Attn:Joe Lucia;Terry McManmom;LT1 through bolts;Motor Mounts

[Larry E.]

Hello:

Attn: Joe

Will replace my solid mounts in my 70 Z-28 with my original motor mounts. Can you tell me how the factory installed the through bolts? Where the
heads and bolts placed the same direction on both sides or where they different? Was the factory consistent when they where installed?

Attn: Terry

Can you look at your 1970 LT1 Corvette and see how the bolts vs. nuts
are placed for me? Are they the same on both sides?

Assemble manual is not very clear on the subject. Of course anybody
else can chime in and help me.

Thanks; Larry Evoskis

[Terry M.]

Re: Attn:Joe Lucia;Terry McManmom;LT1 through bolts;Motor Mounts

I judged engine compartment at the Michigan Regional -- both days, passenger side.

The motor mount bolt on that side goes in from the back -- nut is in front. One would have to have the fuel pump off the engine, and they didn't, in order to install this bolt from the front. Looking at the front one sees a flat washer and then a grip nut -- NO lock washer.

Engine mounts and ground strap are on the same line on the score sheets.

Since I also got the job of judging the ground strap it attaches to a hole in the front of the frame engine mount bracket. From the front of the car one sees a internal star washer and the bolt head for the ground strap.

[Terry M.]

Re: Attn:Joe Lucia;Terry McManmom;LT1 through bolts;Motor Mounts

Larry,
My turn for a question now:
What is wrong with the illustration in the AIM -- UPC 6, Sheet B3? How is this illustration lacking?

[Larry E.]

Re: Attn:Joe Lucia;Terry McManmom;LT1 through bolts;Motor Mounts

Hello Terry:

As I indicated I am dealing with a LT1 but not in a Corvette but in a 70 Z28. Do not have the assembly manual for 70 Corvette but for a Camaro. UPC 6 B3 page 79 in Camaro Assembly manual has to do with radiator
hoses.FYI

Anyway;really apriciate your response and was just wondering when the
factory installed the through bolts if there was any reason behind the
positioning rather then just for convenience for the people on the line either for Corvettes or Camaro's.

Larry

[Terry M.]

Re: Attn:Joe Lucia;Terry McManmom;LT1 through bolts;Motor Mounts

Larry,

My bad. I saw the LT1 reference, and overlooked the F-car application. I received a private e-mail from a member who recounted a different orientation for the through bolts on metal cars, so I don't think it is reasonable to believe that all car lines put those bolts in the same way. I encouraged him to post his recollections here ... but ...

The Corvette AIM page I cited deals with the motor mount install, and is an excellent drawing of the driver's side install. But again, I'm not sure if that applies to your situation. I don't have a Camaro Assembly manual (I do have a '67 Chevelle AIM), but I would expect a page to show the motor mount install to be in there someplace.

My Corvette experience is that the through bolts are installed in the same orientation regardless of engine type -- but my area of interest is limited to C3.

BTW: No star washer under the ground strap bolt head on my car.

[Chuck S.]

Re: Attn:Joe Lucia;Terry McManmom;LT1 through bolts;Motor Mounts

...BTW: No star washer under the ground strap bolt head on my car...

Terry, I started to post this earlier because the ground cable is an area of particular interest to me...the original ground cable on my car had been replaced, and the ground moved to another location.

The AIM shows a star washer (external tooth), but it is located between the ground cable terminal and the inside surface of the motor mount bracket. This configuration is typical of all grounds because the star washer bites into both the wiring terminal and through the paint finish on painted parts to insure a good ground. Looks like a restorer didn't consult his AIM, and was able to skate.

Why the OP thought this board would have any insight into how Carmaro motor mounts were configured is puzzling. I expect the engineers considered the interferences and made a plan to put the motor mount through bolts in whatever direction was easiest on any specific car model assembly line.

[William C.]

Re: Attn:Joe Lucia;Terry McManmom;LT1 through bolts;Motor Mounts

I believe pass car would have the same issue as Corvette driving the orientation on the Pass side, the Fuel Pump is installed on the engine when the bolt is being installed, thus the front to back orientation is difficult if not impossible where on the driver's side, it really is a matter of what is the easiest for the assembler.

[Michael H.]

Re: Attn:Joe Lucia;Terry McManmom;LT1 through bolts;Motor Mounts

Hello Terry:

As I indicated I am dealing with a LT1 but not in a Corvette but in a 70 Z28. Do not have the assembly manual for 70 Corvette but for a Camaro. UPC 6 B3 page 79 in Camaro Assembly manual has to do with radiator
hoses.FYI

Anyway;really apriciate your response and was just wondering when the
factory installed the through bolts if there was any reason behind the
positioning rather then just for convenience for the people on the line either for Corvettes or Camaro's.

Larry

Larry, is there a note stating that the left side motor mount bolt is "to be installed as shown" in the drawing? If not, the installation direction is optional.

[Art A.]

Re: Attn:Joe Lucia;Terry McManmom;LT1 through bolts;Motor Mounts

Larry, I sure that if you look closer in your Camaro AIM you will find a section dealing with the installation of said bolt. If it is not in the regular production engine section 6, it may be towards the back in the LT1 engine option section.

Hello Terry:

As I indicated I am dealing with a LT1 but not in a Corvette but in a 70 Z28. Do not have the assembly manual for 70 Corvette but for a Camaro. UPC 6 B3 page 79 in Camaro Assembly manual has to do with radiator
hoses.FYI

Anyway;really apriciate your response and was just wondering when the
factory installed the through bolts if there was any reason behind the
positioning rather then just for convenience for the people on the line either for Corvettes or Camaro's.

Larry

[Terry M.]

Re: Attn:Joe Lucia;Terry McManmom;LT1 through bolts;Motor Mounts

The AIM shows a star washer (external tooth), but it is located between the ground cable terminal and the inside surface of the motor mount bracket. This configuration is typical of all grounds because the star washer bites into both the wiring terminal and through the paint finish on painted parts to insure a good ground. Looks like a restorer didn't consult his AIM, and was able to skate.

[Chuck S.]

Re: Attn:Joe Lucia;Terry McManmom;LT1 through bolts;Motor Mounts

...My quick look last night through the 1970 AIM couldn't locate the illustration of the ground strap, but I have no doubt you are right on the location of the star washer for exactly the reasons you cite...

It took me a little while to find it myself...it's not in the engine section (UPC 6), but in the electrical section, UPC12, Sheet A11.

[John H.]

Re: Attn:Joe Lucia;Terry McManmom;LT1 through bolts;Motor Mounts

There's no note about directionality of that RH bolt in the '69 Camaro AIM, but it's academic; the fuel pump was in place on every Chevrolet V-8 when it was dropped into the chassis, frame, or subframe, regardless of model, and it was physically impossible to install the bolt front-to-rear with the fuel pump in place.

[Michael H.]

Re: Attn:Joe Lucia;Terry McManmom;LT1 through bolts;Motor Mounts

There's no note about directionality of that RH bolt in the '69 Camaro AIM, but it's academic; the fuel pump was in place on every Chevrolet V-8 when it was dropped into the chassis, frame, or subframe, regardless of model, and it was physically impossible to install the bolt front-to-rear with the fuel pump in place.

Yup, I agree for the right side. I've don't recall any small block car that had the bolt installed front to rear on that side.
The left side may be a different story though. No direction was specified that I know of.

[Michael B.]

Re: Attn:Joe Lucia;Terry McManmom;LT1 through bolts;Motor Mounts

I do recall, as a mechanic in the 70's and 80's, cussing GM for making a bigger job of replacing motor mounts than need be, by installing the rightside bolt from the front, requiring removal of the fuel pump to replace the motor mount. I always put them back in from the rear, thinking about the next guy that would be replacing mounts.

I don't know if it was random but I can't imagine any mechanic pulling a fuel pump to install a bolt from that direction. Because of this, I always assumed the fuel pump was installed after the engine drop.

[Michael H.]

Re: Attn:Joe Lucia;Terry McManmom;LT1 through bolts;Motor Mounts

I do recall, as a mechanic in the 70's and 80's, cussing GM for making a bigger job of replacing motor mounts than need be, by installing the rightside bolt from the front, requiring removal of the fuel pump to replace the motor mount. I always put them back in from the rear, thinking about the next guy that would be replacing mounts.

I don't know if it was random but I can't imagine any mechanic pulling a fuel pump to install a bolt from that direction. Because of this, I always assumed the fuel pump was installed after the engine drop.

I remember that also but from the mid 60's. I also remember the dealer mechanics complaining in the late 60's when the motor mount campaign was active. The flat rate time didn't include R&R fuel pump but several new cars required that it be removed to change the mount.
I wonder if, for some reason, some full size pass cars had the pump installed after the engine was in the chassis? Doesn't make sense but........