Hi,Does anyone have a service manual for t50d.Lift was working fine,then Forward seem to slip.like it wasnt engaging fully.I removed forward spool and electric shift solnoid.Now all I have is rev.
Showing items 1 - 15 of 15 results.
I would say that the SAM valves in the early trucks were a spot that Caterpillar Inc. was trying to put their 'signature" on a truck that was already working as a 'Daewoo' in Korea, that did not work out as well as hoped, because of minor complications unique to the design of this transaxle.
I forgot about the pre update T50D's yes the ones I am speaking of have two solenoid valves that face the front of the lift truck, and that has a directional spool controlled by the solenoids that is inside of a trans control valve.
LTRM,Your talking about the Trans valve on top of transaxle, right?Looks like transmission valve body.The 2 SAMS valve holding pins screw down into it.Thanks Kent
LTRM,
That transaxle did not have a control valve until the update. The inching and pressure regulators were all external. I always felt they thought they may have a problem with the SAMS valve, since the top of the trans case was already ported to accept an extern control valve. Turned out, with a wet brake system, the SAMS valves were an excellent filter!
Those SAM valves only control pilot oil pressure. The actual shift spool is inside the trans valve and may be stuck with a chunk of debris. I would disassemble the trans valve and make sure the directional spool is not stuck. The directional spool shifts from forward and reverse via the pilot oil pressure sent by the SAM valves. The clutch pack oil pressure is not controlled by the SAM valves.
If no luck with this, I will dig out the test port locations and pack pressures for you.
Hey Kent, at this point I would swap the valve assemblies complete with the solenoids attached and see if the problem reverses itself. The pins Edward is talking about that aligns and holds the solenoids on place is on top of the case. It takes an 11 mm wrench to remove each one and then slide the valves out. They have a rather tall hex head, below that an oring, and then a pin about an inch long that engages a hole in the far end of the valve. As I recall, I used a 1/8" welding rod piece about 2" long with the flux removed as an "alignment tool". Keep us posted!
I was thinking that it may be in the forward clutchpack.But I dont understand why rev.is acting the way it is,now. since I only pulled the forward valve.Rev. hasnt been removed,only solnoid changed.Does the holding pin, for the forward valve postion in the outer cylinder of the valve assemble,or go into the inner part.It is in the small hole [same size as pin].Can the inner parts be turned,or the valve its self, Be put in upside down?Im thinking, its a problem with the forward valve.Something Im missing. The valve itself is fairly simple,as far as reassembling it.Im pretty sure its put together right.I dont believe the parts,If assembled wrong would fit back together.[forklit] I may be interested In that valve if you can find it.Thanks so much,Kent
Kent,
The SAMS valve you have in the reverse hole is the same one that was initially in forward and you disassembled and cleaned as I understand it? If this is the case- my bet is that the reassembly did not go well and now it is sending pressure to the reverse pack. The whole set up was a PITA, we use to switch spots as you did in the late 80's and of found defective, replace. Never any luck cleaning them. I did several conversions those days, some in the field even. The SAMS valves were pulled and aluminum blocks were slid in their place. I don't think you can buy a SAMS valve any longer. Maybe Hader can repair yours? I actually had a good used one at the shop, might still be there.
the pin I am referring to, I believe is the same one you are calling as "holding pins back down into valve body on top of trans". if the valve body is not in the correct position (forward to back, and properly rotated to one of 2 possible positions) the pin may fit and screw in but not be in the hole that is the same size (not a slot, but a hole machined to the same diameter as the pin) in the valve outer housing.
however, if you have removed the wires from the same valves, and it stays in reverse anyway (no neutral), then you have a problem in the clutch packs.
if what happens is that once you have gotten it in a gear it sticks, it may be in the sam valve.
Early versions had the cap and pin as separate parts, and the pin could fall down through the valve and get caught in the gears below it, later versions used a different Sam valve scheme.
T50D/8EB3051.Yes I think 85,now.Im not positive,about pin.Ive had this lift about a year.For sell.It had set along time,a couple valves had siezed up in the guides.pulled head done valve job,alls good.used it around the shop for about a year.A customer used it for about a week.It started sliping in forward,But after restart.Forward was ok again.The next morning,forward was out again.I checked voltage from switch ,down to connections going into SAM valve.Then removed cover to sam valve solnoids,both where working.I removed forward valve.dissembled it.Didnt find anything.Switched forward and rev. solnoids. slid forward valve back in place.Did not remove rev valve.[as it was working fine]. ,Screwd holding pins back down into valve body on top of trans.Now Its in rev. all the time.After shifting to rev.It doesnt come out. I can see both solnoids working[.running it, With cover off].I have removed wires from SAM valve.And tried pushing each in by hand.It stays in rev.Untill engine is restarted. So,Edward Im not sure if pin is in exact postion.What pin are you refuring to? Thanks for help Kent.
This is an 80s model unit, but depending on where in the serial number series this was built, the "SAM" valve (directional, solenoid actuated modulating) valve may have a pin that has to fit exactly into the valve, or the the valve will not be in the exact position.
What is the serial number, and are you sure that you got the sam valve back into its proper position?
with the type of shifter control on this truck, first i would verify that you are getting a good signal from the shift control to the solenoid circuit. Those shifters are known to wear out internally, the contact fingers wear off or break causing no signal to the solenoid.
assuming you werent bulldozing with the truck
check the fluid, make sure its not burnt, burnt fluid usually smells really bad and is dark.
if you ARE getting a good signal from the directional control to the solenoids in both directions and the ground is good
you can also try swapping the solenoids and see if the problem moves to the other direction, if it does then you know you have a bad solenoid.
just a couple things to ponder
good luck!
Youve not ever worked on one of these before,have you.Its an early 90s lift,but anyway. I was hopeing someone could e mail a service manual.I know im more than likely ,going to be pulling it apart.Just not wanting to.Thanks for replying Kent.
Forklifts are designed to lift and and carry, not push like a bulldozer or track machine. Most often operators force pallots into place by pushing or pulling. If they drag pallots w/ a chain to the rear of a truck instead of using a hand jack, and reverse packs in the trany will ware.
Likewise, pushing pallots tend to burn the forward clutch packs.
This is a 70's vintage truck, whats the previous history? Nobody will know. My guess its time for a trany.
Forkliftaction accepts no responsibility for forum content and requires forum participants to adhere to our rules of conduct. Click here for more information.
If you are having trouble using the Discussion Forums, please contact us for help.