Torque converter problems with a 50hp Ford 260-C industrial tractor

[Meadowlark Farm]

I have a new orchard in south central Kansas and bought a 1990 Ford 260-C tractor as the main tractor for the operation. It is low and handy and sufficiently powerful for the work required. My question concerns the use of the torque converter lockout. My understanding of the torque converter was that you use the machine without the TC locked in unless you run into heavy draft or start to slip. So the other day while using this tractor with a 5 ft blade to create berms for new tree planting, the transmission started to lag when put into forward or reverse. While in the neutral there was a strong buzzing sound coming from where the TC is located inside the tractor.

I think I smoked the Torque Converter...

So I am going to have to get this repaired and it will probably cost as much as the tractor did. But here are the questions:

1. What is the proper way to use a tractor with a torque converter? (yes I did read the manual, digested all the warnings and there simply is no instruction on draft use of the tractor)

2. The load and work being demanded of the tractor was not that heavy; the motor did not lug down at all at 1750 rpm and the wheels did not slip, so I didnt even have an indication that I was challenging the machine before the transmission started to lag. ( the lag is about 5 seconds long and feels like a gradual development of hydraulic pressure that finally gets the wheels turning, and the 'buzz' from the transmission stops immediately when I engage the forward/reverse out of neutral). Is there an inherent problem with TCs on small tractors for draft use (plowing, chiselling, blading, etc)? Should I get this thing fixed and relegate it to mowing and front end loader usage?

3. Is there a specific problem with the Ford 260-C from early 1990s? Is this just a loser tractor for this kind of work?

Thanks for any comments or help.

 

[RickB]

It is a 20 year old tractor and if the torque converter failed, it wouldn't be the first one to go. Somewhat like clutch discs or torque dampeners, they are more or less a wear item. That said, TQ driven transmissions aren't generally the first choice for high draft loads over the long haul. You could just as easily have a forward/reverse clutchpack problem as a TQ failure. When was the last time the transmission oil and filter were changed?

 

[Meadowlark Farm]

Thanks for the reply.

There is more to the story and it is kind of horrible. I just replaced the TQ 100 hours ago (with a rebuilt one) along with all the seals and bearings. So at that time the transmission fluid and filter was changed. The transmission fluid looks a little bit dark; as if it has gotten hot but it is not black. And there are no visually detectable filings in the fluid. I replaced the TQ for a totally different reason; whenever the tractor ran at 1750 rpm or above for any period of time; mowing with the bush hog for example; it started to drip transmission fluid through the weep hole in the belly of the tractor. Turn out the output shaft bearings and seals were shot and had been for quite awhile, this resulted in the original TQ being damaged thus necessitating its replacement then. So the one I just ruined is a new one. :laughing:

Anyway, I thought there was not actually a clutch in this machine. The manual refers to the 'transmission disconnect' rather than a clutch. Where is the clutchpack in relation to the TQ?

Thanks

 

[RickB]

Torque converters in Fords of that vintage are generally one component of the 4x4 or 8x8 power reversing transmission. What transmission does your 250C have?
The transmission is called a power reversing unit because of the two multiple disc wet clutch packs located immediately behind the TC and providing the means for no-clutch direction changes. Do you have a F/N/R lever clamped to the steering column?

 

[Meadowlark Farm]

Hello..Yes it is a 260-C with an 8x8 power reversing transmission. Yes the FNR is on the steering column.

 

[RickB]

Then you have a forward and a reverse clutch pack. Usually if the TC needs service, the clutchpack piston seals and shaft seals are replaced and the clutch discs and transmission pump are evaluated at that time. If this was done 100 hours ago, it wasn't done correctly. If it wasn't done at that time, you now know why it should have been.

 

[Meadowlark Farm]

That is helpful. I will make sure the clutch packs get worked over.

Thanks a lot and kind regards

 

[Meadowlark Farm]

HEllo Again. After a long pause in the process of getting this tractor going again, (I got busy selling pumpkins and vegetables) I sent it to the shop. They pressure tested it and of course the results indicated some problems with the clutch and torque convertor. Then they drained the fluid and check the screen filter. It was completely blocked with metal filings. They decided to clean it out, replace the fluid and pressure test again. The clutch worked fine and there was no lag in reverse/forward shift. The torque convertor does not seem to be locking in and they think at least the TC lock in solenoid is not working but the machine works. Since there was a problem getting some of the parts anyway, and since it is functional I brought it home and am using it. I used the loader quite a bit with lots of starting/stopping/forward/reverse and there was no problem. Then I did some light discing with a 6ft disc and there was no slippage or evident problem with that either. So evidently what i have is a machine where the TC never locks in but is otherwise fully functional.

Does this mean that the meter is ticking and soon the TC or clutch will finally grind itself up inside, because it never gets to lock in?

What is strange is that neither the manual or any person can tell me the actual purpose of the TC lock in. Some say, "use it when you are on the road" Others say ' lock it in when you are pulling a heavy draft. like a plow" or like when I was using the 5ft blade to build up berms for trees in the orchard.

So the manual for the tractor never says: "Under the following conditions, use the TC Lock in switch" It does warn that it wont stop moving when it is locked in and that is really all.

So do I understand the present condition of the transmission as being analagous to a standard transmission with the clutch pedal alightly engaged? Mostly functional but on an accelerated wear out trajectory?

Thanks for your help on this as I start to get a grip on the situation.

Kind regards