View Full Version : Proper TR Fasteners?

01-21-2007, 11:02 AM
I am starting this thread for all
the guys like me who have almost no
basic automotive repair experience.

1. It took me a while before I learned there
should be NO metric nuts and bolts in my car.

2. So I started taking out all the new metric fasteners
and replacing them with stainless steel American/Brit
nut and bolts and lock washers.

3. Found out THAT was wrong too. SS too weak for most

4. So Once again, I stared taking out the SS and
replacing with high strength #8 steel and nyloks nuts.

Now I find out the nyloks are not correct.

Oh yeah, I forgot. Brass nuts and bolts are not to used

So all you TR guru experts out there: How about some
advice for us beginners as to how to replace fasteners
in our TRs?

As always, thanks so much,

Dale in kinda cold 78* Bayamon, PR

01-21-2007, 11:19 AM
Me again. I have found that if I just stick to SAE threads (24), #5 on non critical stress areas, #8 on high stress areas, and I am good to go. I only use all-metal locking nuts on the drive shaft, otherwise I am a big believer in quality lock washers. Never was a fan of Nyloc nuts.

01-21-2007, 11:19 AM
Geaux (Go) Saints !!!!!

01-21-2007, 11:34 AM
Dale, I agree with Bill. I use all metal locknuts on all critical points, such as driveshafts, suspension bolts, etc.
Stainless is OK for items such as clamp holdowns, trim screws, and such non critical, zero stress areas.
Flat, and lock, washers come in grades just like the bolts.
Try to keep the same grade as the fastener.
Also something to consider is that some of our fasteners are odd lengths, so make sure you have the correct one, if going into a blind hole. I've had to cut 1/8" or so off a bolt to get it the right length for a water pump, for instance.
When using a nut and bolt combination, make sure the unthreaded portion of the bolt passes completely through the assembly.
I pity you, having to put up with only 78* today. Can you see my tears from there?

01-21-2007, 11:35 AM
I'm with Bill on this, grade 8 where strength is necessary and lockwashers where appropriate. SS is nice for the high visibility areas where strength is not a concern.

Bill, I live within earshot of soldier field. Hope your Saints can acclimate to the snow. I'll raise a toast to them during the game.


01-21-2007, 11:48 AM
Really showing my ignorance now.
What exactly is a metal locking nut?

Bill- a good a place as any for this.
Remember all the fasteners that were missing
from my tranny, clutch, etc? I purchased 20
sets of #8 5/16" bolts with locknuts, plus
all the large bolts, lock washers and nuts
for the new TRF tranny mounting piece,
5 sets of #8 3/8" bolts and nylocks plus
the large bolts and nuts to fasten the tranny.
Total cost at $5.10

So how much money did the GDPO save by installing
only 3 K-mart metric bolts?


01-21-2007, 11:50 AM
Dale, an all metal locknut is a locking nut with no nylon insert in it. It is usually made a locknut by a deformation of part of the threads, forming an interference fit to the bolt threads.

01-21-2007, 12:15 PM
I'm sure there are a lot of favorite resources out there, but I was very happy with McMaster-Carr when I searched for the nuts and bolts I needed for my TR4 suspension rebuild:

McMaster Carr Site (https://www.mcmaster.com/)

There are probably cheaper sources, but McMaster excels at having everything in stock and speedy deliver.

By the way, I did use grade 8 nylocs on a few of the suspension pieces to replace the original nylocs - nothing has fallen off yet!


p.s. Bill - Go BEARS (sorry, former northern boy)

01-21-2007, 12:23 PM
To throw a curve into the mess. I've been selling fasteners for many years. When I first started, we were instructed that typical interlocking lock washers are basically useless.
Yes, they work sometimes, ie. when you see scoring on both mating surfaces. But the other 99% of the time they are just for show.
A properly torqued fastener should hold though threadlocker should be used in critical areas. Lock nuts are very effective in a number of applications, but nyloc should only be used once. Other less common lock washers are also very good.
Yes, I have drawers full of lock washers. They were originally on the cars, and for the price, it can be worth the price for that 1%.
A good quality flat washer is also very important in the fastening system. Cheap flats will often distort, causing poor torque grip and possible fastener failure.
You should always use Grade 5 components as a system; the same with Grade 8. Don't mix the two.
Not all fasteners are created equal. Typically, if they have an oily coating, they are imports. These are usually of lesser quality. Unfortunately, this is often what you will find at the local hardware store.
You will also find the SAE threaded fasteners labelled as unf. SAE or unf is fine thread while USS or unc is commonly referred to as coarse.

01-21-2007, 12:34 PM
A couple of resources I've used:
bolt depot & aircraft spruce

01-21-2007, 02:35 PM
Dale, to make life easier for you, TRF has the all-metal locking nuts for your drive shaft. They are cheap enough. In your next order just ask them to throw about 8 in a bag. 4 to use, 4 to lose. Always use the strongest Locktite on the nuts as a backup here. Now, that said, the DPO may have used a Walmart-quality bolt here (drive shaft flange) as well. If I were you, I would get 4 new bolts. I think these are higher than grade 8, or should be. A heck of a lot of power is put on these little bolts, don't gamble. TRF will know what size.

Also, for all your other bolts, Home Depot or Lowe's has a department for specialty bolts. They have both grade 5 and grade 8. I am sure they are imports but strong enough for everything but the drive shaft. I use grade 5 SAE to hold my tranny in place.

01-21-2007, 03:15 PM
Thanks Bill!

I am replacing every bolt and nut in the TR6 as
I come upon them. Including all the body to frame
bolt assemblies (TRF package). Everything the DPO
and his mechanic touched is Krap quality, 1/2assed.

I am fortunate to have a fastener specialty store
ten minutes from home. These guys are Pros and have
been very helpful to me. They buy American whenever
possible. They say India fasteners are worse than Chinese.

Since I started this thread as a learning experience for
all of us beginners, I did not know what the #5 or #8
related to. I knew #8 was better and that's about it.
So I looked it up. Maybe even you mechanical guru
might find what I dug up to be of interest.

Thanks as always-Dale


01-21-2007, 04:27 PM
A couple of resources I've used:
bolt depot & aircraft spruce

Aircraft Spruce is awesome for high quality hardware. They have all kinds of cool stuff for our LBCs.

01-21-2007, 05:47 PM
Hi Dale,

Another important consideration when fitting bolts is the length of the unthreaded shank. In many applications you want to try to avoid having threads inside the hole, where with vibration, flexing, etc., they will act like a milling machine and enlarge or deform the hole over time.

The ideal is a bolt with a shank that's just barely short enough to allow it to be fully and properly tightened (look also for a spec sheet on torques with different bolt grades and sizes... or look in the service manual, which largely follows those standard, engineering guidelines). Sometimes getting the shank just the right length means adding a flat washer or two, or shortening a bolt's threads.

Aircraft (AN) fasteners are, in fact, sized by the length of their shanks (in addition to thread length, diameter and thread pitch) and can be bought in a much wider variety than other types of fasteners. These are expensive and overkill in most applications on a TR, however. I do make a point of using them certain places, such as on the driveshaft.

Yes, all-metal locking nuts are a good idea in some key areas, too (again, the driveshaft). These are sometimes refered to as "jetnuts", and are another carryover from the aviation industry.

Nothing wrong with using Nyloks in some places, but they should only be used once. After the nylon insert is deformed they will no resist loosening very well. (Jetnuts also have limited use, but generally are good for several loosening and tightenings.)

It can be more difficult to find Nylocks in grade 8, however.

Locktite is good stuff! Use it!

There are different types of Locktite. The really tough version requires heating the parts to release the locking effect. Medium hold is generally fine for most automotive applications.

An alternative is stainless steel safety wire. However, it means drilling 1/16" holes in bolds and nuts, which ain't easy if using grade 8 stuff!

When fitting nuts and bolts, I like to get at least five full threads or more for good strength. Some jam nuts and Nylocks in certain sizes or coarseness might not have this many threads.

Use fine threads for strength in most applications. An exception is with certain types of materials. For example, threads into aluminum or cast iron should be coarse.

There are entire books written about fasteners!

01-21-2007, 05:56 PM
All great comments and very well written.

Thanks guys!

And thanks Dale, for the charts.

02-11-2007, 06:19 PM
Is there a reference somewhere that tells exactly
what type, thread, length and grade bolt, nut,
stud etc to use throughout these cars?

For instance my tranny was held in place with one
stud nut and two 1.4" diameter, #2 bolts and washers.

Paul told me to purchase 3/16" #8 bolts and I did.
All 16 are the same length at 1.5" and I purchashed
16 nylocks as well.

How can i determine what the proper bolts and nuts
should be? I never reuse any of Pedro's fasteners.

I threw out the fasteners that held the clutch pieces
to the flywheel. What are the proper bolts to purchase?



02-11-2007, 06:30 PM
dale ,do you have the TRF Green Book?


02-11-2007, 07:04 PM
No, I have the TR blue book and Bentley.
I guess I'll look for the green book.



02-11-2007, 07:39 PM
I might be able to send a PDF version.
I checked it 50 MB maybe not

02-12-2007, 11:18 AM
The green catalog is available for viewing on the 6-Pack website.

02-12-2007, 11:31 AM
Shawn do you need to be a member??

02-12-2007, 11:33 AM
I don't believe you do for that section. I just accessed it without having to log in.

02-12-2007, 11:41 AM
Mine is on a thumb drive. I still am looking for volume 1

04-05-2007, 03:52 PM
I'm resuscitating this thread as I think it's a very good one. My question is, are the SAE nuts and bolts available locally (OSH, Home Depot, etc.) compatible with our UNF threads? Is the pitch the same? In some applications I can just replace a matching nut and bolt together but in others I need to match the threads on the existing part. I seem to be having trouble finding a match at Home Depot, but I hate to have to mail order every nut and bolt individually as I replace them. Answers and/or solutions?

04-05-2007, 04:23 PM
Yes, the UNF threads on the TR's are the same as what we have here. Just look for the "fine threaded" nuts and bolts. I've bought fine threaded nuts and bolts from Home Depot. Their selection isn't very large, but in the more common sizes (1/4-28, 5/16-24, 3/8-24) they had a lot of what I needed.

04-05-2007, 04:42 PM
Loew's seems to have a better selection....or try Fastenal.

04-05-2007, 05:49 PM
If you're rebuilding the whole suspension, go to Fastenall and buy a bag of 100 grade8 nylocs, or McMaster online for that matter. But for onesies twosies, and for fasteners that are not critical to preserving your life (like body mounting bolts,) HD or Lowe's stock Grade5 fine thread hardware in common sizes and are cheap.

What you will find is that many of the TR bolts are 1/4" sizes that you won't find locally and will have to be ordered. An example is the two ball joint bolts on TR4-TR6s, as well as many other front suspension bolts. The 1/2" increment bolts are too long, and if you use Grade8 for suspension (which is my recommendation), you won't be able to cut to length because they are hardened, so you'll have to grind them to length or pay up and get the proper length.

I've got to chime back in on lock nuts. Most of the lock nuts used on TRs are nylocs. They are a one-time use item; once removed, they should be replaced. On critical parts, ALWAYS use new.

All metal lock nuts (metal deforming nuts) are a must on the driveshaft u-joints. You don't want to risk one of the flange bolts coming loose.

But the trouble with using all metal lock nuts everwhere is that they are metal deforming and that obtain their holding power by deforming the bolt thread. After repeated use of them, you have to replace the bolt.

04-06-2007, 11:47 AM
I threw out the fasteners that held the clutch pieces
to the flywheel. What are the proper bolts to purchase?

You did what? Dale, if you are referring to the ultra-high strength bolts that affix the clutch to the flywheel, there is no way you should use Lowe's-quality bolts here. I know that there are aircraft-grade bolts that are at least grade 8 quality. I would never trust a big-box store grade 8 bolt in a critical application.

04-07-2007, 04:36 AM
Hey Bill,

You mis-read my post. I purchase from a specialty
fastener shop. DPO Pedro used K-Mart, Lowes's krap
fasteners. I buy nothing from the cut rate centers.

I use only high strength No 8s for anything that moves
or experiences high vibration. And I buy according to
Allan's suggestion about shank length.

Costly yes. But I have too much time invested in this car
to cut corners on fasteners. I never re-use existing
fasteners if I can help it.


04-07-2007, 05:06 AM
I didn't think, with your professional background, that you would succumb to big-box mentality, Dale. Too many late-night posts. Or my blurry vision.