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Track rod and drag link ends

Posted: Wed Mar 31, 2010 6:35 pm
by Toby
Have just noticed wear in my drag link end. Can I assume that as the cup on the end has a slot and split pin through it that it is adjustable?! Which leads me to ask for any tips when adjusting, such as toe in etc. :? Maybe it'd be easier to swap the link for one without play, then set the tracking? Help! :lol:

Re: Track rod and drag link ends

Posted: Wed Mar 31, 2010 11:50 pm
by Ian Grace
Toby,

Short answer - yes it is adjustable.

Long answer - the very early OHC cars (up to M3098) had track and drag link ends that were of a poor, non-adjustable design. From M3099 to M17882, the steering box drop arm drag link end was similar to the other three ends (but the location of the ball along its length was different). From M17883 on, and including all the SV cars, the drag link at the steering box drop arm was redesigned to have an adjustable cap located with a setscrew and locknut into a slot in the body of the TRE. So to answer your question, on your car, your TRE is adjustable.

The only other difference I know of is that the early (but post M3099) TRE's had adjuster plugs with a single split pin slot in them. At some point this became a cross slot, offering finer adjustment. I know of no record of the chassis number at which this change was effected.

The thing you really want to watch is the wear in the TRE body caused by the neck of the TRE ball. If the TRE body opens up, it is possible for the ball to pop out under road shock and the steering to become disconnected. This happened not long ago on an M Type and caused a very serious accident. Most people check the neck of their TRE balls closely when rebuilding, but sometimes ignore the opening up of the 'keyhole' in the body of the TRE.

Hope this makes sense and helps.

PS - looks like you posted your question 3 times, so I removed the other two. :D

Re: Track rod and drag link ends

Posted: Thu Apr 01, 2010 10:46 am
by Toby
Mine appears to have a split pin. When you grasp the wheel and move it the ball appears to move about 1/4"+ before it moves the rod! :shock:

Re: Track rod and drag link ends

Posted: Thu Apr 01, 2010 12:59 pm
by Trevor Wilkinson
Also the drag link doe not affect tracking, it does on the later Minors control the centralisation of the steering (the travel on either lock) as this is set internally IN the steering box.

Re: Track rod and drag link ends

Posted: Thu Apr 01, 2010 2:29 pm
by Ian Grace
Toby wrote:Mine appears to have a split pin. When you grasp the wheel and move it the ball appears to move about 1/4"+ before it moves the rod! :shock:
Toby, is it possible that extreme play in your steering is causing your vibration problems? Some sort of wheel shimmy? It might not be the brakes at all - but happens when you hit thew brakes? If you have so much play in the steering, I'm surprised the car is driveable even without the vibration. I'd remove all four track rod ends, strip them down and see what you find. Make sure the internal springs aren't totally solid with old, hardened grease. Make sure they are assembled in the correct order - spring, sliding cup, ball, adjuster cup. Make sure the small grease hole in the sliding cup is clear. And check the balls and barrels for wear while they are off the car. While the drag link is off, you can check for any play in your steering box drop arm. Also may be worth checking that the steering drop arms at the wheels are up tight against the stub axles. It's not too big a job. Good luck!

Re: Track rod and drag link ends

Posted: Thu Apr 01, 2010 3:16 pm
by Toby
Yes they are tight, taken off and reassembled when the back plates were changed! Am going to strip the lot but assume that as long as the balls are round I can re-use them. I have spares! I don't think this is the cause of the pedal vibration and graunch but I've learnt that even the unlikely is possible when fixing houses, cars or motorbikes! :D I assume the steering wheel needs to be midway between each lock and wheels straight when re-assembling, what about toe in and setting tracking? I see there's never been discussion of this on the forum so it's a good education for us all! :shock: I can't quite see how with the spring in the joint that it stays together under load anyway :lol: Trying to get my head around the idea of the whole geometry but if I can do compound angles in roofing and make a dodeccahedron out of card at school.... :wink:
PS Must check my manuals for details too! Couldn't find much in my Newnes book of the automobile and other 1920s-1940s repair books, they seem to assume you already know how to do the job. I can tell you how to repair a stanley steamer or the use of compressed air to start a car, or cone clutches and acetylene lighting :lol:

Re: Track rod and drag link ends

Posted: Thu Apr 01, 2010 5:20 pm
by Terry Synnott
Glad this has been raised since have been worrying whether the holes in the barrels on my car have worn excessively. There is no apparent wear on the necks of the balls and not much on the balls themselves and everything seems firm enough when assembled but the holes in the barrels are as follows:
drag link, steering box end: oval shape, 18mm across x 22mm long
drag link nearside wheel end: more a slightly waisted figure of 8 shape rather than a pure oval, 16mm across the waist, 17.8mm is largest measurement across x 24.5mm long
both track rod ends: again a slightly waisted figure of 8 shape rather than a pure oval, 16.5mm across the waist, 17.8mm is largest measurement across x 25mm long
The 3 balls on the steering drop arms are 17.4mm across the diams. showing no visible wear and between 17 to 17.2mm on the diams. showing slight visible wear. The ball on the steering box drop arm is 17.5mm diam with no visible wear.
I'm beginning to think that originally these were circular holes at a small clearance diam. to the balls. I hate going back to old money but would they have done 11/16" for the balls and 45/64" for the clearing holes?!

Re: Track rod and drag link ends

Posted: Thu Apr 01, 2010 7:20 pm
by Ian Grace
Terry,

I don't have measurements, but the original holes were keyhole shape - not circular or even figure of 8. The round end of the keyhole was designed to be large enough for the ball to fit through it for assemble, while the narrow end was where the ball located once assembled, and was narrow enough for the ball to be unable to pop out. Once assembled correctly, the ball should not be able to reach the large end of the keyhole and pop out. The problem is that the narrow end can become worn to the point where it si as big as the ball, and then you only have the cups and a spring holding everything together! Hope that makes sense without a photo. There were photos of all this in an earlier Register Magazine. I'll try to look them out over the weekend and post them here.

Re: Track rod and drag link ends

Posted: Thu Apr 01, 2010 7:23 pm
by Ian Grace
In fact, if you look in the Tech Topics in the Members Area - that from M108 talks about steering and handling problems, and this wear problem specifically. I think the TRE photos I referred to might have been in an earlier issue.

Re: Track rod and drag link ends

Posted: Thu Apr 01, 2010 7:56 pm
by Toby
Cant get the balls off the arms! Have discovered that the wear appears to be the spring compressing as the wheel pulls/pushes the other wheel so I assume this is meant to happen under load and as long as there is no play with the wheels off the ground and post is in slot then all is well? :?

Re: Track rod and drag link ends

Posted: Thu Apr 01, 2010 9:39 pm
by Ian Grace
Toby, the balls can be buggers to get off the arms because they are parallel - the 8 had tapers - which can also be buggers to get off, but, like the wife, they usually succumb to an overnight soaking in WD40, a bit of heat and a swift belt with a lump hammer. :D

I think the reason for the springs is to handle some of the road shock, but they obviously mustn't be so soft that the ball can pop out thru the wide part of the keyhole - hence the need to be able to adjust the spring compression by screwing in the end. I have never seen any data on how tight to screw the end in against the spring, but usually screw it in until it is flush with the end of the barrel and split pin it in that position.

On the other hand, I have had TRE's in the past where the springs have fallen out in several pieces when disassembled - which is never good! I have also had steering box drop arm drag link ends that have been assembled entirely in the wrong order. That Tech Topics article in M 107 has an exploded diagram of the ends to use as reference.

Re: Track rod and drag link ends

Posted: Fri Apr 02, 2010 6:22 am
by halbe
Hello Toby,

The guys from the MG workshop told me to adjust the track rod ends this way:
screw the end in tight against the ball , then turn it back a quarter turn and put the split pin in.

My ends have a single slot so what they do is make that into a cross, Hope that this makes sense to you.

As far as the braking pedal judder is concerned, It might be worth to check your master brake cylinder .

Regards,
Halbe

Re: Track rod and drag link ends

Posted: Fri Apr 02, 2010 5:06 pm
by Toby
Thanks guys, simon rang today to say the same re adjustment. It appears that the play in mine is the spring movement so I will check the slots and reassemble/adjust, then check tracking when I can find the data. The steering was a bit vague so I will also take of steering drop arm and rotate the steering to get a less worn position as suggested in the hand book and check the ball race at the top.
Halbe, I would have to convert to hydraulics to try your idea :D I'm a cable guy!

Re: Track rod and drag link ends

Posted: Fri Apr 02, 2010 7:56 pm
by halbe
so why did i think your car had oily brakes :?

what about this theory then: one of the springs is curling up under braking ......I must be losing it :wink:

Regards,
Halbe

Re: Track rod and drag link ends

Posted: Fri Apr 02, 2010 7:57 pm
by Trevor Wilkinson
Toby, when you are having your juddering problem would it be a good idea to disconnect each brake cable in turn to see if the trouble is confined to one wheel?
Also are you sure that the rear axle is not able to move, is everything tight and located properly? :shock: 8)