Steering column coupling pinch bolts

[mike3md]

Hello all,

 

After a saga with poorly fitted couplings on the 4 and a subsequent replacement rack (the pinion had been mullered at some time by forcing the pinch bolt through across the splines instead of the groove), I now have a TR6 type lower coupling. Should I use high tensile bolts etc to pinch up, as the bolt diameter seems small for the task?

 

(I am also contemplating changing the upper coupling to the later type (as per Ian C and 4VC)

 

I am using ordinary ones at the moment, and after a trip to the Spa Classic(great fun!) notice some play in the splines, and don't think the bolts are up to much more tightening.

 

Thanks

 

Mike

[TR Mitch]

Just had my TR5 MOTd and the lower bolt needed a tighten as the spline was slightly loose. The MOT tester said he couldn't be sure whether he'd tightened it enough or whether the bolt was now winding up on it's soft thread. He said I'd be better off replacing with high tensile bolt (5/16 x 1.5" UNF according to Rimmers diagram).

 

Now to find a source of better quality high tensile bolts & screws.

[RogerH]

Hi Mike/Mitch,

for the 4/4A spline clamp, if the clamp was manufactured correctly them any bolt would suffice.

Sadly any bolt is going to have a hard time as you are trying to compress apprx 1/4 squ inch of steel.

Even your high tensile bolt will struggle.

 

They are easily machined to work corectly

 

I'll try and post a pic of my mod. See the metal removed near the arrow.

 

The 4/4A rubber joint is more comfortable at the steering wheel than the all steel TR6 affair.

 

Roger

Edited August 3, 2012 by RogerH

[BlueTR3A-5EKT]

Interesting....

TR4 started with 1/4 diameter pinch bolts and then TR5 onwards used 5/16 diameter.

The pinch bolt on the UJ of the TR5/6 is a regular material bolt 5/16 x 1.5" unf (HB812)

The pinch bolt on the upper coupling is a 6 digit number and I am guessing that was HT.

Moss certainly used to sell the 1/4 diameter HT bolt as I sourced them all those years ago.

 

High tensile bolts are not the simplest of things to get in imperial sizes now as one offs.

 

Think about using a cap screw as an alternative.

- Link

http://www.fix8.co.uk/products/Fasteners/Socket+Cap+Screws/UNF+socket+Cap+Screw+Self+Colour/5%2F16%22+x+1+1%2F2%22+UNF+Socket+Cap+Screw/3182240544

 

Do not forget that Ford Escort Mk II used the rubber coupling and metal splined bits identical in size to the TR 4. They are clamped using 5/16 pinch bolts and nylocs. A direct replacement for the TR4/4A items. Just add your earth cable!

 

We used to sell these at C&B. It was much cheaper to buy the assembly, and gave the advantage of the bigger pinch bolts and all new splined couplings.

 

The "Rally" Escorts replaced the rubber coupling with an UJ assy. not too unlike the pressed steel replacement types Rover offered for TR6. So that is the route that Ian C has gone on 4VC. If you do go this way, be sure that both couplings are fitted in the same working plane (like a prop shaft) or you will get notchy steering.

 

Used to buy these from BluePrint. - See them at AutoMechanica in Frankfurt this coming Sept.

-link

http://automechanika.messefrankfurt.com/frankfurt/en/besucher/willkommen.html

Now, that is a show worth visiting if you are interested in car parts.

 

Cheers

Peter W

[mike3md]

Roger/Peter,

 

Thanks for the feedback, I will try Roger's mod first, but also check the plane is the same.

 

Mike

[RogerH]

Hi Mike,

I can show you the item on Thursday.

 

Roger

[MikeF]

FWIW

IF you don't have a workshop or appropraite tools, I achieved pretty much the same functionality as Roger's mod by drilling a hole about the same diameter as the metal he removed, positioned at the end of the gap he made and then sawing down to it. I used oversized bolts. It doesn't look as neat of course but the clamp works OK. I wished I had known about the Ford Escort bits though! I might revisit this area when I move on from getting functionality to making it lovely/upgrading.

 

MIke

[JRCWeedon]

Hi

In order to get a snug fit on the splines remove the column intact and put the couplings in a vice until they will only just fit on the splines then bolt them up.

Regards

John