interstate tank front mounts

seattle##gs · Jun 30, 2016

I have searched this forum for ideas on how to mount an interstate tank without having the front studs tearing out. Some very good info to be had.
I have a VERY NICE stock interstate tank (steel) and I want it to stay that way for the next 20 years. I would like to remove the front studs and replace with the Norton muffler mount as suggested but there is a length problem. Are there longer muffler mounts available? How do you get around this problem?

kommando · Jun 30, 2016

There were 2 issues I had with the muffler mounts when I used them on my Interpol tanks, the stud bottomed out in the hole in the tank (Interstate tank may be a longer hole so do check) and the rubber section was not long enough. I got round these by shortening the stud on one side and added one std rubber buffer to the other sides stud.

Fast Eddie · Jun 30, 2016

There is no need for all the thread to screw into the tank though.

An easy way to extend is to simply put a lock nut on the thread before screwing into the tank and adjust to suit.

Matt Spencer · Jun 30, 2016

Put the spacer ( somee G M cars have thick washers , in the engine bay somewhere , Alternator mount ?? ) on the TOP of the rubber sucker ?

Auto Parts Store should have a selection . Maybe one under , too .

Story was they were MINI Exhaust Mount rubbers ? A P Store again , likely theres differant lengths from differant manufacturers , if you were in England in the 60s !

maylar · Jun 30, 2016

The factory used studs with a stack of rubber washers -

http://www.oldbritts.com/1973_g28.html

kommando · Jun 30, 2016

The problem with the stud is that if there is any misalignment between the stud and the frame mount it will put side pressure on the stud and then onto the tank insert, the exhaust mount eliminates this, I changed to them as soon as I saw them posted here as a mod, wish I had done it before as it would have saved a repair to my Interstate tank when the stud insert started to leak.

maylar · Jun 30, 2016

There would be a rubber washer on the nut side of the frame as well, which compensates for any misalignment.

kommando · Jun 30, 2016

That rubber washer is only 3mm thick or so, it will deform but still apply pressure as rubber acts as a spring.

splatt · Jun 30, 2016

I know they do have a problem in that area but at the end of the day the stud isn't pulling that hard , you should be using enough rubber washers to get the tank to be sitting on the top pad as well, one or two underneath, flat steel washer and do the nyloc nut up until it just touches to stop the tank jumping about,

eskasteve · Jun 30, 2016

Back in the late 70's I had a similar problem. My fix was to pull out the foam rubber straps that cushion the tank from the frame backbone. I then covered the backbone with a nice dense piece of carpet padding. I have 4 rubbers on the studs above the frame tab and 2 underneath. Has worked for about 38 years and 45,000 miles.

comnoz · Jul 6, 2016

Here is my solution.
Muffler mounts with rubber washers between the mount and tank to make the correct height. Just a thick metal washer and nut below.
Somewhere north of 100K miles now with no problems. Jim

seattle##gs · Aug 1, 2016

I tried using the lord fittings and they worked very well. There was still clearance between the tank and the backbone. I had to add material to the rear bracket to make it work. All is well

Onder · Aug 1, 2016

I have found that the stack of stock rubber washers get hard with age. Renewing and making sure
you are in the center of the bracket hole seems to work. Dont cinch the nut up very tight at all
secure the nut with loctite, the stud as well. Yes, one rubber under the bracket with a wide washer.

As for the bonded mounts, the old ones seem to be made of softer rubber than the newer ones.
Maybe using the hobot method of waisting them will assist.

nortriubuell · Aug 3, 2016

comnoz said:
Here is my solution.
Muffler mounts with rubber washers between the mount and tank to make the correct height. Just a thick metal washer and nut below.
Somewhere north of 100K miles now with no problems. Jim

+ 1 with what Jim wrote. Works a treat on my Steel Interstate tank

interstate tank front mounts

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