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Eaton Fuller 8ll shift pattern


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My first mack had a mack 9 speed so it had a high/low switch. I understood how it worked. The RD 688 I’m getting has a Eaton fuller 8ll. It has the high/low switch in front of shifter knob but then has a reduction switch on left of shifter knob. When do I use the reduction switch? What’s the sequence?

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R.  1/5.  3/7

L.  2/6.  4/8

Switch on left is used when you need to set the low range (R and 1-4) down even lower.  I'll use it to start out on hills occasionally. 

NOTE!!! While you are supposed to preselect the Hi/Low range switch to go from 4-5 or 5-4, you CANNOT preselect the lo-lo switch.  Treat the lo-lo switch as a shift in a synchronized transmission! Example: from stop, start in low low. Accelerate, punch clutch and hit lo-lo switch to "rear", release clutch.  This will switch you from low low range to low range.  

You can't use low low range and HI range.

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It's pretty much a 10 speed. Full end to end shift pattern:

Lo-low, Low, 1, 2, 3, 4, 5, 6, 7, 8

where the first shift is accomplished by leaving gearahifter in low position and switching the thumb toggle switch while pushing clutch in.

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You have 3 reverse speeds, but you are NEVER supposed to shift the range switches while backing up. Range synchronizers aren't designed to work "backwards." You have:

Lo-low Reverse, Low Reverse, and Hi Reverse.

Hi Reverse will probably never get used unless you are very good with your line of sight going straight back on pavement for like a mile. You'll be using lo-low Reverse for slow detail maneuvers and steep hills and you'll be using Low Reverse when you need your momentum to carry you through a rough patch or you're covering a fairly easy scenario.

 

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I have driven a PoS Intertrashional with an 8LL shifted in this order:

R. 1/5. 4/8

L. 2/6.  3/7

It was not a pleasant shift pattern, the W from 2-3, 6-7 was sticky and was hard on the shoulder to maneuver.

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JoeH thanks for the replies. Here is a question. 
     I’m stopped and gear shift is in Lo.  I move deep reduction switch in (forward).  Lo gear becomes lolo gear.  What happens if I still have deep reduction in and move to 1st or 2nd. Are these gears now lower than they would be if I didn’t have deep reduction switch in? Do I have lolo first, lolo second, lolo third? 

 

 

Edited by Ricky Beals
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I was taught that you can select lo-lo, then shift from lo to 1st, then split 'up' while in 1st. and shift the rest of the gears normally, however, I bet there is a few ways to shift this tranny without over speeding a gear..  This is my favorite Eaton tranny... jojo

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4 minutes ago, Onyx610 said:

Correct, although you will find that as you go through the gears you will be at a crawl.

This is correct. If you shift into the "1st" hole with the deep reduction engaged then subsequently to 2nd then 3rd, etc. you will not gain road speed like you feel like you should and realize what your error is. I was told by an Eaton rep that it is not advised to run the transmission in any gear other than Lo with the deep reduction engaged. Something about lubrication and premature wear but I know of guys who somehow integrate using it (or maybe its using the Lo gear in high range) into their shifting routine in certain instances with no noticeable bad effects.

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i had a triaxle that was severely underpowered. claimed it was a 400, but it was actually turned down to 300 HP.

when loaded with 26 ton and trying to take off on an uphill grade, i would have to shift low low, into 1, then 2, then out of low low second back into first, then back to second. basically i was running it as a 11 speed.

 

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when you are up to your armpits in alligators,

it is hard to remember you only came in to drain the swamp..

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12 minutes ago, tjc transport said:

i had a triaxle that was severely underpowered. claimed it was a 400, but it was actually turned down to 300 HP.

when loaded with 26 ton and trying to take off on an uphill grade, i would have to shift low low, into 1, then 2, then out of low low second back into first, then back to second. basically i was running it as a 11 speed.

 

Yea this is essentially what it’s for or being off road. Also might have its place under a milling machine at times. Instead of slipping the clutch. 

Edited by Onyx610
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the 03 DR was built for off road use. with the giant rears, 8LL and 427 engine, i could idle in lo lo under a milling machine. perfect truck for milling and paving, or off road on site use. it sucked for on highway though, cause i would hit the rev limiter around 58 MPH. 

 the boss hated i always did one or two loads less than everyone else when running asphalt. 

so he kept me on site. which was fine by me. 

when you are up to your armpits in alligators,

it is hard to remember you only came in to drain the swamp..

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9 minutes ago, tjc transport said:

the 03 DR was built for off road use. with the giant rears, 8LL and 427 engine, i could idle in lo lo under a milling machine. perfect truck for milling and paving, or off road on site use. it sucked for on highway though, cause i would hit the rev limiter around 58 MPH. 

 the boss hated i always did one or two loads less than everyone else when running asphalt. 

so he kept me on site. which was fine by me. 

Hahaha yea really, hauling black top all day long gets old quick. On site work would be much better! Sounds like real solid pulling machine you had there…

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I love it when there are multiple answers, and they are all potentially right!  LOL!

Like the man said, the INTENTION is that that lo-lo switch is ONLY used in lo gear (or reverse) and lo range.  Then, it is SUPPOSED to be disengaged...and you are back in lo gear, lo range.  Basically, it is an 8-speed, plus a lo, plus a lo-lo...kinda like it says on the shift plate onyx posted.  Imagine that!

BUT, like jojo said, there are other possibilities.  If you know what the effective "steps" are, you can use them.  It's similar to the old 15-speed RoadRanger I had.  You were SUPPOSED to use the deep reduction to go from 1st through 5th, then disengage the deep reduction and go back to 4th, at which point you would resume your regular "10 speed" pattern.  It gave 12 forward speeds.  BUT, you COULD disengage the deep reduction in an earlier gear and downshift 1 step in the main box.  Worked out about the same.  Their intention was to gather as much road speed as possible before making that air shift.

I have done something similar in a 13-speed RoadRanger, using the "nothing" and "double nothing" gears in hi range while downshifting...to keep from going back into lo range.  But, using "lo" gear in hi range resulted in uneven steps between gears.  IIRC, I had to lug hi 1st (5th gear) down a little lower before going into lo gear on the main.  And, if I still had to go back to lo range, I had to short shift that one (not drag it down as far).

Used some of the "unused" combos on the Mack Quadruplex, as well.  Like Direct and Lo-Split 5th.  They are there, they are just essentially duplicates of other gears.

Like I said, you got a lot of different answers, and they are all potentially right!  Love it!

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"Eagles may soar, but weasels don't get sucked into jet engines."

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I think its more for ground work on sites...  when you are very heavy or stuck or in tight spots,  it's a starter gear...  jojo

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8 hours ago, doubleclutchinweasel said:

I love it when there are multiple answers, and they are all potentially right!  LOL!

Like the man said, the INTENTION is that that lo-lo switch is ONLY used in lo gear (or reverse) and lo range.  Then, it is SUPPOSED to be disengaged...and you are back in lo gear, lo range.  Basically, it is an 8-speed, plus a lo, plus a lo-lo...kinda like it says on the shift plate onyx posted.  Imagine that!

BUT, like jojo said, there are other possibilities.  If you know what the effective "steps" are, you can use them.  It's similar to the old 15-speed RoadRanger I had.  You were SUPPOSED to use the deep reduction to go from 1st through 5th, then disengage the deep reduction and go back to 4th, at which point you would resume your regular "10 speed" pattern.  It gave 12 forward speeds.  BUT, you COULD disengage the deep reduction in an earlier gear and downshift 1 step in the main box.  Worked out about the same.  Their intention was to gather as much road speed as possible before making that air shift.

I have done something similar in a 13-speed RoadRanger, using the "nothing" and "double nothing" gears in hi range while downshifting...to keep from going back into lo range.  But, using "lo" gear in hi range resulted in uneven steps between gears.  IIRC, I had to lug hi 1st (5th gear) down a little lower before going into lo gear on the main.  And, if I still had to go back to lo range, I had to short shift that one (not drag it down as far).

Used some of the "unused" combos on the Mack Quadruplex, as well.  Like Direct and Lo-Split 5th.  They are there, they are just essentially duplicates of other gears.

Like I said, you got a lot of different answers, and they are all potentially right!  Love it!

as with many objectives in life, the best teacher is experience .  the 6 speed  that was introduced back then for construction vehicles  was to give the low hole start out. many drivers were making them 10 speeds. was it right ; NO  but it worked for some.  you weren't suppose to split shift each main. even the quad had a pattern , didn't mean it had to be followed  every shift, do what works for the moment providing clutch wasn't burning .

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That's why I said that others may shift it differently, there own way..  I did a bunch of combos in a Mack 12 speed, and then when I got into an 8LL,, it was less shifting, but still a great tranny..  :) jojo

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2 hours ago, tjc transport said:

i like the "Perfeshaminals" that have to shift every damn gear in an 18 speed.......bobtailing. 

 

To be honest, I rarely used all the splits in a Quad...even when loaded.  Used no more than 6 w/empty trailer.  Could get by with 7-8 with most loads.  Even when heavy and needing to split the main, it was common to skip a gear in the compound.  By the time you got into that hole, it was time to go to the next one anyway.  So, just skip part of a split and keep going.  I only recall a time or two that I actually used all 13-14 progressive shifts in that thing.

Bobtailing in my R600 w/15-speed, I normally only used 4 or 5 gears.

We had one driver who did just what you said, though.  He really wanted everybody to know how good he was with 2 sticks.  It really WAS impressive...until he missed a shift and had to stop and start over!  Then it was REALLY impressive!  LOL!

"Eagles may soar, but weasels don't get sucked into jet engines."

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i do the same thing with the 8ll in the 348 pete.

since the truck is only 18450 empty. i start in second, skip to fourth, then sixth and eighth. in the  W900 empty i run as an 8 speed when empty because with the 65 ton trailer empty is close to 40,000.  loaded i only split the 18 speed when needed. 

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when you are up to your armpits in alligators,

it is hard to remember you only came in to drain the swamp..

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I've heard you can use low hole in the high range as an alternative to dipping into 4th, but I've never wanted to risk my transmission by testing the theory. Mine has enough issues hanging up in gear sometimes. 

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