MF 135 steering box

[Mike NL]

MY 135 8 speed has always had a slight wobble, but since I took the loader off the wheel shimmy at speed got quite bad. The drop arms moved quite a bit with no movement in the steering wheel.
I replaced the drag link ball joints acouple of years and there is no play in the linkage. With the front end jacked up I adjusted the toe-in to so that with play it varied between 1/4" and none ( 1/8" ).
With the links removed and one arm fixed I could move the other one 5mm and the steering wheel 10 cm at the edge.
I hand tightened the top nut about half a turn and now with the steering box on the workbench the play is slightly less. There is some wear on the teeth of the shafts and the bushes show some wear.
I assume it's the shafts that need replacing, but if so, can I also replace the bushes without a reamer?
Also while dismantling I was looking for a ball bearing, shims, peg and tab washer on the left side , but only found the peg as in the photo. If a ball bearing is inserted the peg sticks out too far so I assume this is a modifiction but I would still expect a tab washer?
Any advice welcome. Without experience or a new part to compare with, the term "check for wear" is not always so easy.
Mike

 

[Masseynut(Australia)]

That wear between the gear faces is crucial, and, at a guess, is your problem area.
If the ball joints have been replaced, the toe in adjusted down to 1/4", and have minimal wear in the king-pin bushes, you have done the obvious & simple things to remedy the problem.

Can't remember how Massey panned out the "peg" versus "ball bearing" scenario, and I'll stand corrected, but I believe it was something to do with the "ratio" of the Burman steering box fitted, to each application.
So, take a good look at those "teeth". If there is wear into the face of them, replace them. If not, just replace the bushes and seals. This should fix your problem.
Evan.

 

[DavidP, South Wales]

Hi Mike and Evan,
I would absolutely agree with Evan that the shimmy that you have will be caused by wear on the teeth of the rocker shafts. The two should of course be replaced together.
Perhaps there is a little misunderstanding here.
On the left side of the recirculating nut (a UK magazine called it the 'recalculating' nut recently)you will find the screws, tab, shims and peg. On the right hand side there is a ball bearing to locate the rocker arm in the recal nut.
Adjustment of the peg to ball is a little difficult whilst in situ. It should be set so that there is just a slight drag when turned, ie no looseness.
It is unlikely that the bushes on the rocker shafts will require replacing unless they are visible worn. Oil seals and felt seals, yes.
The top column bearing should be adjusted so that it is just a fraction loose. Tightening the locknut will then remove the remaining play. Check the bearing on the underside of the ball track and the upper nut itself. Wear is common here.
Ideally toe-in should be set with the full weight of the tractor on the floor. However if there is wear present in the rocker shafts you will at best only get an approximate figure.
You have not mentioned whether this is a swept or straight axle tractor. If it is a swept axle, check the axle pivot bush and pin. Significant wear here will affect the steering geometry. Check also that the front radius rod bolts are intact.
DavidP

 

[Mike NL]

Thought it was the shafts but the top bearing looks like it has not worn evenly so I'll replace that as well.
The bushes are scored but I cant "feel" any play. As I don't have the required tools I'll leave them alone.
I was slightly misled by the exploded diagram on the parts list which made it look like there should be a bearing on both sides.
I called it an 8 speed, which to me means straight axle - Do 8 speeds with swept axle also exist ?
Thanks guys - once again a prompt responce from both sides of the globe - Mike.

 

[Masseynut(Australia)]

Mike,
The bushes are available as a "finished" bush, that is, the i.d. when fitted is the correct size and do not require reaming. Sparex part no. is S.40284. Original part no. is 1850 018 M1.
Just to add to this thread, don't "overtighten" the top column nut. The shaft tends to rock back and forth, as it travels from lock to lock. Correct adjustment is to tighten the nut to 10 ft. lbs, then back the nut off one "flat". This tends to create some 'slop" in the shaft, but this is necessary otherwise damage to the column, and bending of the shaft can occur.
Evan.

 

[Laurence Lombard]

Much more learned replies have been made, but two obsevations from me:

1. At the time I had steering problems on a MF240 (just a later version of a 135) a whole new steering box was only slightly more expensive than the two main steering shafts alone, and a lot less trouble. Worth looking at before you start buying parts for your box.

2. I had major wheel shimmy on an IH444. Different steering setup I know (one drag link and the two front wheels joined by a tie rod), but what solved it in that case was to set the toe-in to zero or even out a bit. This was suggested by an old time mechanic - sounded strange but it worked!

Laurence