72 fan hits lower shroud
#1
72 fan hits lower shroud
72 with stock SBO and fan hits shroud intermittently on the bottom of the shroud.
Appears to be correct shroud and fan,
Core support mounts are correct height
Motor mounts look relatively new
Not sure if correct tranny mount is installed.
Could the motor mounts be BBO and dropping the engine lower?
Could the Tranny mount be too tall?
I can't imagine that the front crossmember has sagged but I suppose it's possible.
Sorry for the ignorance but I'm predominantly an A-body Chevelle guy and the Cutlass is one different animal.
Appears to be correct shroud and fan,
Core support mounts are correct height
Motor mounts look relatively new
Not sure if correct tranny mount is installed.
Could the motor mounts be BBO and dropping the engine lower?
Could the Tranny mount be too tall?
I can't imagine that the front crossmember has sagged but I suppose it's possible.
Sorry for the ignorance but I'm predominantly an A-body Chevelle guy and the Cutlass is one different animal.
#2
Could be the radiator top plate is too high. Any idea if the car has the original or correct height radiator? I had that happen before, and when the two top shroud bolts were tightened the shroud would pull up and cause slight contact at the bottom. Loosening the bolts some and adding spacers between the shroud and top plate cured it. Well, a correct height radiator was the real cure, but the spacers alleviated the immediate problem.
#5
Could be the radiator top plate is too high. Any idea if the car has the original or correct height radiator? I had that happen before, and when the two top shroud bolts were tightened the shroud would pull up and cause slight contact at the bottom. Loosening the bolts some and adding spacers between the shroud and top plate cured it. Well, a correct height radiator was the real cure, but the spacers alleviated the immediate problem.
#8
BBO or SBO mounts position the crank center line in the exact same position in the frame. The bottom of all modern olds V8 engines are of the same dimensions and can interchange mounts.
What this means is where one was bolted up, any other modern olds V8 will bolt up with the same mounts and be in the exact same position in the frame.
So, no.
What this means is where one was bolted up, any other modern olds V8 will bolt up with the same mounts and be in the exact same position in the frame.
So, no.
#9
If you could have forced the 2328 rubber motor mounts into place with the frame mounts for the 2261s, the engine would sit an inch HIGHER than stock. You can't go any lower - the oil pan would hit the crossmember.
Possible. Also, check the frame rails where the crossmember bolts up for deformation. I've had cars that were incorrectly jacked under the open section of the frame, causing the lower flange to be bent upward and raising the rear of the trans.
It really isn't. That's about the stiffest and beefiest part of the whole frame.
Could the Tranny mount be too tall?
I can't imagine that the front crossmember has sagged but I suppose it's possible.
#11
#12
First...Let me thank you all for your trouble shooting tips. I've made some progress.
I loosened both lower shroud mounts and re-positioned the shroud to the pax side a bit. Also, one of the lower tabs that the shroud is attached to was bent to the driver side slightly and I bent it back vertical.
I also straightened up the lower pan of the core support as it was slightly bowed upward. There is NO WAY I can see that the shroud can be lowered further, even by using shorter rubber core support mounts without the fenders drooping in front.
I still need to check the radiator top plate. I suspect it's not original because it has the VIN "K" Emissions spec sticker and the car is VIN "H"
The fan is 19" and the clutch/fan mounting is secure.
I'll check the dimensions on the fan shroud to determine which one I have
These steps provided enough clearance so that the fan doesn't hit the shroud but I still have 1 1/2" clearance at the top and only 1/2" at the bottom.
The Tranny crossmember looks to be correct - not bent - and the frame rails are not bent at the crossmember attach points.
One thing I did notice which I've never seen on a GM "A" body: When turning the wheels full right to the stop - the driver side frame horn twisted outward about 1/8" - enough to shift the core support and shroud so that the fan started rubbing. I found no buckling or evidence of a prior collision and no cracks.
I loosened both lower shroud mounts and re-positioned the shroud to the pax side a bit. Also, one of the lower tabs that the shroud is attached to was bent to the driver side slightly and I bent it back vertical.
I also straightened up the lower pan of the core support as it was slightly bowed upward. There is NO WAY I can see that the shroud can be lowered further, even by using shorter rubber core support mounts without the fenders drooping in front.
I still need to check the radiator top plate. I suspect it's not original because it has the VIN "K" Emissions spec sticker and the car is VIN "H"
The fan is 19" and the clutch/fan mounting is secure.
I'll check the dimensions on the fan shroud to determine which one I have
These steps provided enough clearance so that the fan doesn't hit the shroud but I still have 1 1/2" clearance at the top and only 1/2" at the bottom.
The Tranny crossmember looks to be correct - not bent - and the frame rails are not bent at the crossmember attach points.
One thing I did notice which I've never seen on a GM "A" body: When turning the wheels full right to the stop - the driver side frame horn twisted outward about 1/8" - enough to shift the core support and shroud so that the fan started rubbing. I found no buckling or evidence of a prior collision and no cracks.
#16
I had the same issue on my 1970 442. It only occurred when the engine was first started from cold...once warmed up it was fine. Eventually I spotted rubbing marks inside the fan shroud at the bottom. I ended up adding shims per your post above (and per the service manual) and slightly the lower cowl mounts. Problem solved! I checked the shroud, fan, clutch etc and all were correct for the car.
Hope that helps.
Hope that helps.
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