Steering, early or late donuts?

[Richard V]

Hi,

 

As many of you may have realised....before I did , my welding job on the RH suspension turret and fulcrum pin is turning into a complete rebuild of the front of the car. To be honnest, Im kind of resigned to the fact that it probably wont stop ontill I get all the way through the boot handle.

Anyway, the strip down for access has included the stearing column. I have discovered that one of the rubber "donuts" (for want of a better word ) has turned to chewing gum!

The Moss catalogue quotes 2 PN's. 21H5384 Flexible coupling (early type), and 150696 Flexible coupling (later type)

Can anyone tell me from the picture if this is an early or late "donut" and what my TR4 CT 7786O should have fitted.

 

Thanks for any help.

 

Richard.

[TR 2100]

Hi Richard,

 

Your car is early 1962 - I'm sure it will be the 'early' type you

should have, though I don't know what the difference is.

 

They can be tricky to fit - the bolt holes don't seem to line up,

but the trick for fitting is a large jubilee clip round the outside.

 

Don't forget the earthing strip.

 

AlanR

[Alec Pringle]

Hi Richard,

 

I'm looking at a later type rack, similar mounting to the IRS racks, and that has a coupling of the same sort as your photo - with 4 raised triangles either side, and dished down between them. I think I'm right in saying that the earlier couplings were a flatter profile, without such prominent raised triangles.

 

The rack assembly changed at not much past the CT 20,000 mark, so as your car is CT 77,860 it would seem logical that it should have the later type coupling . . . although to be fair, the coupling changed later than the rack assembly, presumably to use up existing coupling stock ? The parts book does, I'm sure, quote change points for the rack assembly and for the subsequent pinion specification change, but not for the coupling change.

 

Cheers,

 

Alec

[Richard V]

Hi Richard,

 

I'm looking at a later type rack, similar mounting to the IRS racks, and that has a coupling of the same sort as your photo - with 4 raised triangles either side, and dished down between them. I think I'm right in saying that the earlier couplings were a flatter profile, without such prominent raised triangles.

 

The rack assembly changed at not much past the CT 20,000 mark, so as your car is CT 77,860 it would seem logical that it should have the later type coupling . . . although to be fair, the coupling changed later than the rack assembly, presumably to use up existing coupling stock ? The parts book does, I'm sure, quote change points for the rack assembly and for the subsequent pinion specification change, but not for the coupling change.

 

Cheers,

 

Alec

 

Hi Alec,

 

Thanks for the info. My CT number is actualy 7786 O, (I should have written it more clearly in my post.) So it is an "early" TR4, but as the Moss catalogue covers 2,3,4 and 4a and many of my parts are common with the 3B im not sure what is concidered as early and late.

If as you say one type is flatter than the other then the final assembly will also change length. I guess this means I will have to be sure of the correct type.

 

And to TR2100, thanks for the jubilee clip tip. I was wondering how I was going to refit, as quite a bit of persuasion was needed to strip them.

 

Cheers,

 

Richard.

[Alec Pringle]

Hi Richard,

 

There's nothing like an extra digit to confuse life . . .

 

Suggest you email your pic to Moss, they can look at both couplings on the shelf and tell you for sure !

 

Cheers,

 

Alec

[svenjauhe]

Hello,

 

Years ago I ordered couplings from Moss and only the later type were available.

One obvious difference to the original (TR4/62) were having a steel belt around the coupling.

 

 

--

Regards Juha

Edited August 29, 2008 by svenjauhe

[TR 2100]

Hi Alec,

 

Thanks for the info. My CT number is actualy 7786 O,

(I should have written it more clearly in my post.)

 

And to TR2100, thanks for the jubilee clip tip. I was wondering how I was going to refit,

as quite a bit of persuasion was needed to strip them.

 

Cheers,

 

Richard.

 

Hi Richard,

 

No problem. I did realise your commission number as 1) TR4s don't go as high

as 78,000 and you did write an 'O' not a '0'. Alec likes his space !!

 

Taking out the bolts is relatively easy as the coupling has been held in that

shape for years. New ones are a different story - they can be way out.

A large clip works an absolute treat - no problem at all. Easy to tighten

gradually until the holes line up just right.

 

AlanR

Edited August 29, 2008 by TR 2100

[ianc]

Use TR6 type universal joints at both ends of the column, together with solid rack mountings - then the steering will work as it ought!

Ian Cornish

[67_gt6]

I did this job on my 4A last night, upper donut. The jubilee clip is a must, but even then I found myself exhausting my knowlege of Old German. B&Q stock some suitable hose clips, I think the one I used was 90-70mm. Slacken off the top pinch bolt too to give yourself some room to manoeuvre. You will have to change the position of the clip a few times to ensure it is squeezing the correct bit of the donut, if you do that from the outset it will probably be an easier job than I made of it.

 

andy

[Richard V]

Hi,

 

Thanks to all of you for the generous advice. As recommended by Alec I sent Moss a picture and they tell me that it is an "early" coupling PN: 21H5384 and that they have stock? They must have had another batch made since Juha was looking.

 

I have just recieved the special cap head drilled bolts from Moss which secure the clamps to the couplings (PN: 150697) and they are about 3/8ths too short. This is the only PN that Moss gives for these bolts dispite the fact that they give two alternates for the coupling.

 

Based on Alec's information... "I'm looking at a later type rack, similar mounting to the IRS racks, and that has a coupling of the same sort as your photo - with 4 raised triangles either side, and dished down between them. I think I'm right in saying that the earlier couplings were a flatter profile, without such prominent raised triangles.".... These bolts I have recieved may be for the other type of coupling, with its flatter profile. Weather this other type is an "early" or "late" is now a little confusing.

 

Any advice would be greatly appreciated. As for the TR6 universals suggested by Ian, my car will never be entered in a show for its origionality and Im sure they work well, but I would like to stay with TR4 parts where possible.

 

Richard.

[Rhodri]

The old coupling I removed had two of these bolts fitted, But I don't know why. Is it to prevent the bolt heads rubbing on the parcel shelf maybe? Bearing in mind that my car has not been used since 1976 then, if this a mod, it is an early mod. You can see that the holes for the cap heads have been drilled out, just to the depth of the heads. The other coupling, the lower one, had normal hex head bolts.

Rod

[had17462]

Hi rod the donuts you show are the same as mine with counter sunk holes.

regards nick.

[67_gt6]

Hi

 

When I replaced my donut the new one had countersunk holes, the old one didn't. I just re-used my old bolts. Should I have used a different type? I inserted the bolts so that the heads were up against the flat side of the donut holes rather than at the countersunk end, as to my mind that is basically the same as before...

 

thanks

 

Andy

[Richard V]

Hi

 

When I replaced my donut the new one had countersunk holes, the old one didn't. I just re-used my old bolts. Should I have used a different type? I inserted the bolts so that the heads were up against the flat side of the donut holes rather than at the countersunk end, as to my mind that is basically the same as before...

 

thanks

 

Andy

 

Thanks Andy,

 

I think you have solved my problem. I will now keep the bolts I have from Moss (which I thaught to be too short) and order 2 new donuts, which according to your information will go with my bolts due to the countersinks.

 

I had to replace the bolts as most of the heads and tails are worn down by chaffing with something, but I cant tell what as the clearance is fine ? So as a warning to anyone who wants to replace their steering donut bolts with parts from Moss: They wont fit unless you also replace the donuts! Mine have the rubber which has become like chewing gum due to oil contamination so problem solved.

 

A side note in the Moss catalogue would have been helpfull, but the forum came to the rescue, so all is well.

 

Thanks guys.

 

Richard.

[Rhodri]

I would check, before you order, that the doughnuts will have these larger holes. I got new ones, not from Moss, but the holes are all small so I will try to drill two out to take the allen screws. Moss also sent me allen headed bolts. I have managed to drill a hole, for the locking wire, at the end of one normal bolt, with a view to replacing the allen bolts. I broke 2 drill bits and the other blunted itself just drilling the one bolt!

Rod

[Richard V]

I would check, before you order, that the doughnuts will have these larger holes. I got new ones, not from Moss, but the holes are all small so I will try to drill two out to take the allen screws. Moss also sent me allen headed bolts. I have managed to drill a hole, for the locking wire, at the end of one normal bolt, with a view to replacing the allen bolts. I broke 2 drill bits and the other blunted itself just drilling the one bolt!

Rod

 

Hi,

 

Just recieved the Donuts from Moss, and guess what...... Yep, small holes all round. I find it a little dissapointing that the moss supplied bolts dont fit the moss supplied donuts, but as others on the forum would say "at least we have somone supplying us with the donuts!" I'll fire up the drill press........

 

Richard.

[Alec Pringle]

Heavens to murgatroyd, doughnuts might not be the easiest things in the world to source, but surely Moss can manage to achieve bolts that fit the damn things ? You know, they're bolts, they come in most sizes . . . Or is that too easy ?

 

Cheers,

 

Alec

[BrianC]

I find it a little dissapointing that the moss supplied bolts dont fit the moss supplied donuts

I trust you've expressed your 'disappointment' to Moss. Personally, I wouldn't modify them as it will invalidate the warranty (Oh, sorry, I'm fantasising again ).

[MikeF]

I bought a doughnut at Malvern and had no problems fitting to my early 4.

I thought about the jubilee clip idea and used my vice instead, no problems - just tighten till bolt goes in. my bolts were the right size, so I didn't have problems there. So far as wiring is concerned I think the 4 just precedes Nylocs but I'm fairly sure they would be technically functional acceptable alternatives to wiring. Alternatively you could easily make some lock tabs which would be easier than drilling bolts. I fitted a TR6 unit joint at the other end and that is an exact drop in, It's too long to explain why I have one of each but if I had planned it properly I would have just used the 6 bits, they are much better and its not as if the change isn't reversible in a few minutes. When I reach the time for non essential stuff I will swap the doughnut out. (At present rate of progress this will be sometime in the 2200s)

The length question doesn't really arise whatever you do as the parts go on to over-long splines which will accommodate small changes easily.

 

 

Mike