TD15c trans problem

[allis4x4man]

First let me say hello, this is my first new thread post and I am hoping someone can help me get a problem on my dozer worked out. My 1980 International TD15C powershift has lost low/forward gear. High/forward, low/reverse and high/reverse work okay. I have checked the pressure at the F1 port on the range selector valve and everything seems right. Anybody have any suggestions as to what to look for next. As stated earlier the only thing lost is low/forward, everything else works as it should. Thanks

 

[68M]

Hi there, TD15c's can be temperamental in their transmissions and some times take a bit to understand but in saying that they are a great tractor. They can suffer from internal leakage in their pistons but if they do they generally slip after changing gear and this will normally affect more than one gear. These transmissions have manifold with plugs in them so that you can check the pressure that is going through each shaft to suppy the pistons. From memory there is one on the front of the trans and one on the back. Without looking at a book I think the rear one is on the P.T.O. shaft (winch drive) which is in line with the input from the torque convertor. The front one is off to one side and will unbolt without removing the trans, when unbolted the end of the shaft is exposed along with 4 piston type seal rings. As I said you can check the pressures here, If you have good pressure here chances are you need to dig deeper, if your pressure is not good here try looking at your control valve. Hopefully this is of some help to you, when the transmission are right they are good and give good service. As I said a great tractor, did a lot of hours on my one and loved it, Good luck.

 

[RDG]

I spent close to 20000 hrs on two 15cs and one 15b back in the 70/80s and never had to many problems with transmissions apart from general wear and tear after many hrs. Check the filter and suction screen for debris from clutch plates etc, how many hrs since last rebuild? could be clutch plates have worn out to the point where they dont work, after all 1st fwd is the one that gets the hardest life. Do you have a shop manual as that may help in trouble shooting. Hope u have a simple fix, what part of NZ are u in. Cheers RDG.

 

[shopguy]

does it have a clutch pressure gauge on the dash ?

 

[allis4x4man]

does it have a clutch pressure gauge on the dash ?

Yes, it does have clutch pressure and when the hi/lo range stick is in neutral, you can shift the powershift and watch the gauge needle "bump" when you shift.

 

[allis4x4man]

I'm from the state of Kentucky in the USA. I do have a service manual but it does not say anything about checking pressure in the end of the shafts. That sounds like that should be the next step. Could you tell me more about where to find these plugs? I did see two 1/2" pipe plugs on the top left hand side of the trans cover could they be the ones? Thanks

 

[68M]

Hi there again, the plugs to check the pressure at the shaft ends are (or should be) located on two bolt on manifolds (about the size of your fist). The rear one is bolted to the rear of the trans and has the winch shaft going through it. It also goes into the bevel gear housing. It cannot be removed without removing the trans from the tractor, but there should be 2 (half inch I think) plugs in it. They could be difficult to get to. The front manifold bolt onto the front of the trans housing with 3 or 4 (3/8 or 7/16 bolts 9/16 or 5/8 heads). This manifold should have 2 plugs in it as well. This manifold can be unbolted and will expose the end of the shaft. I do not have a service manual any more, but have a look in yours to find out which shaft gives you the forward gears.If you have good pressures here I suspect you will be digging deeper. Cheers 68M.

 

[68M]

Be careful not to drop any dirt in these holes as it would not take a lot to block the small holes in the accelerating pistons.68M.

 

[jeff112]

If low forward 1st gear only! slips, then the problem will be in the low clutch pack in the "steering drive" you will need to test that, not the trans, you can watch the drive shaft spin in low first if you want, that would tell you the trans is applying power to the steering drive where the low and hi clutches are. The steering drive clutch pressure should be around 100 psi?. Make sure you have the correct pressure there first before you go further.

 

[68M]

TD 15c's do not have high & low steering (like TD25's). Drive shaft will also spin if trans clutch packs are slipping. Often if there is a problem in a clutch pack, when it is selected it may feel like it wants to engage and drive and may at low idle stop the drive shaft from turning, but as soon as some power is applied it will slip and the drive shaft under the floor plate will spin TD15c's can slip in there steering but chances are it will only be on one side whilst under load. Cheers

 

[RDG]

68m is right in that they dont have a two speed steering like the 25s, I would be looking to see whats in the suction screen and filter, if clutch plates have disintergrated then there could be material in them. Cheers RDG.

 

[allis4x4man]

Pulled suction filter yesterday, was clean. Low forward is the is the only problem, it has nothing. No warning either, just backing up and when shifted from low/reverse to low/forward, no movement at all. Thanks and keep giving me ideas, I really need to get this dozer going!

 

[td15c]

The range selector spool valves are under the seat on top off the trans. If you pull up the floor plates and look next to where the steering levers are attached you will see a flat plate with 8 bolts I think there 3/8 bolts the plate would measure something like 2’’x 8’’ inches. Under that plate there are three spools one is forward speed selector one is revs speed selector the last is lockout. Take the plate off and look at spools see if they are all in the same position or is one hung up. The two speed selector spools will look the same the lock out will be different. The problem will be in your forward speed selector spool.

 

[td15c]

I should have said could it be in the forward speed selector spool. it could also be in the range selector or in the trans.

 

[allis4x4man]

Removed cover from spools, springs were good, spools seemed to move easy enough. When I hooked gauge to the line between the shifting spool and range spool, pressure was up to specs. I have worked on a few Allis Chalmers farm tractor powershift trans before, used compressed air to trouble shoot them. Do you suppose that if I could hook air to the system that I could tell if the spools are moving, or better yet hear if the clutch packs are locking? Just a thought!

 

[RDG]

There are a heap of hoses running from the trans to the selector lever up near the armrest, think they had a plate or something that they all went into at each end with O rings for each hose, may be an O ring has gone there or could be something in the lever control valve it self, guess there would be O rings /seals etc in those places as well that might cause loss of presssure to a clutch pack. RDG.

 

[td15c]

I have not tried the air trick before so cant say yes or no. but you could have some debris in one of the spools or ports.

 

[RDG]

Over on Red Power magazine there is a bloke called Rocko 59 who is an IH mechanic in BC or AB who might be of some help. Cheers RDG.

 

[malcolm]

HI
Now that the suction screen is clean (lucky you) it points to the pilot pressure control system from the lever to
the main spool valve maybee at fault . If you can locate the forward and reverse low gear hoses from the lever
to the valve ,(I know they are all together in a loom) and hard to get at but if you can swap those hoses over
better at the lower end and see wether you loose low reverse ,you will isolate the pilot system from the main
system .you will see from the drawing that forward 1&2 are on the input shaft hope this helps regards Malcolm

 

[jdsmoak64]

have the same problem with my jd450g dozer pushes great at first once it heats up it loses 1st gear im wondering if my fix will be the same as yours can any one help us?