Yikes, so if MIB goes out you just scrap the truck ?? I'm an electronics guy and might could fix it at component level if whatever IC has gone bad is not containing locked or unobtanium code. Wonder if there are any Eproms in the little thing...

DThomas,

The 2007 models do have the variable speed AC hydraulic motors that control the lift speed vice the hydraulic valve. Also on your current lift the MIB assembly is no longer carried and not available through Yale. If my memory serves me right Flight systems does not rebuild them either. Over the years I have worked on these units the MIB gave us the least amount of trouble. Let me know if you need additional information on your lift.

Just realized I wasn't clear in my third paragraph. When I say I also confirmed..blah, blah...I was referring to the 2004 models the dealer had for sale.

I still don't have absolute confirmation that the 2007 AC drive trucks have variable speed hydraulic motor for lift function. It's possible the AC is for traction only and the variable lift motor came later. So, there is still a mystery or two.

OK, mystery solved ! I called the eBay dealer with the 2004 with AC drive. He immediately says "you know, I really need to change that copy...I cut and pasted that from a 2007 NR series ad"

So, sure enough, the first year of Yale reach truck AC drive was with the body style change in 2007.

I also confirmed the carriage lift works exactly like my 2000 year model. You press the joystick forward, the lift hydraulic comes on full speed and the lift speed is controlled by proportional valve only. So you got the same screamin hydraulic motor noise no matter what your lift speed.

So, now I want a 2007 but suspect I can't afford one as they probably sell for twice as much as a 2004 model. :-(

That is good to know about the body style change year as that was a mystery to me also. It's funny with these trucks in that one sees many 2000 to 2004 models but then it seems like the only other Yale reach trucks for sale are really late ones, like 2011 or 2012.

Seems to be a major void from 2005 to 2010 as far as what is out there for sale.

I'm going to call that eBay dealer tomorrow with the 2004 models and really grill him on the AC drive.... maybe to the point of taking off the right inside panel where the drive unit resides to see if it says AC or DC.

Just seems bizarre that Yale would have AC back then but not brag about the fact with a large "AC Equipped" decal or two on the truck. *Unless* AC was a bit of an "experiment" back then and they wanted to wait a bit to see how they performed in the field before they started plastering "AC Drive" stickers :-)

If anyone is wonder why I am obsessed with this I will explain ;-)

The body style changed in 2007 and the AC decal was on there but I don't know if that meant just the drive system or both hydraulics and drive.

After much research I still don't know the first year of AC drives on Yale reach trucks. There is a dealer on eBay who has two 2004 trucks supposedly with AC drives. But the more I look into it that seems highly unlikely in 2004. I have a Crown reach truck brochure from 2006 and AC was not standard on Crown then.

The other reason is when a Yale truck did have AC drives they plastered a large decal on the truck proclaiming such and I have yet to see a single photo of a 2004 or 2005 Yale with such a decal (on original paint machines of course...but one would think even on a repaint the dealer would want to replace that sticker in particular...and yet no one has)

So, for me, the mystery continues....

yep DThomas
now that i re-read it... doh!

in the models that had non-scr controlled hydraulics the speed was controlled by the control valve. On those units the hydraulic motor would spin up to full speed or a pre-determined speed with no variation on the motor itself. The lift speed was controlled by a variable flow valve that changed as you moved the hydraulic control stick/lever.

Now on some of those units i remember seeing a potentiometer on the hydraulic control button or **** which controlled a variable valve on the manifold block but even on those the motor still had a preset speed it ran at which was generally full rated rpm for that motor.

Now if I'm not mistaken the trucks that did have the MIB did control the speed of the motor for the drive and hydraulic system and also the auxillary speeds for the accessory functions , ie: reach, tilt, side shift and even steering but those speeds were also preset speeds according to the auxillary motor speed setting.
As far as the AC trucks those were the first ones that came out with an actual controller that controlled the hydraulic motor speed to regulate lifting and function speeds via the motor instead of the control valve alone.

At least that's the way i remember it, I'd have to dig up my old manuals and bone up a bit to be 100% positive, it has been quite a few years since i dealt with yale trucks though so my memory isn't what it used to be ;o)

J, read my post more carefully. Mine does NOT have that feature, so I'm wondering what year it started. The feature probably has nothing to do with the MIB or not, but more to do with AC motors vs DC motors and how the MIB is programmed to vari the speed of the AC hydraulic motor rather than varying the spool position of the proportional valve.

On problem with calling a Yale dealer is I'm likely to get a younger salesman that has no idea or an older one that thinks I'm nutty for even asking the question in the first place.

i'm going to crawl out on a limb here and take a guess that you probably have one of the first ones. I do remember when they first came out with the MIB contols on those and it was about that time.. 1999 to 2000, give or take a year or so.
BUT.. if you do want to know for sure you will have to call yale ;)
or maybe someone's memory serves them better than mine that can remember for sure.

Dangit guys...don't make me have to call a Yale dealer and ask them ! Spill it ! ;-)