mystery switch 988B

[curly]

I tried getting a picture but it's a no-go. I was using a 988B today and there was a rocker switch on the boom control stick. Nobody knows what it's for, including the CAT mechanic out today to fix the bucket hydraulics. I thought it might be for ride control but I'm pretty sure it wasn't in existence back then.

 

[trainwreck]

on the 988b we have at work there is a rocker switch built into the top of the lift control that has some thing to do with the wheel torque control thingy. its kind of a wheel spin control but all it does it make the already gutless loader even more gutless.

 

[Dwan Hall]

There was 1 here that had the same type of switch. I was a transmition kick down switch. Dropped the transmition 1 gear when filling the bucket.

 

[curly]

Ok thanks I'll check that out. I have a lever for wheel torque control so I'm thinking it may be a kickdown.

 

[NL1CAT]

It is the full torque switch.
There should be a green light on the dash when activated.
If shut off then you can regulate the torque with the lever right from the boom and bucket control.
I used it alot when loading trucks setting the lever at minimum torque , filling the bucket at max torque (switch on) (the 988b hasn't got that much torque anyway ) and then load the truck using min torque (switch off) and pushing the right brake pedal (no disconnect the drive) and keep lots of revs.
I recall the bucket reacts much smoother with lots of revs..
Been a long while since i was on a 988b but that's what i recall of that model.

 

[curly]

Ok that makes alot of sense now! I'll try it out when the dealer gets the bucket cylinders back on. (I didn't break it!)

 

[qball]

careful, i think that switch is for the ejector seat.

 

[BIG D]

Its been a long time ago but my memory 988b the switch in reference gives you full torque as for gutless lets remember when loading spinning wheels is energy wasted the 988b uses a vcdc variable capacity torque converter Thsi should be set for working conditions from previous conversations its very possible full torque is being reached

 

[komatsukid]

the torque button locks up the impeller in the torque converter allowing for direct drive. it was designed to help the machine climb grades and pull hills. this button is not for digging! if you dig in a bank or pile with a hard underfoot with the button on you have a good chance of damaging the driveline.

 

[BIG D]

hi again older 988 had lever you set for torque to wheels this was set for working conditions and yes switch used for hill climbing etc a loader should never spin its wheels and use bucket breakout to load a full bucket using what I call a pumping action of the bucket I believe this feature became automatic in late model loader to eliminate operators that didnt understand how to use vcdc thanks

 

[NL1CAT]

the torque button locks up the impeller in the torque converter allowing for direct drive. it was designed to help the machine climb grades and pull hills. this button is not for digging! if you dig in a bank or pile with a hard underfoot with the button on you have a good chance of damaging the driveline.

The 988b's that i've operated had no converterlock.
The switch is used for quick change of torque so you wouldnt have to pull the lever every time.
The 988g and h have a 4 preset switch for the torque and a switch on the control console to switch to full or preset.
The 988h we have now has also a converter lock switch for direct drive but it won't engage in 1rst front gear and it engages automaticly in the other gears just like on a dumptruck.
Altough i remember a 990 (think was the 1rst series) that did engage the direct drive in 1rst front gear.
It climbed like a tiger!! :thumbsup
The one below was the machine in question.

 

[BIG D]

Thanks for the information its been a long time ago for me but I remember the first 988b to come off the truck I thought it was a long time coming the older 988s tough but very slow a big jump for caterpillor at that time thinking about things the newer 988s had a diaphram in air ratio control that would stretch out and give the perception of a dog when first meshing throttle to the floor there are several causes of a feeling of low power
thanks BIG D

 

[komatsukid]

the 988b we have doesnt have the wheel torque control lever in it anymore. the torque converter is sensitive when the button is not engaged.