News:

Due to a technical issue, some recently uploaded pictures have been lost. We are investigating why this happened but the issue has been resolved so that future uploads should be safe.  You can also Modify your post (MORE...) and re-upload the pictures in your post.

Main Menu

Front motor mounts on '74 ELDO convt.

Started by Viator Trudeau, November 19, 2015, 04:27:30 PM

Previous topic - Next topic

0 Members and 1 Guest are viewing this topic.

Viator Trudeau

What are the signs that the motor mounts need replacing.  The left exhaust pipe is very close to the torison bar and some times touches it making a rattle.  The two reasons i think would be the left mount has callasped  lowering the exhaust to touch torison    bar.or the replacement pipe was installed too low.  The touching location is a couple feet to the rear of the left mount, or is it the rear mount is sagging causing the touching.  I am thinking of collapsing the pipe to   increase the space.
Has any one have any ideas on this?

V. Trudeau

The Tassie Devil(le)

I would hazard a guess that the replacement pipe wasn't bent up correctly.

The best way to check the engine mounts is to put pressure under them to see if they part company, but not that much pressure to tear good ones.

I thought that the Eldorado's had one mount in the front, under the front support, and two at the rear, off the rear drive cover.

Bruce. >:D
'72 Eldorado Convertible (LHD)
'70 Ranchero Squire (RHD)
'74 Chris Craft Gull Wing (SH)
'02 VX Series II Holden Commodore SS Sedan
(Past President Modified Chapter)

Past Cars of significance - to me
1935 Ford 3 Window Coupe
1936 Ford 5 Window Coupe
1937 Chevrolet Sports Coupe
1955 Chevrolet Convertible
1959 Ford Fairlane Ranch Wagon
1960 Cadillac CDV
1972 Cadillac Eldorado Coupe

Scot Minesinger

The exhaust pipe on torsion bar happened to me on a 72 Eldorado and everyone said to adjust it, and I was surprised how much adjustment there is in exhaust pipes, that was one of the easiest cures.

The front center mount seems to be most vulnerable because oil leaks on to it and takes it out.  It is also the most critical.  It is only available as a rebuild.  If pieces of it are coming off, you should replace it.  The back two seem pretty durable.  A way you can get an idea of how they are doing it to watch the movement of the engine when in park and you race the warmed up engine.

To me most rubber parts on a 1974 are ready to be replaced mainly due to age, so it should be on your list.  These mounts are not difficult to replace. 
Fairfax Station, VA  22039 (Washington DC Sub)
1970 Cadillac DeVille Convertible
1970 Cadillac Sedan DeVille
1970 four door Convertible w/Cadillac Warranty

Viator Trudeau

Hello all,  My '74 has two mounts at the front, left and right identical on either of engine, one at the rear, that mount on the cross member where the tortion bars are anchored, a tri angle shaped plate runs up and over the top of the drive chain cover to bolt up to the rear of the trans.  The shop manual shows it.  I obtained a pair of front mounts from Autozone for $30.00 each.  .I am going to look at adjusting the pipe.  The right side pipe has more than adequate space, no doubt the left was installed too low.

V. Trudeau

TJ Hopland

73-78 the eldo engine mounts were more like the RWD cars including a single at the trans.   There is not a lot of room for them to sag before its metal on metal so my bet would be an issue with the exhaust.    Oddly for the 79-85 they went back to the single front mount and 2 at the back.    Guessing the change in 73 had to do with frame changes for the impact bumpers?
StPaul/Mpls, MN USA

73 Eldo convert w/FiTech EFI
80 Eldo Diesel
90 CDV
And other assorted stuff I keep buying for some reason

The Tassie Devil(le)

Thanks for the description.

I was trying to figure out why Cadillac would have changed what was a simple mounting system.

There are none down here for me to have a look at.

Bruce. >:D
'72 Eldorado Convertible (LHD)
'70 Ranchero Squire (RHD)
'74 Chris Craft Gull Wing (SH)
'02 VX Series II Holden Commodore SS Sedan
(Past President Modified Chapter)

Past Cars of significance - to me
1935 Ford 3 Window Coupe
1936 Ford 5 Window Coupe
1937 Chevrolet Sports Coupe
1955 Chevrolet Convertible
1959 Ford Fairlane Ranch Wagon
1960 Cadillac CDV
1972 Cadillac Eldorado Coupe

Viator Trudeau

T.J.    I've the two front motor mounts for a few days now,  your description about metal on metal on the mounts sounds correct as I protected one from scratches and tried to squeeze it in a vice, the rubber is awful stiff or M on M  as you said.  I am going to see if I can shim up at the mount to gain space??? if that works I will return the two mounts to Autozone.     Has any one followed the stock value of AZO lately?   

V.Trudeau  #8697

Viator Trudeau

Scot;   saw your post on adjusting exh. pipes, how do you do that.   I looked under car today and found the exh pipe rubbing on floor board and frame just just inboard of frame ,no room there, at that point.  replacing motor mount wont help.  Hammering on the floor to make more room, floor too thick there.  Will have to come up W/ another idea.  My efforts this PM made a little more room??   

V.  Trudeau

"Cadillac Kid" Greg Surfas 15364

Viator,
Everything up front in the Eldo is very close. I have seen several cars where an accident (traffic collision) has bent things to the point where there is conflict, and if the suspension height is incorrect, the same thing will occur.  My suggestion is to taqke your fqactory service manual and verify all the dimensions shown for correct geometry.
I might also suggest if the above turns out to be okay, take the car to a reputable exhaust shop and have them re-work the head pipes so they clear.  It ias vewry possible that if what your have is adjusted to the best of its ability you may have a car with an incorrectly aligned replacement pipe.
Greg Surfas
Cadillac Kid-Greg Surfas
Director Modified Chapter CLC
CLC #15364
66 Coupe deVille (now gone to the UK)
72 Eldo Cpe  (now cruising the sands in Quatar)
73 Coupe deVille
75 Coupe deElegance
76 Coupe deVille
79 Coupe de ville with "Paris" (pick up) option and 472 motor
514 inch motor now in '73-

Viator Trudeau

RE '74 ELDO motor mounts :  the left side exhaust pipe just got real close to the floor board as discussed in previous posts.where a clutch pedal could be located and makes buzzing, vibration noise, it came on a couple of months ago very gradually.  I think the right side motor mount has sagged down, raising the left exhaust pipe up to touch floorboard,  with the three point engine suspension, the right going down could raise the left a little. I am going to raise right side hoping it will help.

Viator Trudeau

Scot Minesinger

To adjust exhaust pipe loosen the nuts on end of exhaust manifold studs and reposition exhaust pipe as needed (make sure it is not impacting torsion bar, that was my conflict), then retighten.  If this does not do it and you need the exhaust pipe to be lower, you could try some longer bolts and spacers (use 7/16" nuts) at hanger where it anchors to frame behind front seat (when I write behind, I mean the first hanger after seat traveling back from front of car, might be near axle).  Generally if you have the exhaust pipe spaced at least 3/8" clear of everything you will be good.  I did not have to use spacers in hanger to frame anchoring.  There was quite a bit of adjustment available.  Greg was the one who gave me this advice and it worked.  There might be more going on here, but that is how I did it.
Fairfax Station, VA  22039 (Washington DC Sub)
1970 Cadillac DeVille Convertible
1970 Cadillac Sedan DeVille
1970 four door Convertible w/Cadillac Warranty

TJ Hopland

Ideally you want to do this with the car sitting on its wheels.    The torsion bars move around little as they do their thing so its possible to have clearance when its in the air and not when its on the ground.    The other issue is these even when in good condition have a fair amount of flex in the frame so depending on how you are lifting them you can have a lot of things shift around.   It can be a big issue for things like exhaust that go the full length of the car.
StPaul/Mpls, MN USA

73 Eldo convert w/FiTech EFI
80 Eldo Diesel
90 CDV
And other assorted stuff I keep buying for some reason

Scot Minesinger

Good point, I take this for granted and have a set of 6 x 6 x 18" long blocks I put all four wheels on for this type of work.
Fairfax Station, VA  22039 (Washington DC Sub)
1970 Cadillac DeVille Convertible
1970 Cadillac Sedan DeVille
1970 four door Convertible w/Cadillac Warranty