Torque Range?

[SteveHall64Healey]

Does anyone know the torque range for the castellated nuts on the end of the side and cross rods of the steering assembly? Normally a range is specified to allow for lining up the nut with the cotter pin hole.
thanks,
steve

 

[drambuie]

Steve, you may think you are asking a very simple question, and I don't mean to tell you how to make a watch when you are asking for the time! Fastener torque is a very hot topic in the engineering world and keeps evolving all the time. As a proto type Machinist in the web press industry for many years "Retired" I always raided our engineering department combing through our manuals for fastener industry standards. We used some basic formulas, Torque applied/nominal Dia./Coefficent of friction/tension/empirical torque adder and many other considerations such as material, thread pitch, thread angle 29.5 degrees, and so on. But, let's get back to your question, I made a quick check in my "Triumph" Bentley manual that may apply. Tightening the ball joint housing to the upper wish bone 24 to 32 lbf. Tightening torque for the nut securing the ball joint to the vertical link is 35 to 50 lbf. the slotted trunnion nut torque is 50 to 65 lbf. I used my manual when rebuilding my Tr-6 front end with very good results. Of course follow your "Healey manual" for idler end float specs and follow your manual for other related specs as you move around your car. You may want to self educate and research this topic. I always found it interesting.

 

[Bob_Spidell]

I've always thought that giving even an 'advisory' torquing figure for castellated, split pin-secured bolts was a bit specious. You have to align a slot in the nut with the hole for the split pin in the bolt; if you go past one slot but can't torque to the next you either have to back off on the nut or torque some more, and your previous torque reading is now gone anyway. If you tighten to the advisory torque and line up with the hole great; most of the time you will have to either back off or increase torque to get to the next slot. I suspect the torque required to turn a nut or bolt increases exponentially as you tighten. I've learned, while torquing lug nuts in steps for instance, that torquing to 70ft-lbs then final torquing to 100ft-lbs the nuts barely move, so if you torque to 'spec' and you're between slots you may have to torque another 20ft-lbs or more to get to the next slot. These are fairly sizable 'bolts'--7/16" dia. IIRC--which would probably get a torque reading of 40ft-lbs or better. I torque these--and the big nuts on the front axles--as tight as I can get them to align with the hole; unless you tighten with a large breaker bar or put a 'snipe' (pipe) on the wrench you're not going to snap them.

 

[SteveHall64Healey]

Thank you both - very interesting...

 

[drambuie]

Bob, I don't think giving and researching advice on a castellated fastener is a bad thing! We still need to achieve the recommend minimum and maximum torque spec for a particular application when aligning the slot and hole. That is why castellated nuts have such a broad torque range. i highly value my official Bentley Triumph manual because it is much more detailed and specific then my basic Healey workshop manual and gives specific torque specs in relation to different systems such as steering, suspension, rear end, engine and so on...

 

[Healey Nut]

Ok all you torque spec specialists ......when was the last time you had your torque wrenches calibrated ??
And who calibrated them to what standard etc etc .
A simple internet search can find you the torque spec for every size fastener for every type of material , however common sense should tell you that your not going to get 250lbs on a 1/4" grade 5 fastener .
Steering tie rods cross rods and the like all have tapered collars for alignment and an interference fit . The nut and cotter pin is just a token gesture to hold them in place .
Theres only two places I use a torque wrench .....lug nuts and cylinder heads ....everything else is done by my built in torque wrench in my right forearm .

 

[drambuie]

Just checking my Healey manual again and will quote it relating to the side rods. Quote: To dismantle, 1.remove the dust covers from the ball pins and sockets by releasing the clips and levering the covers off. Further dismantling of the socket assemblies is not permissible . 2. Check ball joints for wear. They must be tight enough to prevent end play, yet loose enough to allow free movement. Renew as complete assemblies if necessary. 3. Renew the dust covers if damaged. 4. Examine the side rod for damage. Renew if it is bent or damaged..... Unquote. Well, thigten until there is no end play, yet loose enough to allow free movement is what I think you are looking for pertaining to the side rods. Hope this helps! And don't forget to get your forearm calibrated as Healey nut suggests

 

[drambuie]

Healey nut, actually In the proto type machine industry I was in we had all our micrometer standards calibrated, torque wrenches, indicators and so on calibrated by a outside company every six months. Everything was high precision and some surfaces where measured in helium light bands by other Precision industry's. At that time we did not have Internet access so we relied on our engineering departments many manuals and math formulas, we where all required to learn from and bounce around and work in all departments to learn each other's skills, machining department, fabricating, development, machanical engineering and field work. I was very blessed to work and learn from some very skilled people in each department over the many years. We did leave the electrical to the Sparky's

 

[CraigC]

Just checking my Healey manual again and will quote it relating to the side rods. Quote: To dismantle, 1.remove the dust covers from the ball pins and sockets by releasing the clips and levering the covers off. Further dismantling of the socket assemblies is not permissible . 2. Check ball joints for wear. They must be tight enough to prevent end play, yet loose enough to allow free movement. Renew as complete assemblies if necessary. 3. Renew the dust covers if damaged. 4. Examine the side rod for damage. Renew if it is bent or damaged..... Unquote. Well, thigten until there is no end play, yet loose enough to allow free movement is what I think you are looking for pertaining to the side rods. Hope this helps! And don't forget to get your forearm calibrated as Healey nut suggests

In the instructions you quoted, the part I have highlighted refers to the fit of the pivot ball in the socket, not the pivot ball stud in the steering arm/idler arm/pitman arm. The side rods do need to be torqued when installed. Since that number does not appear in the service manual, the next best thing would be to find the spec for a similarly sized ball joint stud in another British car. If you could check the stud/nut size of the three Triumph parts you mentioned previously, you might find one that matches the size of the Healey side rod pivot stud. The torque range "should" be approximately the same.

Just for reference, modern cars will typically give the minimum torque and follow that by something like "further tighten until cotter pin can be inserted". The lowest number I could find in my Toyota data was 35 ft-lbs, but that was, I believe, for a 10mm stud. I believe the Healey side rod is smaller.

 

[drambuie]

Actually, I was was agreeing with Healey nut at bottom of my response for the original poster to get his forearm calibrated I was simply quoting straight out of the Healey manual steps 1 to 4 for the complete explanation..I was assuming everyone would put together my previous comments as you did about the Triumph fastener specs to get the castellated nut torque In the approximate ball park range, I should have worded it better.

 

[Bob_Spidell]

Bob, I don't think giving and researching advice on a castellated fastener is a bad thing! We still need to achieve the recommend minimum and maximum torque spec for a particular application when aligning the slot and hole. That is why castellated nuts have such a broad torque range. i highly value my official Bentley Triumph manual because it is much more detailed and specific then my basic Healey workshop manual and gives specific torque specs in relation to different systems such as steering, suspension, rear end, engine and so on...

Never said it was a 'bad thing,' just that it isn't particularly useful unless you luck out and hit a slot on the recommended torque. Note that 'torque' readings aren't good enough for some modern assemblies--head bolts, for instance--that specify 'torque-to-yield;' i.e. torque to a particular value then use a degree wheel to turn the bolt an additional amount regardless of torque required.

Another apostasy: Having tried to adjust the front wheel bearings 'by the book'--IIRC it's 0.001-0.003" of end play--last time I did this I adjusted the shim pack to the point I could just feel the tiniest amount of end play (technical term: 'smidgen'). So far, so good (but I only have about 60K miles on the bearings).

We had one of our torque wrenches calibrated by a well-known aircraft mechanic with the strain gauge setup and it was spot on (it's a Craftsmen). And some claim only the beam-type wrenches should be used because you get more 'feel' as you torque as opposed to the clicker type.

 

[SteveHall64Healey]

I opted for the pragmatic approach: I tightened each nut to 30 ft.lbs., then advanced the nut forward the minimum amount required to allow the Cotter pin to pass through.
Steve

 

[Healey Nut]

I opted for the pragmatic approach: I tightened each nut to 30 ft.lbs., then advanced the nut forward the minimum amount required to allow the Cotter pin to pass through.
Steve

Now would that be 30lbs torque clicker wrench or 30lbs calibrated forearm ?:eagerness::eagerness:

 

[SteveHall64Healey]

Allegedly calibrated torque wrench ....