[SOLVED] NH TD5.95 drifts to the right - worse when faster

[GerMarsh]

Hello again more experienced agri people! We have had the 2016 TD5.95 about a year now and I rarely use it on the road. However, when I first bought it I had to fetch a trailer from a neigbbouring farm (only about a mile away) and we (my long suffering wife was in the "instructor's seat"!) nearly ended up in a ditch as I temporarily lost steering.

After a discussion with the supplier, he suggested I check the hydraulic oil level which was indeed at the minimum. I told him that the machine was supposed to be serviced. He reckoned that the oil was not rechecked after putting the front-end loader on it!

I still think it may have a problem though as it tends to drift to the right when travelling along a track or road. Even I soon sussed out that the system is purely hydraulic as there is no mechanical link from the steering wheel to the front wheels. There is no evidence of any oil leak anywhere on the tractor - which I thought unusual! Oh, and the faster I go, the more I have to compensate by constantly turning the steering wheel to the left.

As ever, any help would be gratefully received.

Finally, a warning to other newbies out there to be very careful with your implement! The tractor has been brilliant at our small type of farming and I was actually looking forward to tedding hay a couple of months ago. The contractor had a massive Massey with triple mower and could only just get it through the gateway as the entrance was 90 degree turn from another gate to the road. He suggested I remove some fence as the rake and baler could not get in there. As the fence already had a joint in it, I did so and "secured" the two parts on the outside of the field. Except one half was not that secure and I did not notice that the fence had jumped back into the field. Result: lots of banging noises, snapped fence and post and knackered tedder. Photo attached! (I was shaking like a leaf but no real harm done to the tractor.)

 

[LouNY]

Excessive toe in or out can affect the steering, the other would be bad seals in the steering cylinder, or the orbital motor is bad and leaking by..

 

[Harry in Ky]

Put your money on the steering cylinder piston seal. Orbitrol type steering valves do have problems on occasion but not usually like that.

 

[GerMarsh]

Thank you very much for the responses. I shall clean the areas and check for leaks. As I am not confident in attempting any potential repairs, I willl end up contacting a specialist. (I am confident with small two-stroke engines of the 1970's!!)

 

[GerMarsh]

Please could someone give me an idea where the orbitrol motor is located? I see lots of paying download links for the workshop manual for TD series machines but I have been bitten by one of those with my old Massey in the past.

 

[LouNY]

On the end of the steering shaft, under the dash.

 

[jimglassford]

All vehicles drift to the right due to the crown on the road. You don't realize it is a car because it's suspension geometry minimizes that effect.

 

[GerMarsh]

All vehicles drift to the right due to the crown on the road. You don't realize it is a car because it's suspension geometry minimizes that effect.

I can see how that would work but we drive on the left here and the roads are all single track in any case.

Thanks for the comment though.

 

[GerMarsh]

On the end of the steering shaft, under the dash.

Thank you. I shall see what I can remove to get at it.

 

[LouNY]

Thank you. I shall see what I can remove to get at it.

It is often a royal pain to get to. Personally I would check the easiest first. Jack up the front wheels and verify the bearings and tierod ends are good. Then measure the toe in.
Then to get to the more likely issue check the steering cylinder. Is yours a single cylinder mounted in the center of the axle. Disconnect one hose and put it in a bucket (securely as fluid flow will make a hose jump) if your cylinder is behind the front axle, the hose on the left side would get pressure from the orbitol when trying to turn to the left. So with the left side hose disconnected an attempted turn to the right should move the cylinder rod to turn right with just residue fluid to come out of the cylinder continuous flow wold indicate an issue with the center piston seal.

 

[GerMarsh]

Least of its worries now - I had nearly finished tedding a 5 acre field when there was a bleep, a stop symbol and some error relating to the diesel particulate filter. I should have made a note of the error code but thought I had better stop the engine immediately. Awaiting call back from dealer but I think I have found a way to access the historic error codes.

 

[GerMarsh]

Well, the dealer has nobody who could come out to the machine but I did find out in the manual how to access the error codes. Except I couldn't. It repeated a symbol which I think refers to the engine running on reduced power. After more conversations with the dealer, I decided to give it another go. I noticed that the amber warning symbol also flashed with a few beeps. I think it was three then two then one. Suddenly the warning symbol went out and the tractor started! The dealer person suggested I start a manual regeneration except it does not allow that unless it needs it.

When I just attempted to access the historic error codes, there aren't any! Aaargghhh!

I hope it does not happen again.

 

[GerMarsh]

Well, the dealer has nobody who could come out to the machine but I did find out in the manual how to access the error codes. Except I couldn't. It repeated a symbol which I think refers to the engine running on reduced power. After more conversations with the dealer, I decided to give it another go. I noticed that the amber warning symbol also flashed with a few beeps. I think it was three then two then one. Suddenly the warning symbol went out and the tractor started! The dealer person suggested I start a manual regeneration except it does not allow that unless it needs it.

When I just attempted to access the historic error codes, there aren't any! Aaargghhh!

I hope it does not happen again.

It did with a different error code - 3293. I will start a new thread as that number is not in the manual too.

 

[GerMarsh]

Back to the original problem and steering to the right. A local NH expert had a drive and he told me not to drive it on a road until it is fixed! He suggested that it is indeed a leaking seal but the leak is internal to one of the power steering rams. I think the work required is beyond my meagre skills so I need to find someone appropriate. Thank you all who replied. I think it has had this problem since I bought it but thought it was me!

 

[GerMarsh]

Thanks for all the responses. I had an NH mechanic test drive the machine. His response was: "It's pretty bad, isn't it?"! That explains why I have been battling on our roads with the damn machine!

After various tests, he has suggested changing the seals in both steering cylinders. I have the seals and awaiting a local mechanic to do so. I shall let you know what happens.

One concern I have, though, is that I cannot see why there would be any pressure on either side of the steering cylinders if the steering wheel is not moving. I attempted to find out the relationship between those cylinders and the orbitrol motor but it might as well be quantum mechanics! We shall see.

 

[GerMarsh]

Whilst awaiting for our local fella to replace the seals, I discovered today that there is a large discrepancy between the tyre pressures on the front wheels. The manual states they should be 17.4 psi but the nearside was 25 whilst the offside was 12.2. I don't think that will help the steering. I took it on the road for a test and there is not so much "wandering" but the steering is still imprecise.

 

[RjCorazza]

That's enough difference to notice a steering issue, what are the pressures using a right and left description?

 

[GerMarsh]

That's enough difference to notice a steering issue, what are the pressures using a right and left description?

Sorry - British driving term, I suppose. As I am sat in the tractor, the left rear tyre was 25 whilst the right was 12.2. I was advised to increase the front tyres by a few psi due to it always having a loader fitted. I took it for a drive down the road this morning and it is much better but the steering is very imprecise. Only slight pull to the right though.

 

[GerMarsh]

Local specialist correctly diagnosed the problem being an internal hydraulic leak on at least one of the steering rams. Local ex-agri mechanic changed the seals after a big battle with only one side. The first seal kit was the wrong size - slightly too big. I was lucky that local NH dealer had the correct one in stock (5192826 | Steering Cylinder Seal Kit | New Holland Agriculture | MyCNH GB Store). For anyone else attempting this, there is an external circlip holding in the whole shooting match. After that is removed, the assembly has to be pushed into the ram housing to reveal a spring clip (termed "ring" on the CNH diagrams). The external part of this is aluminium and therefore very soft and susceptible to damage. An inner part of that component (termed "piston" on the diagrams) is steel and when the mechanic eventually managed to remove it after much thumping, it showed signs of corrosion which caused the bloody thing to stick. Specialist mechanics usually create a special tool out of a bit of pipe which can spread the load and minimise risk of damage. I managed to fabricate one with my crappy welding skills. Image attached.

Another point which would have helped diagnosing this problem: When the problem was evident, I could turn the steering wheel very slowly and there would be no movement in the front wheels. I could keep turning the steering wheel for ever! Now, even a small input on the steering wheel results in a movement of the front wheels.

It handles like a different tractor and I now realise that the bloody thing had this problem from the day I bought it.

Thanks to everyone who helped. The information is valuable for someone like me who spent decades doing IT support and consultancy but those learnt skills are absolutely useless in agri-engineering!