• Forum membership has its advantages....

Bolt torque and prep help!

shrive81

Well-Known Member
Hows it going guys I am in the process of final assembly on 4 seat class1 car (best way to describe it) I have been in the process of building this thing for the last 3 years and read to start final assembly this week. I just purchased the proper shank length (grip length) F911 bolts for all the suspension pivots and shock botls along with all the steering as well. The rest of the car will have all Lawson grade 9 bolts for everything else.

My questions as I am not a master fabricator and no formal training but just want to make sure I use the proper specs and techniques during final assembly.

1. What are you guys using for torque specs the suspension bolts are all 3/4" fine thread and the torque specs I have been finding are upwards of 300ft/lbs which seems excessive. Is there a good chart to go off of depending on bolt size and overall length

2. Are you guys seeing better luck with stover or nylock nuts

3. Are you using any type of thread lock, ant seize (on bolt shaft ) etc.

4. Also assuming the best practice is torque from the nut side..


Any other smart ass comments like use a search bar or here we go again are welcome but would prefer constructive comments hahahaha

Thanks Gents
 
Last edited:

Ol' Curmudgeon

RDC's resident crackpot
Any other smart ass comments like use a search bar
Thanks Gents
I recommend a breaker bar instead.

No specific spec, but tight enough to not vibrate loose and loose enough for field repairs worked for our team back in the day (the oughts).

Second the No Nylocks advice. Won't last one tuning session on shocks, for instance.

Looks good!
 

Kyle D

Well-Known Member
This is the torque chart I always reference. It has never failed me. Just remember to torque the bolt in a smooth fashion. Don't jerk the torque wrench. Always use stover locknuts. I personally always use thick washers, not the flimsy thin ones that the bolt house will just hand you because as you torque your bolts you can watch the thin ones deform which is essentially defeating the purpose of having a harder surface spreading the load. If you have a buddy that works at a cat dealer, that's about the best hardware around and employees typically get a healthy discount. Remember there is a percentage per different "lubrication" you will put on your bolts. A good rule of thumb is 30% reduction using either loctite or antiseize. If you go full torque with lubrication on the threads the bolts are going to stretch past their yield point. I hope this stuff makes sense.
Bolt Depot - US Recommended Bolt Torque Table
 

Moss2

Well-Known Member
You want to make sure your sleeves and washers are hard enough to take the load of the high torque otherwise you may be better with a properly torqued lower grade that matches the joint material better.
 

jon coleman

Well-Known Member
fine thread on all susp.no nylock.i use grease w anti seize in it.not as messy as straight a.s. i use standard an washers, they have a certain crushability unlike hardended washers.grease on all surfaces, threads, nut head, bolts , ect, helps keep out moisture.i torque to a spec, and Re torque after quick test bounce.leaf shackles take a few times to take a set.always check grip !!, that is the biggest faliure in off road prep, bolt loosens, threads dig into sleave, things snap.i use grade 8 nuts .if on a critical bolt, i use a top lock style.never use lock washers.they breake.ill use wave washers on low torque apps.last thing, nut'n& bolt'n, before every trip, stick a wrench on All your critical bolts& nuts, to just see they arent looooose
 

jon coleman

Well-Known Member
another good source for fastner apps& torks/ install tips and procedures is a mil- training guide ' ams- amh naval aviation mech.guide.i had one, i forgot the exact name but it had lots of good info on hyd.& nuts- bolts- rivets ect.
 

Bert is my name

Well-Known Member
A quick Google search will usually give you torque specs for a given bolt diameter. Look for a copy of "machinery's handbook". It has more information than you will ever need . I have one in my tool box and one near my lathe.
 

Bert is my name

Well-Known Member
marine grade anti seize on anything you want to come apart.
Nope. C.m.d. number 3 anti scoring lubricant. That stuff is by far the best assembly lubricant for hardware I've ever used. Galling completely disappears. Anti seize oxidizes and will lock up hardware unless it is regularly serviced. C.m.d. makes for smooth torquing and easy disassembly. Trust me on this one. It's worth the money.
 

D-rek

Well-Known Member
Stover nuts on everything. Anti seize on the shanks and red loc tite on the threads. F911 bolts can be hit or miss I prefer the MS bolts for critical items like pivot points but F911 from a reputable source are usually acceptable.
 

jon coleman

Well-Known Member
red loc tite is good , too good on rotor hat bolts.....co worker had issues on a vintage car, owner said he used it on the screws, after some racing heat cycles, well, im gladd i was charged w - preping them...
 

gwizz

Well-Known Member
Nope. C.m.d. number 3 anti scoring lubricant. That stuff is by far the best assembly lubricant for hardware I've ever used. Galling completely disappears. Anti seize oxidizes and will lock up hardware unless it is regularly serviced. C.m.d. makes for smooth torquing and easy disassembly. Trust me on this one. It's worth the money.
even hot exhaust head and turbo stuff? i dunno ive had real good luck with the marine crap especialy hot dissimilar metals. all my misalignment stuff come out fairly easily ect. use it like butter, has a higher working temp than the high temp copper looking stuff. as far as extreme pressure, what exactly is that as far as fastners are concerned?
 

Bert is my name

Well-Known Member
Look it up. It's been around since the 30s or so. As far as high heat applications I wouldn't use it for that. But for suspension assembly, bolt assemblies, bushings bearings, and valve train assembly this stuff is were it's at. If you look in Manley or comp cams catalogs you'll see it. Mcmaster sells it to as well as the machinest supply houses.
 

Josh 8

Well-Known Member
I think it would be wise to read what Moss2 said. Think about it till you understand it. Realize how much torque and squeeze a 3/4 fine thread f911 torqued to chart values puts on a 1/8 flange and tube.
 

jon coleman

Well-Known Member
bolt torque,somtimes tooo much, somtimes not enough, thats why prep guys( top level) are gods....
 
Last edited:
Top