Further Mack Chat

Hi Maxidyne

I think 1980 was around the last few of these fir700 before the Cruiseliner appeared.

Mines an all Mack driveline, 320 cool power with dynatard, 10 speed Mack triple countershaft gearbox, and camelback diffs/suspension.

When travelling bobtail it would break your back teeth, travelling very rough, yet trailer on bearable. I have put a new fancy Isri air seat in her and the ride has become enjoyable again. On the R model chassis and standard power steer, overall is pretty liveable classic truck.

Mine will get a new paint job soon and will post some before and after pictures.

Go the Classic Macks!

I have a similar Fir700 no sleeper with air seat and new cab shocker and new front springs and it kills me to drive to far. I have a hip problem and I would love to do something with the rear springs but don't want to fit air bag yet unless I can find some on Mack diffs. Has anyone tried lighter rear springs?

With these old things, is it possible to just take out every other leaf? (pretty much what I did with the ASW), or is there more to it?

Jarrod.

I have seen some of these Mack F models with a couple of shock absorbers fitted at the back of the cab, as an aftermarket custom system.
Not sure how effective, but assume could not make worse.

For me a modern air seat has done the job!

Cheers Timmsy.

I finally fitted the new foot valve and treadle then used my bosses tilt tray to build up some air Friday night. She started first pop at 70psi after sitting for over a month.



Re the rear springs, not sure if I have mentioned this here before... I have two ideas, keeping in mind I'm going to fit a beaver tail tray and carry my race car. So it'll probably only ever carry 3 tonne over the rear.

I'm going to order some shorter u-bolts and then remove all but the 3 main leaf's for a start (44,000) rear.

My other thought to test this idea first is to just move the top two shortest leaf's to immediately above the main leaf's to see how it rides without having to spend money on ubolts.

I'm also considering placing some acetal (tough engineering plastic) spacers less than 3mm thick between the 3 mains in the ubolt area to remove some of the interleaf friction to loosen up the ride even more.

Need to keep in mind that Spring packs without shock absorbers, rely on interleaf friction to dampen out excessive bounce. Just need to find the time...

Maxi
GuddayM8

Not sure ifn U mentioned U B ride n on Mack Camel Back Springs
if so
Mack produced an air bag adaptor to iron out the bumps wen fitted to the camel back spring
they were fitted to the army macks cos of the troops in the back of mack were suffer n with
kidney bruise n etc from the ruff ride wen there twaz no weight on the springs 2 make m flex

FWIW
Our Mack FR700 8x4 Tilt Tray truck
has the lay across seat to sleep
wen U hit a decent bump in the road U need to duck n pull u're head in
az it would punch U up into the roof

Clikity . ClikClikClik

LOL
TheJoyzOfMotorin

cya

I have been trying to find out about fitting air assist but I like the idea of the nylon slipper, it works on bus springs.

Swishy wrote: Maxi
GuddayM8

Not sure ifn U mentioned U B ride n on Mack Camel Back Springs
if so
Mack produced an air bag adaptor to iron out the bumps wen fitted to the camel back spring
they were fitted to the army macks cos of the troops in the back of mack were suffer n with
kidney bruise n etc from the ruff ride wen there twaz no weight on the springs 2 make m flex

FWIW
Our Mack FR700 8x4 Tilt Tray truck
has the lay across seat to sleep
wen U hit a decent bump in the road U need to duck n pull u're head in
az it would punch U up into the roof

Clikity . ClikClikClik

LOL
TheJoyzOfMotorin

cya

G'day Swishy,
Thanks for the info. So did the air bag go between the spring and trunion?
Your F model looks fantastic.

I was pizzing orange for a couple days after my Nullarbor trip due to the ultra short wheelbase...