New 988H Its here!

[kshansen]

I hadn't dug deep into the system for the documents Per refers. If you need them then PM me with an e-mail address that I can send them to.

Nige if you are responding to me about the TIBU3671 and the REHS4199 I can access the REHS4199 online and was able to get a copy of the TIBU3671 from local dealer and have passed that one on to my boss and he is passing it up the chain of command to see what they might or might not want to do. I don't see it a a big problem as long as we know it's not a parts failure that could cause major damage in the future. It would have been nice to have know this information before we paid to have the tilt cylinder removed and rebuilt. But then I just stumbled on this Forum last week.

 

[Nige]

Check out SEPD0990 as well ......... "A Tilt Regeneration Kit Is Now Available for the 988G and 988H Machines". I think one of the kits listed in that article might be exactly what you're looking for. Not cheap though, about $8000.
If it was me I'd be hitting up my dealer for some participation in the cost of buying the kit from Uncle Caterpillar's cheque book, especially if the machine is out of warranty.

 

[kshansen]

Check out SEPD0990 as well ......... "A Tilt Regeneration Kit Is Now Available for the 988G and 988H Machines". I think one of the kits listed in that article might be exactly what you're looking for. Not cheap though, about $8000.
If it was me I'd be hitting up my dealer for some participation in the cost of buying the kit from Uncle Caterpillar's cheque book, especially if the machine is out of warranty.

Well I've passed the information on to higher powers to see if it goes anywhere.

Besides the cost of the kits is the amount of work needed. As I recall the main control valve has to come right out so it can have one of the spools changed. Then there is some mention of the fact that spools are matched to the valve body when it's made and the new spool might not fit without some extra work. Does not sound like a good project to start the week we start production for the season!

 

[Nige]

I've read through the SI a few times. First up, the implement valve does not have to come out. It's simply a case of removing the end covers, sliding one spool out and installing the replacement. If the replacement is too tight and has to be ground then the original spool can be temporarily installed while this is done. Just that the regeneration function will not work until the replacement spool is in the control valve. A lot of the parts for the modification can be pre-assembled before you down the machine to cut down on the time it takes.

Agree with you though that it's not the sort of thing you tackle unless you are fully tooled up for it and have read the installation instructions every which way for at least a week prior to doing the job.

 

[NL1CAT]

Hi Coalburner,
Is the machine still in one piece, or did they had to pull the pumps allready?
I did see from the pics you have a kind of series 2 988h (the frontend controllevers are different) so those maybe are better machines.
We have 2 988h's with the G-style controls and they have given us a lot of trouble with the pumps, and from what I heard we are not the onlyones.

 

[Karl Robbers]

The joystick on the left controls steering by moving it sideways. There are buttons on the joystick to shift gears and a yellow rocker switch on the front of the joystick to select F-N-R. There are accelerator and brake pedals on the floor like in all loaders.

Two electro-hydraulic finger levers on the right side of the cab control the boom and bucket. These levers are very easy to manipulate using just two fingers, one on each lever. Combined functions are very easy with these electro-hydraulic controls but they lack 'feel' in the controls so they take a bit of getting used to.

I wonder why they don't use twin joysticks like the Cat 2900G LHD does? The left joystick is the exact same as a 2900.

 

[Erica]

Did you find a fix? this has been crazy ride! short of replacing the main harness?

Simple things first, and I know this post is from a while back. There should be a rubber stop assembly to prevent the door hitting the mirror. Maybe it got left out when the reapir work was done to the cab roof after the loader hit the bridge while being transported to the job site..?

Fault Codes
562.09 - Cat Monitor System
585.02 - Transmission Output Speed Sensor #1 (there are 2 sensors)
673.02 - Transmission Output speed Sensor #2 (well golleeeee, do we see a pattern here?)
02 - data erratic, intermittent, or incorrect
09 - control not receiving expected information (I would guess from the transmission speed sensors in this case)

I would suspect a harness connector fault, maybe something as simple as a plug not fully home in a socket.

Event Code E049 is a Coasting in Neutral Warning - naughty, naughty.
Event Code E155 is a High torque converter outlet oil temperature - again naughty, naughty.

Talking about the "wheel power" of the modern generation of loaders, it is the electronics telling the engine what to do when it's detected that the loader is in the pile digging. All the larger loaders from 980 upwards work this way as far as I'm aware. Check out the diagram below.
View attachment 88979

At 1800 RPM the converter can absorb all the torque that the engine can produce, leaving nothing for operating the hydraulics. However if you look at 1200 RPM the engine actually produces more torque than at 1800, the "Torque Rise" all engine manufacturers famously quote.
If the loader is in 1st gear forward, the bucket is on or almost on the floor the floor (as detected by the boom angle sensor), and the ground speed is less than 1mph the "Dig Strategy" is activated. The engine is commanded to go to 1200RPM which in 1st speed should be sufficient to keep the machine moving into the material. At this RPM the converter can only absrob a percentage of the engine power, leaving the rest to run the hydraulics. A lot of operators who've never run the system before equate this to the engine "lacking power" where in actual fact it's the engine doing exactly what it needs to to produce an optimum power balance between the converter and the hydraulic system.

Did you find a fix I have all of the above codes and seem to be experiencing the same problem. This has been a on-going problem! Engine replaced, transmission/torque converter rebuilt, speed sensor's are working fine. Short of replacing the main wire harness I am speechless, forward and reverse direction keep cutting in and out??? any suggestions???

 

[Erica]

Did you find a fix I have all of the above codes and seem to be experiencing the same problem. This has been a on-going problem! Engine replaced, transmission/torque converter rebuilt, speed sensor's are working fine. Short of replacing the main wire harness I am speechless, forward and reverse direction keep cutting in and out??? any suggestions???

 

[Mark250]

Hi Erica, some more information would be helpful and some one may be able to help you (assumptions are made that you have checked all the obvious areas)

1/serial number? PLEASE
2/list of codes and FMIs?
3/do you have access to ET? can you use a data logger?
4/description of problem
when it occurs
how long does it last for
does it resolve itself
do you do something tricky to make it go away
5/is it temperature sensitive ?
6/can you replicate the fault or is it intermittent

I have probably forgotten something to ask but some one will chip in

Regards
Mark 250