that heavy either.
The rear of the car is up on jackstands with a hydraulic floor jack to raise the engine. That 6 foot bar is the nearest thing I've got. I'll use it if I have to. Might be a day or two before I can get back to it. I'll let you all know how it goes.
I thought I could slide it all the way down to the floor from above. The trunk lid is still on, but with the rear up on stands I thought it might be OK.
I recently replaced all the mounts in my 87 2.8L not 2 days ago... sounds like you have / had the same issue we had. For the rear trans mount we ended up removing the bracket to get the necessary clearance for the new mount, along with trimming down the bolts. Eventually we were able to get the mount in but in the process of lining up the engine to the mounts it was about an 1" to the passenger side and about 1" forward. I hate to say this but there really isn't an "easy" way to line it back up other than with blood sweat and tears :/. I will say this though, after lining up the main motor mount and hand threading the nuts to the bolts and using the dog bone as a guide we were able to ling everything up to the front trans mount and it just fell into place for the rear. We ended up doing this with 2 floor jacks which may be necessary, though an engine hoist would be best suited for this if you have one available.
Be patient....take your time...If you get frustrated- Take a break! As for the rear trany mount, you must take off the trans bracket and move it forward as you roll it trany-side down to pull it off the mount....Then the mount will come right out....I have tried to remove it with the bracket left in.....You need more french than there is in france!
Thanks for the advice guys. Last night I raised the engine up to clear all the mounting holes as I described above. Then I tried shifting it over with a shorter pry bar to line up the engine mount first. No luck. I am bringing home that big bruiser of a bar from work. I'll try getting to it again tonight.
We ended up doing this with 2 floor jacks which may be necessary, though an engine hoist would be best suited for this if you have one available.
I tried the big 6' bar. I was able to jimmy the engine around a bit but it just came back to rest in the same spot even though I checked that every motor / tranny mount bolt was clear. I Don't know what is keeping it from shifting.
OK, I borrowed another floor jack and hope to get back to this tomorrow. But I'm not clear on how the second jack helps, or where to place it. I've already got the first jack under the oil pan with a 2 x 4. Where and how should the second one be placed?
[This message has been edited by Rsvl-Rider (edited 04-08-2017).]
I guess I owe you guys an update, and a word of thanks for the help. A couple of weeks ago I did finally get the engine aligned to the holes. My shiny red 88 GT is finally back on the road.
It was quite a long, hot, frustrating experience. The main problem was my inability to access the motor mount nuts from the top of the mount. I am convinced that the lack of access was due to a different cradle-to-engine mount bracket due to the 3.4L conversion done on the car before I purchased it. I'm sure the bracket was installed onto the engine, and the rubber mount mount attached to the bracket before the engine was installed on the cradle, and then into the car. It's the only way it could have been done. Anyway I gave up on that particular mount, especially as the two tranny mounts still looked pretty good.
Once I made that decision I then got hung up by my inability to realign the motor mount to the cradle (which was the basis of the original post). A suggestion was made to use a second hydraulic floor jack. This actually did the trick. I placed it under the tranny pan with a length of 2x4 (long enough to spread the weight across the entire width of the pan). This must have tipped the engine just enough from that side to clear whatever obstruction was keeping me from being able to push the engine back to that side and into position. It was still a struggle but eventually I was able to get it lined up and bolted back down.
Anyway, for what it is worth, I would cautiously recommend this 2nd jack method to anyone that encounters a similar problem.
