FIAT ALLIS FL14B driving on one side only

[Jdkellerman]

Hello all, searching for some help narrowing down a steering/ drive issue with fiat allis fl14b loader. The issue is the left track works flawless, drive,clutch,brake. The right track has no drive at all, brake works fine. So here's what I have done, taken the clutch valve body completely apart and cleaned all valves,check balls, and passages after reinstalling. Immediately on start up before machine is warm right side will drive and brake as it should only after about 30 seconds of moving machine right side stops working. We have the service manual for machine and have taken meticulous time checking the main clutch valve body and brake valves. We have taken this apart twice thinking the issue will be caught. But the issue always stays on the right track every time. It's driving us crazy because the system is so simple it's stupid. We are probably overlooking something very simple but there's not alot of info or parts out there on these machines. Linkages are correctly adjusted. We are just grasping straws hoping that there is not an issue in final drive. Any help would be appreciated

 

[1693TA]

Is there just a single steering clutch compartment filter, or does each side have one? This sounds as if your steering clutch release pressure isn't dumping to sump after letting off the brake pedal. Foot steer if I remember correctly. I'll be your problem is the steering clutch on the affected side isn't reengaging and this would disallow the side to pull yet allow normal brake operation. Make sure the steering clutch compartment filter(s) are clean, or renew them just because of age if not already done so.

 

[Jdkellerman]

Yes it's foot steer, from what I'm seeing in the manual there are 3 oil filters feed pump inlet, outlet, and scavenge pump inlet. All 3 have been checked, no change. Troubleshooting section of the manual says debris or stuck valve. We have disabled whole valve and blown passages clear checked for smooth movement of every valve, no catches or rough spots. The issue has not changed making me think its not the clutch/brake circut. But I'm grasping for ideas now

 

[1693TA]

Get a direct reading pressure gauge into the steering clutch hydraulic circuit on the affected side. I'll bet you do not see that clutch release pressure decay as it should when you let off the foot pedal, or if the pressure does decay you have problems in the steering clutch basket of that side.

 

[1693TA]

Fiat really complicated the brake and steering clutch operation with those tractors. Lots of linkage and then plenty of pumps, valves, hoses, and lines. Great system requiring very little operator effort but problem prone to keep operating as they aged. I think this is where you are.

Going from memory and can't remember if a FL-12B, or E, but there were at a time hydraulic hoses supplied that would "swell" internally choking off hydraulic flow supplying the steering clutch operation. No worries getting them to release, but getting them back to driving, or engaging was the problem. With the system hydraulic "boosted" to lessen operator input, many operators couldn't tell anything changed as the hydraulic assist pushed through the steering clutch release, but would be very slow to reengage the steering clutch. I'm thinking you may have something very similar. Of course a valve or linkage that has so far escaped you could be suspect also.

I don't have any reference material on your tractor so have to stay general in thoughts.

 

[Jdkellerman]

Well we got to the point of ruling everything out with the brake/clutch valve. We took the access cover off the clutch housing to investigate. And there lies the problem in the picture on the right side of the clutch you can see the issue. We stopped for the day, will update as more issues are found

 

[1693TA]

Yep. steering clutch cannot compress to drive the final being hyperextended like that. Post up a photo of the assembly from the book so I can get a look at what is going on. Interested in if a hub, shaft, retention ring, or collar has broken.

 

[Vetech63]

Pinion bearing failure…..common on the 14 series.

 

[1693TA]

Pinion bearing failure…..common on the 14 series.

Shown as #6, or #9 in the diagram possibly?

 

[Jdkellerman]

Sorry for taking a week to get back but you are on the right path. We got the clutch pack out today and it is in good condition still. Been working on pulling the plate for the final drive. The bearing that is on that shaft that goes to the final drive is in very bad shape. Hopefully I get some more time to mess with it this upcoming week to keep updates coming. Thanks for your help TA

 

[Vetech63]

Shown as #6, or #9 in the diagram possibly?

View attachment 291625

Both, but I’ve seen more of #6 fail

 

[1693TA]

Both, but I’ve seen more of #6 fail

Never been into one myself. Only moved them around when new and awaiting shipment.

Researching both of those bearings and they are not inexpensive so must be specialty units.

 

[Vetech63]

I’ve done a dozen or so of those finals way back when I worked for a Fiat Allis dealer. That outer pinion bearing is undersized for the load that final carries and when it fails the bearing rollers start working their way through the gear train until they hit the bottom of the case. If caught early enough the damage can be minimal, but in most cases the outer case that holds that bearing is usually destroyed. I still have all the final drive tooling for those but haven’t done one in 15 years.

 

[1693TA]

 

[Queenslander]

One of the most frustrating things about these final drives is the bearing, No7 in post 9, the edge of which is slightly obstructed by this flange.
The inner case and dead axle have to be removed to replace the rotten #$%*.